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Sample records for barrel toroid superconducting

  1. Cryogenic Characteristics of the ATLAS Barrel Toroid Superconducting Magnet

    CERN Document Server

    Pengo, R; Delruelle, N; Pezzetti, M; Pirotte, O; Passardi, Giorgio; Dudarev, A; ten Kate, H

    2008-01-01

    ATLAS, one of the experiments of the LHC accelerator under commissioning at CERN, is equipped with a large superconducting magnet the Barrel Toroid (BT) that has been tested at nominal current (20500 A). The BT is composed of eight race-track superconducting coils (each one weights about 45 tons) forming the biggest air core toroidal magnet ever built. By means of a large throughput centrifugal pump, a forced flow (about 10 liter/second at 4.5 K) provides the indirect cooling of the coils in parallel. The paper describes the results of the measurements carried out on the complete cryogenic system assembled in the ATLAS cavern situated 100 m below the ground level. The measurements include, among other ones, the static heat loads, i.e., with no or constant current in the magnet, and the dynamic ones, since additional heat losses are produced, during the current ramp-up or slow dump, by eddy currents induced on the coil casing.

  2. The protection system of the superconducting coils in the Barrel Toroid of ATLAS

    CERN Document Server

    Acerbi, E; Volpini, G; Daël, A; Lesmond, C

    1999-01-01

    An analysis of the discharge of the Barrel Toroid under several operating conditions has been carried out. The main critical parameters of the discharge (i.e. the maximum temperature inside the coils, the maximum temperature $9 gradient, the maximum voltage at the coil ends and the maximum decentering forces acting on the BT and ECT magnets) have been calculated for several operating conditions (heaters on, heaters off, short circuit with heaters on or $9 off). The aim of this analysis is to provide a cross check of the protection design of the Barrel Toroid coils with an independent study. The results validate the choice to use a low value of dump resistance, and give some important $9 warning in the case of heater failure or presence of a short circuit. (5 refs).

  3. ATLAS Barrel Toroid magnet reached nominal field

    CERN Multimedia

    2006-01-01

     On 9 November the barrel toroid magnet reached its nominal field of 4 teslas, with an electrical current of 21 000 amperes (21 kA) passing through the eight superconducting coils as shown on this graph

  4. Celebrating the Barrel Toroid commissioning

    CERN Multimedia

    Peter Jenni

    ATLAS invited Funding Agency representatives and Laboratory Heads directly related to the funding and construction of the Barrel Toroid for a small ceremony on 13th December 2006 at Point 1, in order to mark the successful first full excitation of the BT (see last eNews). On that date, which was during the December CERN Council week, several of the Funding Agency Heads or their representatives could be present, representing CEA France, INFN Italy, BMBF Germany, Spain, Sweden, Switzerland, Russia, JINR Dubna and CERN. Speeches were delivered by the ATLAS spokesperson Peter Jenni thanking the Funding Partners in the name of the Collaboration, by Magnet Project Leader Herman ten Kate tracing the BT construction history, and by the CERN Director-General Robert Aymar congratulating all those who have contributed to the successful project. Herman ten Kate addressing the delegates. The text of the introductory address by Peter Jenni is reproduced here. "It is a great pleasure for me to welcome you all here...

  5. ATLAS superconducting toroids and solenoid

    CERN Document Server

    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 ...

  6. Celebration for the ATLAS Barrel Toroid magnet

    CERN Multimedia

    2007-01-01

    Representatives from Funding Agencies and Barrel Toroid Magnet Laboratories during the ceremony. From left to right: Jean Zinn-Justin (Head of DAPNIA/CEA/Saclay), CERN Director-General Robert Aymar, and Roberto Petronzio (President INFN).Allan Clark (DPNC University Geneva) and Enrique Fernandez (IFAE Barcelona) were among the guests visiting the ATLAS cavern. The barrel toroid is visible in the background. A celebration took place at Point 1 on 13 December to toast the recent powering-up of the ATLAS barrel toroid magnet to full field (Bulletin No. 47-48/06). About 70 guests were invited to attend, mainly composed of representatives from funding partners and key members of the laboratory management teams of the barrel toroid magnet, representing CEA France, INFN Italy, BMBF Germany, Spain, Sweden, Switzerland, Russia, JINR Dubna and CERN. An introductory speech by ATLAS spokesperson Peter Jenni the scene for evening. This was followed by the ATLAS magnet system project leader Herman Ten Kate's account of the...

  7. 3D Printing the ATLAS' barrel toroid

    CERN Document Server

    Goncalves, Tiago Barreiro

    2016-01-01

    The present report summarizes my work as part of the Summer Student Programme 2016 in the CERN IR-ECO-TSP department (International Relations – Education, Communication & Outreach – Teacher and Student Programmes). Particularly, I worked closely with the S’Cool LAB team on a science education project. This project included the 3D designing, 3D printing, and assembling of a model of the ATLAS’ barrel toroid. A detailed description of the project' development is presented and a short manual on how to use 3D printing software and hardware is attached.

  8. Superconducting toroid design for the ATLAS experiment at LHC

    International Nuclear Information System (INIS)

    The ATLAS Experiment proposed for LHC will use toroidal magnet systems to achieve high muon momentum resolution. The proposal is based on an air-cored superconducting toroid magnet system consisting of a long barrel toroid with a pair of end cap toroids to provide high resolution at large rapidity. Each end cap toroid will have an outer diameter of approximately 11m and an axis length of 5m and will provide field integrals in the range 4-8Tm over the rapidity span η = 1.5--2.8. This paper presents the magnetic, mechanical and cryogenic design of the end cap toroid magnet systems

  9. First ATLAS Barrel Toroid coil casing arrives at CERN

    CERN Document Server

    2002-01-01

    The first of eight 25-metre long coil casings for the ATLAS experiment's barrel toroid magnet system arrived at CERN on Saturday 2 March by road from Heidelberg. This structure will be part of the largest superconducting toroid magnet ever made.   The first coil casing for the toroidal magnets of Atlas arrives at Building 180. This is the start of an enormous three-dimensional jigsaw puzzle. Each of the eight sets of double pancake coils will be housed inside aluminium coil casings, which in turn will be held inside a stainless steel vacuum vessel. A huge construction, the casing that arrived at CERN measures 25 metres in length and 5 metres in width. It weighs 20 tones. And this is just the beginning of the toroid jigsaw: by early April a batch of four double pancake coils, which altogether weighs 65 tones, will arrive from Ansaldo in Italy. The first vacuum vessel will also be arriving from Felguera in Spain this month. It will take about two years for all these 25 m long structures of casings, coils a...

  10. ATLAS-Lowering the first Barrel Toroid coil

    CERN Multimedia

    CERN Audiovisual Unit

    2004-01-01

    Cranes lowered the first of ATLAS's eight Barrel Toroid coils into the cavern. The part is 25 metres long and the cranes had to hold the 100 tonne coil at a sharp angle while it passed through the 18-metre diameter vertical shaft into the cavern. Then they laid the magnet to a horisontal robust platform. Images from Camera 1

  11. ATLAS-Lowering the first Barrel Toroid coil

    CERN Multimedia

    CERN Audiovisual Unit

    2004-01-01

    Cranes lowered the first of ATLAS's eight Barrel Toroid coils into the cavern. The part is 25 meters long and the cranes had to hold the 100 tonne coil at a sharp angle while it passed through the 18-meter diameter vertical shaft into the cavern. Then they laid the magnet to a horizontal robust platform. Images from Camera 2

  12. ATLAS barrel toroid integration and test area in building 180

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    The ATLAS barrel toroid system consists of eight coils, each of axial length 25.3 m, assembled radially and symmetrically around the beam axis. The coils are of a flat racetrack type with two 'double-pancake' windings made of 20.5 kA aluminium-stabilized niobium-titanium superconductor. The barrel toroid is being assembled in building 180 on the Meyrin site. In the first phase of assembly, the coils are packed into their aluminium-alloy casing. These photos show the double-pancake coils from ANSALDO and the coil casings from ALSTOM. In the foreground is the tooling from COSMI used to turn over the coil casings during this first phase. In the right background is the yellow lifting gantry manufactured at JINR-Dubna, Russia which will transport the coil casings to a heating table for prestressing. Two test benches with magnetic mirror are also visible.

  13. Barrel Toroid fully charged to nominal field, and it works!

    CERN Multimedia

    Herman ten Kate

    After a few weeks of testing up to intermediate currents, finally, on Thursday evening November 9, the current in the Barrel Toroid was pushed up to its nominal value of 20500 A and even 500 A beyond this value to prove that we have some margin. It went surprisingly well. Of course, the 8 coils forming the toroid were already tested individually at the surface but still, some surprise may have come from those parts added to the toroid in the cavern for the first time like the 8 cryoring sections linking the coils as well as the valve box at the bottom in sector 13 regulating the helium flow or the current lead cryostat on the top in sector 5. No training quenches, nothing to worry about, and the test was concluded with a fast dump triggered at 00:40 in the very early morning of November 10. (left) The toroid current during the evening and night of November 9. (right) The test crew oscillated between fear and hope while looking at the control panels as the current approached 21kA. Big relief was in the...

  14. The common cryogenic test facility for the ATLAS barrel and end-cap toroid magnets

    CERN Document Server

    Delruelle, N; Junker, S; Passardi, Giorgio; Pengo, R; Pirotte, O

    2004-01-01

    The large ATLAS toroidal superconducting magnet made of the Barrel and two End-Caps needs extensive testing at the surface of the individual components prior to their final assembly into the underground cavern of LHC. A cryogenic test facility specifically designed for cooling sequentially the eight coils making the Barrel Toroid (BT) has been fully commissioned and is now ready for final acceptance of these magnets. This facility, originally designed for testing individually the 46 tons BT coils, will be upgraded to allow the acceptance tests of the two End-Caps, each of them having 160 tons cold mass. The integrated system mainly comprises a 1.2 kW@4.5 K refrigerator, a 10 kW liquid-nitrogen precooler, two cryostats housing liquid helium centrifugal pumps of respectively 80 g/s and 600 g/s nominal flow and specific instrumentation to measure the thermal performances of the magnets. This paper describes the overall facility with particular emphasis to the cryogenic features adopted to match the specific requ...

  15. The Common Cryogenic Test Facility for the Atlas Barrel and End-Cap Toroid Magnet

    CERN Document Server

    Delruelle, N; Junker, S; Passardi, Giorgio; Pengo, R; Pirotte, O

    2004-01-01

    The large ATLAS toroidal superconducting magnet made of the Barrel and two End-Caps needs extensive testing at the surface of the individual components prior to their final assembly into the underground cavern of LHC. A cryogenic test facility specifically designed for cooling sequentially the eight coils making the Barrel Toroid (BT) has been fully commissioned and is now ready for final acceptance of these magnets. This facility, originally designed for testing individually the 46 tons BT coils, will be upgraded to allow the acceptance tests of the two End-Caps, each of them having a 160 tons cold mass. The integrated system mainly comprises a 1.2 kW@4.5 K refrigerator, a 10 kW liquid-nitrogen precooler, two cryostats housing liquid helium centrifugal pumps of respectively 80 g/s and 600 g/s nominal flow and specific instrumentation to measure the thermal performances of the magnets. This paper describes the overall facility with particular emphasis to the cryogenic features adopted to match the specific re...

  16. The Superconducting Toroid for the New International AXion Observatory (IAXO)

    CERN Document Server

    Shilon, I; Silva, H; Wagner, U; Kate, H H J ten

    2013-01-01

    IAXO, the new International AXion Observatory, will feature the most ambitious detector for solar axions to date. Axions are hypothetical particles which were postulated to solve one of the puzzles arising in the standard model of particle physics, namely the strong CP (Charge conjugation and Parity) problem. This detector aims at achieving a sensitivity to the coupling between axions and photons of one order of magnitude beyond the limits of the current detector, the CERN Axion Solar Telescope (CAST). The IAXO detector relies on a high-magnetic field distributed over a very large volume to convert solar axions to detectable X-ray photons. Inspired by the ATLAS barrel and end-cap toroids, a large superconducting toroid is being designed. The toroid comprises eight, one meter wide and twenty one meters long racetrack coils. The assembled toroid is sized 5.2 m in diameter and 25 m in length and its mass is about 250 tons. The useful field in the bores is 2.5 T while the peak magnetic field in the windings is 5....

  17. Second Barrel Toroid Coil Installed in ATLAS Cavern

    CERN Multimedia

    Tappern, G.

    The second barrel toroid coil was lowered into the ATLAS Cavern on Friday, 26 November. The operation takes approximately five hours of precision crane and winch operations. Before lowering, several checks are made to ensure that no loose items have been left on the coil which would fall during the lowering down the shaft. This is a very difficult, but very important check, with the first coil in position, and partly below the shaft. After changing the winch tooling on Wednesday December 1st, the coil was lifted, rotated and placed into the feet. The girders which support the coil and the Z direction stops had all been pre-set before putting the coil in the feet. The angle is controlled by an inclinometer. When the final adjustments of position have been made, which will locate the coils at the plus/minus two mm level, the connection beams (voussoirs and struts) will be put in place; this requires a complex shimming procedure. This will lock together the two coils into the feet and forms the foundation for th...

  18. Toroidal high temperature superconducting coils for ISTTOK

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, H., E-mail: hf@ipfn.ist.utl.pt [Associacao Euratom/IST, Instituto de Plasmas e Fusao Nuclear, Laboratorio Associado, Instituto Superior Tecnico, 1049-001 Lisboa (Portugal); Goemoery, F. [Institute of Electrical Engineering, Slovak Academy of Sciences, Dubravska cesta 9, 84104 Bratislava (Slovakia); Corte, A. della; Celentano, G. [ENEA C.R. Frascati, Via E. Fermi 45, 00044 Frascati (Italy); Souc, J. [Institute of Electrical Engineering, Slovak Academy of Sciences, Dubravska cesta 9, 84104 Bratislava (Slovakia); Silva, C.; Carvalho, I.; Gomes, R. [Associacao Euratom/IST, Instituto de Plasmas e Fusao Nuclear, Laboratorio Associado, Instituto Superior Tecnico, 1049-001 Lisboa (Portugal); Di Zenobio, A.; Messina, G. [ENEA C.R. Frascati, Via E. Fermi 45, 00044 Frascati (Italy)

    2011-10-15

    High temperature superconductors (HTS) are very attractive to be used in fusion devices mainly due to lower operations costs. The HTS technology has reached a point where the construction of toroidal field coils for a tokamak is possible. The feasibility of a tokamak operating with HTS is extremely relevant and ISTTOK is the ideal candidate for a meaningful test due to its small size (and consequently lower cost) and the possibility to operate in a steady-state inductive regime. In this paper, a conceptual study of the ISTTOK upgrade to a superconducting device is presented, along with the relevant boundary conditions to achieve a permanent toroidal field with HTS. It is shown that the actual state of the art in HTS allows the design of a toroidal field coil capable of generating the appropriate field on plasma axis while respecting the structural specification of the machine.

  19. Toroidal high temperature superconducting coils for ISTTOK

    International Nuclear Information System (INIS)

    High temperature superconductors (HTS) are very attractive to be used in fusion devices mainly due to lower operations costs. The HTS technology has reached a point where the construction of toroidal field coils for a tokamak is possible. The feasibility of a tokamak operating with HTS is extremely relevant and ISTTOK is the ideal candidate for a meaningful test due to its small size (and consequently lower cost) and the possibility to operate in a steady-state inductive regime. In this paper, a conceptual study of the ISTTOK upgrade to a superconducting device is presented, along with the relevant boundary conditions to achieve a permanent toroidal field with HTS. It is shown that the actual state of the art in HTS allows the design of a toroidal field coil capable of generating the appropriate field on plasma axis while respecting the structural specification of the machine.

  20. General Atomic's superconducting toroidal field coil concept

    International Nuclear Information System (INIS)

    General Atomic's concept for a superconducting toroidal field coil is presented. The concept is generic for large tokamak devices, while a specific design is indicated for a 3.8 meter (major radius) ignition/burn machine. The concept utilizes bath cooled NbTi conductor to generate a peak field of 10 tesla at 4.2 K. The design is simple and straightforward, requires a minimum of developmental effort, and draws extensively upon the perspective of past experience in the design and construction of large superconducting magnets for high energy physics. Thus, the primary emphasis is upon economy, reliability, and expeditious construction scheduling. (author)

  1. The CERN Cryogenic Test Facility for the Atlas Barrel Toroid Magnets

    CERN Document Server

    Haug, F; Delruelle, N; Orlic, J P; Passardi, Giorgio; Tischhauser, Johann

    1999-01-01

    The superconducting magnet system of the ATLAS detector will consist of a central solenoid, two end-cap toroidal magnets (ECT) and the barrel toroid magnet (BT) made of eight coils symmetrically placed around the central axis of the detector. The magnets will be tested individually in a 5000 m2 experimental area prior to their final installation at an underground cavern of the LHC Collider. For the BT magnets, a dedicated cryogenic test facility has been designed which is currently under the construction and commissioning phase. A liquid nitrogen pre-cooling unit and a 1200 W@4.5K refrigerator will allow flexible operating conditions via a rather complex distribution and transfer line system. Flow of two-phase helium for cooling the coils is provided by centrifugal pumps immersed in a saturated liquid helium bath. The integration of the pumps in an existing cryostat required the adoption of novel mechanical solutions. Tests conducted permitted the validation of the technical design of the cryostat and its ins...

  2. The CERN cryogenic test facility for the ATLAS barrel toroid magnets

    CERN Document Server

    Haug, F; Delruelle, N; Orlic, J P; Passardi, Giorgio; Tischhauser, Johann

    2000-01-01

    The superconducting magnet system of the ATLAS detector will consist of a central solenoid, two end-cap toroidal magnets (ECT) and the barrel toroid magnet (BT) made of eight coils symmetrically placed around the central axis of the detector. The magnets will be tested individually in a 5000 m/sup 2/ experimental area prior to their final installation at an underground cavern of the LHC Collider. For the BT magnets, a dedicated cryogenic test facility has been designed which is currently under the construction and commissioning phase. A liquid nitrogen pre-cooling unit and a 1200 W@4.5K refrigerator will allow flexible operating conditions via a rather complex distribution and transfer line system. Flow of two-phase helium for cooling the coils is provided by centrifugal pumps immersed in a saturated liquid helium bath. The integration of the pumps in an existing cryostat required the adoption of novel mechanical solutions. Tests conducted permitted the validation of the technical design of the cryostat and i...

  3. First full-size ATLAS barrel toroid coil successfully tested up to 22 kA at 4 T

    CERN Document Server

    Dudarev, A; Benoit, P; Berriaud, C P; Broggi, F; Deront, L; Foussat, A; Junker, S; ten Kate, H H J; Kopeykin, N; Olesen, G; Olyunin, A; Pengo, R; Rabbers, J J; Ravat, S; Rey, J M; Sbrissa, E; Shugaev, I; Stepanov, V; Védrine, P; Volpini, Giovanni

    2005-01-01

    The Superconducting Barrel Toroid is providing (together with the two End-Cap Toroids not presented here) the magnetic field for the muon detectors in the ATLAS Experiment at the LHC at CERN. The toroid with outer dimensions of 25 m length and 20 m diameter, is built up from 8 identical racetrack coils. The coils with 120 turns each are wound with an aluminum stabilized NbTi conductor and operate at 20.5 kA at 3.9 T local field in the windings and is conduction cooled at 4.8 K by circulating forced flow helium in cooling tubes attached to the cold mass. The 8 coils of 25 m * 5 m are presently under construction and the first coils have already been fully integrated and tested. Meanwhile the assembly of the toroid 100 m underground in the ATLAS cavern at CERN has started. The 8 coils are individually tested on surface before installation. In this paper the test of the first coil, unique in size and manufacturing technology, is described in detail and the results are compared to the previous experience with the...

  4. The barrel muon spectrometer of the ATLAS detector has acquired its first cosmic event in a magnetic field produced by the barrel toroid magnet.

    CERN Multimedia

    2006-01-01

    A 3-D event display of a cosmic muon event, showing the path of a muon travelling through three layers of the barrel muon spectrometer. Three of the eight coils of the barrel toroid magnet can be seen in the top half of the drawing.

  5. Models for large superconducting toroidal magnet systems

    International Nuclear Information System (INIS)

    Prior to the design of large GJ toroidal magnet systems it is appropriate to procure small scale models, which can simulate their pertinent properties and allow to investigate their relevant phenomena. The important feature of the model is to show under which circumstances the system performance can be extrapolated to large magnets. Based on parameters such as the maximum magnetic field and the current density, the maximum tolerable magneto-mechanical stresses, a simple method of designing model magnets is presented. It is shown how pertinent design parameters are changed when the toroidal dimensions are altered. In addition some conductor cost estimations are given based on reactor power output and wall loading

  6. Toroidal sensor of superconducting quantum magnetometer

    International Nuclear Information System (INIS)

    The sensor has a high sensitivity achieved by the 100-times higher suppression of external electromagnetic disturbances as compared with sensors used so far. This is given by the design of the sensor which consists of a superconducting induction loop, electrically closed by a superconducting weak junction and made of one single piece of superconducting material in which there is an O-shaped cavity. In the space defined by this cavity there are two coaxial openings for the insertion of the superconducting junction. The parts of the cavity are interconnected with a planar slot. Also inserted in the cavity are two coils - a field coil and a signal coil. The superconducting weak junction is either of a bridge or point type. The sensor may be used in all areas where the measurement of very small variables may be converted to the measurement of magnetic field. (J.B.) 5 figs

  7. Control and monitoring of the Tore Supra toroidal superconducting coils

    International Nuclear Information System (INIS)

    Light nuclei controlled fusion reactions are seen as a possible way to produce nuclear energy. For this reason, the interest in hot plasma researches in tokamaks has increased. The Tore Supra main characteristic is related to the superconducting magnet coils. They allow a suitable energy balance, however, they require an accurate and preventive fault detection. The Tore Supra machine and the different methods to detect a transition (from superconducting to normal mode) in the toroidal coils are described. The voltage of the coils, the pressure of the helium superfluid at 1.8 K and the electric current in the circuit parallel resistances, are measured. A computer aided control system allows the toroidal field monitoring (current in the coils, fault detection). The superconducting magnet configuration chosen for Tore Supra seems to be suitable for future large Tokamak devices

  8. Superconducting toroidal magnets for fusion feasibility experiments and power reactors

    International Nuclear Information System (INIS)

    It has been recognized that large superconducting magnets will have to be developed in order to obtain power economically from a thermonuclear reactor. In the present paper, compelling reasons are offered to illustrate how vital they are even for the sizes envisioned for hydrogen feasibility and D-T burning experiments. Detailed discussion is given on the type of magnets used for the plasma confinement in a tokamak-type machine. Illustrations are given to show that their development is within the present technological progress of superconductivity. The methods used to estimate the cost of such a toroidal system are provided along with how the cost varies with changes in magnet aspect ratio, major radius (proportional to Rsup(1.95) and stored energy (proportional to Esub(S)sup(0.65)). The latter quantity is presented as a valid figure of merit for quickly estimating the cost of any large superconducting toroidal system. (author)

  9. Superconducting Magnet with the Reduced Barrel Yoke for the Hadron Future Circular Collider

    CERN Document Server

    Klyukhin, V I; Berriaud, C; Curé, B; Dudarev, A; Gaddi, A; Gerwig, H; Hervé, A; Mentink, M; Rolando, G; Da Silva, H F Pais; Wagner, U; Kate, H H J ten

    2015-01-01

    The conceptual design study of a hadron Future Circular Collider (FCC-hh) with a center-of-mass energy of the order of 100 TeV in a new tunnel of 80-100 km circumference assumes the determination of the basic requirements for its detectors. A superconducting solenoid magnet of 12 m diameter inner bore with the central magnetic flux density of 6 T is proposed for a FCC-hh experimental setup. The coil of 24.518 m long has seven 3.5 m long modules included into one cryostat. The steel yoke with a mass of 21 kt consists of two barrel layers of 0.5 m radial thickness, and 0.7 m thick nose disk, four 0.6 m thick end-cap disks, and three 0.8 m thick muon toroid disks each side. The outer diameter of the yoke is 17.7 m; the length without the forward muon toroids is 33 m. The air gaps between the end-cap disks provide the installation of the muon chambers up to the pseudorapidity of \\pm 3.5. The conventional forward muon spectrometer provides the measuring of the muon momenta in the pseudorapidity region from \\pm 2.7...

  10. High-frequency toroidal sensor of superconducting quantum magnetometer

    International Nuclear Information System (INIS)

    The toroidal sensor consists of a superconducting induction loop electrically closed with a superconducting weak junction. The sensor features a cylindrical body. The body is integral and is made of superconducting material. It is provided with tow O-shape cavities in which cylindrical signal and exciting coils are installed. The precise cavity geometry and coil fitting is described on an example and shown in figures. The advantages of the configuration include suppression of spurious signals and improvement of the internal sensor shielding against external electromagnetic fields. The device is used for measuring low intensity magnetic fields, e.g., in the measurement of nuclear magnetic resonance, in particle detection, thermometry, geology, medicine, etc. (E.J.). 5 figs

  11. New Superconducting Toroidal Magnet System for IAXO, the International AXion Observatory

    CERN Document Server

    Shilon, I; Silva, H; Wagner, U; Kate, H H J ten

    2013-01-01

    Axions are hypothetical particles that were postulated to solve one of the puzzles arising in the standard model of particle physics, namely the strong CP (Charge conjugation and Parity) problem. The new International AXion Observatory (IAXO) will incorporate the most promising solar axions detector to date, which is designed to enhance the sensitivity to the axion-photon coupling by one order of magnitude beyond the limits of the current state-of-the-art detector, the CERN Axion Solar Telescope (CAST). The IAXO detector relies on a high-magnetic field distributed over a very large volume to convert solar axions into X-ray photons. Inspired by the successful realization of the ATLAS barrel and end-cap toroids, a very large superconducting toroid is currently designed at CERN to provide the required magnetic field. This toroid will comprise eight, one meter wide and twenty one meter long, racetrack coils. The system is sized 5.2 m in diameter and 25 m in length. Its peak magnetic field is 5.4 T with a stored e...

  12. Pareto optimal design of sectored toroidal superconducting magnet for SMES

    Energy Technology Data Exchange (ETDEWEB)

    Bhunia, Uttam, E-mail: ubhunia@vecc.gov.in; Saha, Subimal; Chakrabarti, Alok

    2014-10-15

    Highlights: • The optimization approach minimizes both the magnet size and necessary cable length of a sectored toroidal SMES unit. • Design approach is suitable for low temperature superconducting cable suitable for medium size SMES unit. • It investigates coil parameters with respect to practical engineering aspects. - Abstract: A novel multi-objective optimization design approach for sectored toroidal superconducting magnetic energy storage coil has been developed considering the practical engineering constraints. The objectives include the minimization of necessary superconductor length and torus overall size or volume, which determines a significant part of cost towards realization of SMES. The best trade-off between the necessary conductor length for winding and magnet overall size is achieved in the Pareto-optimal solutions, the compact magnet size leads to increase in required superconducting cable length or vice versa The final choice among Pareto optimal configurations can be done in relation to other issues such as AC loss during transient operation, stray magnetic field at outside the coil assembly, and available discharge period, which is not considered in the optimization process. The proposed design approach is adapted for a 4.5 MJ/1 MW SMES system using low temperature niobium–titanium based Rutherford type cable. Furthermore, the validity of the representative Pareto solutions is confirmed by finite-element analysis (FEA) with a reasonably acceptable accuracy.

  13. SDC muon barrel toroid 1/9.197 scale test model at SSC

    International Nuclear Information System (INIS)

    The purpose of the scale model for the muon barrel toroid (MBT) is to discover any problems in the preliminary design associated with the fabrication, assembly and installation. The information obtained from the model fabrication, assembly, installation, and testing processes will be used to evaluate the MBT preliminary design and to verify the finite element (FE) analysis. The final design of the MBT will take advantage of the experience gained from the test model to improve the design and engineering, fabrication methods, and assembly methods. The goals that are considered relevant to the test model include the following: Verify the in-plane and out-of-plane stiffness of the test model as predicted by the FE analysis. Verify the corner joint stiffness of the test model as predicted by the FE analysis. Verify the fabrication and assembly methods for the blocks, pins and keys on a small scale. Demonstrate the plate flattening scheme on a small scale. Insure that the preliminary design of the MBT can be assembled into the correct shape on a small scale. A magnetic measurement will be performed to record the field density inside an air gap. The main goal is to find out the field distribution for the test model due to geometry variation. The field measurements will also provide the information to verify the magnetic property of the steel material as well as the impact on the field distribution due to material variation

  14. The First ATLAS Barrel Toroid Coil Successfully Tested in Hall 180

    CERN Multimedia

    Rabbers, J J

    2004-01-01

    The first Barrel Toroid coil has been successfully tested with magnetic mirror at nominal current I=20.5 kA, up to a maximum current Imax=22 kA. After 14 days of cooling down, BT1 reached 4.5 Kelvin and the test program started on September 2nd. First the instrumentation and safety systems of the coil were tested at relatively low operating currents, up to 5 kA. Since all the systems and the coil were performing well, the current was increased by steps in several runs, while monitoring and evaluating the temperatures, voltages and mechanics. On early Wednesday morning September 8th the current was ramped up to 22 kA, shown by the red curve in the picture shown below: Thereafter the current was ramped down by a slow dump, where the stored energy of about 130 MJ is dissipated in a resistor/diode ramp down unit. This is the regular way of ramping down the current, which takes about one hour. Thereafter the current was ramped up to 22 kA for a second time, this time a so-called fast dump was initiated, ...

  15. Experiments on large superconducting toroidal coil in LCT

    International Nuclear Information System (INIS)

    The experiment on Large Coil Task (LCT) project which is the works of developing the superconductive coils for nuclear fusion, and has been advanced centering around IEA, was successfully completed on September 3, 1987. In these works which were accompanied by huge hardwares and took 10 years, the contents of the experiment carried out in the Oak Ridge National Laboratory in USA, which was the highlight, and the perspective of the evaluation are described. This paper is intended to let those concerned with the technical development of atomic energy understand the experimental results of LCT coils and the contents of the development of large scale technology. The fundamental constitution of the LCT is as follows. ORNL determined the specification of the performance of superconductive toroidal coils. The participants decided their own specification of the construction. The coils were assembled in torus form, and the aptitude of the construction and materials was tested and evaluated under the same condition. The features of six coils made in USA, Euratom, Switzerland and Japan, the experimental items and the most difficult points, the results of precooling and temperature rise, the characteristics of the Japanese coil, the general comparison of six coils, and the technical problems surrounding coils are reported. (Kako, I.)

  16. Pareto optimal design of sectored toroidal superconducting magnet for SMES

    Science.gov (United States)

    Bhunia, Uttam; Saha, Subimal; Chakrabarti, Alok

    2014-10-01

    A novel multi-objective optimization design approach for sectored toroidal superconducting magnetic energy storage coil has been developed considering the practical engineering constraints. The objectives include the minimization of necessary superconductor length and torus overall size or volume, which determines a significant part of cost towards realization of SMES. The best trade-off between the necessary conductor length for winding and magnet overall size is achieved in the Pareto-optimal solutions, the compact magnet size leads to increase in required superconducting cable length or vice versa The final choice among Pareto optimal configurations can be done in relation to other issues such as AC loss during transient operation, stray magnetic field at outside the coil assembly, and available discharge period, which is not considered in the optimization process. The proposed design approach is adapted for a 4.5 MJ/1 MW SMES system using low temperature niobium-titanium based Rutherford type cable. Furthermore, the validity of the representative Pareto solutions is confirmed by finite-element analysis (FEA) with a reasonably acceptable accuracy.

  17. Barrel-stave model or toroidal model? A case study on melittin pores.

    OpenAIRE

    Yang, L; Harroun, T A; Weiss, T M; Ding, L; Huang, H W

    2001-01-01

    Transmembrane pores induced by amphiphilic peptides, including melittin, are often modeled with the barrel-stave model after the alamethicin pore. We examine this assumption on melittin by using two methods, oriented circular dichroism (OCD) for detecting the orientation of melittin helix and neutron scattering for detecting transmembrane pores. OCD spectra of melittin were systematically measured. Melittin can orient either perpendicularly or parallel to a lipid bilayer, depending on the phy...

  18. Safety analysis of superconducting toroidal field magnet for tokamak experimental fusion reactor

    International Nuclear Information System (INIS)

    Safety analysis of the superconducting toroidal field magnet for a Tokamak experimental fusion reactor has been carried out. Works were accident classification, FMEA and FTA analyses, coil stability and quench behavior calculations, failure detection and coil protection system designs, structure analysis, fracture and fatigue studies, and earthquake response analysis. Accident analysis of cryostat and refrigeration system was also performed. The objective of this work is to reveal technological problems of the toroidal field magnet by safety analysis. (author)

  19. Some characteristics of the superconducting magnetic system of toroidal spectrometer STORS

    International Nuclear Information System (INIS)

    A superconducting toroidal spectrometer (STORS) has been suggested to provide precision measurements of structure functions in muon beams. In this paper we present the calculation of the magnet induction and forces influencing the elements of the magnet, requirements to the reliability and rigidity of the carrying elements of the magnet construction. (author.) 14 refs.; 50 figs.; 4 tabs

  20. Test Results of a 1.2 kg/s Centrifugal Liquid Helium Pump for the ATLAS Superconducting Toroid Magnet System

    CERN Document Server

    Pengo, R; Passardi, Giorgio; Pirotte, O; ten Kate, H H J

    2002-01-01

    The toroid superconducting magnet of ATLAS-LHC experiment at CERN will be indirectly cooled by means of forced flow of liquid helium at about 4.5 K. A centrifugal pump will be used, providing a mass flow of 1.2 kg/s and a differential pressure of 40 kPa (ca. 400 mbar) at about 4300 rpm. Two pumps are foreseen, one for redundancy, in order to feed in parallel the cooling circuits of the Barrel and the two End-Caps toroid magnets. The paper describes the tests carried out at CERN to measure the characteristic curves, i.e. the head versus the mass flow at different rotational speeds, as well as the pump total efficiency. The pump is of the "fullemission" type, i.e. with curved blades and it is equipped with an exchangeable inducer. A dedicated pump test facility has been constructed at CERN, which includes a Coriolis-type liquid helium mass flow meter. This facility is connected to the helium refrigerator used for the tests at CERN of the racetrack magnets of the Barrel and of the End-Cap toroids.

  1. About the Toroidal Magnetic Field of a Tokamak Burning Plasma Experiment with Superconducting Coils

    International Nuclear Information System (INIS)

    In tokamaks, the strong dependence on the toroidal magnetic field of both plasma pressure and energy confinement is what makes possible the construction of small and relatively inexpensive burning plasma experiments using high-field resistive coils. On the other hand, the toroidal magnetic field of tokamaks using superconducting coils is limited by the critical field of superconductivity. In this article, we examine the relative merit of raising the magnetic field of a tokamak plasma by increasing its aspect ratio at a constant value of the peak field in the toroidal magnet. Taking ITER-FEAT as an example, we find that it is possible to reach thermonuclear ignition using an aspect ratio of approximately 4.5 and a toroidal magnetic field of 7.3 T. Under these conditions, fusion power density and neutron wall loading are the same as in ITER [International Thermonuclear Experimental Reactor], but the normalized plasma beta is substantially smaller. Furthermore, such a tokamak would be able to reach an energy gain of approximately 15 even with the deterioration in plasma confinement that is known to occur near the density limit where ITER is forced to operate

  2. Dynamic Stabilization by Modulated Toroidal Current on the HT-7 Superconducting Tokamak

    Institute of Scientific and Technical Information of China (English)

    毛剑珊; 罗家荣; 赵君煜; 张先梅; 揭银先; 高翔; 张守银; 李建刚

    2002-01-01

    The technique of toroidal current modulation has been successfully used in suppressing magnetohydrodynamic (MHD) perturbations effectively on the HT-7 superconducting tokamak. When the ratio of amplitude of plasma modulated current ΔIp versus the equilibrium plasma current Ip0 is about 12 - 30%, the resonance surface is moved outside the island width, and the suppression of MHD perturbations is observed. The disruption induced by tearing mode instability is delayed or avoided. Different formats of frequency modulated are compared.

  3. Design study of superconducting toroidal field magnet for tokamak fusion power reactor

    International Nuclear Information System (INIS)

    Design study of the superconducting toroidal field magnet for a 2000 MW sub(t) tokamak fusion power reactor has been carried out. Performed here were conductor design, magnetic field calculation, design of coil support, stress analysis and design of refrigeration system. The maximum toroidal field at the coil is 12T, providing 6T at the plasma center. Nb3Sn superconductors are employed in the higher field zone. The operation current is 34.72 kA, and the conductors are fully stabilized. The heat load in the magnet is 21.1 kW, and the required liquefaction rate is 36,000 l/h. Many technological problems were revealed by the design study. (auth.)

  4. Mass production and quality control of Nb3Sn superconducting strands for ITER toroidal field coils

    International Nuclear Information System (INIS)

    Superconducting conductors are applied in the toroidal field (TF) coils, poloidal field coils, and central solenoid (CS) in the ITER. The Japan Atomic Energy Agency plans to procure 25% of the TF conductors and 100% of the CS conductors. Mass-produced Nb3Sn superconducting strands for TF conductors have been supplied by two manufacturers since 2008. The total length of the strands is approximately 23,000 km; thus, quality control is extremely important. A statistical process control has been adopted in order to reduce the dispersion of strand performance, and stable performance of the mass-produced strands was achieved. Both manufacturers improved the fabrication yield through mass production. Approximately 72% of the Japanese share in TF strands has been produced as of October 2011. (author)

  5. Tokamak Fusion Core Experiment: design studies based on superconducting and hybrid toroidal field coils. Design overview

    International Nuclear Information System (INIS)

    This document is a design overview that describes the scoping studies and preconceptual design effort performed in FY 1983 on the Tokamak Fusion Core Experiment (TFCX) class of device. These studies focussed on devices with all-superconducting toroidal field (TF) coils and on devices with superconducting TF coils supplemented with copper TF coil inserts located in the bore of the TF coils in the shield region. Each class of device is designed to satisfy the mission of ignition and long pulse equilibrium burn. Typical design parameters are: major radius = 3.75 m, minor radius = 1.0 m, field on axis = 4.5 T, plasma current = 7.0 MA. These designs relay on lower hybrid (LHRH) current rampup and heating to ignition using ion cyclotron range of frequency (ICRF). A pumped limiter has been assumed for impurity control. The present document is a design overview; a more detailed design description is contained in a companion document

  6. Design of a 4.5 MJ/1 MW sectored toroidal superconducting energy storage magnet

    Science.gov (United States)

    Bhunia, Uttam; Akhter, Javed; Nandi, Chinmay; Pal, Gautam; Saha, Subimal

    2014-09-01

    A 4.5 MJ/1 MW superconducting magnetic energy storage (SMES) system is being developed at VECC centre, Kolkata. The magnet system consists of the cryostat and coil assembly comprising eight superconducting solenoid coils made of custom-made NbTi based Rutherford-type cable and arranged in toroidal fashion with finite inter-sector gap. Since the strong electromagnetic force distributed to the coil is asymmetric and non-uniform in nature, a precise 3-D finite element analysis (FEA) has been carried out to design a mechanically stable coil and support structure under various operational scenarios. The results reveal that maximum stress developed on coil and its support structure is below allowable stress limit. Extensive transient analysis has also been carried out to evaluate transient loss and assess the feasibility of using helium re-condensation technology with commercially available cryo-refrigerators. Finally, quench protection scenario has also been discussed suitable for this toroidal-type SMES system. The article investigates the design concept of the cryostat and coil assembly.

  7. ATLAS: Full power for the toroid magnet

    CERN Multimedia

    2006-01-01

    The 9th of November was a memorable day for ATLAS. Just before midnight, the gigantic Barrel toroid magnet reached its nominal field of 4 teslas in the coil windings, with an electrical current of 21000 amperes (21 kA) passing through the eight superconducting coils (as seen on the graph). This achievement was obtained after several weeks of commissioning. The ATLAS Barrel Toroid was first cooled down for about six weeks in July-August to -269°C (4.8 K) and then powered up step-by-step in successive test sessions to 21 kA. This is 0.5 kA above the current required to produce the nominal magnetic field. Afterwards, the current was safely switched off and the stored magnetic energy of 1.1 gigajoules was dissipated in the cold mass, raising its temperature to a safe -218°C (55 K). 'We can now say that the ATLAS Barrel Toroid is ready for physics,' said Herman ten Kate, project leader for the ATLAS magnet system. The ATLAS barrel toroid magnet is the result of a close collaboration between the magnet la...

  8. Toroidal superconducting transformer with cold magnetic core – results of analysis and measurements

    International Nuclear Information System (INIS)

    The paper is focused on a toroidal superconducting transformer with cold magnetic core. The transformer was developed aiming at the solution where magnetic core could operate immersed in LN2, not having much higher power losses than a core operating in room temperature. The second aim is concerned to the perpendicular component of the magnetic flux. It was assumed that it should be minimized. The third aim is required maximal coupling coefficient between windings. Magnetic material METGLAS 2605 SA1 (Metglas Ltd) was selected as the best taking electrical and mechanical properties into account. Numerical analysis of the transformer was carried using ANSYS software. It was assumed that magnetic core could be put inside windings and/or outside of it. The analysis and measurements yield that the best solution is the transformer with magnetic core put inside the windings. Such a construction reduces significantly perpendicular component of the magnetic field in HTS wire. Because outer winding is put on the inner one it gives maximal possible coupling coefficient. The primary and the secondary have the same number of turns. It means bifilar way of winding. The described transformer has the following constructional data: i) diameter of the main circle: 144 mm, ii) maximal diameter: 208 mm, iii) diameter of the small cross-section of the transformer (without external magnetic core): 50 mm and it results with the following parameters: output power 1.59 kVA, power density 700 VA/kg, efficiency: 99.5, coupling coefficient 0.99 at 100 ARMS of input current and maximum flux density 1.2 T.

  9. Quench propagation and protection analysis of the ATLAS Toroids

    CERN Document Server

    Dudarev, A; ten Kate, H H J; Baynham, D Elwyn; Courthold, M J D; Lesmond, C

    2000-01-01

    The ATLAS superconducting magnet system consists of the Barrel Toroid, two End Cap Toroids and the Central Solenoid. However, the Toroids of eight coils each are magnetically separate systems to the Central Solenoid. The Toroids are electrically connected in series and energized by a single power supply. The quench protection system is based on the use of relatively small external dump resistances in combination with quench-heaters activated after a quench event detection to initiate the internal dump of stored energy in all the coils. A rather strong quench-back effect due to eddy-currents in the coil casings at the transport current decay is beneficial for the quench protection efficiency in the event of heater failures. The quench behaviour of the ATLAS Toroids was computer simulated for normal operation of the quench protection system and its complete non-operation (failure) mode. (3 refs).

  10. Toroid magnet test facility

    CERN Multimedia

    2002-01-01

    Because of its exceptional size, it was not feasible to assemble and test the Barrel Toroid - made of eight coils - as an integrated toroid on the surface, prior to its final installation underground in LHC interaction point 1. It was therefore decided to test these eight coils individually in a dedicated test facility.

  11. An important step for the ATLAS toroid magnet

    CERN Multimedia

    2000-01-01

    The ATLAS experiment's prototype toroid coil arrives at CERN from the CEA laboratory in Saclay on 6 October. The world's largest superconducting toroid magnet is under construction for the ATLAS experiment. A nine-metre long fully functional prototype coil was delivered to CERN at the beginning of October and has since been undergoing tests in the West Area. Built mainly by companies in France and Italy under the supervision of engineers from the CEA-Saclay laboratory near Paris and Italy's INFN-LASA, the magnet is a crucial step forward in the construction of the ATLAS superconducting magnet system. Unlike any particle detector that has gone before, the ATLAS detector's magnet system consists of a large toroidal system enclosing a small central solenoid. The barrel part of the toroidal system will use eight toroid coils, each a massive 25 metres in length. These will dwarf the largest toroids in the world when ATLAS was designed, which measure about six metres. So the ATLAS collaboration decided to build a...

  12. A toroidal magnet option

    International Nuclear Information System (INIS)

    The possibility of using, for the ALICE forward muon spectrometer, a superconducting toroidal magnet has been considered in place of the SC dipole. The study has been restricted to the acceptance calculations and to the tracking simulations of the toroidal magnet but without technical investigations. The estimated performances are found maladjusted to the physics requirements of the heavy ion runs. (author)

  13. A novel approach to calculate inductance and analyze magnetic flux density of helical toroidal coil applicable to Superconducting Magnetic Energy Storage systems (SMES)

    Energy Technology Data Exchange (ETDEWEB)

    Alizadeh Pahlavani, M.R., E-mail: Mr_Alizadehp@iust.ac.i [Department of Electrical Engineering, Iran University of Science and Technology (IUST), Power Electronic Research Laboratory (PERL), 16846 Tehran (Iran, Islamic Republic of); Shoulaie, A., E-mail: shoulaie@iust.ac.i [Department of Electrical Engineering, Iran University of Science and Technology (IUST), Power Electronic Research Laboratory (PERL), 16846 Tehran (Iran, Islamic Republic of)

    2010-04-01

    In this paper, formulas are proposed for the self and mutual inductance calculations of the helical toroidal coil (HTC) by the direct and indirect methods at superconductivity conditions. The direct method is based on the Neumann's equation and the indirect approach is based on the toroidal and the poloidal components of the magnetic flux density. Numerical calculations show that the direct method is more accurate than the indirect approach at the expense of its longer computational time. Implementation of some engineering assumptions in the indirect method is shown to reduce the computational time without loss of accuracy. Comparison between the experimental measurements and simulated results for inductance, using the direct and the indirect methods indicates that the proposed formulas have high reliability. It is also shown that the self inductance and the mutual inductance could be calculated in the same way, provided that the radius of curvature is >0.4 of the minor radius, and that the definition of the geometric mean radius in the superconductivity conditions is used. Plotting contours for the magnetic flux density and the inductance show that the inductance formulas of helical toroidal coil could be used as the basis for coil optimal design. Optimization target functions such as maximization of the ratio of stored magnetic energy with respect to the volume of the toroid or the conductor's mass, the elimination or the balance of stress in some coordinate directions, and the attenuation of leakage flux could be considered. The finite element (FE) approach is employed to present an algorithm to study the three-dimensional leakage flux distribution pattern of the coil and to draw the magnetic flux density lines of the HTC. The presented algorithm, due to its simplicity in analysis and ease of implementation of the non-symmetrical and three-dimensional objects, is advantageous to the commercial software such as ANSYS, MAXWELL, and FLUX. Finally, using

  14. A novel approach to calculate inductance and analyze magnetic flux density of helical toroidal coil applicable to Superconducting Magnetic Energy Storage systems (SMES)

    Science.gov (United States)

    Alizadeh Pahlavani, M. R.; Shoulaie, A.

    2010-04-01

    In this paper, formulas are proposed for the self and mutual inductance calculations of the helical toroidal coil (HTC) by the direct and indirect methods at superconductivity conditions. The direct method is based on the Neumann’s equation and the indirect approach is based on the toroidal and the poloidal components of the magnetic flux density. Numerical calculations show that the direct method is more accurate than the indirect approach at the expense of its longer computational time. Implementation of some engineering assumptions in the indirect method is shown to reduce the computational time without loss of accuracy. Comparison between the experimental measurements and simulated results for inductance, using the direct and the indirect methods indicates that the proposed formulas have high reliability. It is also shown that the self inductance and the mutual inductance could be calculated in the same way, provided that the radius of curvature is >0.4 of the minor radius, and that the definition of the geometric mean radius in the superconductivity conditions is used. Plotting contours for the magnetic flux density and the inductance show that the inductance formulas of helical toroidal coil could be used as the basis for coil optimal design. Optimization target functions such as maximization of the ratio of stored magnetic energy with respect to the volume of the toroid or the conductor’s mass, the elimination or the balance of stress in some coordinate directions, and the attenuation of leakage flux could be considered. The finite element (FE) approach is employed to present an algorithm to study the three-dimensional leakage flux distribution pattern of the coil and to draw the magnetic flux density lines of the HTC. The presented algorithm, due to its simplicity in analysis and ease of implementation of the non-symmetrical and three-dimensional objects, is advantageous to the commercial software such as ANSYS, MAXWELL, and FLUX. Finally, using the

  15. The complex and unique ATLAS Toroid family

    CERN Multimedia

    2002-01-01

    Big parts for the toroid magnets that will be used in the ATLAS experiment have been continuously arriving at CERN since March. These structures will create the largest superconducting toroid magnet ever.

  16. Superconductivity

    International Nuclear Information System (INIS)

    Research on superconductivity at ENEA is mainly devoted to projects related to the ITER magnet system. In this framework, ENEA has been strongly involved in the design, manufacturing and test campaigns of the ITER toroidal field model coil (TFMC), which reached a world record in operating current (up to 80 kA). Further to this result, the activities in 2004 were devoted to optimising the ITER conductor performance. ENEA participated in the tasks launched by EFDA to define and produce industrial-scale advanced Nb3Sn strand to be used in manufacturing the ITER high-field central solenoid (CS) and toroidal field (TF) magnets. As well as contributing to the design of the new strand and the final conductor layout, ENEA will also perform characterisation tests, addressing in particular the influence of mechanical stress on the Nb3Sn performance. As a member of the international ITER-magnet testing group, ENEA plays a central role in the measurement campaigns and data analyses for each ITER-related conductor and coil. The next phase in the R and D of the ITER magnets will be their mechanical characterisation in order to define the fabrication route of the coils and structures. During 2004 the cryogenic measurement campaign on the Large Hadron Collider (LHC) by-pass diode stacks was completed. As the diode-test activity was the only LHC contract to be finished on schedule, the 'Centre Europeenne pour la Recherche Nucleaire' (CERN) asked ENEA to participate in an international tender for the cold check of the current leads for the LHC magnets. The contract was obtained, and during 2004, the experimental setup was designed and realised and the data acquisition system was developed. The measurement campaign was successfully started at the end of 2004 and will be completed in 2006

  17. Superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Batistoni, Paola; De Marco, Francesco; Pieroni, Leonardo (ed.)

    2005-07-01

    Research on superconductivity at ENEA is mainly devoted to projects related to the ITER magnet system. In this framework, ENEA has been strongly involved in the design, manufacturing and test campaigns of the ITER toroidal field model coil (TFMC), which reached a world record in operating current (up to 80 kA). Further to this result, the activities in 2004 were devoted to optimising the ITER conductor performance. ENEA participated in the tasks launched by EFDA to define and produce industrial-scale advanced Nb3Sn strand to be used in manufacturing the ITER high-field central solenoid (CS) and toroidal field (TF) magnets. As well as contributing to the design of the new strand and the final conductor layout, ENEA will also perform characterisation tests, addressing in particular the influence of mechanical stress on the Nb3Sn performance. As a member of the international ITER-magnet testing group, ENEA plays a central role in the measurement campaigns and data analyses for each ITER-related conductor and coil. The next phase in the R and D of the ITER magnets will be their mechanical characterisation in order to define the fabrication route of the coils and structures. During 2004 the cryogenic measurement campaign on the Large Hadron Collider (LHC) by-pass diode stacks was completed. As the diode-test activity was the only LHC contract to be finished on schedule, the 'Centre Europeenne pour la Recherche Nucleaire' (CERN) asked ENEA to participate in an international tender for the cold check of the current leads for the LHC magnets. The contract was obtained, and during 2004, the experimental setup was designed and realised and the data acquisition system was developed. The measurement campaign was successfully started at the end of 2004 and will be completed in 2006.

  18. First ATLAS Barrel Toroid Coil Passes Test

    CERN Multimedia

    2004-01-01

    First they secured anything magnetic: metal tools, nuts and bolts, tables. Then they cleared the magnet assembly building, as big as an airplane hangar, and locked it tight. Before turning on the magnet for its maiden test, they waited till the dead of night so no one else would be around.

  19. Superconductivity

    CERN Document Server

    Poole, Charles P; Farach, Horacio A

    1995-01-01

    Superconductivity covers the nature of the phenomenon of superconductivity. The book discusses the fundamental principles of superconductivity; the essential features of the superconducting state-the phenomena of zero resistance and perfect diamagnetism; and the properties of the various classes of superconductors, including the organics, the buckministerfullerenes, and the precursors to the cuprates. The text also describes superconductivity from the viewpoint of thermodynamics and provides expressions for the free energy; the Ginzburg-Landau and BCS theories; and the structures of the high

  20. Superconductivity

    International Nuclear Information System (INIS)

    This report contains lecture notes of the basic lectures presented at the 1st Topsoee Summer School on Superconductivity held at Risoe National Laboratory, June 20-24, 1988. The following lecture notes are included: L.M. Falicov: 'Superconductivity: Phenomenology', A. Bohr and O. Ulfbeck: 'Quantal structure of superconductivity. Gauge angle', G. Aeppli: 'Muons, neutrons and superconductivity', N.F. Pedersen: 'The Josephson junction', C. Michel: 'Physicochemistry of high-Tc superconductors', C. Laverick and J.K. Hulm: 'Manufacturing and application of superconducting wires', J. Clarke: 'SQUID concepts and systems'. (orig.) With 10 tabs., 128 figs., 219 refs

  1. Superconductivity

    CERN Document Server

    Thomas, D B

    1974-01-01

    A short general review is presented of the progress made in applied superconductivity as a result of work performed in connection with the high-energy physics program in Europe. The phenomenon of superconductivity and properties of superconductors of Types I and II are outlined. The main body of the paper deals with the development of niobium-titanium superconducting magnets and of radio-frequency superconducting cavities and accelerating structures. Examples of applications in and for high-energy physics experiments are given, including the large superconducting magnet for the Big European Bubble Chamber, prototype synchrotron magnets for the Super Proton Synchrotron, superconducting d.c. beam line magnets, and superconducting RF cavities for use in various laboratories. (0 refs).

  2. Superconductivity

    International Nuclear Information System (INIS)

    The monograph provides readable introduction to the basics of superconductivity for beginners and experimentalists. For theorists, the monograph provides nice and brief description of the broad spectrum of experimental properties, theoretical concepts with all details, which theorists should learn, and provides a sound basis for students interested in studying superconducting theory at the microscopic level. Special chapter on the theory of high-temperature superconductivity in cuprates is devoted

  3. Superconductivity

    CERN Document Server

    Ketterson, John B

    2008-01-01

    Conceived as the definitive reference in a classic and important field of modern physics, this extensive and comprehensive handbook systematically reviews the basic physics, theory and recent advances in the field of superconductivity. Leading researchers, including Nobel laureates, describe the state-of-the-art in conventional and unconventional superconductors at a particularly opportune time, as new experimental techniques and field-theoretical methods have emerged. In addition to full-coverage of novel materials and underlying mechanisms, the handbook reflects continued intense research into electron-phone based superconductivity. Considerable attention is devoted to high-Tc superconductivity, novel superconductivity, including triplet pairing in the ruthenates, novel superconductors, such as heavy-Fermion metals and organic materials, and also granular superconductors. What’s more, several contributions address superconductors with impurities and nanostructured superconductors. Important new results on...

  4. Toroidal Nematics

    Science.gov (United States)

    Fernandez-Nieves, Alberto

    We will discuss how nematic liquid crystals organize inside toroidal droplets. When the director is parallel to the bounding surface, we find spontaneous reflection symmetry breaking, which we attribute to the role played by saddle-splay contributions to the Frank free energy. When the director is perpendicular to the bounding surface, we find that the structure is reminiscent of the escape radial configuration seen in cylinders, but with a central doubly-twisted organization, which we attribute to the geometry of the torus. We will end by presenting recent experiments with active nematics on the toroidal surface. In this case, topology and activity both affect the structure and dynamics of the material.

  5. Superconductivity:

    Science.gov (United States)

    Sacchetti, N.

    In this paper a short historical account of the discovery of superconductivity and of its gradual development is given. The physical interpretation of its various aspects took about forty years (from 1911 to 1957) to reach a successful description of this phenomenon in terms of a microscopic theory At the very end it seemed that more or less everything could be reasonably interpreted even if modifications and refinements of the original theory were necessary. In 1986 the situation changed abruptly when a cautious but revolutionary paper appeared showing that superconductivity was found in certain ceramic oxides at temperatures above those up to then known. A rush of frantic experimental activity started world-wide and in less than one year it was shown that superconductivity is a much more widespread phenomenon than deemed before and can be found at temperatures well above the liquid air boiling point. The complexity and the number of the substances (mainly ceramic oxides) involved call for a sort of modern alchemy if compounds with the best superconducting properties are to be manufactured. We don't use the word alchemy in a deprecatory sense but just to emphasise that till now nobody can say why these compounds are what they are: superconductors.

  6. Superconductivity

    International Nuclear Information System (INIS)

    During 2007, a large amount of the work was centred on the ITER project and related tasks. The activities based on low-temperature superconducting (LTS) materials included the manufacture and qualification of ITER full-size conductors under relevant operating conditions, the design of conductors and magnets for the JT-60SA tokamak and the manufacture of the conductors for the European dipole facility. A preliminary study was also performed to develop a new test facility at ENEA in order to test long-length ITER or DEMO full-size conductors. Several studies on different superconducting materials were also started to create a more complete database of superconductor properties, and also for use in magnet design. In this context, an extensive measurement campaign on transport and magnetic properties was carried out on commercially available NbTi strands. Work was started on characterising MgB2 wire and bulk samples to optimise their performance. In addition, an intense experimental study was started to clarify the effect of mechanical loads on the transport properties of multi-filamentary Nb3Sn strands with twisted or untwisted superconducting filaments. The experimental activity on high-temperature superconducting (HTS) materials was mainly focussed on the development and characterisation of YBa2Cu3O7-X (YBCO) based coated conductors. Several characteristics regarding YBCO deposition, current transport performance and tape manufacture were investigated. In the framework of chemical approaches for YBCO film growth, a new method, developed in collaboration with the Technical University of Cluj-Napoca (TUCN), Romania, was studied to obtain YBCO film via chemical solution deposition, which modifies the well-assessed metallic organic deposition trifluoroacetate (MOD-TFA) approach. The results are promising in terms of critical current and film thickness values. YBCO properties in films with artificially added pinning sites were characterised in collaboration with TUCN and

  7. Last Few Metres for the Barrel Calorimeter

    CERN Multimedia

    Nyman, T.

    On Friday 4th November, the ATLAS Barrel Calorimeter was moved from its assembly point at the side of the ATLAS cavern to the centre of the toroidal magnet system. The detector was finally aligned, to the precision of within a millimetre, on Wednesday 9th November. The ATLAS installation team, led by Tommi Nyman, after having positioned the Barrel Calorimeter in its final location in the ATLAS experimental cavern UX15. The Barrel Calorimeter which will absorb and measure the energy of photons, electrons and hadrons at the core of the ATLAS detector is 8.6 meters in diameter, 6.8 meters long, and weighs over 1600 Tonnes. It consists of two concentric cylindrical detector elements. The innermost comprises aluminium pressure vessels containing the liquid argon electromagnetic calorimeter and the solenoid magnet. The outermost is an assembly of 64 hadron tile calorimeter sectors. Assembled 18 meters away from its final position, the Barrel Calorimeter was relocated with the help of a railway, which allows ...

  8. SCT Barrel Assembly Complete

    CERN Multimedia

    L. Batchelor

    As reported in the April 2005 issue of the ATLAS eNews, the first of the four Semiconductor Tracker (SCT) barrels, complete with modules and services, arrived safely at CERN in January of 2005. In the months since January, the other three completed barrels arrived as well, and integration of the four barrels into the entire barrel assembly commenced at CERN, in the SR1 building on the ATLAS experimental site, in July. Assembly was completed on schedule in September, with the addition of the innermost layer to the 4-barrel assembly. Work is now underway to seal the barrel thermal enclosure. This is necessary in order to enclose the silicon tracker in a nitrogen atmosphere and provide it with faraday-cage protection, and is a delicate and complicated task: 352 silicon module powertapes, 352 readout-fibre bundles, and over 400 Detector Control System sensors must be carefully sealed into the thermal enclosure bulkhead. The team is currently verifying the integrity of the low mass cooling system, which must be d...

  9. OCLATOR (One Coil Low Aspect Toroidal Reactor)

    International Nuclear Information System (INIS)

    A new approach to construct a tokamak-type reactor(s) is presented. Basically the return conductors of toroidal field coils are eliminated and the toroidal field coil is replaced by one single large coil, around which there will be placed several tokamaks or other toroidal devices. The elimination of return conductors should, in addition to other advantages, improve the accessibility and maintainability of the tokamaks and offer a possible alternative to the search for special materials to withstand large neutron wall loading, as the frequency of changeover would be increased due to minimum downtime. It also makes it possible to have a low aspect ratio tokamak which should improve the β limit, so that a low toroidal magnetic field strength might be acceptable, meaning that the NbTi superconducting wire could be used. This system is named OCLATOR

  10. TRT Barrel milestones passed

    CERN Multimedia

    Ogren, H

    2004-01-01

    The barrel TRT detector passed three significant milestones this spring. The Barrel Support Structure (BSS) was completed and moved to the SR-1 building on February 24th. On March 12th the first module passed the quality assurance testing in Building 154 and was transported to the assembly site in the SR-1 building for barrel assembly. Then on April 21st the final production module that had been scanned at Hampton University was shipped to CERN. TRT Barrel Module Production The production of the full complement of barrel modules (96 plus 9 total spares) is now complete. This has been a five-year effort by Duke University, Hampton University, and Indiana University. Actual construction of the modules in the United States was completed in the first part of 2004. The production crews at each of the sites in the United States have now completed their missions. They are shown in the following pictures. Duke University: Production crew with the final completed module. Indiana University: Module producti...

  11. The MDT Barrel Organ

    CERN Multimedia

    Claudia Marcelloni de Oliveira

    Have you ever looked for an interesting use for the spare detector parts once the construction phase was finished? Henk Tiecke, with the help of Oscar van Petten and Marco Kraan, all from NIKHEF, came up with a great idea for leftover MDT tubes. They simply built a pipe organ! See the MDT Barrel Organ in action, as recorded during a party thrown on the occasion of the first shipment of MDT chambers from NIKHEF to CERN. Want to know more about the organ? Please contact Henk Tiecke. Henk Tiecke playing the MDT Barrel Organ.

  12. Barrelled locally convex spaces

    CERN Document Server

    Pérez Carreras, P

    1987-01-01

    This book is a systematic treatment of barrelled spaces, and of structures in which barrelledness conditions are significant. It is a fairly self-contained study of the structural theory of those spaces, concentrating on the basic phenomena in the theory, and presenting a variety of functional-analytic techniques.Beginning with some basic and important results in different branches of Analysis, the volume deals with Baire spaces, presents a variety of techniques, and gives the necessary definitions, exploring conditions on discs to ensure that they are absorbed by the barrels of the sp

  13. Thin Concrete Barrel Vault

    OpenAIRE

    Kamerling, M.W.

    2013-01-01

    The paper presents the structural design of a thin barrel vault constructed with Fusée Ceramique infill elements. The load transfer is analyzed and validated. For the structure composed of Fusée Ceramique elements, steel and concrete the stresses are calculated and compared to the stresses given in the codes used from 1950 to the present. The advantages and disadvantages of these low rise barrel vaults are showed. Further the possibilities of a light infill to reduce, for structures of concre...

  14. Thin Concrete Barrel Vault

    NARCIS (Netherlands)

    Kamerling, M.W.

    2013-01-01

    The paper presents the structural design of a thin barrel vault constructed with Fusée Ceramique infill elements. The load transfer is analyzed and validated. For the structure composed of Fusée Ceramique elements, steel and concrete the stresses are calculated and compared to the stresses given in

  15. A crystal barrel

    CERN Multimedia

    2007-01-01

    The production of crystals for the barrel of the CMS electromagnetic calorimeter has been completed. This is an important milestone for the experiment, which received the last of its 62,960 crystals on 9 March. The members of the team responsible for the crystal acceptance testing at CERN display the last crystal for the CMS electromagnetic calorimeter barrel. From left to right: Igor Tarasov, Etiennette Auffray and Hervé Cornet.One of the six machines specially developed to measure 67 different parameters on each crystal. Igor Tarasov is seen inserting the last batch of crystals into the machine. The last of the 62,960 CMS barrel crystals arrived at CERN on 9 March. Once removed from its polystyrene protection, this delicate crystal, like thousands of its predecessors, will be inserted into the last of the 36 supermodules of the barrel electromagnetic calorimeter in a few days' time. This marks the end of an important chapter in an almost 15-year-long journey by the CMS crystals team, some of whose member...

  16. Next generation toroidal devices

    International Nuclear Information System (INIS)

    A general survey of the possible approach for the next generation toroidal devices was made. Either surprisingly or obviously (depending on one's view), the technical constraints along with the scientific considerations lead to a fairly limited set of systems for the most favorable approach for the next generation devices. Specifically if the magnetic field strength of 5 T or above is to be created by superconducting coils, it imposes minimum in the aspect ratio for the tokamak which is slightly higher than contemplated now for ITER design. The similar technical constraints make the minimum linear size of a stellarator large. Scientifically, it is indicated that a tokamak of 1.5 times in the linear dimension should be able to produce economically, especially if a hybrid reactor is allowed. For the next stellarator, it is strongly suggested that some kind of helical axis is necessary both for the (almost) absolute confinement of high energy particles and high stability and equilibrium beta limits. The author still favors a heliac most. Although it may not have been clearly stated in the main text, the stability afforded by the shearless layer may be exploited fully in a stellarator. (author)

  17. Paying by the Barrel

    Institute of Scientific and Technical Information of China (English)

    Francis L.Sackitey; Ghana

    2012-01-01

    CHINA'S UNIPEC Asia Co. Ltd. will buy up the entire oil share from Ghana's Jubilee field for the next 15 years in a commercial agreement entered into by the government of Ghana. Under the agreement, the West African nation will be supplying China with 13,000 barrels of crude oil daily to pay for a $3 billion loan granted to Ghana by China under a Master Facility Agreement with the China Development Bank.

  18. Toroidal circular dichroism

    Science.gov (United States)

    Raybould, T. A.; Fedotov, V. A.; Papasimakis, N.; Kuprov, I.; Youngs, I. J.; Chen, W. T.; Tsai, D. P.; Zheludev, N. I.

    2016-07-01

    We demonstrate that the induced toroidal dipole, represented by currents flowing on the surface of a torus, makes a distinct and indispensable contribution to circular dichroism. We show that toroidal circular dichroism supplements the well-known mechanism involving electric dipole and magnetic dipole transitions. We illustrate this with rigorous analysis of the experimentally measured polarization-sensitive transmission spectra of an artificial metamaterial, constructed from elements of toroidal symmetry. We argue that toroidal circular dichroism will be found in large biomolecules with elements of toroidal symmetry and should be taken into account in the interpretation of circular dichroism spectra of organics.

  19. Triggering and measuring bent cosmic muon tracks with the Muon Spectrometer barrel for the first time

    CERN Multimedia

    Fabio Cerutti

    During the ATLAS barrel toroid stability test, bent cosmic muon tracks were seen for the first time in the ATLAS cavern by means of the ATLAS muon spectrometer. The barrel toroid has been powered at its nominal current (20.5 thousand Amperes) and kept in steady state for more than one day during the weekend of 18-19 November (see a report on this test in the Magnet section). During this test one large sector and part of a small sector of the barrel muon spectrometer were readout and used to detect the cosmic muons tracks bent by the toroidal magnetic field. Thirteen muon stations in the feet sectors (sectors 13 and 14) have been used in this test. The muon stations are formed of Resistive Plate Chambers (RPC) that were providing the muon trigger, and Monitored Drift Tubes that were used to measure with high accuracy the muon curvature hence their momentum. The Level-1 Barrel trigger chain was based on the Barrel Middle Large chambers equipped with final production modules on both the on-detector and the o...

  20. Weapons barrel life cycle determination

    Directory of Open Access Journals (Sweden)

    Nebojša Pene Hristov

    2013-10-01

    Full Text Available This article describes the dynamic processes within the gun barrel during the firing process in exploitation. It generally defines the basic principles of constructing tube elements, and shows the distortion of the basic geometry of the tube interior due to wear as well as the impact it causes during exploitation. The article also defines basic empirical models as well as a model based on fracture mechanics for the calculation of a use-life of the barrel, and other elements essential for the safe use of the barrel as the basic weapon element. Erosion causes are analysed in order to control and reduce wear and prolong the lifetime of the gun barrel. It gives directions for the reparation of barrels with wasted resources. In conclusion, the most influential elements of tube wear are given as well as possible modifications of existing systems, primarily propellant charges, with a purpose of prolonging lifetime of gun barrels. The guidelines for a proper determination of the lifetime based on the barrel condition assessment are given as well. INTRODUCTION The barrel as the basic element of each weapon is described as well as the processes occurring during the firing that have impulsive character and are accompanied by large amounts of energy. The basic elements of barrel and itheir constructive characteristics are descibed. The relation between Internal ballistics, ie calculation of the propellant gas pressure in the firing process, and structural elements defined by the barrel material resistance is shown. In general, this part of the study explains the methodology of the gun barrel structural elements calculation, ie. barrel geometry, taking into account the degrees of safety in accordance with Military Standards.   TUBE WEAR AND DEFORMATIONS The weapon barrel gradually wears out during exploitation due to which it no longer satisfies the set requirements. It is considered that the barrel has experienced a lifetime when it fails to fulfill the

  1. Induced toroid structures and toroid polarizabilities

    International Nuclear Information System (INIS)

    The frequency-dependent toroid dipole polarizability γ(ω) of a (nonrelativistic, spinless) hydrogen-like atom in its ground state is calculated analytically in terms of two Gauss hypergeometric functions. The static result reads simply γ(ω=0)=(23/60)α2Z-4a05 (α - fine structure constant, Z - nucleus charge number, a0 - Bohr radius). Comparing the present evaluations for H-like atoms with previous ones for pions, one sees that the role of the induced toroid moments (as against that of the usual electric ones) increases considerably when passing from atomic to particle physics

  2. New Toroid shielding design

    CERN Multimedia

    Hedberg V

    On the 15th of June 2001 the EB approved a new conceptual design for the toroid shield. In the old design, shown in the left part of the figure above, the moderator part of the shielding (JTV) was situated both in the warm and cold areas of the forward toroid. It consisted both of rings of polyethylene and hundreds of blocks of polyethylene (or an epoxy resin) inside the toroid vacuum vessel. In the new design, shown to the right in the figure above, only the rings remain inside the toroid. To compensate for the loss of moderator in the toroid, the copper plug (JTT) has been reduced in radius so that a layer of borated polyethylene can be placed around it (see figure below). The new design gives significant cost-savings and is easier to produce in the tight time schedule of the forward toroid. Since the amount of copper is reduced the weight that has to be carried by the toroid is also reduced. Outgassing into the toroid vacuum was a potential problem in the old design and this is now avoided. The main ...

  3. Invisibility cloaks for toroids.

    Science.gov (United States)

    You, Yu; Kattawar, George W; Yang, Ping

    2009-04-13

    The material properties of toroidal invisibility cloaks are derived based on the coordinate transformation method. The permittivity and permeability tensors for toroidal cloaks are substantially different from those for spherical cloaks, but quite similar to those for 2D cylindrical cloaks because a singularity is involved at the inner boundary in both the cases. The cloaking effect is confirmed by the electric field distribution in the vicinity of toroidal cloaks simulated from the generalized discrete-dipole approximation (DDA) method. This study extends the concept of electromagnetic cloaking of arbitrarily-shaped objects to a complex geometry. PMID:19365485

  4. The PANDA Barrel DIRC

    Science.gov (United States)

    Dzhygadlo, R.; Schwarz, C.; Belias, A.; Gerhardt, A.; Götzen, K.; Kalicy, G.; Krebs, M.; Lehmann, D.; Nerling, F.; Patsyuk, M.; Peters, K.; Schepers, G.; Schmitt, L.; Schwiening, J.; Traxler, M.; Zühlsdorf, M.; Britting, A.; Eyrich, W.; Lehmann, A.; Pfaffinger, M.; Uhlig, F.; Düren, M.; Etzelmüller, E.; Föhl, K.; Hayrapetyan, A.; Kröck, B.; Merle, O.; Rieke, J.; Schmidt, M.; Cowie, E.; Keri, T.; Achenbach, P.; Cardinali, M.; Hoek, M.; Lauth, W.; Schlimme, S.; Sfienti, C.; Thiel, M.

    2016-05-01

    The PANDA detector at the international accelerator Facility for Antiproton and Ion Research in Europe (FAIR) addresses fundamental questions of hadron physics. Experiments concerning charmonium spectroscopy, the search for hybrids and glueballs and the interaction of hidden and open charm particles with nucleons and nuclei will be performed with antiproton beams impinging on hydrogen or nuclear targets. Cooled beams allow the precision scan of resonances in formation experiments. The momentum range of the antiproton beam between 1.5 GeV/c and 15 GeV/c tests predictions by perturbation theory and will reveal deviations originating from strong QCD . An excellent hadronic particle identification will be accomplished by DIRC (Detection of Internally Reflected Cherenkov light) counters. The design for the barrel region is based on the successful BaBar DIRC with several key improvements, such as fast photon timing and a compact imaging region. DIRC designs based on different radiator geometries with several focusing options were studied in simulation. The performance of each design was characterized in terms of photon yield and single photon Cherenkov angle resolution. Selected design options were implemented in prototypes and tested with hadronic particle beams at GSI and CERN.

  5. First Cryogenic Testing of the ATLAS Superconducting Prototype Magnets

    CERN Document Server

    Delruelle, N; Haug, F; Mayri, C; Orlic, J P; Passardi, Giorgio; Pirotte, O; ten Kate, H H J

    2002-01-01

    The superconducting magnet system of the ATLAS detector will consist of a central solenoid, two end-cap toroids and the barrel toroid made of eight coils (BT) symmetrically placed around the central axis of the detector. All these magnets will be individually tested in an experimental area prior to their final installation in the underground cavern of the LHC collider. A dedicated cryogenic test facility has been designed and built for this purpose. It mainly consists of a 1'200 W at 4.5 K refrigerator, a 10 kW liquid nitrogen pre-cooling unit, a cryostat housing liquid helium centrifugal pumps, a distribution valve box and transfer lines. Prior to the start of the series tests of the BT magnets, two model coils are used at this facility. The first one, the so-called B00 of comparatively small size, contains the three different types of superconductors used for the ATLAS magnets which are wound on a cylindrical mandrel. The second magnet, the B0, is a reduced model of basically identical design concept as the...

  6. Barrel-shaped supernova remnants

    International Nuclear Information System (INIS)

    The authors argue that the majority of radio supernova remnants have a three-dimensional distribution of emissivity which is barrel shaped, with little emission from the end-caps. They examine some mechanisms which could produce this distribution

  7. Heat Load Measurements on a Large Superconducting Magnet An Application of a Void Fraction Meter

    CERN Document Server

    Pengo, R; Junker, S; Passardi, Giorgio; ten Kate, H H J

    2004-01-01

    ATLAS is one of the two major experiments of the LHC project at CERN using cryogenics. The superconducting magnet system of ATLAS is composed of the Barrel Toroid (BT), two End Caps Toroids and the Central Solenoid. The BT is formed of 8 race-track superconducting dipoles, each one 25 m long and 5 m wide. A reduced scale prototype (named B0) of one of the 8 dipoles, about one third of the length, has been constructed and tested in a dedicated cryogenic facility at CERN. To simulate the final thermal and hydraulic operating conditions, the B0 was cooled by a forced flow of 4.5 K saturated liquid helium provided by a centrifugal pump of 80 g/s nominal capacity. Both static and dynamic heat loads, generated by the induced currents on the B0 casing during a slow dump or a ramp up, have been measured to verify the expected thermal budget of the entire BT. The instrument used for the heat load measurements was a Void Fraction Meter (VFM) installed on the magnet return line. The instrument constructed at CERN was ca...

  8. The Experiment of Modulated Toroidal Current on HT-7 and HT-6M Tokamak

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The Experiments of Modulated Toroidal Current were done on the HT-6M tokamakand HT-7 superconducting tokamak. The toroidal current was modulated by programming theOhmic heating field. Modulation of the plasma current has been used successfully to suppressMHD activity in discharges near the density limit where large MHD m = 2 tearing modes weresuppressed by sufficiently large plasma current oscillations. The improved Ohmic confinementphase was observed during modulating toroidal current (MTC) on the Hefei Tokamak-6M (HT-6M) and Hefei superconducting Tokamak-7 (HT-7). A toroidal frequency-modulated current,induced by a modulated loop voltage, was added on the plasma equilibrium current. The ratio ofA.C. amplitude of plasma current to the main plasma current △Ip/Ip is about 12% ~ 30%. Thedifferent formats of the frequency-modulated toroidal current were compared.

  9. Approximations to toroidal harmonics

    International Nuclear Information System (INIS)

    Toroidal harmonics P/sub n-1/2/1(cosh μ) and Q/sub n-1/2/1(cosh μ) are useful in solutions to Maxwell's equations in toroidal coordinates. In order to speed their computation, a set of approximations has been developed that is valid over the range 0 -10. The simple method used to determine the approximations is described. Relative error curves are also presented, obtained by comparing approximations to the more accurate values computed by direct summation of the hypergeometric series

  10. Drift in toroidal configurations

    Science.gov (United States)

    Evangelidis, E. A.

    1990-12-01

    This paper considers possible mechanisms involved in amplifying the drift velocity of plasma particles, under conditions of toroidal geometry. It is shown that particles constrained to move on an axisymmetric circular spheroidal surface, develop a sinusoidal motion with a characteristic frequency which depends on the energy of the particles, the value of the isoflux surface, and the value of the general momentum. It is also shown that the incorporation of the effects of toroidal geometry in the Lorentz equation produces a nonambipolar charge-dependent particle flux amplified by a factor 2(q/epsilon) squared.

  11. Aspects of Tokamak toroidal magnet protection

    Energy Technology Data Exchange (ETDEWEB)

    Green, R.W.; Kazimi, M.S.

    1979-07-01

    Simple but conservative geometric models are used to estimate the potential for damage to a Tokamak reactor inner wall and blanket due to a toroidal magnet field collapse. The only potential hazard found to exist is due to the MHD pressure rise in a lithium blanket. A survey is made of proposed protection methods for superconducting toroidal magnets. It is found that the two general classifications of protection methods are thermal and electrical. Computer programs were developed which allow the toroidal magnet set to be modeled as a set of circular filaments. A simple thermal model of the conductor was used which allows heat transfer to the magnet structure and which includes the effect of temperature dependent properties. To be effective in large magnets an electrical protection system should remove at least 50% of the stored energy in the protection circuit assuming that all of the superconductor in the circuit quenches when the circuit is activated. A protection system design procedure based on this criterion was developed.

  12. ID Barrel installed in cryostat

    CERN Multimedia

    Apsimon, R.; Romaniouk, A.

    Wednesday 23rd August was a memorable day for the Inner Detector community as they witnessed the transport and installation of the central part of the inner detector (ID-barrel) into the ATLAS detector. Many members of the collaboration gathered to witness this moment at Point 1. After years of design, construction and commissioning, the outer two detectors (TRT and SCT) of the ID barrel were moved from the SR1 cleanroom to the ATLAS cavern. The barrel was moved across the car park from building 2175 to SX1. Although only a journey of about 100 metres, this required weeks of planning and some degree of luck as far as the weather was concerned. Accelerometers were fitted to the barrel to provide real-time monitoring and no values greater than 0.1 g were recorded, fully satisfying the transport specification for this extremely precise and fragile detector. Muriel, despite her fear of heights, bravely volunteered to keep a close eye on the detector. Swapping cranes to cross the entire parking lot, while Mur...

  13. Superconducting Magnet with the Minimum Steel Yoke for the Hadron Future Circular Collider Detector

    CERN Document Server

    Klyukhin, V I; Ball, A.; Curé, B.; Dudarev, A.; Gaddi, A.; Gerwig, H.; Mentink, M.; Da Silva, H. Pais; Rolando, G.; ten Kate, H. H. J.; Berriaud, C.P.

    2016-01-01

    The conceptual design study of a hadron Future Circular Collider (FCC-hh) with a center-of-mass energy of the order of 100 TeV in a new tunnel of 80-100 km circumference assumes the determination of the basic requirements for its detectors. A superconducting solenoid magnet of 12 m diameter inner bore with the central magnetic flux density of 6 T in combination with two superconducting dipole and two conventional toroid magnets is proposed for a FCC-hh experimental setup. The coil of 23.468 m long has seven 3.35 m long modules included into one cryostat. The steel yoke with a mass of 22.6 kt consists of two barrel layers of 0.5 m radial thickness, and the 0.7 m thick nose disk and four 0.6 m thick end-cap disks each side. The maximum outer diameter of the yoke is 17.7 m; the length is 62.6 m. The air gaps between the end-cap disks provide the installation of the muon chambers up to the pseudorapidity about \\pm 2.7. The superconducting dipole magnets allow measuring the charged particle momenta in the pseudora...

  14. Work on a ATLAS tile calorimeter Barrel

    CERN Multimedia

    Laurent Guiraud

    2000-01-01

    The Tile Calorimeter is designed as one barrel and two extended barrel hadron parts. The calorimeter consists of a cylindrical structure with inner and outer radius of 2280 and 4230 mm respectively. The barrel part is 5640 mm in length along the beam axis, while each of the extended barrel cylinders is 2910 mm long. Each detector cylinder is built of 64 independent wedges along the azimuthal direction. Between the barrel and the extended barrels there is a gap of about 600 mm, which is needed for the Inner Detector and the Liquid Argon cables, electronics and services. The barrel covers the region -1.0barrels cover the region 0.8<|h|<1.7.

  15. Energy dump of the ATLAS superconducting system simulations of electrical and thermal behaviour of magnet system at slow- and fast dump

    CERN Document Server

    van Beek, Martijn; Dudarev, A

    During the slow dump (discharge) of the Barrel Toroidal (superconducting) magnet of the ATLAS detector, the control system gave an alarm that the differences between the voltages over the conductors were too high. The alarm was not due to any danger, because of some sort of phenomenon observed in the first few seconds after start of the discharge. A possible explanation of the differences of the coil voltages is that the changing current through the conductors may cause induced currents in the coil casing around. The goal was to make a simulation of the electrical behaviour of the magnet system during a slow dump. In this way, an explanation can be found for the start phenomenon of the slow dump of the Barrel Toroid. Some extra analyses on the measurements were performed to describe the energy dissipation during a fast dump. This is done by calculating the resistance of the coils during the dump. With the maximum resistance, the maximum temperature can be estimated, which says something about the enthalpy of ...

  16. Design and manufacture of a toroidal-type SMES for combination with real-time digital simulator (RTDS)

    Science.gov (United States)

    Kim, Kwang-min; Kim, A.-Rong; Park, Minwon; Yu, In-Keun; Eom, Bum-Yong; Sim, Kidoek; Kim, Seok-Ho; Sohn, Myung-Hwan; Kim, Hae-Jong; Bae, Joon-Han; Seong, Ki-Cheol

    2011-06-01

    The authors designed and manufactured a toroidal-type superconducting magnetic energy storage (SMES) system. The toroidal-type SMES was designed using a 3D CAD program. The toroidal-type magnet consists of 30 double pancake coils (DPCs). The single pancake coils (SPCs), which constitute the double pancake coils, are arranged at an angle of 6° from each other, based on the central axis of the toroidal-type magnet. The cooling method used for the toroidal-type SMES is the conduction cooling type. When the cooling method for the toroidal-type SMES was designed, the two-stage Gifford-McMahon (GM) refrigerator was considered. The Bi-2223 HTS wire, which was made by soldering brass on both sides of the superconductor, is used for the magnet winding. Finally, the authors connected the toroidal-type SMES to a real-time digital simulator (RSCAD/RTDS) to simulate voltage sag compensation in a power utility.

  17. Mechanical Design of Superconducting Accelerator Magnets

    OpenAIRE

    Toral, Fernando

    2015-01-01

    This paper is about the mechanical design of superconducting accelerator magnets. First, we give a brief review of the basic concepts and terms. In the following sections, we describe the particularities of the mechanical design of different types of superconducting accelerator magnets: solenoids, cos-theta, superferric, and toroids. Special attention is given to the pre-stress principle, which aims to avoid the appearance of tensile stresses in the superconducting coils. A case study on a co...

  18. Elongated toroid fusion device

    International Nuclear Information System (INIS)

    A device for achieving ignition of a plasma with ohmic heating is described comprising: means for defining a toroidal plasma chamber,a and confining gas therein, and means including electrically conductive coils for generating plasma within the chamber and for confining and shaping such plasma substantially into and filling a predetermined single region of the chamber without an axisymmetric internal separatix and ohmically heating the confined plasma to ignition. The predetermined region is toroidal with a major axis defining an axial direction parallel thereto and a transaxial direction perpendicular to the axis and having an axial cross section with an elongation, k, greater than 4, where k is the ratio of the maximum axial dimension of the cross section to the maximum transaxial dimension of the cross section

  19. Bi-2223 HTS winding in toroidal configuration for SMES coil

    Energy Technology Data Exchange (ETDEWEB)

    Kondratowicz-Kucewicz, B; Kozak, S; Kozak, J; Wojtasiewicz, G; Majka, M [Electrotechnical Institute in Warsaw (Poland); Janowski, T, E-mail: t.janowski@pollub.p [Lublin University of Technology (Poland)

    2010-06-01

    Energy can be stored in the magnetic field of a coil. Superconducting Magnetic Energy Storage (SMES) is very promising as a power storage system for load levelling or power stabilizer. However, the strong electromagnetic force caused by high magnetic field and large coil current is a problem in SMES systems. A toroidal configuration would have a much less extensive external magnetic field and electromagnetic forces in winding. The paper describes the design of HTS winding for SMES coil in modular toroid configuration consist of seven Bi-2223 double-pancakes as well as numerical analysis of SMES magnet model using FLUX 3D package. As the results of analysis the paper presents the optimal coil configuration and the parameters such as radius of toroidal magnet, energy stored in magnet and magnetic field distribution.

  20. The PANDA Barrel DIRC detector

    Energy Technology Data Exchange (ETDEWEB)

    Hoek, M., E-mail: matthias.hoek@uni-mainz.de [Institut für Kernphysik, Johannes Gutenberg University Mainz, Mainz (Germany); Dzhygadlo, R.; Gerhardt, A.; Götzen, K.; Hohler, R.; Kalicy, G.; Kumawat, H.; Lehmann, D.; Lewandowski, B.; Patsyuk, M.; Peters, K.; Schepers, G.; Schmitt, L.; Schwarz, C.; Schwiening, J.; Traxler, M.; Zühlsdorf, M. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt (Germany); Dodokhov, V. Kh. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Britting, A.; Eyrich, W. [Friedrich Alexander-University of Erlangen-Nuremberg, Erlangen (Germany); and others

    2014-12-01

    The PANDA experiment at the new Facility for Antiproton and Ion Research in Europe (FAIR) at GSI, Darmstadt, will study fundamental questions of hadron physics and QCD using high-intensity cooled antiproton beams with momenta between 1.5 and 15 GeV/c. Efficient Particle Identification for a wide momentum range and the full solid angle is required for reconstructing the various physics channels of the PANDA program. Hadronic Particle Identification in the barrel region of the detector will be provided by a DIRC counter. The design is based on the successful BABAR DIRC with important improvements, such as focusing optics and fast photon timing. Several of these improvements, including different radiator geometries and optics, were tested in particle beams at GSI and at CERN. The evolution of the conceptual design of the PANDA Barrel DIRC and the performance of complex prototypes in test beam campaigns will be discussed.

  1. Tokamak with liquid metal toroidal field coil

    Science.gov (United States)

    Ohkawa, Tihiro; Schaffer, Michael J.

    1981-01-01

    Tokamak apparatus includes a pressure vessel for defining a reservoir and confining liquid therein. A toroidal liner disposed within the pressure vessel defines a toroidal space within the liner. Liquid metal fills the reservoir outside said liner. Electric current is passed through the liquid metal over a conductive path linking the toroidal space to produce a toroidal magnetic field within the toroidal space about the major axis thereof. Toroidal plasma is developed within the toroidal space about the major axis thereof.

  2. Completion of the TRT Barrel

    CERN Multimedia

    Gagnon, P

    On February 3, the US-TRT team proudly completed the installation of the 96th barrel TRT module on its support structure in the SR building at CERN. This happy event came after many years of R&D initiated in the nineties by the TA1 team at CERN, followed by the construction of the modules in three American institutes (Duke, Hampton and Indiana Universities) from 1996 to 2003. In total, the 96 barrel modules contain 52544 kapton straws, each 4 mm in diameter and strung with a 30 micron gold-plated tungsten wire. Each wire was manually inserted, a feat in itself! The inner layer modules contain 329 straws, the middle layer modules have 520 straws and the outer layer, 793 straws. Thirty- two modules of each type form a full layer. Their special geometry was designed such as to leave no dead region. On average, a particle will cross 36 straws. Kirill Egorov, Chuck Mahlon and John Callahan inserted the last module in the Barrel Support Structure. After completion in the US, all modules were transferred...

  3. Toroidal field coil system for STARFIRE, a preliminary assessment

    International Nuclear Information System (INIS)

    An important element of STARFIRE is the 12-coil superconducting toroidal field coil system which is required to generate 5.6 tesla at the 7.0 m plasma axis, with a peak-to-peak field ripple of 1% (maximum). Internal spatial requirements dictate a clear bore about 15 1/2 m high x 10 m wide, resulting in a total stored energy of 67 GJ

  4. Design status of the NET toroidal coils

    International Nuclear Information System (INIS)

    The Toroidal Field Coil System consists of 16 superconducting coil windings, their coil casings and the intercoil structure. All of these components are located inside a common cryostat vessel and will therefore be at a temperature of about 4.50 degK during operation of the machine. The 16 coils are arranged in a toroidal configuration in order to provide a magnetic field for the confinement of the ring shaped plasma. The inner legs of the D-shaped coils form a vault which is subjected to the centering forces that are caused by the toroidal field itself. The interaction between the poloidal field and the toroidal currents creates Lorentz Forces which are perpendicular to the TF coil plane. Intercoil structure and vault have to resist these forces. The huge size of the coils in combination with the fact that an A15 conductor material has to be used require techniques that are somewhat beyond the present state of the art. Therefore, a conductor and magnet development program has been launched. The development studies carried out by Associated Laboratories in cooperation with NET Team have resulted in several flow cooled composite conductors. Futheron, full size conductor samples were manufactured and two subsize conductors were manufactured and wound into two 12 T model coils. Proposals for the manufacture of the coil winding, the power supply and quench protection system, the cooling system and the instrumentation have been worked out in the course of these studies. To ensure the feasibility of the cois two study contracts have been placed with industry. This report will stress the most difficult aspects of the coil manufacture, the assembly of the winding in its steel casing and the assembly of the 16 coils with the intercoil structure to a toroidal configuration. The results of the thermomechanical and electromagnetic analysis (e.g. eddy currents in coils case, stress, a.c. losses) - will be reported and their impact on the design of the TF system will be

  5. The OPAL muon barrel detector

    Energy Technology Data Exchange (ETDEWEB)

    Akers, R.J. [Manchester Univ. (United Kingdom). Dept. of Phys. and Astron.; Allison, J. [Manchester Univ. (United Kingdom). Dept. of Phys. and Astron.; Ashton, P. [Manchester Univ. (United Kingdom). Dept. of Phys. and Astron.; Bahan, G.A. [Manchester Univ. (United Kingdom). Dept. of Phys. and Astron.; Baines, J.T.M. [Manchester Univ. (United Kingdom). Dept. of Phys. and Astron.; Banks, J.N. [Manchester Univ. (United Kingdom). Dept. of Phys. and Astron.; Barlow, R.J. [Manchester Univ. (United Kingdom). Dept. of Phys. and Astron.; Barnett, S. [Manchester Univ. (United Kingdom). Dept. of Phys. and Astron.; Beeston, C. [Manchester Univ. (United Kingdom). Dept. of Phys. and Astron.; Chrin, J.T.M. [Manchester Univ. (United Kingdom). Dept. of Phys. and Astron.; Clowes, S.G. [Manchester Univ. (United Kingdom). Dept. of Phys. and Astron.; Davies, O.W. [Manchester Univ. (United Kingdom). Dept. of Phys. and Astron.; Duerdoth, I.P. [Manchester Univ. (United Kingdom). Dept. of Phys. and Astron.; Hinde, P.S. [Manchester Univ. (United Kingdom). Dept. of Phys. and Astron.; Hughes-Jones, R.E. [Manchester Univ. (United Kingdom). Dept. of Phys. and Astron.; Lafferty, G.D. [Manchester Univ. (United Kingdom). Dept. of Phys. and Astron.; Loebinger, F.K. [Manchester Univ. (United Kingdom). Dept. of Phys. and Astron.; Macbeth, A.A. [Manchester Univ. (United Kingdom). Dept. of Phys. and Astron.; McGowan, R.F. [Manchester Univ. (United Kingdom). Dept. of Phys. and Astron.; Moss, M.W. [Manchester Univ. (United Kingdom). Dept. of Phys. and Astron.; Murphy, P.G. [Manchester Univ. (United Kingdom). Dept. of Phys. and Astron.; Nijjhar, B. [Manchester Univ. (United Kingdom). Dept. of Phys. and Astron.; O`Dowd, A.J.P. [Manchester Univ. (United Kingdom). Dept. of Phys. and Astron.; Pawley, S.J. [Manchester Univ. (United Kingdom). Dept. of Phys. and Astron.; Phillips, P.D. [Manchester Univ. (United Kingdom). Dept. of Phys. and Astron.; Richards, G.E.

    1995-04-21

    The barrel part of the OPAL muon detector consists of 110 drift chambers forming four layers outside the hadron absorber. Each chamber covers an area of 1.2 m by up to 10.4 m and has two cells with wires parallel to the beam and a drift distance of 297 mm. A detailed description of the design, construction, operation and performance of the sub-detector is given. The system has been operating successfully since the start of LEP in 1989. ((orig.)).

  6. Geometry Design of Wooden Barrels

    Directory of Open Access Journals (Sweden)

    Ivan CISMARU

    2010-12-01

    Full Text Available The aim of this paper is to present a design methodology of the wooden barrel geometry, as an algorithm of successive calculations. Thus, starting from the required elements (volume, length, shape, maximum height of storage space the user will be able to define the geometry which must be obtained by processing. Based on these calculations, one can define the structure, size and shape of the staves in order to establish the processing technology of both components and subassemblies (jacket and bottoms which are to form the final product by their assembling using metal circles.

  7. TRT and SCT barrels merge

    CERN Multimedia

    Wells, P S

    2006-01-01

    The SCT barrel was inserted in the TRT on 17 February, just missing Valentine's day. This was a change of emphasis for the two detectors. In the preceeding months there had been a lot of focus on testing their performance. The TRT had been observing cosmic rays through several sectors of the barrel, and all the modules on each of the four layers of the SCT had been characterised prior to integration. In parallel, the engineering teams, lead by Marco Olcese, Andrea Catinaccio, Eric Perrin, Neil Dixon, Iourii Gusakov, Gerard Barbier and Takashi Kohriki, had been preparing for this critical operation. Figure 1: Neil Dixon and Marco Olcese verifying the final alignment The two detectors had to be painstakingly aligned to be concentric to within a millimetre. The SCT was held on a temporary cantilever stand, and the TRT in the ID trolley had to inch over it. Finally the weight of the SCT was transferred to the rails on the inside of the TRT itself. The SCT services actually protruded a little outside the oute...

  8. Aspects of Tokamak toroidal magnet protection

    International Nuclear Information System (INIS)

    Simple but conservative geometric models are used to estimate the potential for damage to a Tokamak reactor inner wall and blanket due to a toroidal magnet field collapse. The ofly potential hazard found to exist is due to the MHD pressure rise in a lithium blanket. A survey is made of proposed protection methods for superconducting torgidal magnets. It is found that the two general classificatigls of protectign methods are thermal and electrical. Computer programs were developed which aldow the toroidal magnet set to be modeled as a set of circular filaments. A simple thermal model of the conductor was used which allows heat transfer to the magnet structure and which includes the effect of temperature dependent properties. To be effective in large magnets an electrical protection system should remove at least 50% of the stored energy in the protection circuit assuming that all of the superconductor in the circuit quenches when the circuit is activated. A protection system design procedure based on this criterion was developed

  9. The ATLAS installation team, led by Tommi Nyman, after having positioned the Barrel Calorimeter in its final location in the ATLAS experimental cavern UX15

    CERN Document Server

    2005-01-01

    On Friday 4th November, the ATLAS Barrel Calorimeter was moved from its assembly point at the side of the ATLAS cavern to the centre of the toroidal magnet system. The detector was finally aligned, to the precision of within a millimetre, on Wednesday 9th November.

  10. Mechanical Self-shrinkage of Artillery Barrels

    Directory of Open Access Journals (Sweden)

    Ioan Ciorba

    2012-09-01

    Full Text Available Objective of this paper is to define what self-shrink artillery barrel is. She is considered to be a compound barrel like as a thick-walled tube (k>2, in his wall being introduced a state of stress and strain using specific technological proceeds. This type of treatment is aimed to increase the artillery barrel load capacity and wear resistance in operation. The experimental part was realized using an industrial plant at Mechanical Factory of Resita. This part presents a comparative study between mechanical self-shrinkage on artillery head barrel, first using a mandrel and seconds a ball.

  11. Heating of toroidal plasmas

    International Nuclear Information System (INIS)

    The limitations of ohmic heating in achieving the thermonuclear ignition of a low-β toroidal plasma can be overcome by using several heating methods. Such methods are: fast neutral beam injection (possibly combined with an adiabatic compression or any other means) and HF heating, the most interesting schemes being based on plasma resonances. The basic physical phenomena in each method are briefly explained and results obtained are given. A new heating scheme using an outer frequency of a few kHz is described, that makes it possible to locate the exciting coils outside the vacuum vessel (some of these coils can be that producing the vertical magnetic field for the plasma equilibrium)

  12. Prototyping the PANDA Barrel DIRC

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, C., E-mail: C.Schwarz@gsi.de [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt (Germany); Kalicy, G.; Dzhygadlo, R.; Gerhardt, A.; Götzen, K.; Hohler, R.; Kumawat, H.; Lehmann, D.; Lewandowski, B.; Patsyuk, M.; Peters, K.; Schepers, G.; Schmitt, L.; Schwiening, J.; Traxler, M.; Zühlsdorf, M. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt (Germany); Dodokhov, V.Kh. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Britting, A.; Eyrich, W.; Lehmann, A. [Friedrich Alexander-University of Erlangen-Nuremberg, Erlangen (Germany); and others

    2014-12-01

    The design of the Barrel DIRC detector for the future PANDA experiment at FAIR contains several important improvements compared to the successful BABAR DIRC, such as focusing and fast timing. To test those improvements as well as other design options a prototype was build and successfully tested in 2012 with particle beams at CERN. The prototype comprises a radiator bar, focusing lens, mirror, and a prism shaped expansion volume made of synthetic fused silica. An array of micro-channel plate photomultiplier tubes measures the location and arrival time of the Cherenkov photons with sub-nanosecond resolution. The development of a fast reconstruction algorithm allowed to tune construction details of the detector setup with test beam data and Monte-Carlo simulations.

  13. Recent results from Crystal Barrel

    CERN Document Server

    Doser, Michael

    2000-01-01

    The Crystal Barrel detector has collected data on antiproton annihilation on Hydrogen and Deuterium at rest and at momenta up to 1940 MeV/c, accumulating a total of 600 M events with the goal of studying meson spectroscopy and searching for non-qbarq states. This large amount of data has allowed high statistics studies of exclusive final states produced under various initial conditions. Comparisons between different initial and final states greatly constrain the interpretation of these data sets. In particular, the requirement of consistency between fits of 3-body final state Dalitz plots is a powerful tool in the search for non-standard model resonances [1]. More recently, the study of the same Dalitz plot produced from antiproton annihilation on liquid and gaseous hydrogen, on deuterium or on liquid hydrogen at different center-of-mass energies has extended this approach to higher mass resonances.

  14. Toroidal Multipole Confinement Experiment

    International Nuclear Information System (INIS)

    Confinement of plasma is studied in the General Atomic toroidal octopole machine. The magnetic field is produced by four current carrying rings supported inside a contoured conductor. The rings are energized by a transformer core linking the machine. The major radius of the machine is 63.5 cm with an aspect ratio of 5. The magnetic field on the minor axis is zero and increases to 3500 G at the wall between the rings. After crowbarring, the field decays in 6 msec to its half value. The MHD stability calculation has been carried out and the stability is assured up to the plasma pressure of 1016 eV cm-3. Hydrogen plasmas from either a coaxial gun or a pinch gun with ion energies of 50 to 200 eV and with densities of 1014 cm-3 are successfully injected through a port located at the outer conductor wall. After the injection, plasma spreads azimuthally, filling the machine. Electric probes, magnetic probes, and calorimetric probes have been used extensively. Optical spectrometers and particle detectors are also used. The initial plasma density of 1013 cm-'3 decays with a time constant of 700 μsec. The electron temperature decays more quickly in about 100 μsec. No electric or magnetic fluctuations have been observed on any of the probes. Since no provision is made to avoid the plasma loss to the ring supports which penetrate the plasma region, the decay of ion temperature may be attributed to the support loss. (author)

  15. PEGASUS Toroidal Experimental Facility*

    Science.gov (United States)

    Lewicki, B.; Pegasus Group

    1998-11-01

    P EGASUS began operations in June 98 and will study the characteristics of Extremely Low-Aspect Ratio Tokamak (ELART) plasmas. The 2.0m diameter, thin-walled (6.35 mm) vacuum vessel is a continuous stainless steel shell with generous port access. Initial pump down base pressure was 5 × 10-8 torr. The high stress ohmic solenoid is powered by a 15 kV, 4.5 MJ capacitor bank and will be impedance-matched through a 10:1 step-down transformer to extend the pulse length. Operating at peak fields of 13 - 20 T, the solenoid can achieve a flux swing of up to 190mV-s over 60 ms. The toroidal field of 0.1 T on axis is powered by a 3 MVA AC/DC converter capable of 3.5 kA at 600 VDC. The equilibrium and shaping field magnets are powered by 2.2 F of commutated capacitor banks plus a 0.5 MVA programmable switching supply. Modest waveform control is available to compensate for the resistive vacuum vessel and aid in plasma shaping for elongated and diverted plasmas. Operational diagnostics include internal magnetic pickup loops, high resolution and fast framing cameras, and impurity monitoring systems. * *Supported by U.S. DoE grant No. DE-FG02-96ER54375

  16. Compact toroid formation experiments

    International Nuclear Information System (INIS)

    We present the design and experimental performance of a compact toroid (CT) formation experiment. The device has co-axial electrode diameters of 0.9 m (inner) and 1.25 m (outer), and an electrode length of ∼ 1.2 m, including an expansion/drift section. The CT is formed by a 0.1--0.2 Tesla initial radial magnetic field embedded co-axial puff gas discharge. The gas puff is injected with an array of 60 pulsed solenoid driven fast valves. The formation discharge is driven by a 108 microfarad, 40 to 100 KV, 86 to 540 kilojoule 2 to 5 megamp capacitor discharge with ∼ 20 nanohenry initial total discharge inductance. The hardware includes transmission line connections for a Shiva Star (1300 microfarad, up to 120 KV, 0.4 megajoule) capacitor bank driven acceleration discharge. Experimental measurements include current, voltage; azimuthal, radial and axial magnetic field at numerous location; fast photography, optical spectroscopy; microwave, CO2 laser, and He-Ne laser interferometry. Auxiliary experiments include Penning ionization gauge, pressure probe, and breakdown gas trigger diagnostics of gas injection, and Hall probe measurements of magnetic field injection

  17. CALIFA Barrel prototype detector characterisation

    Energy Technology Data Exchange (ETDEWEB)

    Pietras, B., E-mail: benjamin.pietras@usc.es [Universidade de Santiago de Compostela, E-15782 (Spain); Gascón, M. [Universidade de Santiago de Compostela, E-15782 (Spain); Lawrence Berkeley National Laboratory, 1 Cyclotron Rd. Berkeley, CA 94701 (United States); Álvarez-Pol, H. [Universidade de Santiago de Compostela, E-15782 (Spain); Bendel, M. [Technische Universität München, 80333 (Germany); Bloch, T. [Technische Universität Darmstadt, D-64289 Darmstadt (Germany); Casarejos, E. [Universidade de Vigo, E-36310 (Spain); Cortina-Gil, D.; Durán, I. [Universidade de Santiago de Compostela, E-15782 (Spain); Fiori, E. [Gesellschaft für Schwerionenforschung (GSI), D-64291 Darmstadt (Germany); Gernhäuser, R. [Technische Universität München, 80333 (Germany); González, D. [Universidade de Santiago de Compostela, E-15782 (Spain); Kröll, T. [Technische Universität Darmstadt, D-64289 Darmstadt (Germany); Le Bleis, T. [Technische Universität München, 80333 (Germany); Montes, N. [Universidade de Santiago de Compostela, E-15782 (Spain); Nácher, E. [Instituto de Estructura de la Materia, CSIC, E-28006 Madrid (Spain); Robles, M. [Universidade de Santiago de Compostela, E-15782 (Spain); Perea, A. [Instituto de Estructura de la Materia, CSIC, E-28006 Madrid (Spain); Vilán, J.A. [Universidade de Vigo, E-36310 (Spain); Winkel, M. [Technische Universität München, 80333 (Germany)

    2013-11-21

    Well established in the field of scintillator detection, Caesium Iodide remains at the forefront of scintillators for use in modern calorimeters. Recent developments in photosensor technology have lead to the production of Large Area Avalanche Photo Diodes (LAAPDs), a huge advancement on traditional photosensors in terms of high internal gain, dynamic range, magnetic field insensitivity, high quantum efficiency and fast recovery time. The R{sup 3}B physics programme has a number of requirements for its calorimeter, one of the most challenging being the dual functionality as both a calorimeter and a spectrometer. This involves the simultaneous detection of ∼300MeV protons and gamma rays ranging from 0.1 to 20 MeV. This scintillator – photosensor coupling provides an excellent solution in this capacity, in part due to the near perfect match of the LAAPD quantum efficiency peak to the light output wavelength of CsI(Tl). Modern detector development is guided by use of Monte Carlo simulations to predict detector performance, nonetheless it is essential to benchmark these simulations against real data taken with prototype detector arrays. Here follows an account of the performance of two such prototypes representing different polar regions of the Barrel section of the forthcoming CALIFA calorimeter. Measurements were taken for gamma–ray energies up to 15.1 MeV (Maier-Leibnitz Laboratory, Garching, Germany) and for direct irradiation with a 180 MeV proton beam (The Svedberg Laboratoriet, Uppsala, Sweden). Results are discussed in light of complementary GEANT4 simulations. -- Highlights: •Prototypes corresponding to different sections of the forthcoming CALIFA Barrel calorimeter were tested. •The response to both high energy gamma rays and high energy protons was observed. •This response was reproduced by use of R3BROOT simulations, the geometry extrapolated to predict performance of the complete calorimeter. •Effects such as energy straggling of wrapping

  18. Liquid Argon Barrel Cryostat Arrived

    CERN Multimedia

    Pailler, P

    Last week the first of three cryostats for the ATLAS liquid argon calorimeter arrived at CERN. It had travelled for 46 days over several thousand kilometers from Japan to CERN. During three years it has been fabricated by Kawasaki Heavy Industries Ltd. at Harima, close to Kobe, under contract from Brookhaven National Laboratory (BNL) of the U.S.. This cryostat consists of two concentric cylinders made of aluminium: the outer vacuum vessel with a diameter of 5.5 m and a length of 7 m, and the inner cold vessel which will contain the electromagnetic barrel calorimeter immersed in liquid argon. The total weight will be 270 tons including the detectors and the liquid argon. The cryostat is now located in building 180 where it will be equipped with 64 feed-throughs which serve for the passage of 122,880 electrical lines which will carry the signals of the calorimeter. After integration of the calorimeter, the solenoidal magnet of ATLAS will be integrated in the vacuum vessel. A final cold test of the cryostat inc...

  19. Test up to 80 kA of an Al-Stabilized NbTi Cable With the Upgraded Saclay Superconducting Transformer

    CERN Document Server

    Berriaud, C; Donati, A; Gharib, A; Peiro, G; Willering, G

    2014-01-01

    An ATLAS Barrel Toroid conductor was tested in the Saclay High Current Test Facility. The conductor is a Nb-Ti Rutherford cable imbedded in a high purity aluminum stabilizer. The conductor's width was reduced from 57 mm to 30 mm in order to be able to use an existing sample holder. We tried to measure the critical current in background fields of up to 3 T. The field was produced by a 0.8 m long superconducting dipole magnet. The test station was equipped with a superconducting transformer transferring maximum primary and secondary currents of respectively 174 A and 80 kA. The secondary current was measured with flux coils and with a superconducting Direct Control Current Transducer (DCCT), a modified version of the ``Macc+{''} 600 A commercial DCCT from Hitec, which was operated at currents of up to 57 kA. This paper reports on the performance of the test station, on the results of the quench current measurements performed on the stabilized ATLAS conductor and on the difficulties to measure the critical curre...

  20. Applied superconductivity

    CERN Document Server

    Newhouse, Vernon L

    1975-01-01

    Applied Superconductivity, Volume II, is part of a two-volume series on applied superconductivity. The first volume dealt with electronic applications and radiation detection, and contains a chapter on liquid helium refrigeration. The present volume discusses magnets, electromechanical applications, accelerators, and microwave and rf devices. The book opens with a chapter on high-field superconducting magnets, covering applications and magnet design. Subsequent chapters discuss superconductive machinery such as superconductive bearings and motors; rf superconducting devices; and future prospec

  1. High performance railgun barrels for laboratory use

    Science.gov (United States)

    Bauer, David P.; Newman, Duane C.

    1993-01-01

    High performance low-cost, laboratory railgun barrels are now available, comprised of an inherently stiff containment structure which surrounds the bore components machined from 'off the-shelf' materials. The shape of the containment structure was selected to make the barrel inherently stiff. The structure consists of stainless steel laminations which do not compromise the electrical efficiency of the railgun. The modular design enhances the utility of the barrel, as it is easy to service between shots, and can be 're-cored' to produce different configurations and sizes using the same structure. We have produced barrels ranging from 15 mm to 90 mm square bore, a 30 mm round bore, and in lengths varying from 0.25 meters to 10 meters long. Successful tests with both plasma and solid metal armatures have demonstrated the versatility and performance of this design.

  2. Work on the ATLAS semiconductor tracker barrel

    CERN Multimedia

    Maximilien Brice

    2005-01-01

    Precision work is performed on the semiconductor tracker barrel of the ATLAS experiment. All work on these delicate components must be performed in a clean room so that impurities in the air, such as dust, do not contaminate the detector. The semiconductor tracker will be mounted in the barrel close to the heart of the ATLAS experiment to detect the path of particles produced in proton-proton collisions.

  3. First SCT Barrel arrives at CERN

    CERN Multimedia

    Apsimon, R

    Mid-January saw the arrival at CERN of Barrel #3, the first of four SCT barrels. The barrels are formed as low-mass cylinders of carbon fibre skins on a honeycomb carbon core. They are manufactured in industry and then have all the final precision supports added and the final geometric metrology carried out at Geneva University. Barrel #3, complete with its 384 silicon detector modules, arrived by road from Oxford University in England where the modules were mounted using a purpose-built robot. The modules had been selected from the output of all four barrel module building clusters (in Japan, Scandinavia, USA and the UK). Since Barrel #3 will be exposed to high radiation levels within the tracker volume, these modules, representing over half a million readout channels, have been extensively tested at their operational temperature of around -25 degrees Celcius and at voltages of up to 500V. The dangers of shipping such a fragile component of ATLAS were apparent to all and considerable attention was focused...

  4. The TileCal Barrel Test Assembly

    CERN Multimedia

    Leitner, R

    On 30th October, the mechanics test assembly of the central barrel of the ATLAS tile hadronic calorimeter was completed in building 185. It started on 23rd June and is the second wheel for the Tilecal completely assembled this year. The ATLAS engineers and technicians are quick: instead of the 27 weeks initially foreseen for assembling the central barrel of the tile hadronic calorimeter (Tilecal) in building 185, they inserted the last of the 64 modules on 30th October after only 19 weeks. In part, this was due to the experience gained in the dry run assembly of the first extended barrel, produced in Spain, in spring this year (see Bulletin 23/2003); however, the central barrel is twice as long - and twice as heavy. With a length of 6.4 metres, an outer diameter of 8.5 metres and an inner diameter of 4.5 metres, the object weight is 1300 tonnes. The whole barrel cylinder is supported by the stainless steel support structure weighing only 27 tons. The barrel also has to have the right shape: over the whole 8...

  5. Heavy ion toroidal collective accelerator

    International Nuclear Information System (INIS)

    Experiments on HIPAC at Maxwell Laboratories have shown that almost all of the confined electrons are trapped and do not go around the torus. A toroidal electric field produces a negligible toroidal electron current. An ion accelerator where electrons are magnetically contained and their space charge contains ions is considered. A toroidal electric field of suitable magnitude can be applied so that it accelerates all of the ions but does not accelerate most of the electrons. This is possible if the magnetic moment of electrons μsub(e) > μsub(i)/Z, where μsub(i) is the ion magnetic moment and Z is the charge of the ion. Ions would be contained by the electron space-charge electric field E, for energies up to ZeER/2 approximately 100 GeV where Z = 60, E = 107 V/cm and the major radius of the torus is R = 3.3 metres. (author)

  6. RF breakdown by toroidal helicons

    Indian Academy of Sciences (India)

    S K P Tripathi; D Bora; M Mishra

    2001-04-01

    Bounded whistlers are well-known for their efficient plasma production capabilities in thin cylindrical tubes. In this paper we shall present their radio frequency (RF) breakdown and discharge sustaining capabilities in toroidal systems. Pulsed RF power in the electronmagnetohydrodynamic (EMHD) frequency regime is fed to the neutral background medium. After the breakdown stage, discharge is sustained by toroidal bounded whistlers. In these pulsed experiments the behaviour of the time evolution of the discharge could be studied in four distinct phases of RF breakdown, steady state attainment, decay and afterglow. In the steady state average electron density of ≈ 1012 per cc and average electron temperature of ≈ 20 eV are obtained at 10-3 mbar of argon filling pressure. Experimental results on toroidal mode structure, background effects and time evolution of the electron distribution function will be presented and their implications in understanding the breakdown mechanism are discussed.

  7. Hybrid winding concept for toroids

    DEFF Research Database (Denmark)

    Schneider, Henrik; Andersen, Thomas; Knott, Arnold;

    2013-01-01

    This paper proposes a hybrid winding concept for toroids using the traces in a printed circuit board to make connection to bended copper foil cutouts. In a final product a number of strips with a certain thickness would be held by a former and the whole assembly could be placed by pick and...... placement machinery. This opens up the possibility for both an automated manufacturing process and an automated production process of toroidal magnetics such as power inductors, filtering inductors, air core inductors, transformers etc. Both the proposed hybrid and the common wire wound winding...

  8. First assembly phase for the ATLAS toroid coils

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    The ATLAS barrel toroid system consists of eight coils, each of axial length 25.3 m, assembled radially and symmetrically around the beam axis. The coils are of a flat racetrack type with two double-pancake windings made of 20.5 kA aluminium-stabilized niobium-titanium superconductor. In the first phase of assembly, the two 'pancakes' are packed into their vacuum vessel. This is done using bladders filled with resin and glass microbeads under pressure. The resin is heated and, once cooled, holds the pancakes in place. The operation has to be performed on both sides of the coil, which necessitated a special technique to turn the coils over and then transport them to the heating table. Photos 01, 02, 03: Transporting the coil to the heating table using a special lifting gantry manufactured at JINR-Dubna, Russia in preparation for the 'bladderisation' operation.

  9. Intrinsic rotation of toroidally confined magnetohydrodynamics

    OpenAIRE

    Morales, Jorge; Bos, Wouter; Schneider, Kai; Montgomery, David

    2012-01-01

    The spatiotemporal self-organization of viscoresistive magnetohydrodynamics (MHD) in a toroidal geometry is studied. Curl-free toroidal magnetic and electric fields are imposed. It is observed in our simulations that a flow is generated, which evolves from dominantly poloidal to toroidal when the Lundquist numbers are increased. It is shown that this toroidal organization of the flow is consistent with the tendency of the velocity field to align with the magnetic field. Up-down asymmetry of t...

  10. About electromagnetic load, stress state of current-carrying toroidal shell

    International Nuclear Information System (INIS)

    The electromagnetic loads which arise at interaction of toroidal coil's current with its own magnetic field are approximately determined. The values of current density and magnetic field intensity at any point of tore cross-section are obtained. By means of shell's membrane theory the stress state of tore is determined. It is shown that due to the electromagnetic load in the shell both of tensile meridional and compressible toroidal strengths arise. This state differs from case p=const., when one has only tensible strength. The engineering formulas, to determine the strengths are given. The numerical results are given in the case of superconducting Tokamak-7. (Auth.)

  11. Technology of toroidal plasma devices

    International Nuclear Information System (INIS)

    After research into many different magnetic confinement systems, there is now general agreement that the most favorable ones for future fusion reactors are all based on toroidal geometry, as distinct from having open ends like mirror machines. For this reason plasma physics research, even when not aimed directly at the fusion problems, has in recent years increasingly concentrated on toroidal systems. One reason is that by using their good confinement properties the experimenter has available a range of high temperature plasma parameters in quasisteady (or even steady) state conditions not otherwise available on Earth. Despite the wide variety of both geometrical possibilities and sizes, ranging from table-top experiments with plasmas a few centimetres across to near reactor scale ones like JET with plasmas several metres across, toroidal systems have many common features, both in their physical principles and of experimental design: the purpose of this paper is to highlight those common features, using some specific examples for illustration, and emphasizing some of the more practical aspects. It will also try to point out important differences between two of the main classes of toroidal systems

  12. The upgraded Pegasus Toroidal Experiment

    International Nuclear Information System (INIS)

    The Pegasus Toroidal Experiment was developed to explore the physics limits of plasma operation as the aspect ratio (A) approaches unity. Initial experiments on the device found that access to high normalized current and toroidal beta was limited by the presence of large-scale tearing modes. Major upgrades have been conducted of the facility to provide the control tools necessary to mitigate these resistive modes. The upgrades include new programmable power supplies, new poloidal field coils and increased, time-variable toroidal field. First ohmic operations with the upgraded system demonstrated position and current ramp-rate control, as well as improvement in ohmic flux consumption from 2.9 MA Wb-1 to 4.2 MA Wb-1. The upgraded experiment will be used to address three areas of physics interest. First, the kink and ballooning stability boundaries at low A and high normalized current will be investigated. Second, clean, high-current plasma sources will be studied as a helicity injection tool. Experiments with two such sources have produced toroidal currents three times greater than predicted by geometric field line following. Finally, the use of electron Bernstein waves to heat and drive current locally will be studied at the 1 MW level; initial modelling indicates that these experiments are feasible at a frequency of 2.45 GHz

  13. Lowering the first ATLAS toroid

    CERN Multimedia

    Maximilien Brice

    2004-01-01

    The ATLAS detector on the LHC at CERN will consist of eight toroid magnets, the first of which was lowered into the cavern in these images on 26 October 2004. The coils are supported on platforms where they will be attached to form a giant torus. The platforms will hold about 300 tonnes of ATLAS' muon chambers and will envelop the inner detectors.

  14. Toroidal solutions in Horava Gravity

    OpenAIRE

    Ghodsi, Ahmad

    2009-01-01

    Recently a new four-dimensional non relativistic renormalizable theory of gravity was proposed by Horava. This gravity reduces to Einstein gravity at large distances. In this paper by using the new action for gravity we present different toroidal solutions to the equations of motion. Our solutions describe the near horizon geometry with slow rotating parameter.

  15. Onsager relaxation of toroidal plasmas

    International Nuclear Information System (INIS)

    The slow relaxation of isolated toroidal plasmas towards their thermodynamical equilibrium is studied in an Onsager framework based on the entropy metric. The basic tool is a variational principle, equivalent to the kinetic equation, involving the profiles of density, temperature, electric potential, electric current. New minimization procedures are proposed to obtain entropy and entropy production rate functionals. (author)

  16. Extremely high Q-factor toroidal metamaterials

    CERN Document Server

    Basharin, Alexey A; Volsky, Nikita; Kafesaki, Maria; Economou, Eleftherios N; Ustinov, Alexey V

    2016-01-01

    We demonstrate that, owing to the unique topology of the toroidal dipolar mode, its electric/magnetic field can be spatially confined within subwavelength, externally accessible regions of the metamolecules, which makes the toroidal planar metamaterials a viable platform for high Q-factor resonators due to interfering toroidal and other dipolar modes in metamolecules.

  17. ATLAS End Cap toroid in upstanding position

    CERN Multimedia

    2005-01-01

    End Cap toroid The ATLAS End Cap toroid weights 240-ton and is 12-m diameter high. The parts of this vacuum vessel had to be integrated and tested so that End Cap Toroid has no leaks. After that it could be cooled down to 80 K.

  18. Resource Review Board Celebrates the Magnet and Liquid Argon Barrel Tests in Hall 180

    CERN Document Server

    Jenni, P.

    2004-01-01

    Address by the Director-General, R. Aymar, in front of the barrel cryostat. On 25th October 2004 many RRB delegates and guests, ATLAS National Contact Physicists, and colleagues from far and from CERN working on the Liquid Argon calorimeter and the magnet system were gathering in Hall 180 to celebrate the major milestones reached during the past months in this hall: the successful cold tests of the first barrel toroid coil, of the solenoid, and of the barrel Liquid Argon calorimeter. About 250 people spent a relaxing evening after the speeches by the Director-General R. Aymar and by the spokesperson who gave the following address: 'It is a great pleasure for me to welcome you all here in Hall 180 in the name of the ATLAS Collaboration! With a few words I would like to recall why we are actually here today to share, what I hope, is a relaxed and joyful moment. To concentrate it all in one sentence I could say: To thank cordially all the main actors for the enormous work accomplished here over many years,...

  19. Intrinsic rotation of toroidally confined magnetohydrodynamics.

    Science.gov (United States)

    Morales, Jorge A; Bos, Wouter J T; Schneider, Kai; Montgomery, David C

    2012-10-26

    The spatiotemporal self-organization of viscoresistive magnetohydrodynamics in a toroidal geometry is studied. Curl-free toroidal magnetic and electric fields are imposed. It is observed in our simulations that a flow is generated, which evolves from dominantly poloidal to toroidal when the Lundquist numbers are increased. It is shown that this toroidal organization of the flow is consistent with the tendency of the velocity field to align with the magnetic field. Up-down asymmetry of the geometry causes the generation of a nonzero toroidal angular momentum. PMID:23215195

  20. Design and Simulation of Toroidal Twister Model

    Institute of Scientific and Technical Information of China (English)

    TIAN Huifang; LIN Xizhen; ZENG Qinqin

    2006-01-01

    Toroidal composite vessel winded with fiber is a new kind of structural pressure vessels, which not only has high structure efficiency of compound materials pressure vessel, good security and so on, but also has special shape and the property of utilizing toroidal space, and the prospect of the application of toroidal composite vessel winded with fiber is extremely broad. By introducing parameters establishment of toroidal vessel and elaborating the principle of filament winding for toroidal vessel, the design model of filament winding machine for toroidal vessel has been introduced, and the design model has been dynamically simulated by the software of ADAMS, which will give more referrence for the design of real toroidal vessel twister.

  1. TFTR toroidal field coil design

    International Nuclear Information System (INIS)

    The design of the Tokamak Fusion Test Reactor (TFTR) Toroidal Field (TF) magnetic coils is described. The TF coil is a 44-turn, spiral-wound, two-pancake, water-cooled configuration which, at a coil current of 73.3 kiloamperes, produces a 5.2-Tesla field at a major radius of 2.48 meters. The magnetic coils are installed in titanium cases, which transmit the loads generated in the coils to the adjacent supporting structure. The TFTR utilizes 20 of these coils, positioned radially at 180 intervals, to provide the required toroidal field. Because it is very highly loaded and subject to tight volume constraints within the machine, the coil presents unique design problems. The TF coil requirements are summarized, the coil configuration is described, and the problems highlighted which have been encountered thus far in the coil design effort, together with the development tests which have been undertaken to verify the design

  2. Classification of symmetric toroidal orbifolds

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Maximilian; Ratz, Michael; Torrado, Jesus [Technische Univ. Muenchen, Garching (Germany). Physik-Department; Vaudrevange, Patrick K.S. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2012-09-15

    We provide a complete classification of six-dimensional symmetric toroidal orbifolds which yield N{>=}1 supersymmetry in 4D for the heterotic string. Our strategy is based on a classification of crystallographic space groups in six dimensions. We find in total 520 inequivalent toroidal orbifolds, 162 of them with Abelian point groups such as Z{sub 3}, Z{sub 4}, Z{sub 6}-I etc. and 358 with non-Abelian point groups such as S{sub 3}, D{sub 4}, A{sub 4} etc. We also briefly explore the properties of some orbifolds with Abelian point groups and N=1, i.e. specify the Hodge numbers and comment on the possible mechanisms (local or non-local) of gauge symmetry breaking.

  3. Hollow nanotubular toroidal polymer microrings

    Science.gov (United States)

    Lee, Jiyeong; Baek, Kangkyun; Kim, Myungjin; Yun, Gyeongwon; Ko, Young Ho; Lee, Nam-Suk; Hwang, Ilha; Kim, Jeehong; Natarajan, Ramalingam; Park, Chan Gyung; Sung, Wokyung; Kim, Kimoon

    2014-02-01

    Despite the remarkable progress made in the self-assembly of nano- and microscale architectures with well-defined sizes and shapes, a self-organization-based synthesis of hollow toroids has, so far, proved to be elusive. Here, we report the synthesis of polymer microrings made from rectangular, flat and rigid-core monomers with anisotropically predisposed alkene groups, which are crosslinked with each other by dithiol linkers using thiol-ene photopolymerization. The resulting hollow toroidal structures are shape-persistent and mechanically robust in solution. In addition, their size can be tuned by controlling the initial monomer concentrations, an observation that is supported by a theoretical analysis. These hollow microrings can encapsulate guest molecules in the intratoroidal nanospace, and their peripheries can act as templates for circular arrays of metal nanoparticles.

  4. Prospects for toroidal fusion reactors

    International Nuclear Information System (INIS)

    Work on the International Thermonuclear Experimental Reactor (ITER) tokamak has refined understanding of the realities of a deuterium-tritium (D-T) burning magnetic fusion reactor. An ITER-like tokamak reactor using ITER costs and performance would lead to a cost of electricity (COE) of about 130 mills/kWh. Advanced tokamak physics to be tested in the Toroidal Physics Experiment (TPX), coupled with moderate components in engineering, technology, and unit costs, should lead to a COE comparable with best existing fission systems around 60 mills/kWh. However, a larger unit size, ∼2000 MW(e), is favored for the fusion system. Alternative toroidal configurations to the conventional tokamak, such as the stellarator, reversed-field pinch, and field-reversed configuration, offer some potential advantage, but are less well developed, and have their own challenges

  5. Rain Barrels: A Catalyst for Change?

    Science.gov (United States)

    Bakacs, Michele E.; Haberland, Mike; Mangiafico, Salvatore S.; Winquist, Aileen; Obropta, Christopher C.; Boyajian, Amy; Mellor, Sara

    2013-01-01

    Over the past 4 years, rain barrel programming for residents has been implemented in both Northern Virginia and New Jersey as a method for educating the public about stormwater management and water conservation. Program participants demonstrated a significant increase in knowledge of water resource issues. Follow-up surveys showed 58% of New…

  6. CMS : the first barrel ring completed !

    CERN Multimedia

    Laurent Guiraud

    2000-01-01

    On 14 November, the CMS collaboration and the German firm DWE celebrated the successful construction of the detector's first yoke barrel ring. To mark the occasion, those in charge of the construction at CERN and DWE posed for the camera in the middle of the giant component.

  7. ATLAS semiconductor tracker installed into its barrel

    CERN Multimedia

    Maximilien Brice

    2005-01-01

    The ATLAS silicon tracker is installed in the silicon tracker barrel. Absolute precision was required in this operation to ensure that the tracker was inserted without damage through minimal clearance. The installation was performed in a clean room on the CERN site so that no impurities in the air would contaminate the tracker's systems.

  8. Iron Blocks of CMS Magnet Barrel Yoke.

    CERN Multimedia

    2000-01-01

    On the occasion of presenting the CMS Award 2000 to Deggendorfer Werft und Eisenbau GmbH the delivered blocks were inspected at CERN Point 5. From left to right: H. Gerwig (CERN, CMS Magnet Barrel Yoke Coordinator), G. Waurick (CERN), F. Leher (DWE, Project Engineer) and W. Schuster (DWE, Project Manager).

  9. ALEPH separated barrel and end-caps

    CERN Multimedia

    Patrice Loïez

    2001-01-01

    The end-caps can be seen at the left and right of the image with the barrel at the centre. Technicians inspect the end-cap before they begin to take it apart. ALEPH was an experiment on the LEP accelerator, which studied high-energy collisions between electrons and positrons from 1989 to 2000.

  10. Superconducting transistor

    Science.gov (United States)

    Gray, Kenneth E.

    1979-01-01

    A superconducting transistor is formed by disposing three thin films of superconducting material in a planar parallel arrangement and insulating the films from each other by layers of insulating oxides to form two tunnel junctions. One junction is biased above twice the superconducting energy gap and the other is biased at less than twice the superconducting energy gap. Injection of quasiparticles into the center film by one junction provides a current gain in the second junction.

  11. Magnetic Properties of 3D Printed Toroids

    Science.gov (United States)

    Bollig, Lindsey; Otto, Austin; Hilpisch, Peter; Mowry, Greg; Nelson-Cheeseman, Brittany; Renewable Energy; Alternatives Lab (REAL) Team

    Transformers are ubiquitous in electronics today. Although toroidal geometries perform most efficiently, transformers are traditionally made with rectangular cross-sections due to the lower manufacturing costs. Additive manufacturing techniques (3D printing) can easily achieve toroidal geometries by building up a part through a series of 2D layers. To get strong magnetic properties in a 3D printed transformer, a composite filament is used containing Fe dispersed in a polymer matrix. How the resulting 3D printed toroid responds to a magnetic field depends on two structural factors of the printed 2D layers: fill factor (planar density) and fill pattern. In this work, we investigate how the fill factor and fill pattern affect the magnetic properties of 3D printed toroids. The magnetic properties of the printed toroids are measured by a custom circuit that produces a hysteresis loop for each toroid. Toroids with various fill factors and fill patterns are compared to determine how these two factors can affect the magnetic field the toroid can produce. These 3D printed toroids can be used for numerous applications in order to increase the efficiency of transformers by making it possible for manufacturers to make a toroidal geometry.

  12. Melittin-Induced Bilayer Leakage Depends on Lipid Material Properties: Evidence for Toroidal Pores

    OpenAIRE

    Allende, Daniel; Simon, S. A.; McIntosh, Thomas J.

    2004-01-01

    The membrane-lytic peptide melittin has previously been shown to form pores in lipid bilayers that have been described in terms of two different structural models. In the “barrel stave” model the bilayer remains more or less flat, with the peptides penetrating across the bilayer hydrocarbon region and aggregating to form a pore, whereas in the “toroidal pore” melittin induces defects in the bilayer such that the bilayer bends sharply inward to form a pore lined by both peptides and lipid head...

  13. Structural design of the toroidal configuration of the HTS SMES cooling system

    Science.gov (United States)

    Yeom, H. K.; Koh, D. Y.; Ko, J. S.; Kim, H. B.; Hong, Y. J.; Kim, S. H.; Seong, K. C.

    2011-11-01

    The superconducting magnetic energy storage (SMES) system is working on around 30 K, because the magnet is made of high temperature superconductor. To maintain the cryogenic temperature, the superconducting coil is cooled by cryogen, helium gas or liquid neon. But there are some weak points in the cryogen cooling system. For example periodic charge of the cryogen and size is big and so on. So, we have designed the conduction cooling system for toroidal configuration HTS SMES. The toroidal type HTS SMES has some merits, so it is very small magnetic field leakage, and magnetic field applied perpendicular to the tape surface can be reduced. Our system has 28 numbers of HTS double pancake coils and they are arrayed toroidal configuration. The toroidal inner radius is 162 mm, and outer radius is 599 mm, and height is about 162 mm. In this study, we have designed the cooling structure and analyzed temperature distribution of cooling path, thermal stress and deformation of the cooling structure.

  14. Structural design of the toroidal configuration of the HTS SMES cooling system

    Energy Technology Data Exchange (ETDEWEB)

    Yeom, H.K., E-mail: hkyeom@kimm.re.kr [Cryogenic Engineering Team of Korea Institute of Machinery and Materials, 104 Sinseong-no, Yuseong-gu, Daejeon 305-343 (Korea, Republic of); Koh, D.Y.; Ko, J.S.; Kim, H.B.; Hong, Y.J. [Cryogenic Engineering Team of Korea Institute of Machinery and Materials, 104 Sinseong-no, Yuseong-gu, Daejeon 305-343 (Korea, Republic of); Kim, S.H. [Mechanical Engineering Department of Changwon National University, 65 Sonamu 5-gil, Euichang-gu, Changwon 641-773 (Korea, Republic of); Seong, K.C. [Applied Superconducting Research Team of Korea Electrotechnology Research Institute, 70 Bulmosan-gil, Seongsan-gu, Changwon 641-120 (Korea, Republic of)

    2011-11-15

    The superconducting magnetic energy storage (SMES) system is working on around 30 K, because the magnet is made of high temperature superconductor. To maintain the cryogenic temperature, the superconducting coil is cooled by cryogen, helium gas or liquid neon. But there are some weak points in the cryogen cooling system. For example periodic charge of the cryogen and size is big and so on. So, we have designed the conduction cooling system for toroidal configuration HTS SMES. The toroidal type HTS SMES has some merits, so it is very small magnetic field leakage, and magnetic field applied perpendicular to the tape surface can be reduced. Our system has 28 numbers of HTS double pancake coils and they are arrayed toroidal configuration. The toroidal inner radius is 162 mm, and outer radius is 599 mm, and height is about 162 mm. In this study, we have designed the cooling structure and analyzed temperature distribution of cooling path, thermal stress and deformation of the cooling structure.

  15. Toroidal magnet system conceptual design for the ELMO Bumpy Torus Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Luton, Jr, J. N.; Yeh, H. T.

    1977-01-01

    The ELMO Bumpy Torus Reactor (EBTR) is a fusion reactor device based on the concept of toroidally linked mirrors. To minimize engineering uncertainties, the EBTR superconducting magnet system is designed so that it could be built with existing or near-term technology. The design uses identical coils in standard modules, thus facilitating commercialization. The reference design uses 48 modules and produces 4000 MW(th).

  16. 10 tesla toroidal field magnet system for General Atomic's PGFR concept

    International Nuclear Information System (INIS)

    General Atomic's concept for a reactor compatible superconducting toroidal field coil is presented. The concept employs bath cooled, copper stabilized NbTi conductor to generate 10 tesla at a nominal temperature of 4.50K. The emphasis of this paper is on the coil configuration, stability criterion, cryodynamic performance, and support of magnetic loads. The guiding principles of the design are fabrication economy, reactor compatibility, and operational reliability

  17. Precise mapping of the magnetic field in the CMS barrel yoke using cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Chatrchyan, S. [Yerevan Physics Institute (Aremenia); et al.,

    2010-03-01

    The CMS detector is designed around a large 4 T superconducting solenoid, enclosed in a 12000-tonne steel return yoke. A detailed map of the magnetic field is required for the accurate simulation and reconstruction of physics events in the CMS detector, not only in the inner tracking region inside the solenoid but also in the large and complex structure of the steel yoke, which is instrumented with muon chambers. Using a large sample of cosmic muon events collected by CMS in 2008, the field in the steel of the barrel yoke has been determined with a precision of 3 to 8% depending on the location.

  18. Precise Mapping of the Magnetic Field in the CMS Barrel Yoke using Cosmic Rays

    CERN Document Server

    Chatrchyan, S; Sirunyan, A M; Adam, W; Arnold, B; Bergauer, H; Bergauer, T; Dragicevic, M; Eichberger, M; Erö, J; Friedl, M; Frühwirth, R; Ghete, V M; Hammer, J; Hänsel, S; Hoch, M; Hörmann, N; Hrubec, J; Jeitler, M; Kasieczka, G; Kastner, K; Krammer, M; Liko, D; Magrans de Abril, I; Mikulec, I; Mittermayr, F; Neuherz, B; Oberegger, M; Padrta, M; Pernicka, M; Rohringer, H; Schmid, S; Schöfbeck, R; Schreiner, T; Stark, R; Steininger, H; Strauss, J; Taurok, A; Teischinger, F; Themel, T; Uhl, D; Wagner, P; Waltenberger, W; Walzel, G; Widl, E; Wulz, C E; Chekhovsky, V; Dvornikov, O; Emeliantchik, I; Litomin, A; Makarenko, V; Marfin, I; Mossolov, V; Shumeiko, N; Solin, A; Stefanovitch, R; Suarez Gonzalez, J; Tikhonov, A; Fedorov, A; Karneyeu, A; Korzhik, M; Panov, V; Zuyeuski, R; Kuchinsky, P; Beaumont, W; Benucci, L; Cardaci, M; De Wolf, E A; Delmeire, E; Druzhkin, D; Hashemi, M; Janssen, X; Maes, T; Mucibello, L; Ochesanu, S; Rougny, R; Selvaggi, M; Van Haevermaet, H; Van Mechelen, P; Van Remortel, N; Adler, V; Beauceron, S; Blyweert, S; D'Hondt, J; De Weirdt, S; Devroede, O; Heyninck, J; Kalogeropoulos, A; Maes, J; Maes, M; Mozer, M U; Tavernier, S; Van Doninck, W; Van Mulders, P; Villella, I; Bouhali, O; Chabert, E C; Charaf, O; Clerbaux, B; De Lentdecker, G; Dero, V; Elgammal, S; Gay, A P R; Hammad, G H; Marage, P E; Rugovac, S; Vander Velde, C; Vanlaer, P; Wickens, J; Grunewald, M; Klein, B; Marinov, A; Ryckbosch, D; Thyssen, F; Tytgat, M; Vanelderen, L; Verwilligen, P; Basegmez, S; Bruno, G; Caudron, J; Delaere, C; Demin, P; Favart, D; Giammanco, A; Grégoire, G; Lemaitre, V; Militaru, O; Ovyn, S; Piotrzkowski, K; Quertenmont, L; Schul, N; Beliy, N; Daubie, E; Alves, G A; Pol, M E; Souza, M H G; Carvalho, W; De Jesus Damiao, D; De Oliveira Martins, C; Fonseca De Souza, S; Mundim, L; Oguri, V; Santoro, A; Silva Do Amaral, S M; Sznajder, A; Fernandez Perez Tomei, T R; Ferreira Dias, M A; Gregores, E M; Novaes, S F; Abadjiev, K; Anguelov, T; Damgov, J; Darmenov, N; Dimitrov, L; Genchev, V; Iaydjiev, P; Piperov, S; Stoykova, S; Sultanov, G; Trayanov, R; Vankov, I; Dimitrov, A; Dyulendarova, M; Kozhuharov, V; Litov, L; Marinova, E; Mateev, M; Pavlov, B; Petkov, P; Toteva, Z; Chen, G M; Chen, H S; Guan, W; Jiang, C H; Liang, D; Liu, B; Meng, X; Tao, J; Wang, J; Wang, Z; Xue, Z; Zhang, Z; Ban, Y; Cai, J; Ge, Y; Guo, S; Hu, Z; Mao, Y; Qian, S J; Teng, H; Zhu, B; Avila, C; Baquero Ruiz, M; Carrillo Montoya, C A; Gomez, A; Gomez Moreno, B; Ocampo Rios, A A; Osorio Oliveros, A F; Reyes Romero, D; Sanabria, J C; Godinovic, N; Lelas, K; Plestina, R; Polic, D; Puljak, I; Antunovic, Z; Dzelalija, M; Brigljevic, V; Duric, S; Kadija, K; Morovic, S; Fereos, R; Galanti, M; Mousa, J; Papadakis, A; Ptochos, F; Razis, P A; Tsiakkouri, D; Zinonos, Z; Hektor, A; Kadastik, M; Kannike, K; Müntel, M; Raidal, M; Rebane, L; Anttila, E; Czellar, S; Härkönen, J; Heikkinen, A; Karimäki, V; Kinnunen, R; Klem, J; Kortelainen, M J; Lampén, T; Lassila-Perini, K; Lehti, S; Lindén, T; Luukka, P; Mäenpää, T; Nysten, J; Tuominen, E; Tuominiemi, J; Ungaro, D; Wendland, L; Banzuzi, K; Korpela, A; Tuuva, T; Nedelec, P; Sillou, D; Besancon, M; Chipaux, R; Dejardin, M; Denegri, D; Descamps, J; Fabbro, B; Faure, J L; Ferri, F; Ganjour, S; Gentit, F X; Givernaud, A; Gras, P; Hamel de Monchenault, G; Jarry, P; Lemaire, M C; Locci, E; Malcles, J; Marionneau, M; Millischer, L; Rander, J; Rosowsky, A; Rousseau, D; Titov, M; Verrecchia, P; Baffioni, S; Bianchini, L; Bluj, M; Busson, P; Charlot, C; Dobrzynski, L; Granier de Cassagnac, R; Haguenauer, M; Miné, P; Paganini, P; Sirois, Y; Thiebaux, C; Zabi, A; Agram, J L; Besson, A; Bloch, D; Bodin, D; Brom, J M; Conte, E; Drouhin, F; Fontaine, J C; Gelé, D; Goerlach, U; Gross, L; Juillot, P; Le Bihan, A C; Patois, Y; Speck, J; Van Hove, P; Baty, C; Bedjidian, M; Blaha, J; Boudoul, G; Brun, H; Chanon, N; Chierici, R; Contardo, D; Depasse, P; Dupasquier, T; El Mamouni, H; Fassi, F; Fay, J; Gascon, S; Ille, B; Kurca, T; Le Grand, T; Lethuillier, M; Lumb, N; Mirabito, L; Perries, S; Vander Donckt, M; Verdier, P; Djaoshvili, N; Roinishvili, N; Roinishvili, V; Amaglobeli, N; Adolphi, R; Anagnostou, G; Brauer, R; Braunschweig, W; Edelhoff, M; Esser, H; Feld, L; Karpinski, W; Khomich, A; Klein, K; Mohr, N; Ostaptchouk, A; Pandoulas, D; Pierschel, G; Raupach, F; Schael, S; Schultz von Dratzig, A; Schwering, G; Sprenger, D; Thomas, M; Weber, M; Wittmer, B; Wlochal, M; Actis, O; Altenhöfer, G; Bender, W; Biallass, P; Erdmann, M; Fetchenhauer, G; Frangenheim, J; Hebbeker, T; Hilgers, G; Hinzmann, A; Hoepfner, K; Hof, C; Kirsch, M; Klimkovich, T; Kreuzer, P; Lanske, D; Merschmeyer, M; Meyer, A; Philipps, B; Pieta, H; Reithler, H; Schmitz, S A; Sonnenschein, L; Sowa, M; Steggemann, J; Szczesny, H; Teyssier, D; Zeidler, C; Bontenackels, M; Davids, M; Duda, M; Flügge, G; Geenen, H; Giffels, M; Haj Ahmad, W; Hermanns, T; Heydhausen, D; Kalinin, S; Kress, T; Linn, A; Nowack, A; Perchalla, L; Poettgens, M; Pooth, O; Sauerland, P; Stahl, A; Tornier, D; Zoeller, M H; Aldaya Martin, M; Behrens, U; Borras, K; Campbell, A; Castro, E; Dammann, D; Eckerlin, G; Flossdorf, A; Flucke, G; Geiser, A; Hatton, D; Hauk, J; Jung, H; Kasemann, M; Katkov, I; Kleinwort, C; Kluge, H; Knutsson, A; Kuznetsova, E; Lange, W; Lohmann, W; Mankel, R; Marienfeld, M; Meyer, A B; Miglioranzi, S; Mnich, J; Ohlerich, M; Olzem, J; Parenti, A; Rosemann, C; Schmidt, R; Schoerner-Sadenius, T; Volyanskyy, D; Wissing, C; Zeuner, W D; Autermann, C; Bechtel, F; Draeger, J; Eckstein, D; Gebbert, U; Kaschube, K; Kaussen, G; Klanner, R; Mura, B; Naumann-Emme, S; Nowak, F; Pein, U; Sander, C; Schleper, P; Schum, T; Stadie, H; Steinbrück, G; Thomsen, J; Wolf, R; Bauer, J; Blüm, P; Buege, V; Cakir, A; Chwalek, T; De Boer, W; Dierlamm, A; Dirkes, G; Feindt, M; Felzmann, U; Frey, M; Furgeri, A; Gruschke, J; Hackstein, C; Hartmann, F; Heier, S; Heinrich, M; Held, H; Hirschbuehl, D; Hoffmann, K H; Honc, S; Jung, C; Kuhr, T; Liamsuwan, T; Martschei, D; Mueller, S; Müller, Th; Neuland, M B; 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Cline, D; Cousins, R; Erhan, S; Hauser, J; Ignatenko, M; Jarvis, C; Mumford, J; Plager, C; Rakness, G; Schlein, P; Tucker, J; Valuev, V; Wallny, R; Yang, X; Babb, J; Bose, M; Chandra, A; Clare, R; Ellison, J A; Gary, J W; Hanson, G; Jeng, G Y; Kao, S C; Liu, F; Liu, H; Luthra, A; Nguyen, H; Pasztor, G; Satpathy, A; Shen, B C; Stringer, R; Sturdy, J; Sytnik, V; Wilken, R; Wimpenny, S; Branson, J G; Dusinberre, E; Evans, D; Golf, F; Kelley, R; Lebourgeois, M; Letts, J; Lipeles, E; Mangano, B; Muelmenstaedt, J; Norman, M; Padhi, S; Petrucci, A; Pi, H; Pieri, M; Ranieri, R; Sani, M; Sharma, V; Simon, S; Würthwein, F; Yagil, A; Campagnari, C; D'Alfonso, M; Danielson, T; Garberson, J; Incandela, J; Justus, C; Kalavase, P; Koay, S A; Kovalskyi, D; Krutelyov, V; Lamb, J; Lowette, S; Pavlunin, V; Rebassoo, F; Ribnik, J; Richman, J; Rossin, R; Stuart, D; To, W; Vlimant, J R; Witherell, M; Apresyan, A; Bornheim, A; Bunn, J; Chiorboli, M; Gataullin, M; Kcira, D; Litvine, V; Ma, Y; Newman, H B; Rogan, C; Timciuc, V; Veverka, J; Wilkinson, R; Yang, Y; Zhang, L; Zhu, K; Zhu, R Y; Akgun, B; Carroll, R; Ferguson, T; Jang, D W; Jun, S Y; Paulini, M; Russ, J; Terentyev, N; Vogel, H; Vorobiev, I; Cumalat, J P; Dinardo, M E; Drell, B R; Ford, W T; Heyburn, B; Luiggi Lopez, E; Nauenberg, U; Stenson, K; Ulmer, K; Wagner, S R; Zang, S L; Agostino, L; Alexander, J; Blekman, F; Cassel, D; Chatterjee, A; Das, S; Gibbons, L K; Heltsley, B; Hopkins, W; Khukhunaishvili, A; Kreis, B; Kuznetsov, V; Patterson, J R; Puigh, D; Ryd, A; Shi, X; Stroiney, S; Sun, W; Teo, W D; Thom, J; Vaughan, J; Weng, Y; Wittich, P; Beetz, C P; Cirino, G; Sanzeni, C; Winn, D; Abdullin, S; Afaq, M A; Albrow, M; Ananthan, B; Apollinari, G; Atac, M; Badgett, W; Bagby, L; Bakken, J A; Baldin, B; Banerjee, S; Banicz, K; Bauerdick, L A T; Beretvas, A; Berryhill, J; Bhat, P C; Biery, K; Binkley, M; Bloch, I; Borcherding, F; Brett, A M; Burkett, K; Butler, J N; Chetluru, V; Cheung, H W K; Chlebana, F; Churin, I; Cihangir, S; Crawford, M; Dagenhart, W; Demarteau, M; Derylo, G; Dykstra, D; Eartly, D P; Elias, J E; Elvira, V D; Evans, D; Feng, L; Fischler, M; Fisk, I; Foulkes, S; Freeman, J; Gartung, P; Gottschalk, E; Grassi, T; Green, D; Guo, Y; Gutsche, O; Hahn, A; Hanlon, J; Harris, R M; Holzman, B; Howell, J; Hufnagel, D; James, E; Jensen, H; Johnson, M; Jones, C D; Joshi, U; Juska, E; Kaiser, J; Klima, B; Kossiakov, S; Kousouris, K; Kwan, S; Lei, C M; Limon, P; Lopez Perez, J A; Los, S; Lueking, L; Lukhanin, G; Lusin, S; Lykken, J; Maeshima, K; Marraffino, J M; Mason, D; McBride, P; Miao, T; Mishra, K; Moccia, S; Mommsen, R; Mrenna, S; Muhammad, A S; Newman-Holmes, C; Noeding, C; O'Dell, V; Prokofyev, O; Rivera, R; Rivetta, C H; Ronzhin, A; Rossman, P; Ryu, S; Sekhri, V; Sexton-Kennedy, E; Sfiligoi, I; Sharma, S; Shaw, T M; Shpakov, D; Skup, E; Smith, R P; Soha, A; Spalding, W J; Spiegel, L; Suzuki, I; Tan, P; Tanenbaum, W; Tkaczyk, S; Trentadue, R; Uplegger, L; Vaandering, E W; Vidal, R; Whitmore, J; Wicklund, E; Wu, W; Yarba, J; Yumiceva, F; Yun, J C; Acosta, D; Avery, P; Barashko, V; Bourilkov, D; Chen, M; Di Giovanni, G P; Dobur, D; Drozdetskiy, A; Field, R D; Fu, Y; Furic, I K; Gartner, J; Holmes, D; Kim, B; Klimenko, S; Konigsberg, J; Korytov, A; Kotov, K; Kropivnitskaya, A; Kypreos, T; Madorsky, A; Matchev, K; Mitselmakher, G; Pakhotin, Y; Piedra Gomez, J; Prescott, C; Rapsevicius, V; Remington, R; Schmitt, M; Scurlock, B; Wang, D; Yelton, J; Ceron, C; Gaultney, V; Kramer, L; Lebolo, L M; Linn, S; Markowitz, P; Martinez, G; Rodriguez, J L; Adams, T; Askew, A; Baer, H; Bertoldi, M; Chen, J; Dharmaratna, W G D; Gleyzer, S V; Haas, J; Hagopian, S; Hagopian, V; Jenkins, M; Johnson, K F; Prettner, E; Prosper, H; Sekmen, S; Baarmand, M M; Guragain, S; Hohlmann, M; Kalakhety, H; Mermerkaya, H; Ralich, R; Vodopiyanov, I; Abelev, B; Adams, M R; Anghel, I M; Apanasevich, L; Bazterra, V E; Betts, R R; Callner, J; Castro, M A; Cavanaugh, R; Dragoiu, C; Garcia-Solis, E J; Gerber, C E; Hofman, D J; Khalatian, S; Mironov, C; Shabalina, E; Smoron, A; Varelas, N; Akgun, U; Albayrak, E A; Ayan, A S; Bilki, B; Briggs, R; Cankocak, K; Chung, K; Clarida, W; Debbins, P; Duru, F; Ingram, F D; Lae, C K; McCliment, E; Merlo, J P; Mestvirishvili, A; Miller, M J; Moeller, A; Nachtman, J; Newsom, C R; Norbeck, E; Olson, J; Onel, Y; Ozok, F; Parsons, J; Schmidt, I; Sen, S; Wetzel, J; Yetkin, T; Yi, K; Barnett, B A; Blumenfeld, B; Bonato, A; Chien, C Y; Fehling, D; Giurgiu, G; Gritsan, A V; Guo, Z J; Maksimovic, P; Rappoccio, S; Swartz, M; Tran, N V; Zhang, Y; Baringer, P; Bean, A; Grachov, O; Murray, M; Radicci, V; Sanders, S; Wood, J S; Zhukova, V; Bandurin, D; Bolton, T; Kaadze, K; Liu, A; Maravin, Y; Onoprienko, D; Svintradze, I; Wan, Z; Gronberg, J; Hollar, J; Lange, D; Wright, D; Baden, D; Bard, R; Boutemeur, M; Eno, S C; Ferencek, D; Hadley, N J; Kellogg, R G; Kirn, M; Kunori, S; Rossato, K; Rumerio, P; Santanastasio, F; Skuja, A; Temple, J; Tonjes, M B; Tonwar, S C; Toole, T; Twedt, E; Alver, B; Bauer, G; Bendavid, J; Busza, W; Butz, E; Cali, I A; Chan, M; D'Enterria, D; Everaerts, P; Gomez Ceballos, G; Hahn, K A; Harris, P; Jaditz, S; Kim, Y; Klute, M; Lee, Y J; Li, W; Loizides, C; Ma, T; Miller, M; Nahn, S; Paus, C; Roland, C; Roland, G; Rudolph, M; Stephans, G; Sumorok, K; Sung, K; Vaurynovich, S; Wenger, E A; Wyslouch, B; Xie, S; Yilmaz, Y; Yoon, A S; Bailleux, D; Cooper, S I; Cushman, P; Dahmes, B; De Benedetti, A; Dolgopolov, A; Dudero, P R; Egeland, R; Franzoni, G; Haupt, J; Inyakin, A; Klapoetke, K; Kubota, Y; Mans, J; Mirman, N; Petyt, D; Rekovic, V; Rusack, R; Schroeder, M; Singovsky, A; Zhang, J; Cremaldi, L M; Godang, R; Kroeger, R; Perera, L; Rahmat, R; Sanders, D A; Sonnek, P; Summers, D; Bloom, K; Bockelman, B; Bose, S; Butt, J; Claes, D R; Dominguez, A; Eads, M; Keller, J; Kelly, T; Kravchenko, I; Lazo-Flores, J; Lundstedt, C; Malbouisson, H; Malik, S; Snow, G R; Baur, U; Iashvili, I; Kharchilava, A; Kumar, A; Smith, K; Strang, M; Alverson, G; Barberis, E; Boeriu, O; Eulisse, G; Govi, G; McCauley, T; Musienko, Y; Muzaffar, S; Osborne, I; Paul, T; Reucroft, S; Swain, J; Taylor, L; Tuura, L; Anastassov, A; Gobbi, B; Kubik, A; Ofierzynski, R A; Pozdnyakov, A; Schmitt, M; Stoynev, S; Velasco, M; Won, S; Antonelli, L; Berry, D; Hildreth, M; Jessop, C; Karmgard, D J; Kolberg, T; Lannon, K; Lynch, S; Marinelli, N; Morse, D M; Ruchti, R; Slaunwhite, J; Warchol, J; Wayne, M; Bylsma, B; Durkin, L S; Gilmore, J; Gu, J; Killewald, P; Ling, T Y; Williams, G; Adam, N; Berry, E; Elmer, P; Garmash, A; Gerbaudo, D; Halyo, V; Hunt, A; Jones, J; Laird, E; Marlow, D; Medvedeva, T; Mooney, M; Olsen, J; Piroué, P; Stickland, D; Tully, C; Werner, J S; Wildish, T; Xie, Z; Zuranski, A; Acosta, J G; Bonnett Del Alamo, M; Huang, X T; Lopez, A; Mendez, H; Oliveros, S; Ramirez Vargas, J E; Santacruz, N; Zatzerklyany, A; Alagoz, E; Antillon, E; Barnes, V E; Bolla, G; Bortoletto, D; Everett, A; Garfinkel, A F; Gecse, Z; Gutay, L; Ippolito, N; Jones, M; Koybasi, O; Laasanen, A T; Leonardo, N; Liu, C; Maroussov, V; Merkel, P; Miller, D H; Neumeister, N; Sedov, A; Shipsey, I; Yoo, H D; Zheng, Y; Jindal, P; Parashar, N; Cuplov, V; Ecklund, K M; Geurts, F J M; Liu, J H; Maronde, D; Matveev, M; Padley, B P; Redjimi, R; Roberts, J; Sabbatini, L; Tumanov, A; Betchart, B; Bodek, A; Budd, H; Chung, Y S; de Barbaro, P; Demina, R; Flacher, H; Gotra, Y; Harel, A; Korjenevski, S; Miner, D C; Orbaker, D; Petrillo, G; Vishnevskiy, D; Zielinski, M; Bhatti, A; Demortier, L; Goulianos, K; Hatakeyama, K; Lungu, G; Mesropian, C; Yan, M; Atramentov, O; Bartz, E; Gershtein, Y; Halkiadakis, E; Hits, D; Lath, A; Rose, K; Schnetzer, S; Somalwar, S; Stone, R; Thomas, S; Watts, T L; Cerizza, G; Hollingsworth, M; Spanier, S; Yang, Z C; York, A; Asaadi, J; Aurisano, A; Eusebi, R; Golyash, A; Gurrola, A; Kamon, T; Nguyen, C N; Pivarski, J; Safonov, A; Sengupta, S; Toback, D; Weinberger, M; Akchurin, N; Berntzon, L; Gumus, K; Jeong, C; Kim, H; Lee, S W; Popescu, S; Roh, Y; Sill, A; Volobouev, I; Washington, E; Wigmans, R; Yazgan, E; Engh, D; Florez, C; Johns, W; Pathak, S; Sheldon, P; Andelin, D; Arenton, M W; Balazs, M; Boutle, S; Buehler, M; Conetti, S; Cox, B; Hirosky, R; Ledovskoy, A; Neu, C; Phillips II, D; Ronquest, M; Yohay, R; Gollapinni, S; Gunthoti, K; Harr, R; Karchin, P E; Mattson, M; Sakharov, A; Anderson, M; Bachtis, M; Bellinger, J N; Carlsmith, D; Crotty, I; Dasu, S; Dutta, S; Efron, J; Feyzi, F; Flood, K; Gray, L; Grogg, K S; Grothe, M; Hall-Wilton, R; Jaworski, M; Klabbers, P; Klukas, J; Lanaro, A; Lazaridis, C; Leonard, J; Loveless, R; Magrans de Abril, M; Mohapatra, A; Ott, G; Polese, G; Reeder, D; Savin, A; Smith, W H; Sourkov, A; Swanson, J; Weinberg, M; Wenman, D; Wensveen, M; White, A

    2010-01-01

    The CMS detector is designed around a large 4 T superconducting solenoid, enclosed in a 12000-tonne steel return yoke. A detailed map of the magnetic field is required for the accurate simulation and reconstruction of physics events in the CMS detector, not only in the inner tracking region inside the solenoid but also in the large and complex structure of the steel yoke, which is instrumented with muon chambers. Using a large sample of cosmic muon events collected by CMS in 2008, the field in the steel of the barrel yoke has been determined with a precision of 3 to 8% depending on the location.

  19. Superconducting technology

    International Nuclear Information System (INIS)

    Superconductivity has a long history of about 100 years. Over the past 50 years, progress in superconducting materials has been mainly in metallic superconductors, such as Nb, Nb-Ti and Nb3Sn, resulting in the creation of various application fields based on the superconducting technologies. High-Tc superconductors, the first of which was discovered in 1986, have been changing the future vision of superconducting technology through the development of new application fields such as power cables. On basis of these trends, future prospects of superconductor technology up to 2040 are discussed. In this article from the viewpoints of material development and the applications of superconducting wires and electronic devices. (author)

  20. Beam Transport in Toroidal Magnetic Field

    CERN Document Server

    Joshi, N; Meusel, O; Ratzinger, U

    2016-01-01

    The concept of a storage ring with toroidal magnetic field was presented in the two previous EPAC conferences. Here we report the first results of experiments performed with beam transport in toroidal magnetic fields and details of the injection system. The beam transport experiments were carried out with 30 degree toroidal segments with an axial magnetic field of 0.6T. The multi turn injection system relies on a transverse injection coil together with an electric kicker system.

  1. Centrifugal barrel polishing of 1.3 GHz Nb cavities

    International Nuclear Information System (INIS)

    Superconducting radio-frequency (SRF) cavities are the key components of particle accelerators such as the European X-ray Free Electron Laser (XFEL, under construction) and the planned future International Linear Collider (ILC). Steady progress in surface treatment techniques of SRF cavities in both the achievable quality factor Q and the accelerating electric field Eacc makes new accelerators and ambitious projects feasible. One of the alternative surface preparation techniques which is actually being explored is centrifugal barrel polishing (CBP) pioneered at KEK in Japan in mid-nineties by T. Hiuchi et al. CBP is a mechanical polishing of cavities and results in around 10 x smaller surface roughness and mirror-like surface as compared to chemistry alone. Q and Eacc are expected to be at least as high as for chemically treated cavities. CBP eliminates the bulk chemistry and has the potential to completely replace the chemistry. The University of Hamburg is installing a CBP machine to study it as a cavity preparation and repair technique for 9-cell 1.3 GHz SRF cavities at the Deutsche Elektronen-Synchrotron (DESY). The setup and first commissioning tests will be presented and discussed.

  2. Trapped particle dynamics in toroidally rotating plasmas

    International Nuclear Information System (INIS)

    A detailed single particle orbit analysis is toroidally rotating plasma yields new analytical formulas for the second adiabatic invariant, the bounce frequency, and the precession frequency up to the first order correction in ρpi(poloidal ion gyroradium)/Lv(scale length of rotation velocity), for toroidal flow values of the order of ion thermal velocity. Toroidal plasma rotation effects on the trapped ion instabilities in tokamaks are investigated in the context of local theory. Toroidal plasma rotation increases both the fraction of trapped particles and their precession drift velocity. Consequently, the growth rate of trapped ion instability increases in both dissipative and collisionless regimes

  3. Computational modelling of compact toroidal plasmas

    International Nuclear Information System (INIS)

    Preliminary simulations of the formation of compact toroids are presented. This work is in support of current experiments in which compact toroids - a minimum magnetic energy configuration with linked toroidal and poloidal flux - are being formed, accelerated and compressed. Simulations were performed using MACH2, a 2D magnetohydrodynamic code with a newly implemented Van Lear transport scheme. Simulations also include a detailed modelling of the initial poloidal flux distribution produced by the external solenoidal coils, which is through to significantly effect the toroid's formation

  4. Pellet injection and toroidal confinement

    International Nuclear Information System (INIS)

    The proceedings of a technical committee meeting on pellet injection and toroidal confinement, held in Gut Ising, Federal Republic of Germany, 24-26 October, 1988, are given in this report. Most of the major fusion experiments are using pellet injectors; these were reported at this meeting. Studies of confinement, which is favorably affected, impurity transport, radiative energy losses, and affects on the ion temperature gradient instability were given. Studies of pellet ablation and effects on plasma profiles were presented. Finally, several papers described present and proposed injection guns. Refs, figs and tabs

  5. Microstructures Formation by Fluorocarbon Barrel Plasma Etching

    OpenAIRE

    A. El Amrani; Tadjine, R.; F. Y. Moussa

    2008-01-01

    The aim of our study is to generate microstructures in order to improve optical properties of monocrystalline silicon. By mean of fluorocarbon plasma barrel texturing and under certain process conditions, silicon turned black. As a result of silicon surface-plasma particles reactions, porous microstructures are formed, while a longer process time microspikes are developed. These microstructures are responsible of the high level of light trapping on almost the whole range of the usable portion...

  6. Alignment of the MSGC barrel support structure

    International Nuclear Information System (INIS)

    The MSGC barrel is a sub-part of the tracking system of the CMS experiment at the LHC. The mechanical support structure of the MSGC barrel consists of ladder-like support beams carrying the detector modules and of four disks supporting the ladders. The required alignment precision of the modules, a few tens of micrometers, is designed to be obtained by precise part manufacture and by careful measurement of the alignment during the assembly of the structure. In the paper the use of digital photogrammetry for the measurement of the alignment of the disks and for the structural verification is presented. Digital photogrammetry was chosen from a number of potential methods after a careful evaluation. The use of photogrammetry for the structural verification of a prototype is presented. The displacements were measured both of unloaded and loaded disk by using photogrammetry and linear displacement transducers for verification. The displacements obtained from the two measurement methods corresponded well, not only to each other, but also to the results given by finite element analysis. The structural verification will be done and the alignment procedure will be tested with a full-sized prototype of a half of the MSGC barrel. Preparations for the photogrammetry measurements are presented and the design of the required supplementary equipment is shown. (authors)

  7. Interface superconductivity

    International Nuclear Information System (INIS)

    Highlights: • We discuss interfacial superconductivity, a field boosted by the discovery of the superconducting interface between LaAlO. • This system allows the electric field control and the on/off switching of the superconducting state. • We compare superconductivity at the interface and in bulk doped SrTiO. • We discuss the role of the interfacially induced Rashba type spin–orbit. • We briefly discuss superconductivity in cuprates, in electrical double layer transistor field effect experiments. • Recent observations of a high Tc in a monolayer of FeSe deposited on SrTiO3 are presented. - Abstract: Low dimensional superconducting systems have been the subject of numerous studies for many years. In this article, we focus our attention on interfacial superconductivity, a field that has been boosted by the discovery of superconductivity at the interface between the two band insulators LaAlO3 and SrTiO3. We explore the properties of this amazing system that allows the electric field control and on/off switching of superconductivity. We discuss the similarities and differences between bulk doped SrTiO3 and the interface system and the possible role of the interfacially induced Rashba type spin–orbit. We also, more briefly, discuss interface superconductivity in cuprates, in electrical double layer transistor field effect experiments, and the recent observation of a high Tc in a monolayer of FeSe deposited on SrTiO3

  8. Technical Diagnostics of Tank Cannon Smooth Barrel Bore and Ramming Device

    OpenAIRE

    Jiri Balla; Stanislav Prochazka; Robert Jankovych; Stanislav Beer; Zbynek Krist; Michal Kovarik

    2015-01-01

    The technical diagnostics of 125 mm tank cannon 2A46 smooth barrel and ramming devices are discussed respectively. Focuses on barrel diagnostics and suggests new procedures based on reconstructed BG20 Gun Barrel Bore Gauge System, measuring internal diameter of the barrel bore. The new system measures throughout the whole barrel bore the inner diameter not only at the beginning of barrel bore as it was usually measured before. Different nature of barrel wear was revealed between barrels firin...

  9. Toroidal Theory of MHD Instabilities

    International Nuclear Information System (INIS)

    We continue with the adventures of the Alfven wave and its two magnetosonic companions as they travel in the curved space of magnetic surfaces and field lines (Sec. 2), find themselves trapped in singularities of an unprecedented richness (Sec. 3), decide to get themselves better maps of the landscape to do the required twisting while some of their youthful energy is leaking away (Sec. 4), cause trouble at the edge of a powerful empire (Sec. 5), and finally see the light in a distant future (Sec. 6). Needed on the trip are the evolution equations of both ideal and resistive MHD 'derived' in reference [1], the solutions to the toroidal equilibrium equations discussed in reference [2], the general background on spectral theory of inhomogeneous plasmas presented in reference [3], which is extended in the two directions of toroidal geometry and resistivity in this lecture [4]. This leads to such intricate dynamics that numerical techniques are virtually the only way to proceed. This aspect is further elaborated in reference [5] on numerical techniques

  10. EMPACT: Electrons Muons Partons with Air Core Toroids

    International Nuclear Information System (INIS)

    The EMPACT experiment utilizes a broad approach to maximize its discovery potential for new phenomena accessible at the SSC. The high resolution detector has a balances emphasis on, and large acceptance for, electrons, muons, jets, and noninteracting particles, and is capable of utilizing the ultimate luminosity of the SSC. The detector emphasizes excellent calorimetry augmented by TRD tracking, and employs an innovative system of superconducting air core toroids for muon measurements. Significant engineering effort has established the feasibility of a baseline detector concept and has addressed the related issues of support facilities, assembly, and detector integration. The design has been tested against the challenges of predicted phenomena, with the expectation that this will optimize the capacity for observing the unexpected. EMPACT's international collaboration has unprecedented support from major aerospace industries who are providing tools and expertise for project design and integration, which will assure that a detector optimized for performance and cost will be available for the first collisions at the new laboratory

  11. Development of manufacturing technologies for ITER toroidal field coil conductors

    International Nuclear Information System (INIS)

    The Japan Atomic Energy Agency (JAEA) is responsible for procuring 25% of the ITER toroidal field (TF) coil conductors as the Japanese Domestic Agency (JADA) for the ITER project. The TF conductor is a circular shaped, cable-in-conduit conductor, composed of a cable and a stainless-steel conduit (jacket). The outer diameter and maximum length of the TF conductor are 43.7 mm and 760 m, respectively. JAEA has constructed a new conductor manufacturing facility. Prior to starting the conductor manufacturing, JAEA manufactured a 760 m-long Cu dummy conductor as a conductor manufacturing process qualification, such as processes of welding, cable insertion, compaction and spooling. All manufacturing processes have been qualified and JAEA has started to fabricate superconducting conductors for the TF coils. (author)

  12. Observation of Central Toroidal Rotation Induced by ICRF on EAST

    Science.gov (United States)

    Pan, Xiayun; Wang, Fudi; Zhang, Xinjun; Lyu, Bo; Chen, Jun; Li, Yingying; Fu, Jia; Shi, Yuejiang; Yu, Yi; Ye, Minyou; Wan, Baonian

    2016-02-01

    Core plasma rotation of both L-mode and H-mode discharges with ion cyclotron range of frequency (ICRF) minority heating (MH) scheme was measured with a tangential X-ray imaging crystal spectrometer on EAST (Experimental Advanced Superconducting Tokamak). Co-current central impurity toroidal rotation change was observed in ICRF-heated L- and H-mode plasmas. Rotation increment as high as 30 km/s was generated at ∼1.7 MW ICRF power. Scaling results showed similar trend as the Rice scaling but with significant scattering, especially in L-mode plasmas. We varied the plasma current, toroidal field and magnetic configuration individually to study their effect on L-mode plasma rotation, while keeping the other major plasma parameters and heating unchanged during the scanning. It was found that larger plasma current could induce plasma rotation more efficiently. A scan of the toroidal magnetic field indicated that the largest rotation was obtained for on-axis ICRF heating. A comparison between lower-single-null (LSN) and double-null (DN) configurations showed that LSN discharges rendered a larger rotation change for the same power input and plasma parameters. supported by the National Magnetic Confinement Fusion Science Program of China (Nos. 2013GB112004 and 2015GB103002), National Natural Science Foundation of China (Nos. 11175208, 11305212, 11375235, 11405212 and 11261140328), the Innovative Program of Development Foundation of Hefei Center for Physical Science and Technology (2014FXCX003) and Brain Korea 21 Program for Leading Universities & Students (BK21 PLUS)

  13. Toroidal Alfven wave stability in ignited tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, C.Z.; Fu, G.Y.; Van Dam, J.W.

    1989-01-01

    The effects of fusion-product alpha particles on the stability of global-type shear Alfven waves in an ignited tokamak plasma are investigated in toroidal geometry. Finite toroidicity can lead to stabilization of the global Alfven eigenmodes, but it induces a new global shear Alfven eigenmodes, which is strongly destabilized via transit resonance with alpha particles. 8 refs., 2 figs.

  14. Electrostatics of a Family of Conducting Toroids

    Science.gov (United States)

    Lekner, John

    2009-01-01

    An exact solution is found for the electrostatic potential of a family of conducting charged toroids. The toroids are characterized by two lengths "a" and "b", with "a" greater than or equal to "2b". They are closed, with no hole in the "doughnut". The results are obtained by considering the potential of two equal charges, displaced from the…

  15. Magnetoelastic instabilities and vibrations of superconducting-magnet systems

    International Nuclear Information System (INIS)

    This report describes the research accomplished under Depatment of Energy/NSF grants associated with the structural design of superconducting magnets for magnetic fusion reactors. The main results pertain to magnetomechanical instabilities in toroidal and poloidal field magnets for proposed fusion reactors. One major accomplishment was the building and testing of a 1/75th scale superconducting structural model of a 16 coil Tokamak reactor. Using this model the buckling of toroidal and poloidal field coils under different constraints was observed. A series of dynamic tests were performed, including the effect of currents on natural frequencies, poloidal-toroidal coil interaction, and buckling induced superconducting-normal quench of the coils. The stability of poloidal coils in a toroidal magnet field were investigated with the 16 coil torus. A superconducting poloidal coil was observed to become statically unstable or buckle as the current approached a certain value. Magnetoelastic buckling of other magnet systems such as a yin-yang pair of magnets, Ioffe coils, and discrete coil solenoids were also studied

  16. Parametric design studies of toroidal magnetic energy storage units

    International Nuclear Information System (INIS)

    Superconducting magnetic energy storage (SMES) units have a number of advantages as storage devices. Electrical current is the input, output and stored medium, allowing for completely solid-state energy conversion. The magnets themselves have no moving parts. The round-trip efficiency is higher than those for batteries, compressed air or pumped hydro. Output power can be very high, allowing complete discharge of the unit within a few seconds. Finally, the unit can be designed for a very large number of cycles, limited basically by fatigue in the structural components. A small systems code has been written to produce and evaluate self-consistent designs for toroidal superconducting energy storage units. The units can use either low temperature or high temperature superconductors. The coils have 'D' shape where the conductor and its stabilizer/structure is loaded only in tension and the centering forces are borne by a bucking cylinder. The coils are convectively cooled from a cryogenic reservoir in the bore of the coils. The coils are suspended in a cylindrical metal shell which protects the magnet during rail, automotive or shipboard use. It is important to note that the storage unit does not rely on its surroundings for structural support, other than normal gravity and inertial loads. This paper presents designs for toroidal energy storage units produced by the systems code. A wide range of several parameters have been considered, resulting in units storing from 1 MJ to 72 GJ. Maximum fields range from 5 t to 20 T. The masses and volumes of the coils, bucking cylinder, coolant, insulation and outer shell are calculated. For unattended use, the allowable operating time using only the boiloff of the cryogenic fluid for refrigeration is calculated. For larger units, the coils have been divided into modules suitable for normal truck or rail transport. 8 refs., 5 tabs

  17. Cutoff frequency of toroidal plasma waveguide

    International Nuclear Information System (INIS)

    The cutoff frequencies of E and H-modes of empty and plasma filled toroidal waveguides are evaluated. The effects of space curvature and plasma density on cutoff frequencies for both modes are investigated. Using a suitable variable change, a scalar wave equation in the direction of propagation was obtained. The study indicates that the curvature in the direction of wave propagation in toroidal waveguide has an analogous effect as a straight waveguide filled with anisotropic media. The Rayleigh-Schrodinger perturbation method was employed to solve for cutoff frequencies in the first order of approximation. In the limit of small space curvature, the toroidal waveguide cutoff frequencies for both E and H-modes approach those of TM and TE modes of empty cylindrical waveguide with a radius equal to toroidal waveguide minor radius. The analysis shows that the curvature in the direction of propagation in toroidal waveguides leads to the removal of the degeneracy between E and H-modes

  18. Asymmetric Magnon Excitation by Spontaneous Toroidal Ordering

    Science.gov (United States)

    Hayami, Satoru; Kusunose, Hiroaki; Motome, Yukitoshi

    2016-05-01

    The effects of spontaneous toroidal ordering on magnetic excitation are theoretically investigated for a localized spin model that includes a staggered Dzyaloshinsky-Moriya interaction and anisotropic exchange interactions, which arise from the antisymmetric spin-orbit coupling and the multiorbital correlation effect. We show that the model exhibits a Néel-type antiferromagnetic order, which simultaneously accompanies a ferroic toroidal order. We find that the occurrence of toroidal order modulates the magnon dispersion in an asymmetric way with respect to the wave number: a toroidal dipole order on the zigzag chain leads to a band-bottom shift, while a toroidal octupole order on the honeycomb lattice gives rise to a valley splitting. These asymmetric magnon excitations could be a source of unusual magnetic responses, such as nonreciprocal magnon transport. A variety of modulations are discussed while changing the lattice and magnetic symmetries. The implications regarding candidate materials for asymmetric magnon excitations are presented.

  19. Toroidal Vortices in Resistive Magnetohydrodynamic Equilibria

    CERN Document Server

    Montgomery, D C; Li, S; Montgomery, David; Bates, Jason W.; Li, Shuojun

    1996-01-01

    Resistive steady states in toroidal magnetohydrodynamics (MHD), where Ohm's law must be taken into account, differ considerably from ideal ones. Only for special (and probably unphysical) resistivity profiles can the Lorentz force, in the static force-balance equation, be expressed as the gradient of a scalar and thus cancel the gradient of a scalar pressure. In general, the Lorentz force has a curl directed so as to generate toroidal vorticity. Here, we calculate, for a collisional, highly viscous magnetofluid, the flows that are required for an axisymmetric toroidal steady state, assuming uniform scalar resistivity and viscosity. The flows originate from paired toroidal vortices (in what might be called a ``double smoke ring'' configuration), and are thought likely to be ubiquitous in the interior of toroidally driven magnetofluids of this type. The existence of such vortices is conjectured to characterize magnetofluids beyond the high-viscosity limit in which they are readily calculable.

  20. Development of Toroidal Core Transformers

    Energy Technology Data Exchange (ETDEWEB)

    Leon, Francisco

    2014-05-31

    The original objective of this project was to design, build and test a few prototypes of singlephase dry-type distribution transformers of 25 kVA, 2.4 kV primary to 120 V transformers using cores made of a continuous steel strip shaped like a doughnut (toroid). At different points during the development of the project, the scope was enhanced to include the more practical case of a 25 kVA transformer for a 13.8 kV primary system voltage. Later, the scope was further expanded to design and build a 50 kVA unit to transformer voltage from 7.62 kV to 2x120 V. This is a common transformer used by Con Edison of New York and they are willing to test it in the field. The project officially started in September 2009 and ended in May 2014. The progress was reported periodically to DOE in eighteen quarterly reports. A Continuation Application was submitted to DOE in June 2010. In May 2011 we have requested a non-cost extension of the project. In December 2011, the Statement of Project Objectives (SOPO) was updated to reflect the real conditions and situation of the project as of 2011. A second Continuation Application was made and funding was approved in 2013 by DOE and the end date was extended to May 2014.The technical challenges that were overcome in this project include: the development of the technology to pass the impulse tests, derive a model for the thermal performance, produce a sound mechanical design, and estimate the inrush current. However, the greatest challenge that we faced during the development of the project was the complications of procuring the necessary parts and materials to build the transformers. The actual manufacturing process is relatively fast, but getting all parts together is a very lengthy process. The main products of this project are two prototypes of toroidal distribution transformers of 7.62 kV (to be used in a 13.8 kV system) to 2x120 V secondary (standard utilization voltage); one is rated at 25 kVA and the other at 50 kVA. The 25 k

  1. Tokamak with mechanical compression of toroidal magnetic field

    Science.gov (United States)

    Ohkawa, Tihiro

    1981-01-01

    A tokamak apparatus includes a pressure vessel for defining a reservoir and confining liquid therein. A collapsible toroidal liner disposed within the pressure vessel defines a toroidal space within the liner. Liquid metal fills the reservoir outside said liner. A toroidal magnetic field is developed within the toroidal space about the major axis thereof. A toroidal plasma is developed within the toroidal space about the major axis thereof. Pressure is applied to the liquid metal to collapse the liner and reduce the volume of the toroidal space, thereby increasing the toroidal magnetic flux density therein.

  2. Compact toroid fueling for ITER

    International Nuclear Information System (INIS)

    Experimental and theoretical work indicates that deep fueling of ITER may be possible by Compact Toroid (CT) injection. CT velocities sufficient for center fueling of a reactor have been demonstrated in the RACE device. CT injections into the TdeV tokamak have achieved central penetration at 1.4 T, and have increased the particle inventory by more than 30% without disruption. Tests on the MARAUDER device have achieved CT mass-densities suitable for injection into 5 T tokamaks. Techniques for producing multiple-shot CT's with passive electric switching are being tested on CTIX. The advantages of deep fueling by CT injection include profile peaking to reach ignition, profile control, low tritium inventory and others. In this paper, the CT experimental results are summarized, a conceptual design of a CT fueler for ITER is presented, and the implications on ITER operation and fuel cycle are discussed. 16 refs., 2 figs., 1 tab

  3. NCSX Toroidal Field Coil Design

    Energy Technology Data Exchange (ETDEWEB)

    Kalish, M.; Rushinski, J.; Myatt, L.; Brooks, A.; Dahlgren, F.; Chrzanowski, J.; Reiersen, W.; Freudenberg, K.

    2005-10-07

    The National Compact Stellarator Experiment (NCSX) is an experimental device whose design and construction is underway at the Department of Energy's Princeton Plasma Physics Laboratory (PPPL). The primary coil systems for the NCSX device consist of the twisted plasma-shaping Modular Coils, the Poloidal Field Coils, and the Toroidal Field (TF) Coils. The TF Coils are D-shaped coils wound from hollow copper conductor, and vacuum impregnated with a glass-epoxy resin system. There are 18 identical, equally spaced TF coils providing 1/R field at the plasma. They operate within a cryostat, and are cooled by LN2, nominally, to 80K. Wedge shaped castings are assembled to the inboard face of these coils, so that inward radial loads are reacted via the nesting of each of the coils against their adjacent partners. This paper outlines the TF Coil design methodology, reviews the analysis results, and summarizes how the design and analysis support the design requirements.

  4. The crystal barrel spectrometer at LEAR

    International Nuclear Information System (INIS)

    The Crystal Barrel spectrometer used at LEAR, CERN to study the products of anti pp and anti pd annihilations is described. A 1380 element array of CsI crystals measures photons from the decay of π0, η, η' and ω mesons. A segmented drift chamber in a 1.5 T magnetic field is used to identify and measure charged particles. A fast on-line trigger on charged and neutral multiplicities and on the invariant mass of secondary particles is available. The performance of the detector is discussed. (orig.)

  5. Superconducting cavities

    International Nuclear Information System (INIS)

    The basic properties of superconducting cavities for electron accelerators are discussed with special emphasis on the following topics: technical motivation for the use of superconducting cavities; surface impedance; the critical field of superconductors; anomalous losses; materials other than niobium; technological achievements for accelerating cavities. (author)

  6. Interface superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Gariglio, S., E-mail: stefano.gariglio@unige.ch [DQMP, Université de Genève, 24 Quai E.-Ansermet, CH-1211 Genève (Switzerland); Gabay, M. [Laboratoire de Physique des Solides, Bat 510, Université Paris-Sud 11, Centre d’Orsay, 91405 Orsay Cedex (France); Mannhart, J. [Max Planck Institute for Solid State Research, 70569 Stuttgart (Germany); Triscone, J.-M. [DQMP, Université de Genève, 24 Quai E.-Ansermet, CH-1211 Genève (Switzerland)

    2015-07-15

    Highlights: • We discuss interfacial superconductivity, a field boosted by the discovery of the superconducting interface between LaAlO. • This system allows the electric field control and the on/off switching of the superconducting state. • We compare superconductivity at the interface and in bulk doped SrTiO. • We discuss the role of the interfacially induced Rashba type spin–orbit. • We briefly discuss superconductivity in cuprates, in electrical double layer transistor field effect experiments. • Recent observations of a high T{sub c} in a monolayer of FeSe deposited on SrTiO{sub 3} are presented. - Abstract: Low dimensional superconducting systems have been the subject of numerous studies for many years. In this article, we focus our attention on interfacial superconductivity, a field that has been boosted by the discovery of superconductivity at the interface between the two band insulators LaAlO{sub 3} and SrTiO{sub 3}. We explore the properties of this amazing system that allows the electric field control and on/off switching of superconductivity. We discuss the similarities and differences between bulk doped SrTiO{sub 3} and the interface system and the possible role of the interfacially induced Rashba type spin–orbit. We also, more briefly, discuss interface superconductivity in cuprates, in electrical double layer transistor field effect experiments, and the recent observation of a high T{sub c} in a monolayer of FeSe deposited on SrTiO{sub 3}.

  7. ATLAS TRT Barrel in Test Beam

    CERN Multimedia

    Luehring, F

    In July, the TRT group made a highly successful test of 6 Barrel TRT modules in the ATLAS H8 testbeam. Over 3000 TRT straw tubes (4 mm diameter gas drift tubes) were instrumented and found to operate well. The prototype represents 1/16 of the ATLAS TRT barrel and was assembled from TRT modules produced as spares. This was the largest scale test of the TRT to this date and the measured detector performance was as good as or better than what was expected in all cases. The 2004 TRT testbeam setup before final cabling was attached. The readout chain and central DAQ system used in the TRT testbeam is a final prototype for the ATLAS experiment. The TRT electronics used to read out the data were: The Amplifier/Shaper/Discriminator with Baseline Restoration (ASDBLR) chip is the front-end analog chip that shapes and discriminates the electronic pulses generated by the TRT straws. The Digital Time Measurement Read Out Chip (DTMROC) measures the time of the pulse relative to the beam crossing time. The TRT-ROD ...

  8. Parametric modeling of zoom lens barrels

    Science.gov (United States)

    Pierce, Charles W.

    2001-12-01

    Today's customer requires zoom lens designs that are compact, inexpensive, and at six-sigma quality levels. While incorporating these customer requirements, a design team must often work within compressed design cycles and minimal product development budgets. These customer and project constraints, coupled with the inherent complexity of a zoom lens module, force the design team to try new and innovative techniques to deliver their products. This paper presents the methods used to develop lens barrels for several zoom lens module projects at Eastman Kodak Company. The lens barrel, a critical interface between the mechanical and optical systems, presented a technical barrier from both an engineering analysis and manufacturing perspective. The method used to overcome these barriers consisted of identifying several key functional parameters, creating a parameter-driven 3-D solid model in a commercially available CAD system, and then using the model to make iterative, data-driven design decisions while leveraging the model to create engineering drawings and the necessary prototypes and production tooling. As a result, the designs were able to meet their size, cost, and design cycle time requirements while realizing a better than anticipated first pass yield and quality level.

  9. Barrel Bolt Cracking in a German PWR

    Energy Technology Data Exchange (ETDEWEB)

    Kilian, R.; Maussner, G. [AREVA GmbH (Germany); Koenig, G. [EnBW Kernkraft GmbH (Germany)

    2011-07-01

    In this paper, the results of failure analysis of cracked barrel bolts will be shown. The barrel bolts are made of German material number 1.4571 corresponding to 316 Ti. To ensure that the required mechanical properties are achieved, the material used was cold worked. At the end of the eighties, the bolts were installed to replace Inconel X- 750 bolts. The design used is a 'star bolt'. In 2005, cracking was first observed. In this report, the results of destructive examinations showing intergranular stress corrosion cracking will be presented. M16-Bolts exhibited cracking only in the area of cup, preventing unintentional loosening. All selected and examined M12-Bolts showed similar crack initiation in the head. Cracks may initiate on transition radii between the head and shank. The shank and thread of all bolts (M12 and M16) exhibited no indications of cracking. Bolts that experienced cracking could be clearly identified through visual inspection. The ultrasonic testing technique applied confirmed crack locations in the head. All cracks were attributed to Intergranular Stress Corrosion Cracking (IGSCC). Fracture surfaces exhibited relatively thin, dark layers and, in addition to corrosion products of the base metal, the debris on the shank and head also contained traces of Al, Si, Cu and Zn. (authors)

  10. Cosmic Ray Data in TRT Barrel

    CERN Multimedia

    M. Hance

    "I had a great day in August when I went into SR1," said Daniel Froidevaux, former project leader of the ATLAS Transition Radiation Tracker, "not only had all SCT barrels arrived at CERN, but there were cosmic ray tracks seen in the TRT!" Daniel's excitement was mirrored by the rest of the TRT collaboration when, on July 29, the first cosmic ray tracks were seen in the barrel. Along with many others in the community, Daniel was quick to point out that this is the cumulative result of years of R&D, test beam work, and an intense installation and integration schedule. Indeed, the cosmic ray readout is only possible through the coordination of many efforts, from detector mechanics to module assembly, power and high voltage control, cooling, gas systems, electronics and cabling, data acquisition, and monitoring. "Many people have worked very hard on the the TRT, some of them for more than 10 years," said Brig Williams, the leader of the UPenn group responsible for much of the TRT front end electronics. He ...

  11. The toroid moment of Majorana neutrino

    International Nuclear Information System (INIS)

    The total set of electromagnetic characteristics of Majorana neutrinos is considered. It is shown that in the static limit (mi=mf=mν) the Majorana neutrinos possess only one electromagnetic characteristic, the toroidal dipole moment (anapole). We have calculated the diagonal toroidal moment (form factor) of the Majorana neutrino in the one-loop approximation of the Standard Model by the dispersion method. All external particles are on the mass shells and there are no problems with the physical interpretation of the final result. Different applications of the toroidal moment of Majorana neutrino are also discussed. 12 refs., 2 figs., 1 tab

  12. Barrel for the compression, transport and storage or low activity solid waste

    International Nuclear Information System (INIS)

    The barrel made of spherolitic cast iron has devices for fitting lifting equipment with a barrel jacket, barrel floor and a barrel lid set on a top flange of the barrel jacket, which is connected by fixing screws to the top flange. The solid waste can be compressed in the barrel by a compression press. The package of solid waste produced in this way can be tensioned against the barrel jacket. (orig./HP)

  13. Design and Calculation of the Resistance Circles for Wooden Barrels

    Directory of Open Access Journals (Sweden)

    Adriana FOTIN

    2011-03-01

    Full Text Available The aim of this paper is to present a design methodology for the circles of wooden barrels, usingappropriate strength calculations, so as to provide tightness while maintaining the integrity of the woodenmaterial embedded in the barrel structure, in the jacket and bottom staves, respectively.Based on these calculations, the circle dimensions (length, width and thickness can be defined,depending on the barrel type (for transport or storage and their relation to the barrel bottoms.Defining the dimensional characteristics of the circles is mandatory, as these are safety elements in thebarrel operation.

  14. Design study of toroidal magnets for tokamak experimental power reactors

    International Nuclear Information System (INIS)

    This report contains the results of a six-month study of superconducting toroidal field coils for a Tokamak Experimental Power Reactor to be built in the late 1980s. The designs are for 8 T and 12 T maximum magnetic field at the superconducting winding. At each field level two main concepts were generated; one in which each of the 16 coils comprising the system has an individual vacuum vessel and the other in which all the coils are contained in a single vacuum vessel. The coils have a D shape and have openings of 11.25 m x 7.5 m for the 8 T coils and 10.2 m x 6.8 m for the 12 T coils. All the designs utilize rectangular cabled conductor made from copper stabilized Niobium Titanium composite which operates at 4.2 K for the 8 T design and at 2.5 K for the 12 T design. Manufacturing procedures, processes and schedule estimates are also discussed

  15. First assembly phase for the ATLAS toroid coils

    CERN Multimedia

    Patrice Loïez

    2003-01-01

    The ATLAS barrel toroid system consists of eight coils, each of axial length 25.3 m, assembled radially and symmetrically around the beam axis. The coils are of a flat racetrack type with two double-pancake windings made of 20.5 kA aluminium-stabilized niobium-titanium superconductor. In the first phase of assembly, the two 'pancakes' are packed into their vacuum vessel. This is done using bladders filled with resin and glass microbeads under pressure. The resin is heated and, once cooled, holds the pancakes in place. The operation has to be performed on both sides of the coil, which necessitated a special technique to turn the coils over and then transport them to the heating table. Photos 01, 02, 03: Use of the overhead travelling crane to hoist the coil up and then tilt it over, the coil frame's metal feet being used as rotational pivots, supporting half the coil's weight. Once it has been turned over, the coil, now with only half the frame, is transported to the heating table using a special lifting gant...

  16. Tokamak with in situ magnetohydrodynamic generation of toroidal magnetic field

    Science.gov (United States)

    Schaffer, Michael J.

    1986-01-01

    A tokamak apparatus includes an electrically conductive metal pressure vessel for defining a chamber and confining liquid therein. A liner disposed within said chamber defines a toroidal space within the liner and confines gas therein. The metal vessel provides an electrically conductive path linking the toroidal space. Liquid metal is forced outwardly through the chamber outside of the toroidal space to generate electric current in the conductive path and thereby generate a toroidal magnetic field within the toroidal space. Toroidal plasma is developed within the toroidal space about the major axis thereof.

  17. Toroidal Horizons in Binary Black Hole Mergers

    CERN Document Server

    Bohn, Andy; Teukolsky, Saul A

    2016-01-01

    We find the first binary black hole event horizon with a toroidal topology. It had been predicted that generically the event horizons of merging black holes should briefly have a toroidal topology, but such a phase has never been seen prior to this work. In all previous binary black hole simulations, in the coordinate slicing used to evolve the black holes, the topology of the event horizon transitions directly from two spheres during the inspiral to a single sphere as the black holes merge. We present a coordinate transformation to a foliation of spacelike hypersurfaces that "cut a hole" through the event horizon surface, resulting in a toroidal event horizon. A torus could potentially provide a mechanism for violating topological censorship. However, these toroidal event horizons satisfy topological censorship by construction, because we can always trivially apply the inverse coordinate transformation to remove the topological feature.

  18. LASL toroidal reversed-field pinch programme

    International Nuclear Information System (INIS)

    The determination of the absolute energy loss due to radiation from impurities in the LASL toroidal reversed-field pinch experiment ZT-S is reported. The measurements show that over half the energy loss is accounted for by this mechanism. Thomson-scattering electron density measurements indicate only a gradual increase in temperature as the filling pressure is reduced, indicating an increased energy loss at lower pressures. Cylindrical and toroidal simulations of the experiment indicate either that a highly radiative pinch boundary or anomalous transport is needed to match the experimental results. New effects on the equilibrium due to plasma flows induced by the toroidal geometry are predicted by the toroidal simulations. The preliminary results on the low-temperature discharge cleaning of the ZT-S torus are reported. A description of the upgrade of the ZT-S experiment and the objectives, construction and theoretical predictions for the new ZT-40 experiment are given. (author)

  19. PIV-Analysis of collapsing toroidal droplets

    Science.gov (United States)

    Pairam, Ekapop; Berger, Eric; Fernandez-Nieves, Alberto; Georgia Tech Team

    2012-11-01

    Toroidal droplets are unstable and always undergo a transformation into spherical droplets driven by surface tension. They either break ala Rayleigh-Plateau if the torus is thin or grow fatter to become a single spherical droplet if the torus is fat. We analyze the velocity field inside and outside the toroidal droplet as it transforms into spherical droplets using the particle image velocimetry (PIV) method and compare with recent theoretical calculations for this process. NSF CAREER.

  20. Temperature detection circuit on the low-temperature superconducting coils

    International Nuclear Information System (INIS)

    Experimental Advanced Superconducting Tokamak (EAST) is the fully superconducting Tokamak. The EAST magnet system comprises 16 D-shaped toroidal field coils and 14 poloidal field coils which are cooled by supercritical helium at 4.2 K and 3.8 K. The temperature of superconducting coils is measured by Cernox as a new type low-temperature sensor, and monitored during the cooling and operation. The helium temperature can offer reference for quench signal. In this paper, a technique for the weak temperature signal measurement of superconducting coils is introduced, and its weak voltage is extracted from the intrinsic noise of the amplifier by the low-noise instrumentation amplifier, filter circuit, and high-linearity analog optocoupler. The temperature detection circuit works accurately and safely whether in cooling or operating process. This technique is an effective for the temperature detection on the low-temperature superconducting coils. (authors)

  1. Anomalous transport in toroidal plasmas

    International Nuclear Information System (INIS)

    When the magnetic moment of particle is conserved, there are three mechanisms which cause anomalous transport. These are: variation of magnetic field strength in flux surface, variation of electrostatic potential in flux surface, and destruction of flux surface. The anomalous transport of different groups of particles resulting from each of these mechanisms is different. This fact can be exploited to determine the cause of transport operative in an experimental situation. This approach can give far more information on the transport than the standard confinement time measurements. To implement this approach, we have developed Monte Carlo codes for toroidal geometries. The equations of motion are developed in a set of non-canonical, practical Boozer co-ordinates by means of Jacobian transformations of the particle drift Hamiltonian equations of motion. Effects of collisions are included by appropriate stochastic changes in the constants of motion. Effects of the loop voltage on particle motions are also included. We plan to apply our method to study two problems: the problem of the hot electron tail observed in edge region of ZT-40, and the energy confinement time in TOKAPOLE II. For the ZT-40 problem three situations will be considered: a single mode in the core, a stochastic region that covers half the minor radius, a stochastic region that covers the entire plasma. A turbulent spectrum of perturbations based on the experimental data of TOKAPOLE II will be developed. This will be used to simulate electron transport resulting from ideal instabilities and resistive instabilities in TOKAPOLE II

  2. Superconducting device

    International Nuclear Information System (INIS)

    The present invention provides a superconducting device to be used in a thermonuclear device and capable of unifying a current distribution in a parallel superconducting main line without consumption of liquid helium caused by Joule loss. That is, the device has a paired coils comprising a coil comprising one of plurality of superconducting wires and another coil comprising the other of plurality of superconducting wires and having a reverse winding or negative mutual inductance relative to the coil. A circuit comprising a portion of a main line is disposed to the one coil of the paired coils, and a circuit comprising the remainder of the main line is connected to the other coil each in series. The circuit has a parallel constitution. Such a constitution can provide an effect of unifying the current distribution in the main line without consumption of liquid helium due to Joule loss. (I.S.)

  3. Superconducting linac

    International Nuclear Information System (INIS)

    This project has two goals: to design, build, and test a small superconducting linac to serve as an energy booster for heavy ions from an FN tandem electrostatic accelerator, and to investigate various aspects of superconducting rf technology. The main design features of the booster are described, a status report on various components (resonators, rf control system, linac control system, cryostats, buncher) is given, and plans for the near future are outlined. Investigations of superconducting-linac technology concern studies on materials and fabrication techniques, resonator diagnostic techniques, rf-phase control, beam dynamics computer programs, asymmetry in accelerating field, and surface-treatment techniques. The overall layout of the to-be-proposed ATLAS, the Argonne Tandem-Linac Accelerator System, is shown; the ATLAS would use superconducting technology to produce beams of 5 to 25 MeV/A. 6 figures

  4. Low-n shear Alfven spectra in axisymmetric toroidal plasmas

    International Nuclear Information System (INIS)

    In toroidal plasmas, the toroidal magnetic field is nonuniform over a magnetic surface and causes coupling of different poloidal harmonics. It is shown both analytically and numerically that the toroidicity not only breaks up the shear Alfven continuous spectrum, but also creates new, discrete, toroidicity-induced shear Alfven eigenmodes with frequencies inside the continuum gaps. Potential applications of the low-n toroidicity-induced shear Alfven eigenmodes on plasma heating and instabilities are addressed. 17 refs., 4 figs

  5. Experimental Phenomena of Improved Ohmic Confinement Induced by Modulated Toroidal Current on the HT-7 Tokamak

    Institute of Scientific and Technical Information of China (English)

    毛剑珊; 罗家融; P.Phillips; 赵君煜; 揭银先; 吴振伟; 胡立群; 李建刚

    2002-01-01

    The phenomena of improved ohmic confinement have been observed during the modulation of the toroidal curranton the Hefei superconducting Tokamak-7 (HT-7). In the experiment, the programming ohmic heating field wasmodulated. A toroidal frequency-modulated current induced by modulated loop voltage was added on the plasmaequilibrium current. The ratio of ac amplitude of the plasma current to the main plasma current is about 12-30%.These improved plasma confinement phenomena include the facts that the average electron density and the centralelectron temperature both increase, the Dα radiation from the edge is reduced, the magnetohydrodynamics isobviously suppressed by oscillating plasma current, eand the global energy confinement time increases by 27-45%o.It is found that the faster the modulation is, the more effective the improved ohmic confinement phase.

  6. Resistive instabilities in toroidal confinement

    International Nuclear Information System (INIS)

    Low-m tearing modes constitute the dominant instability problem in present-day tokamaks. In this paper, the stability criteria for representative current profiles with q(0) values in the vicinity of unity are reviewed; sawtooth reconnection to q(0) values just at, or slightly exceeding, unity is generally destabilizing to the m = 2, n = 2 and m = 3, n = 2 modes and limits the range of stable profile shapes. Major disruptions can be produced by the simultaneous growth of m = 2, n = 1 and m = 3, n = 2 magnetic islands, leading to destabilization of higher-order modes and to the overlapping of several island chains. Internal disruptions---or sawteeth---arise in a variety of forms other than that produced by the classically reconnecting m = 1 mode. In some case, the q(r) value is apparently close to unity over a large central part of the plasma; in other cases, the q(0) value remains substantially below unity throughout a sawtooth cycle. Toroidal effects are sufficient to stabilize the resistive m = 1 mode in the latter case. Feedback stabilization of m ≥ 2 modes by rf heating or current drive, applied locally at the magnetic islands, appears feasible; feedback by island current drive is much more efficient, in terms of the radio-frequency power required, than feedback by island heating. Feedback stabilization of the m = 1 resistive mode---although yielding particularly beneficial effects for resistive-tearing and high-beta stability by allowing q(0) values substantially below unity---is more problematical, unless the m = 1 ideal MHD mode can be given sufficient positive stability. This appears possible, however, either by strong triangular shaping of the central flux surfaces or by appropriate tailoring of the current profile in the vicinity of the q = 1 surface

  7. Long-wavelength microinstabilities in toroidal plasmas

    International Nuclear Information System (INIS)

    Realistic kinetic toroidal eigenmode calculations have been carried out to support a proper assessment of the influence of long-wavelength microturbulence on transport in tokamak plasmas. In order to efficiently evaluate large-scale kinetic behavior extending over many rational surfaces, significant improvements have been made to a toroidal finite element code used to analyze the fully two-dimensional (r,θ) mode structures of trapped-ion and toroidal ion temperature gradient (ITG) instabilities. It is found that even at very long wavelengths, these eigenmodes exhibit a strong ballooning character with the associated radial structure relatively insensitive to ion Landau damping at the rational surfaces. In contrast to the long-accepted picture that the radial extent of trapped-ion instabilities is characterized by the ion-gyroradius-scale associated with strong localization between adjacent rational surfaces, present results demonstrate that under realistic conditions, the actual scale is governed by the large-scale variations in the equilibrium gradients. Applications to recent measurements of fluctuation properties in TFTR L-mode plasmas indicate that the theoretical trends appear consistent with spectral characteristics as well as rough heuristic estimates of the transport level. Benchmarking calculations in support of the development of a three-dimensional toroidal gyrokinetic code indicate reasonable agreement with respect to both the properties of the eigenfunctions and the magnitude of the eigenvalues during the linear phase of the simulations of toroidal ITG instabilities

  8. Azimuthal Sisyphus effect for atoms in a toroidal all-optical trap

    Energy Technology Data Exchange (ETDEWEB)

    Lembessis, V. E. [Department of Physics and Astronomy, College of Science, King Saud University, Riyadh 11451 (Saudi Arabia); Ellinas, D. [Technical University of Crete, Department of Sciences M PHI Q Research Unit GR-731 00 Chania, Crete (Greece); Babiker, M. [Department of Physics, University of York, Heslington, York YO10 5DD, England (United Kingdom)

    2011-10-15

    It is shown that an optical arrangement in which two identical counterpropagating Laguerre-Gaussian doughnut beams LG(l,0) and LG(-l,0) with orthogonal linear polarizations e {sub x} and e {sub y} can lead to azimuthal polarization gradients and an as yet undiscovered azimuthal Sisyphus effect. It is demonstrated that this effect can be utilized in the creation and control of a persistent current of superfluid atoms circulating in a toroidal trap. Such a physical system has recently been highlighted as the basis for an atomic superconducting quantum interference device (SQUID) and ultimately for the realization of atom circuits.

  9. Conceptual studies of toroidal field magnets for the tokamak experimental power reactor. Final report

    International Nuclear Information System (INIS)

    This report documents the principal results of a Conceptual Design Study for the Superconducting Toroidal Field System for a Tokamak Experimental Power Reactor. Two concepts are described for peak operating fields at the windings of 8 tesla, and 12 tesla, respectively. The design and manufacturing considerations are treated in sufficient detail that cost and schedule estimates could be developed. Major uncertainties in the design are identified and their potential impact discussed, along with recommendations for the necessary research and development programs to minimize these uncertainties. The minimum dimensions of a sub-size test coil for experimental qualification of the full size design are developed and a test program is recommended

  10. Toroidal field coil system of the Oak Ridge EPR reference design

    International Nuclear Information System (INIS)

    A refined design of the toroidal field (TF) coil system for the Oak Ridge Tokamak Experimental Power Reactor (EPR) study is presented. This design is based on cable conductor cooled by force-flow supercritical helium. It uses superconducting multifilamentary Nb3Sn for a maximum design field of 11 T at the coil windings. A hybrid system which uses NbTi at low field regions is recommended. The coil structure consists of stainless steel segments welded together to form a continuous stiff honeycomb. Conductor optimization and stability analysis specifically applicable to the forced-flow cooled conductors are given

  11. Conceptual studies of toroidal field magnets for the tokamak experimental power reactor. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Buncher, B.R.; Chi, J.W.H.; Fernandez, R.

    1976-10-26

    This report documents the principal results of a Conceptual Design Study for the Superconducting Toroidal Field System for a Tokamak Experimental Power Reactor. Two concepts are described for peak operating fields at the windings of 8 tesla, and 12 tesla, respectively. The design and manufacturing considerations are treated in sufficient detail that cost and schedule estimates could be developed. Major uncertainties in the design are identified and their potential impact discussed, along with recommendations for the necessary research and development programs to minimize these uncertainties. The minimum dimensions of a sub-size test coil for experimental qualification of the full size design are developed and a test program is recommended.

  12. ORNL Levitated Toroidal Multipole Program

    International Nuclear Information System (INIS)

    We are studying confinement of gun-injected and microwave-produced plasmas in a levitated toroidal quadrupole in which internal hoop supports are not present to limit plasma confinement. Electromagnetic levitation is made possible by reducing the 60 Hz skin depth in the copper walls with liquid nitrogen cooling. The cooling also increases the magnetic field lifetime so that an e-folding time of 17 ms was measured after crowbarring. Computations indicate that in a properly designed, larger device, an e-folding time of 100 ms can be reached. Washer-gun hydrogen plasmas and Bostick-type lithium gun plasmas were injected into the levitated quadrupole with typical parameters: B ≥ 3 kG, Te ≈ 3 eV, ni ≈ 109 cm-3, and 1 i i ≈ 1010 cm-3, Te ≈ 30 eV, and τ/τBohm ≈ 30. Density fluctuations (Δn/n) in the region of good field curvature were less than 0.05 and in the region of bad curvature 0.10-0.25. With the removal of the magnetic well (by removing the inner hoop), τ/τBohm and ni each dropped a factor of 4 and Δn/n became greater than 0.25. Recent experiments using 200 W at λ = 3 cm have produced plasmas with higher densities (n > 1011 cm-3 assuming Te ≈ 100 eV), higher temperatures (Te ≈ 100 eV) and longer lifetimes (τ ≈ 80 μs ≈ 40 τBohm) than in the λ = 12 cm experiments. Detailed probe measurements of density and temperature are consistent with models for plasma behaviour based on computed magnetic field plots. Probe data show clear evidence of the changes in heating zones during the variation of the sinusoidal magnetic field and a large obstacle intercepting all flux lines effectively prevents the formation of the plasma. We are also studying a levitated helical hexapole, whose advantages over the quadrupole are a better ratio of connection length to radius of bad curvature and more confinement volume. (author)

  13. Superconducting magnets

    International Nuclear Information System (INIS)

    This report provides a self-consistent description of a magnetic field in the aperture of a superconducting magnet and details how this field can be calculated in a magnet with cos θ current distribution in the coils. A description of an apparatus that can be used to measure the field uniformity in the aperture has been given. Finally, a detailed description of the magnet being developed for use in the Superconducting Super Collider is given. When this machine is built, it will be by far the largest application of superconductivity to date and promises to make possible the experimental discoveries needed to understand the basic laws of nature governing the world in which we live

  14. Tokamak with liquid metal for inducing toroidal electrical field

    Science.gov (United States)

    Ohkawa, Tihiro

    1981-01-01

    A tokamak apparatus includes a vessel for defining a reservoir and confining liquid therein. A toroidal liner disposed within said vessel defines a toroidal space within the liner confines gas therein. Liquid metal fills the reservoir outside the liner. A magnetic field is established in the liquid metal to develop magnetic flux linking the toroidal space. The gas is ionized. The liquid metal and the toroidal space are moved relative to one another transversely of the space to generate electric current in the ionized gas in the toroidal space about its major axis and thereby heat plasma developed in the toroidal space.

  15. Superconductivity, magnetics, cryogenics, and vacuum coating

    International Nuclear Information System (INIS)

    The Engineering Sciences Department continued to provide consultation, design, and experiment to support the plasma physics activities of the Division while inaugurating a comprehensive program to develop superconducting magnets for toroidal fusion devices. This newly funded program is aimed at producing toroidal superconducting magnets for an experimental power reactor by the mid 1980's. Other superconducting work, such as the 14-T niobium tin solenoid designed last year for use in Moessbauer experiments, has been fabricated, successfully tested, and delivered to the Physics Division. This coil, which used a 1.27-cm wide Nb3Sn conductor operating at 14 T with a coil current density of 11,000 A/cm, represents an advance in the state-of-the-art. The conceptual design was provided for a subcooler to extend the ORMAK operating temperature to 700K and thus allow operation at fields up to 25 kG with the present generators. The detailed design, fabrication, installation supervision, and acceptance testing of the subcooler were provided by the UCCND engineering organization. Further support to the ORMAK program was provided by the vacuum-coating activity through an investigation of sputtering erosion of the ORMAK liner. In addition, a program was undertaken to develop a variety of refractory surfaces of metals, alloys, and intermetallic compounds on stainless steel for use as first walls in future fusion devices. Adherent thick-film metallic and compound coatings deposited in vacuum by several mechanisms were produced and tested. (U.S.)

  16. Microstructures Formation by Fluorocarbon Barrel Plasma Etching

    International Nuclear Information System (INIS)

    The aim of our study is to generate microstructures in order to improve optical properties of monocrystalline silicon. By mean of fluorocarbon plasma barrel texturing and under certain process conditions, silicon turned black. As a result of silicon surface-plasma particles reactions, porous microstructures are formed, while a longer process time micro spikes are developed. These microstructures are responsible of the high level of light trapping on almost the whole range of the usable portion of the solar spectrum. In the wavelength range of 400-1100 nm, the AM 1.5 G weighted reflection has been reduced to 6.20%. In addition to good trapping, this surface morphology leads to superior absorption, which is about 95% in the 600-1000 nm range and decreases to 36% at 1200 nm. This material is thus less transparent and absorbs near infrared light far more than the untreated silicon. Secondary ion mass spectrometry shows that elements from the ambient gas are deposited or superficially introduced into the silicon. In addition to surface texturing, these impurities are probably the reason of absorptance enhancement. Moreover, a pore formation mechanism is proposed.

  17. PREFACE: Superconducting materials Superconducting materials

    Science.gov (United States)

    Charfi Kaddour, Samia; Singleton, John; Haddad, Sonia

    2011-11-01

    The discovery of superconductivity in 1911 was a great milestone in condensed matter physics. This discovery has resulted in an enormous amount of research activity. Collaboration among chemists and physicists, as well as experimentalists and theoreticians has given rise to very rich physics with significant potential applications ranging from electric power transmission to quantum information. Several superconducting materials have been synthesized. Crucial progress was made in 1987 with the discovery of high temperature superconductivity in copper-based compounds (cuprates) which have revealed new fascinating properties. Innovative theoretical tools have been developed to understand the striking features of cuprates which have remained for three decades the 'blue-eyed boy' for researchers in superconductor physics. The history of superconducting materials has been notably marked by the discovery of other compounds, particularly organic superconductors which despite their low critical temperature continue to attract great interest regarding their exotic properties. Last but not least, the recent observation of superconductivity in iron-based materials (pnictides) has renewed hope in reaching room temperature superconductivity. However, despite intense worldwide studies, several features related to this phenomenon remain unveiled. One of the fundamental key questions is the mechanism by which superconductivity takes place. Superconductors continue to hide their 'secret garden'. The new trends in the physics of superconductivity have been one of the two basic topics of the International Conference on Conducting Materials (ICoCoM2010) held in Sousse,Tunisia on 3-7 November 2010 and organized by the Tunisian Physical Society. The conference was a nice opportunity to bring together participants from multidisciplinary domains in the physics of superconductivity. This special section contains papers submitted by participants who gave an oral contribution at ICoCoM2010

  18. IASCC evaluation of core barrel weld line in PWR

    International Nuclear Information System (INIS)

    There is a concern of IASCC (Irradiation Assisted Stress Corrosion Cracking) in Core barrel weld line in long term operation because it is located near the core region and exposed to high neutron flux and there is weld-induced residual stress. In this report, weld-induced residual stress analysis method for EBW (Electron Beam Welding) is validated by comparing calculated residual stress with measured stress in a mock-up. Using this analysis method, stress of Core barrel EBW weld line in operating condition is calculated and it is confirmed that the probability of IASCC initiation in weld line of Core barrel is considered to be low. (authors)

  19. A Classification Scheme For Toroidal Molecules

    CERN Document Server

    Berger, J; Berger, Jorge; Avron, Joseph E.

    1995-01-01

    We construct a class of periodic tilings of the plane, which corresponds to toroidal arrangements of trivalent atoms, with pentagonal, hexagonal and heptagonal rings. Each tiling is characterized by a set of four integers and determines a toroidal molecule. The tiling rules are motivated by geometric considerations and the tiling patterns are rich enough to describe a wide class of toroidal carbon molecules, with a broad range of shapes and numbers of atoms. The molecular dimensions are simply related to the integers that determine the tiling. The configurational energy and the delocalisation energy of several molecules obtained in this way were computed for Tersoff and H\\"uckel models. The results indicate that many of these molecules are not strained, and may be expected to be stable. We studied the influence of size on the H\\"{u}ckel spectrum: it bears both similarities and differences as compared with the case of tubules.

  20. Quasisymmetric toroidal plasmas with large mean flows

    International Nuclear Information System (INIS)

    Geometric condition for quasisymmetric toroidal plasmas with large mean flows on the order of the ion thermal speed are investigated. Equilibrium momentum balance equations including the inertia term due to the large flow velocity are used to show that, for rotating quasisymmetic plasmas with no local currents crossing flux surfaces, all components of the metric tensor should be independent of the toroidal angle in the Boozer coordinates, and consequently these systems need to be rigorously axisymmetric. Unless the local radial currents vanish, the Boozer coordinates do not exist and the toroidal flow velocity cannot take any value other than a very limited class of eigenvalues corresponding to very rapid rotation especially for low beta plasmas. (author)

  1. Toroidal mode-conversion in the ICRF

    International Nuclear Information System (INIS)

    Mode-conversion is studied in the ion-cyclotron range of frequencies (ICRF) taking into account the toroidal geometry relevant for tokamaks. The global wavefields obtained using the gyrokinetic toroidal PENN code illustrate how the fast wave propagates to the neighborhood of the ion-ion hybrid resonance, where it is converted to a slow wave which deposits the wave energy through resonant interactions with the particles. The power deposition profiles obtained are dramatically different from the toroidal resonance absorption, showing that Budden's model is not a good approximation in the torus. Radially and poloidally localized wavefield structures characteristic of slow wave eigenmodes are predicted and could in experiments be driven to large amplitudes so as to interact efficiently with fast particles. (author) 5 figs., 1 tab., 48 refs

  2. Toroidal mode conversion in the ICRF

    International Nuclear Information System (INIS)

    Mode conversion is studied in the ion cyclotron range of frequencies (ICRF), taking into account the toroidal geometry relevant for tokamaks. The global wavefields obtained using the gyrokinetic toroidal PENN code illustrate how the fast wave propagates to the neighbourhood of the ion-ion hybrid resonance, where it is converted to a slow wave that deposits the wave energy through resonant Landau and cyclotron interactions with the particles. The power deposition profiles obtained are dramatically different from the toroidal resonance absorption, showing that Budden's fluid model is not a good approximation in the torus. Radially and poloidally localized wavefield structures characteristic of slow wave eigenmodes are predicted, which could be used in experiments to form transport barriers and to interact with fast particles. (author)

  3. Toroidal Horizons in Binary Black Hole Mergers

    OpenAIRE

    Bohn, Andy; Kidder, Lawrence E.; Teukolsky, Saul A.

    2016-01-01

    We find the first binary black hole event horizon with a toroidal topology. It had been predicted that generically the event horizons of merging black holes should briefly have a toroidal topology, but such a phase has never been seen prior to this work. In all previous binary black hole simulations, in the coordinate slicing used to evolve the black holes, the topology of the event horizon transitions directly from two spheres during the inspiral to a single sphere as the black holes merge. ...

  4. Toroidal Precession as a Geometric Phase

    Energy Technology Data Exchange (ETDEWEB)

    J.W. Burby and H. Qin

    2012-09-26

    Toroidal precession is commonly understood as the orbit-averaged toroidal drift of guiding centers in axisymmetric and quasisymmetric configurations. We give a new, more natural description of precession as a geometric phase effect. In particular, we show that the precession angle arises as the holonomy of a guiding center's poloidal trajectory relative to a principal connection. The fact that this description is physically appropriate is borne out with new, manifestly coordinate-independent expressions for the precession angle that apply to all types of orbits in tokamaks and quasisymmetric stellarators alike. We then describe how these expressions may be fruitfully employed in numerical calculations of precession.

  5. Some properties of toroidal isodynamic magnetostatic equilibria

    Energy Technology Data Exchange (ETDEWEB)

    Aly, J.-J. [AIM, Unite Mixte de Recherche CEA, CNRS, Universite Paris VII, UMR no 7158, Centre d' Etudes de Saclay, F-91191 Gif sur Yvette Cedex (France)

    2011-09-15

    We establish some general properties of a 3D isodynamic magnetostatic equilibrium admitting a family of nested toroidal flux surfaces. In particular, we use the virial theorem to prove a simple relation between the total pressure (magnetic + thermal) and the magnetic pressure on each flux surface, and we derive some useful consequences of the latter. We also show the constancy on each rational surface of two integrals along magnetic lines. As a simple application of our results, we show the nonexistence of an equilibrium with vanishing toroidal current, and of an equilibrium with closed lines.

  6. Anomalous transport equations in toroidal plasmas

    International Nuclear Information System (INIS)

    Reduced transport equations for a toroidal plasma with fluctuations are derived. These equations include the effects of both anomalous and standard neoclassical transport, and allow clarification of the structure of convective fluxes caused by electrostatic and magnetic fluctuations. Special attention is paid to the combined effects of fluctuations and toroidicity on the transport. The formulation retains the effects of a magnetic field inhomogeneity on the anomalous transport. It is shown that phase space diffusion caused by the gradient in the equilibrium magnetic field appears as a pinch flux in the real space

  7. Optical spectroscopic analysis of compact toroids

    International Nuclear Information System (INIS)

    Time- and space-resolved plasma emission spectra from the Weapons Laboratory compact toroid (MARAUDER) experiment have been recorded using an optical multichannel analyzer (OMA). The OMA is optically coupled to the emitting plasmas using fiber optic cables. Results are presented in terms of the composition and purity of plasma species and ionization states for compact toroids formed of hydrogen and argon. The authors use relative line strengths with a collisional radiative equilibrium (CRE) model to estimate the plasma temperature and density. Electron density has also been determined from line profile analysis of the Hβ line in hydrogen

  8. Optimal design of HTS magnets for a modular toroid-type 2.5 MJ SMES using multi-grouped particle swarm optimization

    International Nuclear Information System (INIS)

    Superconducting magnetic energy storage (SMES) is one of the promising power system applications of superconducting technology and has been actively researched and developed worldwide. Generally, there are three types of SMES-solenoid, multiple solenoid, and toroid. Among these types, toroid type seems to require more wires than solenoid type and multiple solenoid type at the same operating current. However toroid type reduces normal field in the wire and stray field dramatically because magnetic field is confined inside the coil. So, the total length of wire in the toroid type can be reduced in comparison with that in the solenoid type by increasing operating current. In this paper, a 2.5 MJ class SMES with HTS magnets of single solenoid, multiple solenoid and modular toroid type were optimized using a recently developed multi-modal optimization technique named multi-grouped particle swarm optimization (MGPSO). The objective of the optimization was to minimize the total length of HTS superconductor wires satisfying some equality and inequality constraints. The stored energy and constraints were calculated using 3D magnetic field analysis techniques and an automatic tetrahedral mesh generator. Optimized results were verified by 3D finite element method (FEM).

  9. Optimal design of HTS magnets for a modular toroid-type 2.5 MJ SMES using multi-grouped particle swarm optimization

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.Y.; Kwak, S.Y.; Seo, J.H. [Seoul National University (Korea, Republic of); Lee, S.Y.; Park, S.H. [Korea Polytechnic University (Korea, Republic of); Kim, W.S. [Seoul National University (Korea, Republic of); Lee, J.K. [Woosuk University (Korea, Republic of); Bae, J.H.; Kim, S.H.; Sim, K.D.; Seong, K.C. [Korea Electrotechnology Research Institute (Korea, Republic of); Jung, H.K. [Seoul National University (Korea, Republic of); Choi, K., E-mail: choidal@kpu.ac.k [Korea Polytechnic University (Korea, Republic of); Hahn, S. [Seoul National University (Korea, Republic of)

    2009-10-15

    Superconducting magnetic energy storage (SMES) is one of the promising power system applications of superconducting technology and has been actively researched and developed worldwide. Generally, there are three types of SMES-solenoid, multiple solenoid, and toroid. Among these types, toroid type seems to require more wires than solenoid type and multiple solenoid type at the same operating current. However toroid type reduces normal field in the wire and stray field dramatically because magnetic field is confined inside the coil. So, the total length of wire in the toroid type can be reduced in comparison with that in the solenoid type by increasing operating current. In this paper, a 2.5 MJ class SMES with HTS magnets of single solenoid, multiple solenoid and modular toroid type were optimized using a recently developed multi-modal optimization technique named multi-grouped particle swarm optimization (MGPSO). The objective of the optimization was to minimize the total length of HTS superconductor wires satisfying some equality and inequality constraints. The stored energy and constraints were calculated using 3D magnetic field analysis techniques and an automatic tetrahedral mesh generator. Optimized results were verified by 3D finite element method (FEM).

  10. Optimal design of HTS magnets for a modular toroid-type 2.5 MJ SMES using multi-grouped particle swarm optimization

    Science.gov (United States)

    Lee, S. Y.; Kwak, S. Y.; Seo, J. H.; Lee, S. Y.; Park, S. H.; Kim, W. S.; Lee, J. K.; Bae, J. H.; Kim, S. H.; Sim, K. D.; Seong, K. C.; Jung, H. K.; Choi, K.; Hahn, S.

    2009-10-01

    Superconducting magnetic energy storage (SMES) is one of the promising power system applications of superconducting technology and has been actively researched and developed worldwide. Generally, there are three types of SMES-solenoid, multiple solenoid, and toroid. Among these types, toroid type seems to require more wires than solenoid type and multiple solenoid type at the same operating current. However toroid type reduces normal field in the wire and stray field dramatically because magnetic field is confined inside the coil. So, the total length of wire in the toroid type can be reduced in comparison with that in the solenoid type by increasing operating current. In this paper, a 2.5 MJ class SMES with HTS magnets of single solenoid, multiple solenoid and modular toroid type were optimized using a recently developed multi-modal optimization technique named multi-grouped particle swarm optimization (MGPSO). The objective of the optimization was to minimize the total length of HTS superconductor wires satisfying some equality and inequality constraints. The stored energy and constraints were calculated using 3D magnetic field analysis techniques and an automatic tetrahedral mesh generator. Optimized results were verified by 3D finite element method (FEM).

  11. Superconductive detectors

    International Nuclear Information System (INIS)

    Various attempts to use superconductors in the field of radiation detection are reviewed with particular emphasis on the stimulating perspectives offered by superconducting tunnel devices. Applications in the context of energy spectroscopy as well as in the fast discrimination are discussed in the light of recent results. In this framework the central role of nonequilibrium state of superconductors is analyzed in some detail. (orig.)

  12. Superconducting magnets

    International Nuclear Information System (INIS)

    This report discusses the following topics on superconducting magnets: D19B and -C: The next steps for a record-setting magnet; D20: The push beyond 10 T: Beyond D20: Speculations on the 16-T regime; other advanced magnets for accelerators; spinoff applications; APC materials development; cable and cabling-machine development; and high-Tc superconductor at low temperature

  13. Superconducting materials

    International Nuclear Information System (INIS)

    This report discusses the following topics: Fermi liquid nesting in high temperature superconductors; optical properties of high temperature superconductors; Hall effect in superconducting La2-xSrxCuO4; source of high transition temperatures; and prospects for new superconductors

  14. The effect of sheared toroidal rotation on pressure driven magnetic islands in toroidal plasmas

    Science.gov (United States)

    Hegna, C. C.

    2016-05-01

    The impact of sheared toroidal rotation on the evolution of pressure driven magnetic islands in tokamak plasmas is investigated using a resistive magnetohydrodynamics model augmented by a neoclassical Ohm's law. Particular attention is paid to the asymptotic matching data as the Mercier indices are altered in the presence of sheared flow. Analysis of the nonlinear island Grad-Shafranov equation shows that sheared flows tend to amplify the stabilizing pressure/curvature contribution to pressure driven islands in toroidal tokamaks relative to the island bootstrap current contribution. As such, sheared toroidal rotation tends to reduce saturated magnetic island widths.

  15. Comparison between two possible CMS Barrel Muon Readout Architectures

    International Nuclear Information System (INIS)

    A comparison between two possible readout arquitectures for the CMS muon barrel readout electronics is presented, including various aspects like costs, reliability, installation, staging and maintenance. A review of the present baseline architecture is given in the appendix. (Author)

  16. Performance of a Rain Barrel Sharing Network under Climate Change

    OpenAIRE

    Seong Jin Noh; Eun-Sung Chung; Yongwon Seo

    2015-01-01

    Rain barrels can be technically shared through social practices or mutual agreement between individual households. This study proposes the evaluation system for a rain barrel sharing network (RBSN) considering three performance criteria of reliability, resiliency, and vulnerability, under plausible climate change scenarios. First, this study shows how the system can be improved in terms of the performance criteria using historical daily rainfall data based on the storage-reliability-yield rel...

  17. Response of superconducting coils to internal heating

    International Nuclear Information System (INIS)

    Development testing of six different superconducting toroidal field coils from four countries in the Large Coil Task has included investigation of each coil's tolerance for various forms of heating, such as may be encountered in the magnets of a fusion reactor. Embedded heaters and temperature and voltage sensors in the coils were used in stability tests, simulated nuclear heating tests, and measurements of current-sharing temperature at high fields and currents. Results were gratifying and promise to be useful in design of magnets for reactors

  18. New material equations for electromagnetism with toroid polarizations

    International Nuclear Information System (INIS)

    With regard to the toroid contributions, a modified system of equations of electrodynamics moving continuous media has been obtained. Alternative formalisms to introduce the toroid moment contributions in the equations of electromagnetism has been worked out. The two four-potential formalism has been developed. Lorentz transformation laws for the toroid polarizations has been given. Covariant form of equations of electrodynamics of continuous media with toroid polarizations has been written. (author)

  19. Trapped ion mode in toroidally rotating plasmas

    International Nuclear Information System (INIS)

    The influence of radially sheared toroidal flows on the Trapped Ion Mode (TIM) is investigated using a two-dimensional eigenmode code. These radially extended toroidal microinstabilities could significantly influence the interpretation of confinement scaling trends and associated fluctuation properties observed in recent tokamak experiments. In the present analysis, the electrostatic drift kinetic equation is obtained from the general nonlinear gyrokinetic equation in rotating plasmas. In the long perpendicular wavelength limit kτρbi much-lt 1, where ρbi is the average trapped-ion banana width, the resulting eigenmode equation becomes a coupled system of second order differential equations nmo for the poloidal harmonics. These equations are solved using finite element methods. Numerical results from the analysis of low and medium toroidal mode number instabilities are presented using representative TFTR L-mode input parameters. To illustrate the effects of mode coupling, a case is presented where the poloidal mode coupling is suppressed. The influence of toroidal rotation on a TFTR L-mode shot is also analyzed by including a beam species with considerable larger temperature. A discussion of the numerical results is presented

  20. Reduced Magnetohydrodynamic Equations in Toroidal Geometry

    Institute of Scientific and Technical Information of China (English)

    REN Shen-Ming; YU Guo-Yang

    2001-01-01

    By applying a new assumption of density, I.e. R2 p = const, the continuity equation is satisfied to the order ofe2`+with e being the inverse aspect ratio. In the case of large aspect ratio, a set of reduced magnetohydrodynamicequations in toroidal geometry are obtained. The new assumption about the density is supported by experimentalobservation to some extent.

  1. Chiral Anomaly in Toroidal Carbon Nanotubes

    OpenAIRE

    Sasaki, K.

    2001-01-01

    It is pointed out that the chiral anomaly in 1+1 dimensions should be observed in toroidal carbon nanotubes on a planar geometry with varying magnetic field. We show that the chiral anomaly is closely connected with the persistent current in a one-dimensional metallic ring.

  2. Toroidal groups line bundles, cohomology and quasi-Abelian varieties

    CERN Document Server

    Kopfermann, Klaus

    2001-01-01

    Toroidal groups are the connecting link between torus groups and any complex Lie groups. Many properties of complex Lie groups such as the pseudoconvexity and cohomology are determined by their maximal toroidal subgroups. Quasi-Abelian varieties are meromorphically separable toroidal groups. They are the natural generalisation of the Abelian varieties. Nevertheless, their behavior can be completely different as the wild groups show.

  3. On the stabilization of toroidal pinches by finite larmor radius effects and toroidal magnetic field

    International Nuclear Information System (INIS)

    The radial eigenvalue problem for internal modes in a large aspect ratio toriodal pinch has been solved. A particularly stable regime for a weak but nonzero toroidal magnetic field has been found. (31 refs.)

  4. 0.54-MJ superconducting magnetic energy transfer and storage

    International Nuclear Information System (INIS)

    A superconducting energy storage coil designed to store 300 kJ of energy was operated with stored energy up to 0.54 MJ. The energy was transferred from the coil in periods from 1 to 2.4 ms. Hysteresis loss and losses from all effects during pulsed energy transfer were observed. The coil is described and the test results are presented. Also included is a description of a METS (magnetic energy transfer and storage) driven adiabatic plasma compression system for a large toroidal theta-pinch reactor test and of a 300-kJ, monolithic conductor, superconducting pulsed energy storage coil

  5. First qualification of ITER Toroidal Field Coil conductor jacketing

    Energy Technology Data Exchange (ETDEWEB)

    Hamada, Kazuya, E-mail: hamada.kazuya@jaea.go.jp [Japan Atomic Energy Agency (Japan); Takahashi, Yoshikazu; Isono, Takaaki; Nunoya, Yoshihiko; Matsui, Kunihiro; Kawano, Katsumi; Oshikiri, Masayuki; Tsutsumi, Fumiaki; Koizumi, Norikiyo; Nakajima, Hideo; Okuno, Kiyoshi [Japan Atomic Energy Agency (Japan); Matsuda, Hidemitsu; Yano, Yoshitaka [Nippon Steel Engineering Co. Ltd (Japan); Devred, Arnauld; Bessette, Denis [ITER Organization (France)

    2011-10-15

    The Japan Atomic Energy Agency (JAEA) has the responsibility to procure 25% of the ITER Toroidal Field Coil conductors as the Japanese Domestic Agency (JADA) in the ITER project. The TF conductor is a circular shaped, cable-in-conduit conductor, composed of a cable and a stainless steel conduit (jacket). The outer diameter and maximum length of the TF conductor are 43.7 mm and 760 m, respectively. JAEA started to produce strand, cables and jacket sections and to construct a conductor manufacturing (jacketing) facility in 2008. Following preparation in December 2009 of the jacketing facility, the dummy cable, the jacket sections and fabrication procedures, such as welding, cable insertion, compaction and spooling, JAEA manufactured a 760 m long Cu dummy conductor for process qualification. Into the 760 m long Cu dummy conductor jacketing, JAEA successfully inserted the cable with a maximum force of 32 kN. The outer diameter of the cross section of the spooled conductor was 43.7 {+-} 0.15 mm, which complies with the ITER target requirement of 43.7 {+-} 0.3 mm. Following qualification of all manufacturing processes, JAEA has started to fabricate superconducting conductors for the TF coils.

  6. First qualification of ITER Toroidal Field Coil conductor jacketing

    International Nuclear Information System (INIS)

    The Japan Atomic Energy Agency (JAEA) has the responsibility to procure 25% of the ITER Toroidal Field Coil conductors as the Japanese Domestic Agency (JADA) in the ITER project. The TF conductor is a circular shaped, cable-in-conduit conductor, composed of a cable and a stainless steel conduit (jacket). The outer diameter and maximum length of the TF conductor are 43.7 mm and 760 m, respectively. JAEA started to produce strand, cables and jacket sections and to construct a conductor manufacturing (jacketing) facility in 2008. Following preparation in December 2009 of the jacketing facility, the dummy cable, the jacket sections and fabrication procedures, such as welding, cable insertion, compaction and spooling, JAEA manufactured a 760 m long Cu dummy conductor for process qualification. Into the 760 m long Cu dummy conductor jacketing, JAEA successfully inserted the cable with a maximum force of 32 kN. The outer diameter of the cross section of the spooled conductor was 43.7 ± 0.15 mm, which complies with the ITER target requirement of 43.7 ± 0.3 mm. Following qualification of all manufacturing processes, JAEA has started to fabricate superconducting conductors for the TF coils.

  7. Completion of the ITER toroidal field model coil

    International Nuclear Information System (INIS)

    In the scope of the ITER EDA a Toroidal Field Model Coil (TFMC) has been manufactured accompanied by a thorough Quality Assurance (QA) test program. This large superconducting coil has been conceptually designed by the ITER European Home Team (EUHT) and manufactured by European industry. The coil is being completed and will be tested at the Forschungszentrum Karlsruhe in spring 2001. The race track shaped winding is made of a cable-in-conduit conductor in a circular 316LN stainless steel jacket. From this conductor five double pancake (DP) modules were fabricated. Results of conductor and DP manufacture were already presented at previous conferences and are therefore only summarized here. The paper concentrates on the subsequent manufacturing steps, namely the stacking of the DP modules, the insulation and impregnation of the winding pack, the outer joint manufacture by electron beam welding, the assembly of the winding pack with the stainless steel case, the mounting of the helium pipes, the sensors and the busbars. To assemble the coil into the TOSKA facility and to fit it to the EU-LCT coil a heavy Inter-Coil Structure (ICS) has been built, in which the TFMC will rest on four wedges

  8. EMPACT: Electrons Muons Partons with Air Core Toroids

    Energy Technology Data Exchange (ETDEWEB)

    Marx, M.D. (State Univ. of New York, Stony Brook, NY (USA))

    1990-05-25

    The EMPACT experiment utilizes a broad approach to maximize its discovery potential for new phenomena accessible at the SSC. The high resolution detector has a balances emphasis on, and large acceptance for, electrons, muons, jets, and noninteracting particles, and is capable of utilizing the ultimate luminosity of the SSC. The detector emphasizes excellent calorimetry augmented by TRD tracking, and employs an innovative system of superconducting air core toroids for muon measurements. Significant engineering effort has established the feasibility of a baseline detector concept and has addressed the related issues of support facilities, assembly, and detector integration. The design has been tested against the challenges of predicted phenomena, with the expectation that this will optimize the capacity for observing the unexpected. EMPACT's international collaboration has unprecedented support from major aerospace industries who are providing tools and expertise for project design and integration, which will assure that a detector optimized for performance and cost will be available for the first collisions at the new laboratory.

  9. Analysis of spiky net toroidal current in the magnetized toroidal plasma from the point of view of helicity conservation

    International Nuclear Information System (INIS)

    It has been observed that 'runaway oscillations' in the toroidal current of the magnetized resistive toroidal plasma may cause continuous tearing activity, resulting in 'spiky' net toroidal current and modulation of toroidal and poloidal magnetic fields of the plasma with a definite phase relationship, depending upon the magnitude of vertical magnetic field. The present experimental results on current decay and recovery are explained from the point of view of helicity conservation. (author)

  10. Installation of CMS EB (ECAL Barrel) Supermodules 5 and 13 inside HB+ (HCAL Barrel) on 26/27 April 2006

    CERN Multimedia

    2006-01-01

    The first two barrel "supermodules" of the CMS Electromagnetic Calorimeter (ECAL) have been inserted into the barrel hadron calorimeter (HCAL) in the CMS experimental hall (called SX5) in Cessy in preparation for the forthcoming magnet test and cosmic challenge (MTCC). Each of the two supermodules contains 1700 lead tungstate crystals in glass-fibre alveolar support structures, with associated avalanche photodiodes (APDs, for scintillation light detection), electronics and cooling system.

  11. A barrel-related interneuron in layer 4 of rat somatosensory cortex with a high intra-barrel connectivity

    OpenAIRE

    Koelbl, C.; Helmstaedter, Moritz; Lübke, Joachim; Feldmeyer, Dirk

    2015-01-01

    Synaptic connections between identified fast-spiking (FS), parvalbumin (PV)-positive interneurons, and excitatory spiny neurons in layer 4 (L4) of the barrel cortex were investigated using patch-clamp recordings and simultaneous biocytin fillings. Three distinct clusters of FS L4 interneurons were identified based on their axonal morphology relative to the barrel column suggesting that these neurons do not constitute a homogeneous interneuron population. One L4 FS interneuron type had an axon...

  12. Dynamical model for the toroidal sporadic meteors

    Energy Technology Data Exchange (ETDEWEB)

    Pokorný, Petr; Vokrouhlický, David [Institute of Astronomy, Charles University, V Holešovičkách 2, CZ-18000 Prague 8 (Czech Republic); Nesvorný, David [Department of Space Studies, Southwest Research Institute, 1050 Walnut Street, Suite 300, Boulder, CO 80302 (United States); Campbell-Brown, Margaret; Brown, Peter, E-mail: petr.pokorny@volny.cz, E-mail: vokrouhl@cesnet.cz, E-mail: davidn@boulder.swri.edu, E-mail: margaret.campbell@uwo.ca, E-mail: pbrown@uwo.ca [Department of Physics and Astronomy, University of Western Ontario, London, ON N6A 3K7 (Canada)

    2014-07-01

    More than a decade of radar operations by the Canadian Meteor Orbit Radar have allowed both young and moderately old streams to be distinguished from the dispersed sporadic background component. The latter has been categorized according to broad radiant regions visible to Earth-based observers into three broad classes: the helion and anti-helion source, the north and south apex sources, and the north and south toroidal sources (and a related arc structure). The first two are populated mainly by dust released from Jupiter-family comets and new comets. Proper modeling of the toroidal sources has not to date been accomplished. Here, we develop a steady-state model for the toroidal source of the sporadic meteoroid complex, compare our model with the available radar measurements, and investigate a contribution of dust particles from our model to the whole population of sporadic meteoroids. We find that the long-term stable part of the toroidal particles is mainly fed by dust released by Halley type (long period) comets (HTCs). Our synthetic model reproduces most of the observed features of the toroidal particles, including the most troublesome low-eccentricity component, which is due to a combination of two effects: particles' ability to decouple from Jupiter and circularize by the Poynting-Robertson effect, and large collision probability for orbits similar to that of the Earth. Our calibrated model also allows us to estimate the total mass of the HTC-released dust in space and check the flux necessary to maintain the cloud in a steady state.

  13. SUPERCONDUCTING PHOTOINJECTOR

    Energy Technology Data Exchange (ETDEWEB)

    BEN-ZVI,I.; BURRILL, A.; CALAGA, R.; CHANG, X.; GROVER, R.; GUPTA, R.; HAHN, H.; HAMMONS, L.; KAYRAN, D.; KEWISCH, J.; LAMBIASE, R.; LITVINENKO, V.; MCINTYRE, G.; NAIK, D.; PATE, D.; PHILLIPS, D.; POZDEYEV, E.; RAO, T.; SMEDLEY, J.; THAN, R.; TODD, R.; WEISS, D.; WU, Q.; ZALTSMAN, A.; ET AL.

    2007-08-26

    One of the frontiers in FEL science is that of high power. In order to reach power in the megawatt range, one requires a current of the order of one ampere with a reasonably good emittance. The superconducting laser-photocathode RF gun with a high quantum efficiency photocathode is the most natural candidate to provide this performance. The development of a 1/2 cell superconducting photoinjector designed to operate at up to a current of 0.5 amperes and beam energy of 2 MeV and its photocathode system are the subjects covered in this paper. The main issues are the photocathode and its insertion mechanism, the power coupling and High Order Mode damping. This technology is being developed at BNL for DOE nuclear physics applications such as electron cooling at high energy and electron ion colliders..

  14. Color superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Wilczek, F. [Institute for Advanced Study, Princeton, NJ (United States)

    1997-09-22

    The asymptotic freedom of QCD suggests that at high density - where one forms a Fermi surface at very high momenta - weak coupling methods apply. These methods suggest that chiral symmetry is restored and that an instability toward color triplet condensation (color superconductivity) sets in. Here I attempt, using variational methods, to estimate these effects more precisely. Highlights include demonstration of a negative pressure in the uniform density chiral broken phase for any non-zero condensation, which we take as evidence for the philosophy of the MIT bag model; and demonstration that the color gap is substantial - several tens of MeV - even at modest densities. Since the superconductivity is in a pseudoscalar channel, parity is spontaneously broken.

  15. Development of compact toroids injector for direct plasma controls

    International Nuclear Information System (INIS)

    The application of the compact toroids injector for direct plasma controls has been investigated. The compact toroids injection can fuel particles directly into the core of the plasma and modify the plasma profiles at the desired locations. The acceleration tests of the compact toroids have been conducted at Himeji Institute of Technology. The tests showed that the hydrogen compact toroid was accelerated up to 80km/s and the plasma density of the compact toroid was compressed to 1.2 x 1021m-3. (orig.)

  16. The Segmented Bifilar Contrawound Toroidal Helical Antenna.

    Science.gov (United States)

    Vanvoorhies, Kurt Louis

    The segmented bifilar contrawound toroidal helical antenna, a.k.a. QuadContra antenna creates a toroidal magnetic current whose radiated electromagnetic fields emulate those of an electric dipole located normal to the plane of the toroidal helix. This antenna is a magnetic dual of the constant current electric loop antenna. Its principal advantages of reduced size and low profile result from both its circular geometry and from the velocity factor of its slow wave contrawound helical structure. This antenna is constructed by winding two conductors in contrawound relation to each other on a toroidal form, dividing the winding into an even number of segments, and reversing the pitch sense of each conductor from one segment to another. Feed ports are located on the conductors at the segment boundaries, and are connected in alternate phase to a central signal terminal via balanced and tuned transmission line elements. At resonance, each winding segment supports a quarter-wave sinusoidal current distribution. Toroidal electric current components are canceled, and poloidal current components are enhanced in the resulting anti-symmetric mode current distribution. This study measured and simulated the velocity factor, input impedance, bandwidth and simulated the radiation gain and pattern for a variety of linear and toroidal structures. The velocity factor, modeled as a power function of the ratio of axial winding length to wire length, was two to three times slower for the anti-symmetric mode contrawound helix than for a comparable monofilar helix. The radiation characteristics of the antenna were simulated using the OSU ESP4 Moment Method based program, after making extensive improvements to accommodate a wide variety of antenna configurations and to automatically find resonant frequencies. The simulated QuadContra antenna radiates with vertically polarization in a dipole-like pattern having a gain about 2 dB less than the dipole. The gain falls off dramatically for

  17. A dip structure in the intrinsic toroidal rotation near the edge of the EAST Ohmic plasmas

    International Nuclear Information System (INIS)

    The main ion toroidal velocity, vt, in the outermost 4 cm of the confined region and in the scrap-off layer of Ohmic L-mode plasmas in the EAST superconducting tokamak was measured using Mach probes. At about 1 cm inside the separatrix a local minimum in vt was observed, from where a cocurrent rotation increased towards the plasma center and towards the separatrix. The radial width of the vt dip was 1-2 cm, situated at the same location of a dip structure in radial electric field and steep gradients in density and electron temperature profiles. It was observed in both divertor and limiter configurations. Similar dip structure in vt was recently observed near the H-mode plasma edge of the ASDEX-U and DIII-D tokamaks. The velocity in our experiments amounts to ∼20 km/s, which is at the same level of those from ASDEX-U and DIII-D H-mode, suggesting that it is not an exclusive feature of the H-mode. To find out its origin, the toroidal torques induced by neutral friction, neoclassical viscosity, collisional perpendicular shear viscosity, ion orbit loss and turbulent Reynolds stress were estimated using the measured parameters. Our results indicate that in this particular parameter regime the neutral friction was the dominant damping force. The calculated cocurrent toroidal torque by the neoclassical viscosity dominates over those from the collisional perpendicular shear viscosity, ion orbit loss and turbulent Reynolds stress. These results are potentially important for the understanding of boundary conditions for the intrinsic toroidal momentum in tokamak plasmas. (author)

  18. Muon dynamics in a toroidal sector magnet

    International Nuclear Information System (INIS)

    The present scenario for the cooling channel in a high brightness muon collider calls for a quasi-continuous solenoidal focusing channel. The beam line consists of a periodic array of hydrogen absorbers immersed in a solenoid with alternating focusing field and rf linacs at the zero field points. Solenoids and toroidal sectors have a natural place in muon collider design given the large emittance of the beam and consequently, the large transverse momentum of the initial pion beam or the decay muon beam. Bent solenoids as shown were studied for use at the front end of the machine, as part of the capture channel and more recently as part of a diagnostic setup to measure the position and momentum of muons. The authors present a Hamiltonian formulation of muon dynamics in toroidal sector solenoids (bent solenoid)

  19. Anomalous transport theory for toroidal helical plasmas

    International Nuclear Information System (INIS)

    Anomalous transport coefficients in toroidal helical plasmas are studied, based on the innovative theoretical method. The self-sustained turbulence is analyzed by balancing the nonlinear growth due to the current diffusivity with the nonlinear damping by the ion viscosity and thermal conductivity. Interchange and ballooning mode turbulence is investigated, and the geometrical dependence of the anomalous transport coefficient is clarified. Variation of transport owing to the geometrical difference in toroidal helical plasmas is illustrated. The mechanism for confinement improvement is searched for. To verify the nonlinear destabilization and the self-sustained state, the nonlinear simulation of the interchange mode turbulence is performed in a sheared slab. It is demonstrated that the nonlinear enhancement of the growth rate occurs when the fluctuation amplitude exceeds the critical level. In the saturation stage, the fluctuation level becomes higher associated with the enhanced nonlinear growth. (author)

  20. Diffusiophoresis of a charged toroidal polyelectrolyte.

    Science.gov (United States)

    Tseng, Shiojenn; Hsu, Yen-Rei; Hsu, Jyh-Ping

    2016-06-01

    Considering recent application of concentration driven motion of charged nanoparticles in sensing technology, we model the diffusiophoresis of an isolated toroidal polyelectrolyte (PE) for the first time. Choosing an aqueous KCl solution for illustration, its behavior under various conditions is simulated by varying the double layer thickness, the size of toroid, and its softness and fixed charge density. We show that the behavior of the present PE can be different both quantitatively and qualitatively from that of the corresponding spherical PE. This arises from the competition of the hydrodynamic force and the electric force acting on a PE. The geometry and the nature of a PE can also influence appreciably its behavior, yielding complicated and interesting results. PMID:26970033

  1. Antimicrobial Peptides in Toroidal and Cylindrical Pores

    OpenAIRE

    Mihajlovic, Maja; Lazaridis, Themis

    2010-01-01

    Antimicrobial peptides (AMPs) are small, usually cationic peptides, which permeabilize biological membranes. Their mechanism of action is still not well understood. Here we investigate the preference of alamethicin and melittin for pores of different shapes, using molecular dynamics (MD) simulations of the peptides in pre-formed toroidal and cylindrical pores. When an alamethicin hexamer is initially embedded in a cylindrical pore, at the end of the simulation the pore remains cylindrical or ...

  2. Kinetic Damping of Toroidal Alfven Eigenmodes

    Energy Technology Data Exchange (ETDEWEB)

    G.Y. Fu; H.L. Berk; A. Pletzer

    2005-05-03

    The damping of Toroidal Alfven Eigenmodes in JET plasmas is investigated by using a reduced kinetic model. Typically no significant damping is found to occur near the center of the plasma due to mode conversion to kinetic Alfven waves. In contrast, continuum damping from resonance near the plasma edge may be significant, and when it is, it gives rise to damping rates that are compatible with the experimental observations.

  3. Toroidal geometry subroutines for MORSE-CG

    International Nuclear Information System (INIS)

    The equations, coding, and procedures that are required to include a torus in the Combinatorial Geometry subroutines of the MORSE-CG code are described. The derivation and solutions of the quartic equation that describes a torus along with additional subroutines and the modifications to existing subroutines required to carry out the transport of neutrons and gamma rays in toroidal geometry are presented. The input requirements and a sample problem are included

  4. Stellarator approach to toroidal plasma confinement

    International Nuclear Information System (INIS)

    An overview is presented of the development and current status of the stellarator approach to controlled thermonuclear confinement. Recent experimental, theoretical, and systems developments have made this concept a viable option for the evolution of the toroidal confinement program. Some experimental study of specific problems associated with departure from two-dimensional symmetry must be undertaken before the full advantages and opportunities of steady-state, net-current-free operation can be realized

  5. FMEA on the superconducting torus for the Jefferson Lab 12 GeV accelerator upgrade

    International Nuclear Information System (INIS)

    As part of the Jefferson Lab 12GeV accelerator upgrade project, Hall B requires two conduction cooled superconducting magnets. One is a magnet system consisting of six superconducting trapezoidal racetrack-type coils assembled in a toroidal configuration and the second is an actively shielded solenoidal magnet system consisting of 5 coils. Both magnets are to be wound with Superconducting Super Collider-36 NbTi strand Rutherford cable soldered into a copper channel. This paper describes the various failure modes in torus magnet along with the failure modes that could be experienced by the torus and its interaction with the solenoid which is located in close proximity

  6. The impact of acceleration on barrel/launch package design

    International Nuclear Information System (INIS)

    This paper discusses the impact of launch acceleration on the design of electromagnetic launcher barrels and on the design of associated launch packages. This is of particular interest because launch package size and mass directly affect the overall armament system size and mass. A common design approach is to use as the peak launch acceleration, the maximum acceleration which the projectile can be designed to withstand. While this approach will minimize barrel length, it may also yield an excessively large overall system size and mass, especially for the long, slender projectile configurations which are desired for high aero-thermal and terminal ballistics performance. An alternate design approach is described which balances the goals of reducing barrel length with reducing launch package mass. Results illustrate the benefits of this balanced design approach on overall armament system size and mass

  7. Electron accelerator based system for assay of transuranic waste barrels

    International Nuclear Information System (INIS)

    A complete assay system for 208-liter barrels contianing transuranic wastes has been developed. The system consists of an 8-MeV commercial electron accelerator, neutron moderating cavity housing the waste barrel and containing neutron detectors, high resolution germanium gamma spectrometer, and x-ray radiography camera (both film and real time). The electron linac is used to produce bremsstrahlung and high-intensity pulsed neutron flux, both of which are used to interrogate the fissionable materials. The Differential Dieaway Technique is used to assay the amounts of fissile and fertile materials. The neutron flux is also used in the Prompt Gamma Activation Assay to determine and to quantify the matrix elements present in the barrels. This information is then used to correct the assay of fissionable material. The bremsstrahlung too, is also used by x-ray radiography system to further identify the matrix

  8. Correcting the Chromatic Aberration in Barrel Distortion of Endoscopic Images

    Directory of Open Access Journals (Sweden)

    Y. M. Harry Ng

    2003-04-01

    Full Text Available Modern endoscopes offer physicians a wide-angle field of view (FOV for minimally invasive therapies. However, the high level of barrel distortion may prevent accurate perception of image. Fortunately, this kind of distortion may be corrected by digital image processing. In this paper we investigate the chromatic aberrations in the barrel distortion of endoscopic images. In the past, chromatic aberration in endoscopes is corrected by achromatic lenses or active lens control. In contrast, we take a computational approach by modifying the concept of image warping and the existing barrel distortion correction algorithm to tackle the chromatic aberration problem. In addition, an error function for the determination of the level of centroid coincidence is proposed. Simulation and experimental results confirm the effectiveness of our method.

  9. Treatment Method for Fermi Barrel Sodium Metal Residues

    International Nuclear Information System (INIS)

    Fermi barrels are 55-gallon drums that once contained bulk sodium metal from the shutdown Fermi 1 breeder reactor facility, and now contain residual sodium metal and other sodium/air reaction products. This report provides a residual sodium treatment method and proposed quality assurance steps that will ensure that all residual sodium is deactivated and removed from the Fermi barrels before disposal. The treatment method is the application of humidified carbon dioxide to the residual sodium followed by a water wash. The experimental application of the treatment method to six Fermi barrels is discussed, and recommendations are provided for further testing and evaluation of the method. Though more testing would allow for a greater refinement of the treatment technique, enough data has been gathered from the tests already performed to prove that 100% compliance with stated waste criteria can be achieved

  10. First two barrel ECAL supermodules inserted in CMS HCAL

    CERN Multimedia

    K.Bell

    2006-01-01

    The first two barrel "supermodules" for the CMS Electromagnetic Calorimeter (ECAL) have been inserted into the barrel hadron calorimeter (HCAL) in the experimental hall (called SX5) in Cessy in preparation for the forthcoming magnet test and cosmic challenge (MTCC). Each of the two supermodules contains 1700 lead tungstate crystals in glass-fibre alveolar support structures, with associated avalanche photodiodes (APDs, for scintillation light detection), electronics and cooling system. The barrel ECAL will consist of 36 supermodules, many of which have already been produced (see CERN Bulletin 17-18, 2006). Team from CMS ECAL, CMS Integration and CEA-DAPNIA were involved in the insertion, with the production/integration of the supermodules themselves involving many technicians, engineers and physicists from many institutes. From left to right: Olivier Teller, Maf Alidra and Lucien Veillet.

  11. Toroidal rotation and halo current produced by disruptions

    Science.gov (United States)

    Strauss, Henry; Sugiyama, Linda; Paccagnella, Roberto; Breslau, Joshua; Jardin, Stephen

    2013-10-01

    In several experiments including JET, it was observed that disruptions were accompanied by toroidal rotation. There is a concern that there may be a resonance between rotating toroidal perturbations and the resonant frequencies of the ITER vacuum vessel, causing enhanced damage. MHD simulations with M3D demonstrate that disruptions produce toroidal rotation. The toroidal velocity can produce several rotations of the sideways force during a disruption. Edge localized modes (ELMs) also produce poloidal and toroidal rotation. A theory of rotation produced by MHD activity will be presented. In the case of ELMs, the theory gives toroidal rotation Alfven Mach number, Mϕ ~10-2βN . This is consistent with a scaling for intrinsic toroidal rotation in H mode tokamaks. It was also discovered on JET that disruptions were accompanied by toroidal variation of the plasma current Iϕ. From ∇ . j = 0 , the toroidal current variation ΔIϕ is proportional to the 3D halo current, ∮Jn Rdl , where Jn is the normal current density at the wall. The 3D halo current is calculated analytically and computationally. A bound on ΔIϕ /Iϕ is found, proportional to the halo current fraction and toroidal peaking factor. Supported by USDOE and ITER.

  12. An overview on research developments of toroidal continuously variable transmissions

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    As environmental protection agencies enact new regulations for automotive fuel economy and emission, the toroidal continuously variable transmissions (CVTs) keep on contribute to the advent of system technologies for better fuel consumption of automobiles with internal combustion engines (ICE). Toroidal CVTs use infinitely adjustable drive ratios instead of stepped gears to achieve optimal performance. Toroidal CVTs are one of the earliest patents to the automotive world but their torque capacities and reliability have limitations in the past. New developments and implementations in the control strategies, and several key technologies have led to development of more robust toroidal CVTs, which enables more extensive automotive application of toroidal CTVs. This paper concerns with the current development, upcoming and progress set in the context of the past development and the traditional problems associated with toroidal CVTs.

  13. Macroscopic electromagnetic response of metamaterials with toroidal resonances

    CERN Document Server

    Savinov, V; Zheludev, N I

    2013-01-01

    Toroidal dipole, first described by Ia. B. Zeldovich [Sov. Phys. JETP 33, 1184 (1957)], is a distinct electromagnetic excitation that differs both from the electric and the magnetic dipoles. It has a number of intriguing properties: static toroidal nuclear dipole is responsible for parity violation in atomic spectra; interactions between static toroidal dipole and oscillating magnetic dipole are claimed to violate Newton's Third Law while non-stationary charge-current configurations involving toroidal multipoles have been predicted to produce vector potential in the absence of electromagnetic fields. Existence of the toroidal response in metamaterials was recently demonstrated and is now a growing field of research. However, no direct analytical link has yet been established between the transmission and reflection of macroscopic electromagnetic media and toroidal dipole excitations. To address this essential gap in electromagnetic theory we have developed an analytical approach linking microscopic and macrosc...

  14. Superconducting accelerator technology

    International Nuclear Information System (INIS)

    Modern and future accelerators for high energy and nuclear physics rely increasingly on superconducting components to achieve the required magnetic fields and accelerating fields. This paper presents a practical overview of the phenomenon of superconductivity, and describes the design issues and solutions associated with superconducting magnets and superconducting rf acceleration structures. Further development and application of superconducting components promises increased accelerator performance at reduced electric power cost

  15. Itinerant Ferromagnetism and Superconductivity

    OpenAIRE

    Karchev, Naoum

    2004-01-01

    Superconductivity has again become a challenge following the discovery of unconventional superconductivity. Resistance-free currents have been observed in heavy-fermion materials, organic conductors and copper oxides. The discovery of superconductivity in a single crystal of $UGe_2$, $ZrZn_2$ and $URhGe$ revived the interest in the coexistence of superconductivity and ferromagnetism. The experiments indicate that: i)The superconductivity is confined to the ferromagnetic phase. ii)The ferromag...

  16. Space applications of superconductivity

    Science.gov (United States)

    Sullivan, D. B.; Vorreiter, J. W.

    1979-01-01

    Some potential applications of superconductivity in space are summarized, e.g., the use of high field magnets for cosmic ray analysis or energy storage and generation, space applications of digital superconducting devices, such as the Josephson switch and, in the future, a superconducting computer. Other superconducting instrumentation which could be used in space includes: low frequency superconducting sensors, microwave and infrared detectors, instruments for gravitational studies, and high-Q cavities for use as stabilizing elements in clocks and oscillators.

  17. 100 years of superconductivity

    CERN Document Server

    Rogalla, Horst

    2011-01-01

    Even a hundred years after its discovery, superconductivity continues to bring us new surprises, from superconducting magnets used in MRI to quantum detectors in electronics. 100 Years of Superconductivity presents a comprehensive collection of topics on nearly all the subdisciplines of superconductivity. Tracing the historical developments in superconductivity, the book includes contributions from many pioneers who are responsible for important steps forward in the field.The text first discusses interesting stories of the discovery and gradual progress of theory and experimentation. Emphasizi

  18. High-temperature superconductivity

    International Nuclear Information System (INIS)

    After a short account of the history of experimental studies on superconductivity, the microscopic theory of superconductivity, the calculation of the control temperature and its possible maximum value are presented. An explanation of the mechanism of superconductivity in recently discovered superconducting metal oxide ceramics and the perspectives for the realization of new high-temperature superconducting materials are discussed. 56 refs, 2 figs, 3 tabs

  19. Superconductive communication transmission

    International Nuclear Information System (INIS)

    Recent developments in superconducting techniques have made possible the application of superconductivity in communication cables. Extensive studies have been made, and several experimental coaxial lines and superconductive communication cables have been produced and tested. The attenuation and transmission capacities of superconductive coaxial lines are greatly improved compared with existing cables. Furthermore, the cost of superconductive communication cables is far less than that of existing cables. (author)

  20. Macroscopic electromagnetic response of metamaterials with toroidal resonances

    OpenAIRE

    Savinov, V.; Fedotov, V. A.; Zheludev, N. I.

    2013-01-01

    Toroidal dipole, first described by Ia. B. Zeldovich [Sov. Phys. JETP 33, 1184 (1957)], is a distinct electromagnetic excitation that differs both from the electric and the magnetic dipoles. It has a number of intriguing properties: static toroidal nuclear dipole is responsible for parity violation in atomic spectra; interactions between static toroidal dipole and oscillating magnetic dipole are claimed to violate Newton's Third Law while non-stationary charge-current configurations involving...

  1. ATLAS barrel hadron tile calorimeter: spacers plates mass production

    International Nuclear Information System (INIS)

    In this article we expose the main problems of the mass production of the so-called 'spacer plates' for the ATLAS Barrel Hadron Tile Calorimeter. We describe all practical solutions of these problems. Particularly we present the measurement procedures and calculation schemes we used for the spacers dimensions determination. The results of the calculations are presented

  2. Measurement Technology on 200 Liters Barrels of Radioactive Waste

    Institute of Scientific and Technical Information of China (English)

    BAI; Lei; SHAO; Jie-wen; LIU; Da-ming; LIU; Hong-bin; CHENG; Yi-mei; HE; Li-xia; ZHU; Li-qun

    2012-01-01

    <正>The measurement device on 200 liters barrel of radioactive waste is designed following the rule of orderly measurement automatically, by using the technology of non-destructive to measure the mass of radioactive waste produced from fuel cycle. Device objects as shown in Fig. 1, which consists of the

  3. Acquired double-barrel oesophagus in epidermolysis bullosa dystrophica.

    OpenAIRE

    Warren, R B; Warner, T F; Gilbert, E. F.; Pellet, J R

    1980-01-01

    An unusual case of epidermolysis bullosa dystrophica with extensive stenosis, high perforation, and dissection of the oesophagus forming a "double-barrel" structure is described. Gastric epithelium found in the upper oesophagus is thought to be of metaplastic origin and caused by repeated minor trauma with repair.

  4. New results in meson spectroscopy from the crystal barrel experiment

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, C.A. [Carnegie Mellon Univ., Pittsburgh, PA (United States)

    1994-04-01

    Recent observations by the Crystal Barrel experiment of two scalar resonances, f{sub o}(1365) and a{sub o}(1450) have allowed the authors to clarify the members of the scalar nonet. In addition, a third scalar, f{sub o}(1500), appears to be supernumerary, and is a candidate for the scalar glueball expected near 1500 MeV.

  5. 49 CFR 178.510 - Standards for wooden barrels.

    Science.gov (United States)

    2010-10-01

    ... PACKAGINGS Non-bulk Performance-Oriented Packaging Standards § 178.510 Standards for wooden barrels. (a) The... the purpose intended. (2) The body and heads must be of a design appropriate to the capacity and... as follows: (1) The wood used must be of good quality, straight-grained, well-seasoned and free...

  6. Toroidal plasma enhanced CVD of diamond films

    International Nuclear Information System (INIS)

    An inductively coupled toroidal plasma source is used as an alternative to microwave plasmas for chemical vapor deposition of diamond films. The source, operating at a frequency of 400 kHz, synthesizes diamond films from a mixture of argon, methane, and hydrogen. The toroidal design has been adapted to create a highly efficient environment for diamond film deposition: high gas temperature and a short distance from the sample to the plasma core. Using a toroidal plasma geometry operating in the medium frequency band allows for efficient (≈90%) coupling of AC line power to the plasma and a scalable path to high-power and large-area operation. In test runs, the source generates a high flux of atomic hydrogen over a large area, which is favorable for diamond film growth. Using a deposition temperature of 900–1050 °C and a source to sample distance of 0.1–2.0 cm, diamond films are deposited onto silicon substrates. The results showed that the deposition rate of the diamond films could be controlled using the sample temperature and source to sample spacing. The results also show the films exhibit good-quality polycrystalline diamond as verified by Raman spectroscopy, x-ray diffraction, and scanning electron microscopy. The scanning electron microscopy and x-ray diffraction results show that the samples exhibit diamond (111) and diamond (022) crystallites. The Raman results show that the sp3 peak has a narrow spectral width (FWHM 12 ± 0.5 cm−1) and that negligible amounts of the sp2 band are present, indicating good-quality diamond films

  7. Edge ambipolar potential in toroidal fusion plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Spizzo, G., E-mail: gianluca.spizzo@igi.cnr.it; Vianello, N.; Agostini, M.; Puiatti, M. E.; Scarin, P.; Spolaore, M.; Terranova, D. [Consorzio RFX, Euratom-ENEA Association and Istituto Gas Ionizzati del CNR, Corso Stati Uniti, 4 35127 Padova (Italy); White, R. B. [Plasma Physics Laboratory, Princeton University, P.O. Box 451, Princeton, New Jersey 08543 (United States); Abdullaev, S. S.; Schmitz, O. [Institut für Energieforschung-Plasmaphysik, Association EURATOM-FZJ, Jülich (Germany); Cavazzana, R. [Consorzio RFX, Euratom-ENEA Association, Corso Stati Uniti, 4 35127 Padova (Italy); Ciaccio, G. [Dipartimento di Fisica, Università degli studi di Padova, Padova (Italy)

    2014-05-15

    A series of issues with toroidally confined fusion plasmas are related to the generation of 3D flow patterns by means of edge magnetic islands, embedded in a chaotic field and interacting with the wall. These issues include the Greenwald limit in Tokamaks and reversed-field pinches, the collisionality window for ELM mitigation with the resonant magnetic perturbations (RMPs) in Tokamaks, and edge islands interacting with the bootstrap current in stellarators. Measurements of the 2D map of the edge electric field E{sup r}(r=a,θ,ϕ) in the RFX reversed-field pinch show that E{sup r} has the same helicity of the magnetic islands generated by a m/n perturbation: in fact, defining the helical angle u=mθ−nϕ+ωt, maps show a sinusoidal dependence as a function of u, E{sup r}=E{sup ~r}sin u. The associated E × B flow displays a huge convective cell with v(a)≠0 which, in RFX and near the Greenwald limit, determines a stagnation point for density and a reversal of the sign of E{sup r}. From a theoretical point of view, the question is how a perturbed toroidal flux of symmetry m/n gives rise to an ambipolar potential Φ=Φ{sup ~}sin u. On the basis of a model developed with the guiding center code ORBIT and applied to RFX and the TEXTOR tokamak, we will show that the presence of an m/n perturbation in any kind of device breaks the toroidal symmetry with a drift proportional to the gyroradius ρ, thus larger for ions (ρ{sub i} ≫ ρ{sub e}). Immediately, an ambipolar potential arises to balance the drifts, with the same symmetry as the original perturbation.

  8. Monitoring and controlling TORE SUPRA toroidal field system status after a year of operating experience at nominal current

    International Nuclear Information System (INIS)

    This paper reports on the superconducting toroidal field system of TORE SUPRA which stands out as one of the major aspects of this tokamak. The test of the system in November 1989 up to 1455 A (4.5T on the plasma axis), followed by an operation during about one year appears as a major milestone. During this period, special attention has been paid to the system monitoring. Five detection systems acting independently ensure a good reliability of the safety procedure in case of resistive transition. The classical differential voltage detection plays an important part

  9. Toroidal mode number estimation of the edge-localized modes using the KSTAR 3-D electron cyclotron emission imaging system

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J.; Yun, G. S., E-mail: gunsu@postech.ac.kr; Lee, J. E.; Kim, M.; Choi, M. J.; Lee, W. [Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Park, H. K. [Ulsan National Institute of Science and Technology, Ulsan 689-798 (Korea, Republic of); Domier, C. W.; Luhmann, N. C. [University of California at Davis, Davis, California 95616 (United States); Sabbagh, S. A.; Park, Y. S. [Columbia University, New York, New York 10027 (United States); Lee, S. G.; Bak, J. G. [National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of)

    2014-06-15

    A new and more accurate technique is presented for determining the toroidal mode number n of edge-localized modes (ELMs) using two independent electron cyclotron emission imaging (ECEI) systems in the Korea Superconducting Tokamak Advanced Research (KSTAR) device. The technique involves the measurement of the poloidal spacing between adjacent ELM filaments, and of the pitch angle α{sub *} of filaments at the plasma outboard midplane. Equilibrium reconstruction verifies that α{sub *} is nearly constant and thus well-defined at the midplane edge. Estimates of n obtained using two ECEI systems agree well with n measured by the conventional technique employing an array of Mirnov coils.

  10. Electrical disruption in toroidal plasma of hydrogen

    International Nuclear Information System (INIS)

    The initial phase of ionization of a toroidal plasma produced in hydrogen was investigated using zero-dimensional model. The model describes the temporal evolution of plasma by spatial medium of particle density and temperature, on whole plasma volume. The energy and particle (electrons and ions) balance equations are considered. The electron loss is due to ambipolar diffusion in the presence of magnetic field. The electron energy loss involves ionization, Coulomb interaction and diffusion. The ohmic heating converter gives the initial voltage necessary to disruption. (M.C.K.)

  11. Plasma current resonance in asymmetric toroidal systems

    Energy Technology Data Exchange (ETDEWEB)

    Hazeltine, R. D. [Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712 (United States); Catto, Peter J. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, 167 Albany Street, Cambridge, Massachusetts 02139 (United States)

    2015-09-15

    The well-known singularity in the magnetic differential equation for plasma current in an asymmetric toroidal confinement system is resolved by including in the pressure tensor corrections stemming from finite Larmor radius. The result provides an estimate of the amplitude of spikes in the parallel current that occur on rational magnetic surfaces. Resolution of the singularity is shown to depend on both the ambipolarity condition—the requirement of zero surface-averaged radial current—and the form of the magnetic differential equation near the rational surface.

  12. Proposal to produce large compact toroids

    International Nuclear Information System (INIS)

    Relatively large, hot compact toroids might be produced in the annular space between two concentric one-turn coils. With currents in the two coils flowing in the same direction, the magnetic fields on each side of the plasma are in opposite directions. As the fields are raised, the plasma ring is heated and compressed radially towards the center of the annular space. By the addition of two sets of auxiliary coils, the plasma ring can be ejected out one end of the two-coil system into a long axial magnetic field

  13. Electric disruption in a hydrogen toroidal plasma

    International Nuclear Information System (INIS)

    By using a zero-dimensional model the ionizing initial phase of a toroidal plasma produced in hydrogen was investigated. The model consists on describing the plasma time evolution through the density and particle temperature space averaged on the plasma volume. The involved equations are energy and particles balance equations (electrons and ions). The electron loss is due to ambipolar diffusion in the presence of magnetic field. The electron energy loss is due to ionizing, processes of Coulomb interaction and diffusion. The ohmic heating transformer gives a initial voltage necessary to the breaking

  14. Toroidal membrane vesicles in spherical confinement

    CERN Document Server

    Bouzar, Lila; Müller, Martin Michael

    2015-01-01

    We investigate the morphology of a toroidal fluid membrane vesicle confined inside a spherical container. The equilibrium shapes are assembled in a geometrical phase diagram as a function of scaled area and reduced volume of the membrane. For small area the vesicle can adopt its free form. When increasing the area, the membrane cannot avoid contact and touches the confining sphere along a circular contact line, which extends to a zone of contact for higher area. The elastic energies of the equilibrium shapes are compared to those of their confined counterparts of spherical topology to predict under which conditions a topology change is favored energetically.

  15. Toroidal membrane vesicles in spherical confinement.

    Science.gov (United States)

    Bouzar, Lila; Menas, Ferhat; Müller, Martin Michael

    2015-09-01

    We investigate the morphology of a toroidal fluid membrane vesicle confined inside a spherical container. The equilibrium shapes are assembled in a geometrical phase diagram as a function of scaled area and reduced volume of the membrane. For small area the vesicle can adopt its free form. When increasing the area, the membrane cannot avoid contact and touches the confining sphere along a circular contact line, which extends to a zone of contact for higher area. The elastic energies of the equilibrium shapes are compared to those of their confined counterparts of spherical topology to predict under which conditions a topology change is favored energetically. PMID:26465512

  16. Drift waves in general toroidal geometry

    International Nuclear Information System (INIS)

    A model, based on gyro-kinetic ions and fluid electrons, to study drift waves in low-beta [beta = (kinetic pressure)/(magnetic pressure)] stellarator plasmas is presented. The model equations are written in straight-field-line coordinates and are valid for arbitrary, fully three-dimensional configurations with closed, nested magnetic surfaces. An implicit method, coupled with a subcycling technique for the electrons, is used to solve the time-dependent, along-the-field-line equations. Numerical calculations are carried out for a 3-field-period toroidal heliac. The geometrical effects that enter the model equations are calculated and displayed in physical space using advanced visualization techniques

  17. Pulsar Wind Nebulae with Thick Toroidal Structure

    OpenAIRE

    Chevalier, Roger A.; Reynolds, Stephen P.

    2011-01-01

    We investigate a class of pulsar wind nebulae that show synchrotron emission from a thick toroidal structure. The best studied such object is the small radio and X-ray nebula around the Vela pulsar, which can be interpreted as the result of interaction of a mildly supersonic inward flow with the recent pulsar wind. Such a flow near the center of a supernova remnant can be produced in a transient phase when the reverse shock reaches the center of the remnant. Other nebulae with a thick toroida...

  18. Burn control resulting from toroidal field ripple

    International Nuclear Information System (INIS)

    The enhanced transport due to toroidal magnetic field ripple is proposed as a means of averting thermal runaway in a tokamak reactor in the post-ignition stage. A theoretical analysis applied to a typical reactor design reveals that peak-to-average edge ripple of the order of 2% is sufficient to terminate the thermal excursion at reasonable values of β without significantly increasing the difficulty of reaching ignition. These analytic predictions, which are shown to agree well with radial transport code results, suggest that a properly specified ripple is one way of achieving a controlled burn in tokamak reactors. (author)

  19. Continuum damping of ideal toroidal Alfven eigenmodes

    International Nuclear Information System (INIS)

    A perturbation theory based on the two dimensional (2D) ballooning transform is systematically developed for ideal toroidal Alfven eigenmodes (TAEs). A formula, similar to the Fermi golden rule for decaying systems in quantum mechanics, is derived for the continuum damping rate of the TAE; the decay (damping) rate is expressed explicitly in terms of the coupling of the TAE to the continuum spectrum. Numerical results are compared with previous calculations. It is found that in some narrow intervals of the parameter mε the damping rate varies very rapidly. These regions correspond precisely to the root missing intervals of the numerical solution by Rosenbluth et al

  20. 3D blob dynamics in toroidal geometry

    DEFF Research Database (Denmark)

    Nielsen, Anders Henry; Reiser, Dirk

    DIESEL code is an extension of the ESEL code [1]. It solves a simple interchange model in full 3D tokamak geometry, where the toroidal direction is divided into a number of drift planes. On each drift plane the equations are solved in a domain corresponding to the full 2D cross section of the tokamak and...... communicate parallel with the nearest drift planes using parameterized velocities, the ion sound speed, Cs for the density equation and the Alfvén speed VA for the vorticity equation. Results show that a decrease of Alfvénic interaction of electric potential and current density leads to the expected radial...

  1. A superconducting transformer system for high current cable testing.

    Science.gov (United States)

    Godeke, A; Dietderich, D R; Joseph, J M; Lizarazo, J; Prestemon, S O; Miller, G; Weijers, H W

    2010-03-01

    This article describes the development of a direct-current (dc) superconducting transformer system for the high current test of superconducting cables. The transformer consists of a core-free 10,464 turn primary solenoid which is enclosed by a 6.5 turn secondary. The transformer is designed to deliver a 50 kA dc secondary current at a dc primary current of about 50 A. The secondary current is measured inductively using two toroidal-wound Rogowski coils. The Rogowski coil signal is digitally integrated, resulting in a voltage signal that is proportional to the secondary current. This voltage signal is used to control the secondary current using a feedback loop which automatically compensates for resistive losses in the splices to the superconducting cable samples that are connected to the secondary. The system has been commissioned up to 28 kA secondary current. The reproducibility in the secondary current measurement is better than 0.05% for the relevant current range up to 25 kA. The drift in the secondary current, which results from drift in the digital integrator, is estimated to be below 0.5 A/min. The system's performance is further demonstrated through a voltage-current measurement on a superconducting cable sample at 11 T background magnetic field. The superconducting transformer system enables fast, high resolution, economic, and safe tests of the critical current of superconducting cable samples. PMID:20370213

  2. A Superconducting transformer system for high current cable testing

    Energy Technology Data Exchange (ETDEWEB)

    Godeke, A.; Dietderich, D. R.; Joseph, J. M.; Lizarazo, J.; Prestemon, S. O.; Miller, G.; Weijers, H. W.

    2010-02-15

    This article describes the development of a direct-current (dc) superconducting transformer system for the high current test of superconducting cables. The transformer consists of a core-free 10 464 turn primary solenoid which is enclosed by a 6.5 turn secondary. The transformer is designed to deliver a 50 kA dc secondary current at a dc primary current of about 50 A. The secondary current is measured inductively using two toroidal-wound Rogowski coils. The Rogowski coil signal is digitally integrated, resulting in a voltage signal that is proportional to the secondary current. This voltage signal is used to control the secondary current using a feedback loop which automatically compensates for resistive losses in the splices to the superconducting cable samples that are connected to the secondary. The system has been commissioned up to 28 kA secondary current. The reproducibility in the secondary current measurement is better than 0.05% for the relevant current range up to 25 kA. The drift in the secondary current, which results from drift in the digital integrator, is estimated to be below 0.5 A/min. The system's performance is further demonstrated through a voltage-current measurement on a superconducting cable sample at 11 T background magnetic field. The superconducting transformer system enables fast, high resolution, economic, and safe tests of the critical current of superconducting cable samples.

  3. Design of Radioactive Reference Barrels and Simulation Verification of Linear Source

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Shell source method was used to prepare radioactive reference barrel for the calibration of gamma scan device because filling method in normal ways produces "hot" points easily and decrease the safety in transportation of the barrel.

  4. Mouse barrel cortex functionally compensates for deprivation produced by neonatal lesion of whisker follicles.

    Science.gov (United States)

    Melzer, P; Crane, A M; Smith, C B

    1993-12-01

    In the murine somatosensory pathway, the metabolic whisker map in barrel cortex derived with the autoradiographic deoxyglucose method is spatially in register with the morphological whisker map represented by the barrels. The barrel cortex of adult mice, in which we had removed three whisker follicles from the middle row of whiskers shortly after birth, contained a disorganized zone surrounded by enlarged barrels with partially disrupted borders. With the fully quantitative autoradiographic deoxyglucose method, we investigated in barrel cortex of such mice the magnitude and the pattern of metabolic responses evoked by the deflection of whiskers. Most remarkably, the simultaneous deflection of six whiskers neighbouring the lesion activated not only the territory of the corresponding barrels, but also the unspecifiable area intercalated between the clearly identified barrels. This metabolic whisker map, unpredictable from the morphological 'barrel' map, may reflect a functional compensation for the deficit in input. PMID:8124517

  5. A conceptual design of superconducting spherical tokamak reactor

    International Nuclear Information System (INIS)

    This paper presents a fusion reactor concept named 'JUST (Japanese Universities' Super Tokamak reactor)'. From the plasma confinement system to the power generation system is evaluated in this work. JUST design has features as follows: the superconducting magnet, the steady state operation with high bootstrap current fraction, the easy replacement of neutron damaged first wall, the high heat flux in the divertor, and the low cost (or high β). By winding the OH solenoid over the center stack of toroidal field coil, we have the low aspect ratio and the 80cm thick neutron shield to protect the superconducting center stack. JUST is designed by using the 0-D transport code under the assumption that the energy confinement time is 1.8 times of the IPB98(y,2) scaling. Main parameters are as follows: the major radius of 4.5m, the aspect ratio of 1.8, the elongation ratio of 2.5, the toroidal field of 2.36T, the plasma current of 18MA, the toroidal beta of 22%, the central electron and ion temperature of 15keV and the fusion thermal power of 2.4GW. By using the mercury heat exchanger and the steam turbine, the heat efficiency is 33% and the electric power is 0.74GW. (author)

  6. Microwave produced plasma in a Toroidal Device

    Science.gov (United States)

    Singh, A. K.; Edwards, W. F.; Held, E. D.

    2010-11-01

    A currentless toroidal plasma device exhibits a large range of interesting basic plasma physics phenomena. Such a device is not in equilibrium in a strict magneto hydrodynamic sense. There are many sources of free energy in the form of gradients in plasma density, temperature, the background magnetic field and the curvature of the magnetic field. These free energy sources excite waves and instabilities which have been the focus of studies in several devices in last two decades. A full understanding of these simple plasmas is far from complete. At Utah State University we have recently designed and installed a microwave plasma generation system on a small tokamak borrowed from the University of Saskatchewan, Saskatoon, Canada. Microwaves are generated at 2.45 GHz in a pulsed dc mode using a magnetron from a commercial kitchen microwave oven. The device is equipped with horizontal and vertical magnetic fields and a transformer to impose a toroidal electric field for current drive. Plasmas can be obtained over a wide range of pressure with and without magnetic fields. We present some preliminary measurements of plasma density and potential profiles. Measurements of plasma temperature at different operating conditions are also presented.

  7. Propulsion using the electron spiral toroid

    International Nuclear Information System (INIS)

    A new propulsion method is proposed which could potentially reduce propellant needed for space travel by three orders of magnitude. It uses the newly patented electron spiral toroid (EST), which stores energy as magnetic field energy. The EST is a hollow toroid of electrons, all spiraling in parallel paths in a thin outer shell. The electrons satisfy the coupling condition, forming an electron matrix. Stability is assured as long as the coupling condition is satisfied. The EST is held in place with a small external electric field; without an external magnetic field. The EST system is contained in a vacuum chamber. The EST can be thought of as an energetic entity, with electrons at 10,000 electron volts. Propulsion would not use combustion, but would heat propellant through elastic collisions with the EST surface and eject them for thrust. Chemical rocket combustion heats propellant to 4000 deg. C; an EST will potentially heat the propellant 29,000 times as much, reducing propellant needs accordingly. The thrust can be turned ON and OFF. The EST can be recharged as needed

  8. Design description of the Advanced Toroidal Facility

    International Nuclear Information System (INIS)

    The Advanced Toroidal Facility (ATF) is a large torsatron being designed at Oak Ridge National Laboratory (ORNL) to replace the Impurity Study Experiment (ISX-B) tokamak. ATF will have a major radius of 2.1 m and an average plasma minor radius of 0.3 m. Major components of the device include the coil sets, structure, and vacuum vessel. The coil sets are designed for broad operating envelopes, including the capability to drive up to 100 kA of plasma current, to produce helical axis configurations, and to operate continuously at one-half the baseline currents. The ATF structure consists of a 40-mm-thick stainless steel toroidal shell encasing the helical coil set. The shell is constructed from 24 identical upper and lower segments, with 12 pairs of intermediate panels to provide access to the helical field (HF) coil joints. The lower portion of the shell also serves as an assembly fixture for the HF coil set. The vacuum vessel is a highly contoured 6-mm-thick stainless steel shell closely fitting the bore and sidewalls of the HF coil winding to provide maximum volume for the plasma. Forty-eight large ports allow good access for diagnostics and neutral beam injection

  9. Computational simulation of compact toroidal plasma formation

    International Nuclear Information System (INIS)

    The following computational efforts are part of the MARAUDER (magnetically accelerated rings to achieve ultra-high directed energy and radiation) research program at the High Energy Plasma Division of the Weapons Laboratory. The program is investigating plasma toroids with magnetic fields similar to those of tokamaks. These fields confine the plasma between a pair of cylindrical conductors. The objective of the research is to first form such toroids and then compress and accelerate them. A 500 kJ capacitor bank will be used for the formation, and the 9 MJ Shiva Star will be used for acceleration. The first set of experiments and current computational work consider only the formation process. The computer program used for these simulations is MACH2. It is a two-dimensional MHD code and was originally developed by Mission Research Corporation under a Weapons Laboratory contract to support z-pinch research. MACH2 is an Arbitrary Lagrangian-Eulerian code with an adaptive mesh capability. Its diffusion routines use a multigrid technique to accelerate convergence. Recently, a second-order advection scheme has been added

  10. Transport and Dynamics in Toroidal Fusion Systems

    Energy Technology Data Exchange (ETDEWEB)

    Schnack, Dalton D

    2006-05-16

    This document reports the successful completion of the OFES Theory Milestone for FY2005, namely, Perform parametric studies to better understand the edge physics regimes of laboratory experiments. Simulate at increased resolution (up to 20 toroidal modes), with density evolution, late into the nonlinear phase and compare results from different types of edge modes. Simulate a single case including a study of heat deposition on nearby material walls. The linear stability properties and nonlinear evolution of Edge Localized Modes (ELMs) in tokamak plasmas are investigated through numerical computation. Data from the DIII-D device at General Atomics (http://fusion.gat.com/diii-d/) is used for the magnetohydrodynamic (MHD) equilibria, but edge parameters are varied to reveal important physical effects. The equilibrium with very low magnetic shear produces an unstable spectrum that is somewhat insensitive to dissipation coefficient values. Here, linear growth rates from the non-ideal NIMROD code (http://nimrodteam.org) agree reasonably well with ideal, i.e. non-dissipative, results from the GATO global linear stability code at low toroidal mode number (n) and with ideal results from the ELITE edge linear stability code at moderate to high toroidal mode number. Linear studies with a more realistic sequence of MHD equilibria (based on DIII-D discharge 86166) produce more significant discrepancies between the ideal and non-ideal calculations. The maximum growth rate for the ideal computations occurs at toroidal mode index n=10, whereas growth rates in the non-ideal computations continue to increase with n unless strong anisotropic thermal conduction is included. Recent modeling advances allow drift effects associated with the Hall electric field and gyroviscosity to be considered. A stabilizing effect can be observed in the preliminary results, but while the distortion in mode structure is readily apparent at n=40, the growth rate is only 13% less than the non-ideal MHD

  11. Experience with operation of a large magnet system in the international fusion superconducting magnet test facility

    International Nuclear Information System (INIS)

    Superconducting toroidal field systems, including coils and ancillaries, are being developed through international collaboration in the Large Coil Task. Focal point is a test facility in Oak Ridge where six coils will be tested in a toroidal array. Shakedown of the facility and preliminary tests of the first three coils (from Japan, Switzerland, and the US) were accomplished in 1984. Useful data were obtained on performance of the helium refrigerator and distribution system, power supplies, control and data acquisition systems and voltages, currents, strains, and acoustic emission in the coils. Performance was generally gratifying except for the helium system, where improvements are being made

  12. Feasibility Study on Welding Structure of the HT-7U Toroidal Field Coil Case

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The Toroidal Field (TF) coil case of the HT-7U superconducting tokamak device is made of austenitic stainless steel 316LN and is designed to operate at cryogenic temperature (4 K). 316LN can retain high strength and fracture toughness at 4 K. Feasibility study on technical process of welding has been experimentally considered as a hopeful joint method for suppression of post-welding deformation and reduction of over-heating. Meanwhile the final range of stress in- tensity and the stress intensity factor (K) for pre-cracks of welding structure have been determined by using J-integral. These related results are optimistic and have shown that there's no problem in strength and fracture toughness at the vicinity of the pre-crack tip. This paper introduces the welding structure of TF coil case in detail.

  13. Estimation of plasma position from tangentially viewed images on a toroidally symmetric device

    International Nuclear Information System (INIS)

    Images of plasma from a fast-framing camera are the most intuitive and reliable data to understand the status of tokamak plasmas. Generation, movement, size variation, and disruptions of plasmas can be clearly observed from these images. However, it is not a simple task to obtain the exact positions and sizes of plasmas using these images because measured two-dimensional images inevitably lose the three-dimensional position information of their targets. In this paper, the exact positions and sizes of plasmas have been calculated from tangentially viewed images using the toroidal symmetry of the plasma in the Korea Superconducting Tokamak Advanced Research (KSTAR) device. The positions and sizes of the plasmas have been manually determined with displayed cursors on images and automatically determined using a correlation factor with calculated virtual plasma images as well. These two results correspond well with each other. The estimated positions have also been compared with those obtained from magnetic diagnostics analysis.

  14. Performance of a Folded-Strip Toroidally Wound Induction Machine

    DEFF Research Database (Denmark)

    Jensen, Bogi Bech; Jack, Alan G.; Atkinson, Glynn J.; Mecrow, Barrie C.

    2011-01-01

    This paper presents the measured experimental results from a four-pole toroidally wound induction machine, where the stator is constructed as a pre-wound foldable strip. It shows that if the machine is axially restricted in length, the toroidally wound induction machine can have substantially sho...

  15. Effect of toroidal magnetic field and plasma rotation on compact toriequilibria

    International Nuclear Information System (INIS)

    The effect of toroidal magnetic field and plasma rotation on compact tori equilibrium configurations is studied. It is found that the equilibrium configurations exist in any toroidal fields. The field dependences of toroidal parameters are analyzed. The effect of opening of the toroidal separatrix and the influence of the toroidal magnetic field, toroidal rotation, the pressure profile type behind the separatrix on it is studied as well. 13 refs.; 11 figs.; 2 tabs

  16. Plasmonic Toroidal Dipolar Response under Radially Polarized Excitation

    Science.gov (United States)

    Bao, Yanjun; Zhu, Xing; Fang, Zheyu

    2015-01-01

    Plasmonic toroidal resonance has attracted growing interests because of its low loss electromagnetic properties and potential high sensitive nanophotonic applications. However, the realization in a metamaterial requires three-dimensional complicated structural design so far. In this paper, we design a simple metal-dielectric-metal (MIM) sandwich nanostructure, which exhibits a strong toroidal dipolar resonance under radially polarized excitation. The toroidal dipole moment as the dominant contribution for the scattering is demonstrated by the mirror-image method and further analyzed by Lagrangian hybridization model. The proposed toroidal configuration also shows a highly tolerant for misalignment between the structure center and the incident light focus. Our study proves the way for the toroidal plasmonic application with the cylindrical vector beams. PMID:26114966

  17. Toroidal gyrofluid equations for simulations of tokamak turbulence

    International Nuclear Information System (INIS)

    A set of nonlinear gyrofluid equations for simulations of tokamak turbulence are derived by taking moments of the nonlinear toroidal gyrokinetic equation. The moment hierarchy is closed with approximations that model the kinetic effects of parallel Landau damping, toroidal drift resonances, and finite Larmor radius effects. These equations generalize the work of Dorland and Hammett [Phys. Fluids B 5, 812 (1993)] to toroidal geometry by including essential toroidal effects. The closures for phase mixing from toroidal rB and curvature drifts take the basic form presented in Waltz, et al. [Phys. Fluids B 4, 3138 (1992)], but here a more rigorous procedure is used, including an extension to higher moments, which provides significantly improved accuracy. In addition, trapped ion effects and collisions are incorporated. This reduced set of nonlinear equations accurately models most of the physics considered important for ion dynamics in core tokamak turbulence and is simple enough to be used in high resolution direct numerical simulations

  18. Simulation and reconstruction of the PANDA Barrel DIRC

    Science.gov (United States)

    Dzhygadlo, R.; Gerhardt, A.; Go¨tzen, K.; Hohler, R.; Kalicy, G.; Kumawat, H.; Lehmann, D.; Lewandowski, B.; Patsyuk, M.; Peters, K.; Schepers, G.; Schmitt, L.; Schwarz, C.; Schwiening, J.; Traxler, M.; Zühlsdorf, M.; Dodokhov, V. Kh.; Britting, A.; Eyrich, W.; Lehmann, A.; Uhlig, F.; Düren, M.; Fo¨hl, K.; Hayrapetyan, A.; Kro¨ck, B.; Merle, O.; Rieke, J.; Cowie, E.; Keri, T.; Montgomery, R.; Rosner, G.; Achenbach, P.; Cardinali, M.; Hoek, M.; Lauth, W.; Sfienti, C.; Thiel, M.; Bühler, P.; Gruber, L.; Marton, J.; Suzuki, K.

    2014-12-01

    Hadronic particle identification (PID) in the barrel region of the PANDA experiment at the new Facility for Antiproton and Ion Research in Europe (FAIR) at GSI, Darmstadt will be provided by a DIRC (Detection of Internally Reflected Cherenkov light) counter. To optimize the performance and reduce the detector cost, detailed simulations of different design elements, such as the width of the radiators, the shape of the expansion volume, and the type of focusing system, were performed using Geant. Custom reconstruction algorithms were developed to match the detector geometry. We will discuss the single photon resolution and photon yield as well as the PID performance for the Barrel DIRC baseline design and several detector design options.

  19. Simulgeo and its application for the muon barrel position monitor

    International Nuclear Information System (INIS)

    The design process of the Muon Barrel Position Monitor of the CMS (compact muon solenoid) experiment for LHC is at the origin of the need of a software like Simulgeo. The software Silmugeo started to be developed in 1995 in order to allow the study of many systems. The idea of Simulgeo is to automatically make the modelling of a system and automatically construct the design matrix. This paper makes in part 2 an overview of the possibilities of Simulgeo, in part 3 it presents the standard objects. In part 4, it explains the mathematical basis and in part 5 the computing aspect. In part 6, it shows an application to the Muon Barrel Position Monitor Project and, in part 7, it mentions other projects where it has been used

  20. Experiences developing socially acceptable interactions for a robotic trash barrel

    DEFF Research Database (Denmark)

    Yang, Stephen; Mok, Brian Ka Jun; Sirkin, David;

    2015-01-01

    Service robots in public places need to both understand environmental cues and move in ways that people can understand and predict. We developed and tested interactions with a trash barrel robot to better understand the implicit protocols for public interaction. In eight lunch-time sessions sprea...... as having intentions and desires; c) mistakes in navigation are indicators of autonomous control, rather than a remote operator; and d) repeated mistakes and struggling behavior polarized responses as either ignoring or endearing....... strategies that seemed to evoke clear engagement and responses, both positive and negative. Observations and interviews show that a) people most welcome the robot's presence when they need its services and it actively advertises its intent through movement; b) people create mental models of the trash barrel...

  1. Electron identification at STAR and the Barrel Preshower detector

    Science.gov (United States)

    Cervantes, Matt

    2007-10-01

    The Barrel Electromagnetic Calorimeter (BEMC) in the STAR experiment at RHIC is a sampling lead scintillator consisting of 4800 towers. The data from the first 2 layers of each tower is read out separately and formally defines the Barrel Preshower (BPRS) detector. The BPRS distinguishes between electrons developing a shower early in the calorimeter tower as opposed to interactions that occur beyond these first 2 layers. We will report on the commissioning of the BPRS into the STAR detector and its implementation into an electron-based analysis. We present the standard method of particle identification currently used for electron selection and investigate the effect of using the BPRS detector. Comparison of such an analysis with and without the BPRS will be shown.

  2. WORKSHOPS: Radiofrequency superconductivity

    International Nuclear Information System (INIS)

    In the continual push towards higher energy particle beams, superconducting radiofrequency techniques now play a vital role, highlighted in the fifth workshop on radiofrequency superconductivity, held at DESY from 19 - 24 August 1991

  3. Perturbing macroscopic magnetohydrodynamic stability for toroidal plasmas

    Science.gov (United States)

    Comer, Kathryn J.

    We have introduced a new perturbative technique to rapidly explore the dependence of long wavelength ideal magnetohydrodynamic (MHD) instabilities on equilibrium profiles, shaping properties, and wall parameters. Traditionally, these relations are studied with numerical parameter scans using computationally intensive stability codes. Our perturbative technique first finds the equilibrium and stability using traditional methods. Subsequent small changes in the original equilibrium parameters change the stability. We quickly find the new stability with an expansion of the energy principle, rather than with another run of the stability codes. We first semi-analytically apply the technique to the screw pinch after eliminating compressional Alfven wave effects. The screw pinch results validate the approach, but also indicate that allowable perturbations to equilibria with certain features may be restricted. Next, we extend the approach to toroidal geometry using experimental equilibria and a simple constructed equilibrium, with the ideal MHD stability code GATO. Stability properties are successfully predicted from perturbed toroidal equilibria when only the vacuum beyond the plasma is perturbed (through wall parameter variations), rather than the plasma itself. Small plasma equilibrium perturbations to both experimental and simple equilibria result in very large errors to the predicted stability, and valid results are found only over a narrow range of most perturbations. Despite the large errors produced when changing plasma parameters, the wall perturbations revealed two useful applications of this technique. Because the calculations are non-iterative matrix multiplications, the convergence issues that can disrupt a full MHD stability code are absent. Marginal stability, therefore, is much easier to find with the perturbative technique. Also, the perturbed results can be input as the initial guess for the eigenvalue for a full stability code, and improve subsequent

  4. Room Temperature Superconductivity

    OpenAIRE

    Luiz, Adir Moyses

    2011-01-01

    This is the first book on the subject of room-temperature superconductivity. The main purpose of the book is twofold. First, to show that, under suitable conditions, superconductivity can occur above room temperature. Secondly, to present general guidelines on how to synthesize a room temperature superconductor. The book begins with an introduction into the physics of the superconducting state and superconducting materials. The mechanisms of conventional, half-conventional and unconventional ...

  5. Engineering Superconducting Phase Qubits

    OpenAIRE

    Blatter, G.; Geshkenbein, V. B.; Ioffe, L.

    1999-01-01

    The superconducting phase qubit combines Josephson junctions into superconducting loops and defines one of the promising solid state device implementations for quantum computing. While conventional designs are based on magnetically frustrated superconducting loops, here we discuss the advantages offered by $\\pi$-junctions in obtaining naturally degenerate two-level systems. Starting from a basic five-junction loop, we show how to construct degenerate two-level junctions and superconducting ph...

  6. Superconducting Power Generation

    CERN Document Server

    Rabinowitz, M

    2000-01-01

    The superconducting ac generator has the greatest potential for large-scale commercial application of superconductivity that can benefit the public. Electric power is a vital ingredient of modern society, and generation may be considered to be the vital ingredient of a power system. This articles gives background, and an insight into the physics and engineering of superconducting power generation.

  7. Basic principle of superconductivity

    OpenAIRE

    De Cao, Tian

    2007-01-01

    The basic principle of superconductivity is suggested in this paper. There have been two vital wrong suggestions on the basic principle, one is the relation between superconductivity and the Bose-Einstein condensation (BEC), and another is the relation between superconductivity and pseudogap.

  8. Toroidicity and shape dependence of peeling mode growth rates in axisymmetric toroidal plasmas

    International Nuclear Information System (INIS)

    The growth rate of the peeling mode instability with large toroidal mode number is calculated for general axisymmetric toroidal plasmas, including tokamaks and the spherical torus (ST) equilibia by using formalism presented by Connor et al. Analytic equilibia with non-zero edge current density and quasi-uniform current profiles are assumed. It is found that in sharp D-shape tokamak plasma, the derivative of the safety factor with respect to the poloidal flux becomes very large, making the perturbed poloidal motion very large, in turn making a significant reduction of the growth rate of the peeling mode, similar to the X-point effect in diverted plasma. The large aspect ratio effect is also studied, which reduces the growth rate further. (physics of gases, plasmas, and electric discharges)

  9. Helicity of a toroidal vortex with swirl

    Science.gov (United States)

    Bannikova, E. Yu.; Kontorovich, V. M.; Poslavsky, S. A.

    2016-04-01

    Based on the solutions of the Bragg-Hawthorne equation, we discuss the helicity of a thin toroidal vortex in the presence of swirl, orbital motion along the torus directrix. The relation between the helicity and circulations along the small and large linked circumferences (the torus directrix and generatrix) is shown to depend on the azimuthal velocity distribution in the core of the swirling ring vortex. In the case of nonuniform swirl, this relation differs from the well-known Moffat relation, viz., twice the product of such circulations multiplied by the number of linkages. The results can find applications in investigating the vortices in planetary atmospheres and the motions in the vicinity of active galactic nuclei.

  10. Helicity of the toroidal vortex with swirl

    CERN Document Server

    Bannikova, Elena Yu; Poslavsky, Sergey A

    2016-01-01

    On the basis of solutions of the Bragg-Hawthorne equations we discuss the helicity of thin toroidal vortices with the swirl - the orbital motion along the torus diretrix. It is shown that relationship of the helicity with circulations along the small and large linked circles - directrix and generatrix of the torus - depends on distribution of the azimuthal velocity in the core of the swirling vortex ring. In the case of non-homogeneous swirl this relationship differs from the well-known Moffat relationship - the doubled product of such circulations multiplied by the number of links. The results can be applied to vortices in planetary atmospheres and to vortex movements in the vicinity of active galactic nuclei.

  11. Nonideal magnetohydrodynamic instabilities and toroidal magnetic confinement

    International Nuclear Information System (INIS)

    The marked divergence of experimentally observed plasma instability phenomena from the predictions of ideal magnetohydrodynamics led in the early 1960s to the formulations of finite-resistivity stability theory. Beginning in the 1970s, advanced plasma diagnostics have served to establish a detailed correspondence between the predictions of the finite-resistivity theory and experimental plasma behavior - particularly in the case of the resistive kink mode and the tokamak plasma. Nonlinear resistive-kink phenomena have been found to govern the transport of magnetic flux and plasma energy in the reversed-field pinch. The other predicted finite-resistivity instability modes have been more difficult to identify directly and their implications for toroidal magnetic confinement are still unresolved

  12. Toroidal microinstability studies of high temperature tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Rewoldt, G.; Tang, W.M.

    1989-07-01

    Results from comprehensive kinetic microinstability calculations are presented showing the effects of toroidicity on the ion temperature gradient mode and its relationship to the trapped-electron mode in high-temperature tokamak plasmas. The corresponding particle and energy fluxes have also been computed. It is found that, although drift-type microinstabilities persist over a wide range of values of the ion temperature gradient parameter /eta//sub i/ /equivalent to/ (dlnT/sub i//dr)/(dlnn/sub i//dr), the characteristic features of the dominant mode are those of the /eta//sub i/-type instability when /eta//sub i/ > /eta//sub ic/ /approximately/1.2 to 1.4 and of the trapped-electron mode when /eta//sub i/ < /eta//sub ic/. 16 refs., 7 figs.

  13. ATF [Advanced Toroidal Facility] data management

    International Nuclear Information System (INIS)

    Data management for the Advanced Toroidal Facility (ATF), a stellarator located at Oak Ridge National Laboratory (ORNL), is provided by DMG, a locally developed, VAX-based software system. DMG is a data storage and retrieval software system that provides the user interface to ATF raw and analyzed data. Data are described in terms of data models and data types and are organized as signals into files, which are internally documented. The system was designed with user accessibility, software maintainability, and extensibility as primary goals. Extensibility features include compatibility with ATF as it moves from pulsed to steady-state operation and capability for use of the DMG system with experiments other than ATF. DMG is implemented as a run-time library of routines available as a shareable image. General-purpose and specialized data acquisition and analysis applications have been developed using the DMG system. This paper describes the DMG system and the interfaces to it. 4 refs., 2 figs

  14. The theory of toroidally confined plasmas

    CERN Document Server

    White, Roscoe B

    2014-01-01

    This graduate level textbook develops the theory of magnetically confined plasma, with the aim of bringing the reader to the level of current research in the field of thermonuclear fusion. It begins with the basic concepts of magnetic field description, plasma equilibria and stability, and goes on to derive the equations for guiding center particle motion in an equilibrium field. Topics include linear and nonlinear ideal and resistive modes and particle transport. It is of use to workers in the field of fusion both for its wide-ranging account of tokamak physics and as a kind of handbook or formulary. This edition has been extended in a number of ways. The material on mode-particle interactions has been reformulated and much new information added, including methodology for Monte Carlo implementation of mode destabilization. These results give explicit means of carrying out mode destabilization analysis, in particular for the dangerous fishbone mode. A new chapter on cyclotron motion in toroidal geometry has ...

  15. Advanced toroidal facility vaccuum vessel stress analyses

    International Nuclear Information System (INIS)

    The complex geometry of the Advance Toroidal Facility (ATF) vacuum vessel required special analysis techniques in investigating the structural behavior of the design. The response of a large-scale finite element model was found for transportation and operational loading. Several computer codes and systems, including the National Magnetic Fusion Energy Computer Center Cray machines, were implemented in accomplishing these analyses. The work combined complex methods that taxed the limits of both the codes and the computer systems involved. Using MSC/NASTRAN cyclic-symmetry solutions permitted using only 1/12 of the vessel geometry to mathematically analyze the entire vessel. This allowed the greater detail and accuracy demanded by the complex geometry of the vessel. Critical buckling-pressure analyses were performed with the same model. The development, results, and problems encountered in performing these analyses are described. 5 refs., 3 figs

  16. Nonideal magnetohydrodynamic instabilities and toroidal magnetic confinement

    Energy Technology Data Exchange (ETDEWEB)

    Furth, H.P.

    1985-05-01

    The marked divergence of experimentally observed plasma instability phenomena from the predictions of ideal magnetohydrodynamics led in the early 1960s to the formulations of finite-resistivity stability theory. Beginning in the 1970s, advanced plasma diagnostics have served to establish a detailed correspondence between the predictions of the finite-resistivity theory and experimental plasma behavior - particularly in the case of the resistive kink mode and the tokamak plasma. Nonlinear resistive-kink phenomena have been found to govern the transport of magnetic flux and plasma energy in the reversed-field pinch. The other predicted finite-resistivity instability modes have been more difficult to identify directly and their implications for toroidal magnetic confinement are still unresolved.

  17. Fluid interaction with spinning toroidal tanks

    Science.gov (United States)

    Fester, D. A.; Anderson, J. E.

    1977-01-01

    An experimental study was conducted to evaluate propellant behavior in spinning torroidal tanks that could be used in a retropropulsion system of an advanced outer-planet Pioneer orbiter. Information on propellant slosh and settling and on ullage orientation and stability was obtained. The effects of axial acceleration, spin rate, spin-rate change, and spacecraft wobble, both singly and in combination, were evaluated using a one-eighth scale transparent tank in one-g and low-g environments. Liquid loadings ranged from 5% to 96% full. The impact of a surface tension acquisition device was assessed by comparison with bare-tank results. The testing simulated the behavior of the fluorine/hydrazine and nitrogen textroxide/monomethylhydrazine propellants. Results are presented that indicate that no major fluid behavior problems would be encountered with any of the four propellants in the toroidal tanks of a spin-stabilized orbiter spacecraft.

  18. Technical Diagnostics of Tank Cannon Smooth Barrel Bore and Ramming Device

    Directory of Open Access Journals (Sweden)

    Jiri Balla

    2015-09-01

    Full Text Available The technical diagnostics of 125 mm tank cannon 2A46 smooth barrel and ramming devices are discussed respectively. Focuses on barrel diagnostics and suggests new procedures based on reconstructed BG20 Gun Barrel Bore Gauge System, measuring internal diameter of the barrel bore. The new system measures throughout the whole barrel bore the inner diameter not only at the beginning of barrel bore as it was usually measured before. Different nature of barrel wear was revealed between barrels firing sub-calibre and high explosive projectiles. A method for ramming device diagnostics is presented. An accurate method was proposed, determining projectile extraction force from barrel, as one of the main ramming device parameters for weapons that are used in all areas of armed forces. Results are based on experimental methods assessing the extraction forces from barrel after projectile loading. These tests were performed as a series of tests with consequent technical diagnostics according to the new Czech Defence Standards (derived from NATO standards. The results are presented as the new methodologies for diagnostics of 125 mm barrel 2A46 and ramming devices of tank T-72 for use by technical logistic units in the Czech Republic Armed Forces.

  19. Plasma Density Distribution Profile in Toroidal Discharge

    International Nuclear Information System (INIS)

    Tokamak is an electrode less toroidal plasma discharge system whichcontains and heats the plasma by using magnetic field and heating system suchas RF and neutral beams respectively. Using the system, tokamak is expectedto be a most advanced facility in fusion reactor concept. The importantparameters in tokamak are plasma current, plasma discharge voltage,temperature and density, plasma density profile and confinement time.However, the facility belonged to this center (P3TM) is very simple thatmeans a toroidal discharge without confinement magnetic filed and anadditional heating. The preceding result showed that it had been obtainedsome important parameters such as plasma current, discharge current, plasmavoltage and induced poloidal magnetic field. While plasma temperature andplasma density and its profile have not been observed. The one of somediagnostics to be used to determine this parameter is a Langmuir probe.Langmuir probe is an oldest diagnostic tool, simple and quite easy to bemade. The most advantage by using this probe is its ability to measure thecurrent locally. In this experiment, the home made Langmuir probe is atungsten wire with 0.8 mm in diameter enveloped by glass tube and inserted intorus tube. The torus is operated at 1 mbar argon gas pressure and 7.5 kVoperating voltage. The power source is a 330006 Maxwell type capacitor with15 micro farad, and charging system is a 825-100 Hipotronics model which canhold 20 kV of voltage and deliver 100 mA of current. The experiment resultshowed that the relative radial density profile has an exponential relationwith the approaching function is nrel ∝ e-0.54r, r isradial position. (author)

  20. Petascale Parallelization of the Gyrokinetic Toroidal Code

    Energy Technology Data Exchange (ETDEWEB)

    Ethier, Stephane; Adams, Mark; Carter, Jonathan; Oliker, Leonid

    2010-05-01

    The Gyrokinetic Toroidal Code (GTC) is a global, three-dimensional particle-in-cell application developed to study microturbulence in tokamak fusion devices. The global capability of GTC is unique, allowing researchers to systematically analyze important dynamics such as turbulence spreading. In this work we examine a new radial domain decomposition approach to allow scalability onto the latest generation of petascale systems. Extensive performance evaluation is conducted on three high performance computing systems: the IBM BG/P, the Cray XT4, and an Intel Xeon Cluster. Overall results show that the radial decomposition approach dramatically increases scalability, while reducing the memory footprint - allowing for fusion device simulations at an unprecedented scale. After a decade where high-end computing (HEC) was dominated by the rapid pace of improvements to processor frequencies, the performance of next-generation supercomputers is increasingly differentiated by varying interconnect designs and levels of integration. Understanding the tradeoffs of these system designs is a key step towards making effective petascale computing a reality. In this work, we examine a new parallelization scheme for the Gyrokinetic Toroidal Code (GTC) [?] micro-turbulence fusion application. Extensive scalability results and analysis are presented on three HEC systems: the IBM BlueGene/P (BG/P) at Argonne National Laboratory, the Cray XT4 at Lawrence Berkeley National Laboratory, and an Intel Xeon cluster at Lawrence Livermore National Laboratory. Overall results indicate that the new radial decomposition approach successfully attains unprecedented scalability to 131,072 BG/P cores by overcoming the memory limitations of the previous approach. The new version is well suited to utilize emerging petascale resources to access new regimes of physical phenomena.

  1. Energy metrics for driving competitiveness of countries: Energy weakness magnitude, GDP per barrel and barrels per capita

    International Nuclear Information System (INIS)

    Energy metrics is the development of a whole new theoretical framework for the conception and measurement of energy and economic system performances, energy efficiency and productivity improvements with important political economy implications consistent with the best use of all natural and economic resources. The purpose of this research is to present some vital energy indicators based on magnitude and scale of energy weakness, GDP per barrel of oil that is an indicator of energy productivity and barrels (of oil) per capita that is an indicator of energy efficiency. Energy metrics can support the monitoring of energy and economic system performances in order to design effective energy strategy and political economy interventions focused on the 'competitive advantage' increase of countries in modern economies.

  2. ATLAS's superconducting solenoid takes up position

    CERN Multimedia

    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.

  3. Superconducting microfabricated ion traps

    CERN Document Server

    Wang, Shannon X; Labaziewicz, Jaroslaw; Dauler, Eric; Berggren, Karl; Chuang, Isaac L

    2010-01-01

    We fabricate superconducting ion traps with niobium and niobium nitride and trap single 88Sr ions at cryogenic temperatures. The superconducting transition is verified and characterized by measuring the resistance and critical current using a 4-wire measurement on the trap structure, and observing change in the rf reflection. The lowest observed heating rate is 2.1(3) quanta/sec at 800 kHz at 6 K and shows no significant change across the superconducting transition, suggesting that anomalous heating is primarily caused by noise sources on the surface. This demonstration of superconducting ion traps opens up possibilities for integrating trapped ions and molecular ions with superconducting devices.

  4. Torus CLAS12-Superconducting Magnet Quench Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kashikhin, V. S. [Fermilab; Elouadhiri, L. [Jefferson Lab; Ghoshal, P. K. [Jefferson Lab; Kashy, D. [Jefferson Lab; Makarov, A. [Fermilab; Pastor, O. [Jefferson Lab; Quettier, L. [Jefferson Lab; Velev, G. [Fermilab; Wiseman, M. [Jefferson Lab

    2014-01-01

    The JLAB Torus magnet system consists of six superconducting trapezoidal racetrack-type coils assembled in a toroidal configuration. These coils are wound with SSC-36 Nb-Ti superconductor and have the peak magnetic field of 3.6 T. The first coil manufacturing based on the JLAB design began at FNAL. The large magnet system dimensions (8 m diameter and 14 MJ of stored energy) dictate the need for quench protection. Each coil is placed in an aluminum case mounted inside a cryostat and cooled by 4.6 K supercritical helium gas flowing through a copper tube attached to the coil ID. The large coil dimensions and small cryostat thickness drove the design to challenging technical solutions, suggesting that Lorentz forces due to transport currents and eddy currents during quench and various failure scenarios are analyzed. The paper covers the magnet system quench analysis using the OPERA3d Quench code.

  5. Electromagnetic, stress and thermal analysis of the Superconducting Magnet

    CERN Document Server

    Ren, Yong

    2015-01-01

    Within the framework of the National Special Project for Magnetic Confined Nuclear Fusion Energy of China, the design of a superconducting magnet project as a test facility of the Nb3Sn coil or NbTi coil for the Chinese Fusion Engineering Test Reactor (CFETR) has been carried out not only to estimate the relevant conductor performance but also to implement a background magnetic field for CFETR CS insert and toroidal field (TF) insert coils. The superconducting magnet is composed of two parts: the inner part with Nb3Sn cable-in-conduit conductor (CICC) and the outer part with NbTi CICC. Both parts are connected in series and powered by a single DC power supply. The superconducting magnet can be cooled with supercritical helium at inlet temperature of 4.5 K. The total inductance and stored energy of the superconducting magnet are about 0.278 H and 436.6 MJ at an operating current of 56 kA respectively. An active quench protection circuit was adopted to transfer the stored magnetic energy of the superconducting ...

  6. Precision electronics and measurement techniques for the superconducting joint resistance

    International Nuclear Information System (INIS)

    The Superconducting Tokamak has different superconducting magnet systems, such as The Toroidal Field (TF), Poloidal field (PF) and Center solenoid (CS) magnet system. Each magnet coil has ∼ 1-2 nΩ low DC resistance joints as per the construction criteria and mechanical constraints. The measurement of such a low resistances is critical at the operating condition of 5 K helium temperature and 10 kA DC transport current. The development of electronics and instrumentation are challenging due to the measured signal intensity, large temperature gradient, large DC as well as time varing magnetic field ∼ 3 T and tokamak harsh noisy environment. A signal-conditioning electronics with large signal gain of 125 × 103 was developed for the low-DC superconducting joint resistance measurements. The measurement techniques followed to carry out these measurements by taking into account the thermo-electric potentials, lead resistance, non ohmic contacts, device heating etc. This paper presents the electronics design, measurement precision and different measurement techniques to measure the low-DC superconducting joint resistance.The paper also identifies the role of standard instruments and results of superconducting joints resistance measurement in the laboratory scale experiment. (author)

  7. Present Status of the KSTAR Superconducting Magnet System Development

    Institute of Scientific and Technical Information of China (English)

    Keeman Kim; J. Y. Choi; H. Yonekawa; A. Chertovskikh; Y. B. Chang; J. S. Kim; C. S. Kim; D. J. Kim; N. H Song; K. P. Kim; Y. J. Song; H. K. Park; I. S. Woo; W. S. Han; D. K. Lee; Y. K. Oh; K. W. Cho; J.S.Park; G. S. Lee; H. J. Lee; T. K. Ko; S. J. Lee; K. R. Park; B. S. Lim; S. I. Lee; M. K. Kim; Y. Chu; W. H. Chung; S. H. Baek

    2004-01-01

    The mission of Korea Superconducting Tokamak Advanced Research (KSTAR) project is to develop an advanced steady-state superconducting tokamak for establishing a scientific and technological basis for an attractive fusion reactor. Because one of the KSTAR mission is to achieve a steady-state operation, the use of superconducting coils is an obvious choice for the magnet system. The KSTAR superconducting magnet system consists of 16 Toroidal Field (TF) coils and 14 Poloidal Field (PF) coils. Internally-cooled Cable-In-Conduit Conductors (CICC) are put into use in both the TF and PF coil systems. The TF coil system provides a field of 3.5 T at the plasma center and the PF coil system is able to provide a flux swing of 17 V-sec. The major achievement in KSTAR magnet-system development includes the development of CICC, the development of a full-size TF model coil, the development of a coil system for background magnetic-field generation , the construction of a large-scale superconducting magnet and CICC test facility. TF and PF coils are in the stage of the fabrication to pave the way for the scheduled completion of KSTAR completion by the end of 2006.

  8. Kinetic effect of toroidal rotation on the geodesic acoustic mode

    Energy Technology Data Exchange (ETDEWEB)

    Guo, W., E-mail: wfguo@ipp.ac.cn; Ye, L.; Zhou, D.; Xiao, X. [Institute of Plasma Physics, Chinese Academy of Science, Hefei, Anhui 230031 (China); Wang, S. [Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2015-01-15

    Kinetic effects of the toroidal rotation on the geodesic acoustic mode are theoretically investigated. It is found that when the toroidal rotation increases, the damping rate increases in the weak rotation regime due to the rotation enhancement of wave-particle interaction, and it decreases in the strong rotation regime due to the reduction of the number of resonant particles. Theoretical results are consistent with the behaviors of the geodesic acoustic mode recently observed in DIII-D and ASDEX-Upgrade. The kinetic damping effect of the rotation on the geodesic acoustic mode may shed light on the regulation of turbulence through the controlling the toroidal rotation.

  9. Toroidal dipole resonances in the relativistic random phase approximation

    CERN Document Server

    Vretenar, D; Ring, P

    2002-01-01

    The isoscalar toroidal dipole strength distributions in spherical nuclei are calculated in the framework of a fully consistent relativistic random phase approximation, based on effective mean-field Lagrangians with nonlinear meson self-interaction terms. It is suggested that the recently observed "low-lying component of the isoscalar dipole mode" might in fact correspond to the toroidal giant dipole resonance. Although predicted by several theoretical models, the existence of toroidal resonances has not yet been confirmed in experiment. In the present analysis the vortex dynamics of these states is displayed by the corresponding velocity fields.

  10. Laser-induced production of large carbon-based toroids

    International Nuclear Information System (INIS)

    We report on the production of large carbon-based toroids (CBTs) from fullerenes. The process involves two-step laser irradiation of a mixed fullerene target (76% C60, 22% C70). Transmission electron microscopy (TEM) clearly identifies toroidal-shaped structures as well as Q-shaped constructs. The typical diameters of the CBTs are ∼0.2-0.3 μm with tubular diameters of ∼50-100 nm, but toroids as wide as 0.5 μm are observed making them nanostructures on the verge of being microstructures

  11. Toroidal Spiral Strings in Higher-dimensional Spacetime

    CERN Document Server

    Igata, Takahisa

    2010-01-01

    We report on our progress in research of separability of the Nambu-Goto equation for test strings with a symmetric configuration in a shape of toroidal spiral in a five-dimensional Kerr-AdS black hole. In particular, for a Hopf loop string which is a special class of the toroidal spirals, we show the complete separation of variables occurs in two cases, Kerr background and Kerr-AdS background with equal angular momenta. We also obtain the dynamical solution for the Hopf loop around a black hole and for the general toroidal spiral in Minkowski background.

  12. Quantum field theory on toroidal topology: Algebraic structure and applications

    Energy Technology Data Exchange (ETDEWEB)

    Khanna, F.C., E-mail: khannaf@uvic.ca [Department of Physics and Astronomy, University of Victoria, Victoria, BC V8P 5C2 (Canada); TRIUMF, Vancouver, BC, V6T 2A3 (Canada); Malbouisson, A.P.C., E-mail: adolfo@cbpf.br [Centro Brasileiro de Pesquisas Físicas/MCT, 22290-180, Rio de Janeiro, RJ (Brazil); Malbouisson, J.M.C., E-mail: jmalboui@ufba.br [Instituto de Física, Universidade Federal da Bahia, 40210-340, Salvador, BA (Brazil); Santana, A.E., E-mail: asantana@unb.br [International Center for Condensed Matter Physics, Instituto de Física, Universidade de Brasília, 70910-900, Brasília, DF (Brazil)

    2014-06-01

    The development of quantum theory on a torus has a long history, and can be traced back to the 1920s, with the attempts by Nordström, Kaluza and Klein to define a fourth spatial dimension with a finite size, being curved in the form of a torus, such that Einstein and Maxwell equations would be unified. Many developments were carried out considering cosmological problems in association with particle physics, leading to methods that are useful for areas of physics, in which size effects play an important role. This interest in finite size effect systems has been increasing rapidly over the last decades, due principally to experimental improvements. In this review, the foundations of compactified quantum field theory on a torus are presented in a unified way, in order to consider applications in particle and condensed matter physics. The theory on a torus Γ{sub D}{sup d}=(S{sup 1}){sup d}×R{sup D−d} is developed from a Lie-group representation and c{sup ∗}-algebra formalisms. As a first application, the quantum field theory at finite temperature, in its real- and imaginary-time versions, is addressed by focusing on its topological structure, the torus Γ{sub 4}{sup 1}. The toroidal quantum-field theory provides the basis for a consistent approach of spontaneous symmetry breaking driven by both temperature and spatial boundaries. Then the superconductivity in films, wires and grains are analyzed, leading to some results that are comparable with experiments. The Casimir effect is studied taking the electromagnetic and Dirac fields on a torus. In this case, the method of analysis is based on a generalized Bogoliubov transformation, that separates the Green function into two parts: one is associated with the empty space–time, while the other describes the impact of compactification. This provides a natural procedure for calculating the renormalized energy–momentum tensor. Self interacting four-fermion systems, described by the Gross–Neveu and Nambu

  13. Design study of toroidal magnets for tokamak experimental power reactors. [NbTi alloys

    Energy Technology Data Exchange (ETDEWEB)

    Stekly, Z.J.J.; Lucas, E.J. (eds.)

    1976-12-01

    This report contains the results of a six-month study of superconducting toroidal field coils for a Tokamak Experimental Power Reactor to be built in the late 1980s. The designs are for 8 T and 12 T maximum magnetic field at the superconducting winding. At each field level two main concepts were generated; one in which each of the 16 coils comprising the system has an individual vacuum vessel and the other in which all the coils are contained in a single vacuum vessel. The coils have a D shape and have openings of 11.25 m x 7.5 m for the 8 T coils and 10.2 m x 6.8 m for the 12 T coils. All the designs utilize rectangular cabled conductor made from copper stabilized Niobium Titanium composite which operates at 4.2 K for the 8 T design and at 2.5 K for the 12 T design. Manufacturing procedures, processes and schedule estimates are also discussed.

  14. Fabrication of Nb3Sn cables for ITER toroidal field coils

    International Nuclear Information System (INIS)

    Cable-in-conduit conductors for ITER toroidal field (TF) coils will be operated at 68 kA and 11.8 T. The cable is composed of 1,422 strands with a diameter of 0.82 mm. There were two options for initial procurement. For option 2, the twist pitches at lower stages are longer than in option 1. Trials were performed to assess the feasibility of these options. In the trials for option 1, the nominal outer diameter of sub-cables and reduction schedule of final cables were evaluated and finalized. In the trials for option 2, problems were encountered at the third stage cabling. These problems were resolved through increasing the die size in that stage and improving the tension balance of the second-stage cables to reduce friction between the die and the cable, and also through avoiding loose twisting at both edges of the third cables. Option 2 was finally selected in 2009 based on superconducting performance enhancement of the cable. After the qualification of the fabrication procedure using fabrication of a 760-m dummy cable and a 415-m superconducting cable, mass production of the cables started in March 2010. (author)

  15. Status of European manufacture of Toroidal Field conductor and strand for JT-60SA project

    International Nuclear Information System (INIS)

    In the framework of the JT-60SA project, part of the Broader Approach (BA) agreement, EURATOM provides to Japan, the Toroidal Field (TF) magnet system, consisting of 18 superconducting coils. The procurement of the conductor for the TF coils is managed by Fusion for Energy, acting as EU representative in the BA agreement. The TF conductor procurement is split into two contracts, one dedicated to the production of Niobium Titanium (NbTi) and Cu strand and the other to TF conductor production through strand cabling and cable jacketing operations. The TF conductor is a rectangular-shaped cable-in-conduit conductor formed by 486 (0.81 mm diameter) strands (2/3 NbTi–1/3 Cu) wrapped in a stainless steel foil and embedded into a stainless steel jacket. The 18 TF coils require (including spares) 115 ‘Unit Lengths’ (UL) of such conductor, each 240 m long for a total of about 28 km. Correspondingly about 10,000 km for NbTi and 5000 km for Cu strand are produced. The Japanese company Furukawa Electric Co. (FEC) is in charge of TF strand manufacture while the Italian company Italian Consortium for Applied Superconductivity (ICAS) is in charge of cabling and jacketing of TF conductor ULs. In the paper, we provide information on the production stages presently achieved in TF strand and conductor contracts

  16. Tight aspect ratio tokamak power reactor with superconducting TF coils

    International Nuclear Information System (INIS)

    Tight aspect ratio tokamak power reactor with super-conducting toroidal field (TF) coils has been proposed. A center solenoid coil system and an inboard blanket were discarded. The key point was how to find the engineering design solution of the TF coil system with the high field and high current density. The coil system with the center post radius of less than 1 m can generate the maximum field of ∼ 20 T. This coil system causes a compact reactor concept, where the plasma major and minor radii of 3.75 m and 1.9 m, respectively and the fusion power of 1.8 GW. (author)

  17. Halo current diagnostic system of experimental advanced superconducting tokamak.

    Science.gov (United States)

    Chen, D L; Shen, B; Granetz, R S; Sun, Y; Qian, J P; Wang, Y; Xiao, B J

    2015-10-01

    The design, calibration, and installation of disruption halo current sensors for the Experimental Advanced Superconducting Tokamak are described in this article. All the sensors are Rogowski coils that surround conducting structures, and all the signals are analog integrated. Coils with two different cross-section sizes have been fabricated, and their mutual inductances are calibrated. Sensors have been installed to measure halo currents in several different parts of both the upper divertor (tungsten) and lower divertor (graphite) at several toroidal locations. Initial measurements from disruptions show that the halo current diagnostics are working well. PMID:26520954

  18. Tight aspect ratio tokamak power reactor with superconducting TF coils

    International Nuclear Information System (INIS)

    Tight aspect ratio tokamak power reactor with super-conducting toroidal field (TF) coils has been proposed. A center solenoid coil system and an inboard blanket were discarded. The key point was how to find the engineering design solution of the TF coil system with the high and high current density. The coil system with the center post radius of less than 1 m can generate the maximum field of ∼20 T. This coil system causes, a compact reactor concept, where the plasma major and minor radii o 3.75 m and 1.9 m, respectively and the fusion power of 1.8 GW. (author)

  19. The ATLAS Barrel Level-1 Muon Trigger Processor Performances

    CERN Document Server

    Bocci, V; Ciapetti, G; De Pedis, D; Di Girolamo, A; Di Mattia, A; Gennari, E; Luci, C; Nisati, A; Pasqualucci, E; Pastore, F; Petrolo, E; Spila, F; Vari,, R; Veneziano, S; Zanelli, L; Aielli, G; Cardarelli, R; Di Ciaccio, A; Di Simone, A; Di Stante, L; Salamon, A; Santonico, R; Aloisio, A; Alviggi, M G; Canale, V; Carlino, G; Conventi, F; De Asmundis, R; Della Pietra, M; Delle Volpe, D; Iengo, P; Izzo, V; Migliaccio, A; Patricelli, S; Sekhniaidze, G; Brambilla, Elena; Cataldi, G; Gorini, E; Grancagnolo, F; Perrino, R; Primavera, M; Spagnolo, S; Aprodo, V; Bartos, D; Buda, S; Constantin, S; Dogaru, M; Magureanu, C; Pectu, M; Prodan, L; Rusu, A; Uroseviteanu, C

    2005-01-01

    The ATLAS level-1 muon trigger will select events with high transverse momentum and tag them to the correct machine bunch-crossing number with high efficiency. Three stations of dedicated fast detectors provide a coarse pT measurement, with tracking capability on bending and non-bending pro jections. In the Barrel region, hits from doublets of Resistive Plate Chambers are processed by custom ASIC, the Coincidence Matrices, which performs almost all the functionalities required by the trigger algorithm and the readout. In this paper we present the performance of the level-1 trigger system studied on a cosmic test stand at CERN, concerning studies on expected trigger rates and efficiencies.

  20. Revolution from Diogenes’ barrel (2) [and] Green design dictionary

    OpenAIRE

    Kolakowski, Marcin Mateusz

    2005-01-01

    Diogenes' barrel Is low-tech timeless? How high is "high" and how low is "low"? Is low-tech the next, higher level in the development of high-tech? This article is an introduction to the world of low-tech. "High-tech seems to be a self-corroborating superlative which needs no justification. Isn't perfecting technology an obvious consequence of the development of mankind, and actually of its natural evolution? And then, isn't contradicting this thesis a dangerous heresy, a crime, or an a...

  1. Theoretical Exploration of Barrel-Shaped Drops on Cactus Spines.

    Science.gov (United States)

    Luo, Cheng

    2015-11-01

    To survive an arid environment, desert cacti are capable of harvesting water from fog by transporting condensed water drops using their spines. Cactus spines have a conical shape. In this work, on the basis of the difference of liquid pressure, a new theoretical model has been developed for a barrel-shaped liquid drop on a conical wire. This model is further simplified to interpret the effects of contact angles, conical angle, surface microgrooves, and gravity on the drop movement along a cactus spine. PMID:26473466

  2. Final states with strangeness from Crystal Barrel and Asterix

    International Nuclear Information System (INIS)

    We discuss φ production in anti pp annihilation at rest from the Asterix and Crystal Barrel experiments and compare the branching ratios to similar final states without strangeness. The ωπ0/φπ0 production ratio is unexpectedly low. In the search for new states, the φπ0 mass spectrum shows no evidence for a resonance in the 1450 MeV/c2 mass range but the K*K0π0 Dalitz plot shows interesting structure. (orig.)

  3. The Electromagentic Barrel Calorimeter for the GlueX Experiment

    OpenAIRE

    Barbi, M

    2006-01-01

    The electromagnetic barrel calorimeter is one of the main components of the planned GlueX experiment. It will consist of 48 modules made of consecutive layers of 4 m long lead sheet and fast green scintillator fibers for an overall number of approximately 3000 readout channels with silicon photomultiplier-based photo-sensors for light collection. The calorimeter is expected to achieve energy and time resolution better than 5%/sqrt(E)+2% and 200 ps, respectively. In this contribution we presen...

  4. The Electromagnetic Barrel Calorimeter for the GlueX Experiment

    International Nuclear Information System (INIS)

    The electromagnetic barrel calorimeter is one of the main components of the planned GlueX experiment. It will consist of 48 modules made of consecutive layers of 4 m long lead sheet and fast green scintillator fibers for an overall number of approximately 3000 readout channels with silicon-photomultiplier-based photo-sensors for light collection. The calorimeter is expected to achieve energy and time resolution better than 5% bigsl √(E)+ 2% and 200 ps, respectively. In this contribution we present an overview of the calorimeter design and some preliminary studies of its performance using Monte Carlo simulations and beam test measurements

  5. The Electromagentic Barrel Calorimeter for the GlueX Experiment

    CERN Document Server

    Barbi, M

    2006-01-01

    The electromagnetic barrel calorimeter is one of the main components of the planned GlueX experiment. It will consist of 48 modules made of consecutive layers of 4 m long lead sheet and fast green scintillator fibers for an overall number of approximately 3000 readout channels with silicon photomultiplier-based photo-sensors for light collection. The calorimeter is expected to achieve energy and time resolution better than 5%/sqrt(E)+2% and 200 ps, respectively. In this contribution we present an overview of the calorimeter design and some preliminary studies of its performance using Monte Carlo simulations and beam test measurements.

  6. Silicon photomultiplier characterization for the GlueX barrel calorimeter

    International Nuclear Information System (INIS)

    GlueX is a new detector being constructed at Jefferson Laboratory to study gluonic excitations and confinement via the detection of exotic meson states. The hermetic detector includes a barrel calorimeter where the photodetectors must operate in a high magnetic field exceeding 0.5 T. After extensive tests with a variety of sensors, the chosen photodetector will be a custom silicon photomultiplier (SiPM) array manufactured by Hamamatsu Corporation. This paper will focus on the characterization of the first 80 production samples of these SiPMs, including dark rate, photodetection efficiency (PDE), crosstalk, response uniformity and radiation tolerance.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-12-01

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

  8. Structure design of the Westinghouse superconducting magnet for the Large Coil Program

    International Nuclear Information System (INIS)

    In the on-going development of superconducting toroidal field coils for tokamak reactors, the Large Coil Program (LCP) managed by Union Carbide Corporation will include the design, fabrication, and testing of large superconducting coils to determine their feasibility for use in the magnetic fusion energy effort. Structural analysis of the large coil is essential to ensure adequate safety in the test coil design and confidence in the scalability of the design. This paper will discuss the action of tensile and shear loads on the various materials used in the coil. These loads are of magnetic and thermal origin

  9. Design study of the FER (fusion experimental reactor) superconducting magnet system

    International Nuclear Information System (INIS)

    The preliminary design study of the superconducting magnet system for the Fusion Experimental Reactor (FER) [1] is in progress at the Japan Atomic Energy Research Institute (JAERI). This paper describes the technical specifications and the design concepts of the 12-T toroidal field (TF) coil system, the 12-T central solenoid (CS) coil system, and the 7-T equilibrium field (EF) coil system, all of which satisfy the technical requirements of the superconducting magnet system of the FER. 8 refs., 6 figs., 4 tabs

  10. Superconductivity in aromatic hydrocarbons

    International Nuclear Information System (INIS)

    Highlights: • Aromatic superconductor is one of core research subjects in superconductivity. Superconductivity is observed in certain metal-doped aromatic hydrocarbons. Some serious problems to be solved exist for future advancement of the research. This article shows the present status of aromatic superconductors. - Abstract: ‘Aromatic hydrocarbon’ implies an organic molecule that satisfies the (4n + 2) π-electron rule and consists of benzene rings. Doping solid aromatic hydrocarbons with metals provides the superconductivity. The first discovery of such superconductivity was made for K-doped picene (Kxpicene, five benzene rings). Its superconducting transition temperatures (Tc’s) were 7 and 18 K. Recently, we found a new superconducting Kxpicene phase with a Tc as high as 14 K, so we now know that Kxpicene possesses multiple superconducting phases. Besides Kxpicene, we discovered new superconductors such as Rbxpicene and Caxpicene. A most serious problem is that the shielding fraction is ⩽15% for Kxpicene and Rbxpicene, and it is often ∼1% for other superconductors. Such low shielding fractions have made it difficult to determine the crystal structures of superconducting phases. Nevertheless, many research groups have expended a great deal of effort to make high quality hydrocarbon superconductors in the five years since the discovery of hydrocarbon superconductivity. At the present stage, superconductivity is observed in certain metal-doped aromatic hydrocarbons (picene, phenanthrene and dibenzopentacene), but the shielding fraction remains stubbornly low. The highest priority research area is to prepare aromatic superconductors with a high superconducting volume-fraction. Despite these difficulties, aromatic superconductivity is still a core research target and presents interesting and potentially breakthrough challenges, such as the positive pressure dependence of Tc that is clearly observed in some phases of aromatic hydrocarbon superconductors

  11. Influence of toroidal rotation on resistive tearing modes in tokamaks

    International Nuclear Information System (INIS)

    Influence of toroidal equilibrium plasma rotation on m/n = 2/1 resistive tearing modes is studied numerically using a 3D toroidal MHD code (CLT). It is found that the toroidal rotation with or without shear can suppress the tearing instability and the Coriolis effect in the toroidal geometry plays a dominant role on the rotation induced stabilization. For a high viscosity plasma (τR/τV ≫ 1, where τR and τV represent resistive and viscous diffusion time, respectively), the effect of the rotation shear combined with the viscosity appears to be stabilizing. For a low viscosity plasmas (τR/τV ≪ 1), the rotation shear shows a destabilizing effect when the rotation is large

  12. Recent advances in the stability theory of toroidal plasmas

    International Nuclear Information System (INIS)

    Many of the most persistent instabilities of a magnetically confined plasma have short wavelength perpendicular to the magnetic field but long wavelength parallel to it. Such instabilities are difficult to treat in a toroidal system because the simple eikonal representation of short wavelength oscillations. X(r) = Y(r) esup(iS(r)/γ) with γ << 1 proves to be incompatible with the other requirements of toroidal periodicity and long parallel wavelength (which would require BETA.ΔS = O). A new method of representing perturbations in a torus will be outlined. By using this, the two-dimensional stability problem posed by an axisymmetric toroidal equilibrium can be reduced to that of solving a one-dimensional eigenvalue equation. This technique essentially completes the linear stability theory of magnetohydrodynamic modes in a toroidal plasma, and is also applicable to the investigation of micro-instabilities that are described by the Vlasov-Maxwell equations. (author)

  13. Influence of toroidal rotation on resistive tearing modes in tokamaks

    Science.gov (United States)

    Wang, S.; Ma, Z. W.

    2015-12-01

    Influence of toroidal equilibrium plasma rotation on m/n = 2/1 resistive tearing modes is studied numerically using a 3D toroidal MHD code (CLT). It is found that the toroidal rotation with or without shear can suppress the tearing instability and the Coriolis effect in the toroidal geometry plays a dominant role on the rotation induced stabilization. For a high viscosity plasma (τR/τV ≫ 1, where τR and τV represent resistive and viscous diffusion time, respectively), the effect of the rotation shear combined with the viscosity appears to be stabilizing. For a low viscosity plasmas (τR/τV ≪ 1), the rotation shear shows a destabilizing effect when the rotation is large.

  14. Influence of toroidal rotation on resistive tearing modes in tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Wang, S.; Ma, Z. W., E-mail: zwma@zju.edu.cn [Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310027 (China)

    2015-12-15

    Influence of toroidal equilibrium plasma rotation on m/n = 2/1 resistive tearing modes is studied numerically using a 3D toroidal MHD code (CLT). It is found that the toroidal rotation with or without shear can suppress the tearing instability and the Coriolis effect in the toroidal geometry plays a dominant role on the rotation induced stabilization. For a high viscosity plasma (τ{sub R}/τ{sub V} ≫ 1, where τ{sub R} and τ{sub V} represent resistive and viscous diffusion time, respectively), the effect of the rotation shear combined with the viscosity appears to be stabilizing. For a low viscosity plasmas (τ{sub R}/τ{sub V} ≪ 1), the rotation shear shows a destabilizing effect when the rotation is large.

  15. Effect of toroidicity during lower hybrid mode conversion

    International Nuclear Information System (INIS)

    The effect of toroidicity during lower hybrid mode conversion is examined by treating the wave propagation in an inhomogeneous medium as an eigenvalue problem for ω2(m,n),m,n poloidal and toroidal wave numbers. Since the frequency regime near ω2 = ω/sub LH/2 is an accumulation point for the eigenvalue spectrum, the degenerate perturbation technique must be applied. The toroidal eigenmodes are constructed by a zeroth order superposition of monochromatic solutions with different poloidal dependence m, thus they generically exhibit a wide spectrum in k/sub parallel/ for given fixed ω2 even for small inverse aspect ratio epsilon. In case that the average is in the neighborhood of k/sub min/, the minimum wave number for accessibility of the mode conversion regime, it is expected that excitation of toroidal modes rather than geometric optics will determine the wave coupling to the plasma

  16. Turbulent and neoclassical toroidal momentum transport in tokamak plasmas

    International Nuclear Information System (INIS)

    The goal of magnetic confinement devices such as tokamaks is to produce energy from nuclear fusion reactions in plasmas at low densities and high temperatures. Experimentally, toroidal flows have been found to significantly improve the energy confinement, and therefore the performance of the machine. As extrinsic momentum sources will be limited in future fusion devices such as ITER, an understanding of the physics of toroidal momentum transport and the generation of intrinsic toroidal rotation in tokamaks would be an important step in order to predict the rotation profile in experiments. Among the mechanisms expected to contribute to the generation of toroidal rotation is the transport of momentum by electrostatic turbulence, which governs heat transport in tokamaks. Due to the low collisionality of the plasma, kinetic modeling is mandatory for the study of tokamak turbulence. In principle, this implies the modeling of a six-dimensional distribution function representing the density of particles in position and velocity phase-space, which can be reduced to five dimensions when considering only frequencies below the particle cyclotron frequency. This approximation, relevant for the study of turbulence in tokamaks, leads to the so-called gyrokinetic model and brings the computational cost of the model within the presently available numerical resources. In this work, we study the transport of toroidal momentum in tokamaks in the framework of the gyrokinetic model. First, we show that this reduced model is indeed capable of accurately modeling momentum transport by deriving a local conservation equation of toroidal momentum, and verifying it numerically with the gyrokinetic code GYSELA. Secondly, we show how electrostatic turbulence can break the axisymmetry and generate toroidal rotation, while a strong link between turbulent heat and momentum transport is identified, as both exhibit the same large-scale avalanche-like events. The dynamics of turbulent transport are

  17. Low-aspect-ratio toroidal equilibria of electron clouds

    International Nuclear Information System (INIS)

    Toroidal electron clouds with a low aspect ratio (as small as 1.3) and lasting for thousands of poloidal rotation periods have been formed in the laboratory. Characteristic toroidal effects like a large inward shift of the minor axis of equipotential contours, elliptical and triangular deformations, etc., have been observed experimentally for the first time. The results of new analytic and numerical investigations of low-aspect-ratio electron cloud equilibria, which reproduce many of the observed features, are also presented

  18. Effective toroidal curvature and error field on NBT

    International Nuclear Information System (INIS)

    The effective toroidal curvature and the poloidal drift velocity for transit electrons with v sub(parallel)/v = 1 are measured for NBT-I device by use of an electron beam probing. The axis of the drift surfaces shifts inward by 12 cm due to the toroidal effect. The error field averaged along the torus is found to be spatially varying and is 1.1 x 10-3 at the minor axis. (author)

  19. Numerical solution of quasilinear kinetic diffusion equations in toroidal plasmas

    OpenAIRE

    Höök, Lars Josef

    2013-01-01

    One of the main challenges for the realization of a working fusion power plant is an increased detailed understanding of kinetic phenomena in toroidal plasmas. The tokamak is a toroidal, magnetically confined plasma device and is currently the main line towards a power plant. The spatial and temporal scales in a tokamak plasma are extreme and the only tractable path for quantitative studies is to rely on computer simulations. Present day simulation codes can resolve only some of these scales....

  20. Efficient magnetic fields for supporting toroidal plasmas

    Science.gov (United States)

    Landreman, Matt; Boozer, Allen H.

    2016-03-01

    The magnetic field that supports tokamak and stellarator plasmas must be produced by coils well separated from the plasma. However, the larger the separation, the more difficult it is to produce a given magnetic field in the plasma region, so plasma configurations should be chosen that can be supported as efficiently as possible by distant coils. The efficiency of an externally generated magnetic field is a measure of the field's shaping component magnitude at the plasma compared to the magnitude near the coils; the efficiency of a plasma equilibrium can be measured using the efficiency of the required external shaping field. Counterintuitively, plasma shapes with low curvature and spectral width may have low efficiency, whereas plasma shapes with sharp edges may have high efficiency. Two precise measures of magnetic field efficiency, which correctly identify such differences in difficulty, will be examined. These measures, which can be expressed as matrices, relate the externally produced normal magnetic field on the plasma surface to the either the normal field or current on a distant control surface. A singular value decomposition (SVD) of either matrix yields an efficiency ordered basis for the magnetic field distributions. Calculations are carried out for both tokamak and stellarator cases. For axisymmetric surfaces with circular cross-section, the SVD is calculated analytically, and the range of poloidal and toroidal mode numbers that can be controlled to a given desired level is determined. If formulated properly, these efficiency measures are independent of the coordinates used to parameterize the surfaces.

  1. Toroidal nanotraps for cold polar molecules

    Science.gov (United States)

    Salhi, Marouane; Passian, Ali; Siopsis, George

    2015-09-01

    Electronic excitations in metallic nanoparticles in the optical regime that have been of great importance in surface-enhanced spectroscopy and emerging applications of molecular plasmonics, due to control and confinement of electromagnetic energy, may also be of potential to control the motion of nanoparticles and molecules. Here, we propose a concept for trapping polarizable particles and molecules using toroidal metallic nanoparticles. Specifically, gold nanorings are investigated for their scattering properties and field distribution to computationally show that the response of these optically resonant particles to incident photons permit the formation of a nanoscale trap when proper aspect ratio, photon wavelength, and polarization are considered. However, interestingly the resonant plasmonic response of the nanoring is shown to be detrimental to the trap formation. The results are in good agreement with analytic calculations in the quasistatic limit within the first-order perturbation of the scalar electric potential. The possibility of extending the single nanoring trapping properties to two-dimensional arrays of nanorings is suggested by obtaining the field distribution of nanoring dimers and trimers.

  2. Experimental study of high beta toroidal plasmas

    International Nuclear Information System (INIS)

    Experiments on the Wisconsin Levitated Toroidal Octupole have produced a wide range of stable high β plasmas with β significantly above single fluid MHD theory predictions. A stable β approx. 8% plasma, twice the fluid limit, is obtained with 5 rho/sub i/ approx. L/sub n/ and tau/sub β/ approx. = 6000 tau/sub Alfven/ = 600 μsec. The enhanced stability is explained with a kinetic treatment that includes the effect of finite ion gyroradius which couples the ballooning mode to an ion drift wave. In a more collisional, large gyroradius (2 rho/sub i/ approx. L/sub n/) regime, a stable β approx. 35% plasma is obtained with a decay time of 1000 Alfven times. Measurement of the equilibrium magnetic field in this regime indicates that the diamagnetic current density is five times smaller than predicted by ideal MHD, probably due to ion gyroviscosity. Particle transport is anomalous and ranges from agreement with the classical diffusion rate at the highest beta, lowest field plasma (B/sub P/ = 200 G), to thirteen times the classical rate in a β=11%, high field plasma (B/sub P/ = 860 G) where the level of enhancement increase with magnetic field. Fluctuations in density, electrostatic potential, and magnetic field have been studied in plasmas with β from 0.1% to 40%

  3. Sawtooth Instability in the Compact Toroidal Hybrid

    Science.gov (United States)

    Herfindal, J. L.; Maurer, D. A.; Hartwell, G. J.; Ennis, D. A.; Knowlton, S. F.

    2015-11-01

    Sawtooth instabilities have been observed in the Compact Toroidal Hybrid (CTH), a current-carrying stellarator/tokamak hybrid device. The sawtooth instability is driven by ohmic heating of the core plasma until the safety factor drops below unity resulting in the growth of an m = 1 kink-tearing mode. Experiments varying the vacuum rotational transform from 0.02 to 0.13 are being conducted to study sawtooth property dependance on vacuum flux surface structure. The frequency of the sawtooth oscillations increase from 2 kHz to 2.8 kHz solely due the decrease in rise time of the oscillation, the crash time is unchanged. CTH has three two-color SXR cameras, a three-channel 1mm interferometer, and a new bolometer system capable of detecting the signatures of sawtooth instabilities. The new bolometer system consists of two cameras, each containing a pair of diode arrays viewing the plasma directly or through a beryllium filter. Electron temperature measurements are found with the two-color SXR cameras through a ratio of the SXR intensities. Impurity radiation can drastically affect the electron temperature measurement, therefore new filters consisting of aluminum and carbon were selected to avoid problematic line radiation while maximizing the signal for a 100 eV plasma. This work is supported by U.S. Department of Energy Grant No. DE-FG02-00ER54610.

  4. Ballooning mode spectrum in general toroidal systems

    Energy Technology Data Exchange (ETDEWEB)

    Dewar, R.L.; Glasser, A.H.

    1982-04-01

    A WKB formalism for constructing normal modes of short-wavelength ideal hydromagnetic, pressure-driven instabilities (ballooning modes) in general toroidal magnetic containment devices with sheared magnetic fields is developed. No incompressibility approximation is made. A dispersion relation is obtained from the eigenvalues of a fourth order system of ordinary differential equations to be solved by integrating along a line of force. Higher order calculations are performed to find the amplitude equation and the phase change at a caustic. These conform to typical WKB results. In axisymmetric systems, the ray equations are integrable, and semiclassical quantization leads to a growth rate spectrum consisting of an infinity of discrete eigenvalues, bounded above by an accumulation point. However, each eigenvalue is infinitely degenerate. In the nonaxisymmetric case, the rays are unbounded in a four dimensional phase space, and semiclassical quantization breaks down, leading to broadening of the discrete eigenvalues and accumulation point of the axisymmetric case into continuum bands. Analysis of a model problem indicates that the broadening of the discrete eigenvalues is numerically very small, the dominant effect being broadening of the accumulation point.

  5. Tearing Mode Stability of Evolving Toroidal Equilibria

    Science.gov (United States)

    Pletzer, A.; McCune, D.; Manickam, J.; Jardin, S. C.

    2000-10-01

    There are a number of toroidal equilibrium (such as JSOLVER, ESC, EFIT, and VMEC) and transport codes (such as TRANSP, BALDUR, and TSC) in our community that utilize differing equilibrium representations. There are also many heating and current drive (LSC and TORRAY), and stability (PEST1-3, GATO, NOVA, MARS, DCON, M3D) codes that require this equilibrium information. In an effort to provide seamless compatibility between the codes that produce and need these equilibria, we have developed two Fortran 90 modules, MEQ and XPLASMA, that serve as common interfaces between these two classes of codes. XPLASMA provides a common equilibrium representation for the heating and current drive applications while MEQ provides common equilibrium and associated metric information needed by MHD stability codes. We illustrate the utility of this approach by presenting results of PEST-3 tearing stability calculations of an NSTX discharge performed on profiles provided by the TRANSP code. Using the MEQ module, the TRANSP equilibrium data are stored in a Fortran 90 derived type and passed to PEST3 as a subroutine argument. All calculations are performed on the fly, as the profiles evolve.

  6. Pseudo-Anosov flows in toroidal manifolds

    CERN Document Server

    Barbot, Thierry

    2010-01-01

    We first prove rigidity results for pseudo-Anosov flows in prototypes of toroidal 3-manifolds: we show that a pseudo-Anosov in a Seifert fibered manifold is up to finite covers topologically conjugate to a geodesic flow. We also show that a pseudo-Anosov flow in a solv manifold is topologically conjugate to a suspension Anosov flow. Then we analyse immersed and embedded incompressible tori in optimal position with respect to a pseudo-Anosov flow. We also study the interaction of a pseudo-Anosov flow with possible Seifert fibered pieces in the torus decomposition: if the fiber is associated to a periodic orbit of the flow, we produce a standard form for the flow in the piece using Birkhoff annuli. Finally we introduce several new classes of examples, some of which are generalized pseudo-Anosov flows which have one prong singularities. The examples show that the results above in Seifert fibered and solvable manifolds do not apply to one prong pseudo-Anosov flows. In addition we also construct a large new class ...

  7. ''Turbulent Equipartition'' Theory of Toroidal Momentum Pinch

    International Nuclear Information System (INIS)

    The mode-independent part of magnetic curvature driven turbulent convective (TuroCo) pinch of the angular momentum density (Hahm et al., Phys. Plasmas 14,072302 (2007)) which was originally derived from the gyrokinetic equation, can be interpreted in terms of the turbulent equipartition (TEP) theory. It is shown that the previous results can be obtained from the local conservation of 'magnetically weighted angular momentum density', nmi U#parallel# R/B2, and its homogenization due to turbulent flows. It is also demonstrated that the magnetic curvature modification of the parallel acceleration in the nonlinear gyrokinetic equation in the laboratory frame, which was shown to be responsible for the TEP part of the TurCo pinch of angular momentum density in the previous work, is closely related to the Coriolis drift coupling to the perturbed electric field. In addition, the origin of the diffusive flux in the rotating frame is highlighted. Finally, it is illustrated that there should be a difference in scalings between the momentum pinch originated from inherently toroidal effects and that coming from other mechanisms which exist in a simpler geometry.

  8. Compact toroid injection into C-2U

    Science.gov (United States)

    Roche, Thomas; Gota, H.; Garate, E.; Asai, T.; Matsumoto, T.; Sekiguchi, J.; Putvinski, S.; Allfrey, I.; Beall, M.; Cordero, M.; Granstedt, E.; Kinley, J.; Morehouse, M.; Sheftman, D.; Valentine, T.; Waggoner, W.; the TAE Team

    2015-11-01

    Sustainment of an advanced neutral beam-driven FRC for a period in excess of 5 ms is the primary goal of the C-2U machine at Tri Alpha Energy. In addition, a criteria for long-term global sustainment of any magnetically confined fusion reactor is particle refueling. To this end, a magnetized coaxial plasma-gun has been developed. Compact toroids (CT) are to be injected perpendicular to the axial magnetic field of C-2U. To simulate this environment, an experimental test-stand has been constructed. A transverse magnetic field of B ~ 1 kG is established (comparable to the C-2U axial field) and CTs are fired across it. As a minimal requirement, the CT must have energy density greater than that of the magnetic field it is to penetrate, i.e., 1/2 ρv2 >=B2 / 2μ0 . This criteria is easily met and indeed the CTs traverse the test-stand field. A preliminary experiment on C-2U shows the CT also capable of penetrating into FRC plasmas and refueling is observed resulting in a 20 - 30% increase in total particle number per single-pulsed CT injection. Results from test-stand and C-2U experiments will be presented.

  9. Turbulent Equipartition Theory of Toroidal Momentum Pinch

    Energy Technology Data Exchange (ETDEWEB)

    T.S. Hahm, P.H. Diamond, O.D. Gurcan, and G. Rewaldt

    2008-01-31

    The mode-independet part of magnetic curvature driven turbulent convective (TuroCo) pinch of the angular momentum density [Hahm et al., Phys. Plasmas 14,072302 (2007)] which was originally derived from the gyrokinetic equation, can be interpreted in terms of the turbulent equipartition (TEP) theory. It is shown that the previous results can be obtained from the local conservation of "magnetically weighted angular momentum density," nmi U|| R/B2, and its homogenization due to turbulent flows. It is also demonstrated that the magnetic curvature modification of the parallel acceleration in the nonlinear gyrokinetic equation in the laboratory frame, which was shown to be responsible for the TEP part of the TurCo pinch of angular momentum density in the previous work, is closely related to the Coriolis drift coupling to the perturbed electric field. In addition, the origin of the diffusive flux in the rotating frame is highlighted. Finally, it is illustratd that there should be a difference in scalings between the momentum pinch originated from inherently toroidal effects and that coming from other mechanisms which exist in a simpler geometry.

  10. Confinement and heating of high beta plasma with emphasis on compact toroids. Compact toroid research

    International Nuclear Information System (INIS)

    Two older projects associated with very high energy density plasmas, specifically the High Density Field Reversed Configuration and the Liner Plasma Compression Experiment, have been completed. Attention has been turned to compact toroid experiments of more conventional density, and three experiments have been initiated. These include the Coaxial Slow Source Experiment, the Variable Length FRC Experiment, and Variable Angle CthetaP Experiment. In each case, the project was begun in order to provide basic plasma physics information on specific unresolved issues of progammatic importance to the national CT Program

  11. First physics pulses in the Barrel Electromagnetic Calorimeter with cosmics

    CERN Multimedia

    Laurent Serin

    2006-01-01

    The electromagnetic barrel calorimeter has been installed in its final position in October 2005. Since then, the calorimeter is being equipped with front-end electronics. Starting in April 2006, electronics calibration runs are taken a few times per week to debug the electronics and to study the performance in the pit (stability, noise). Today, 10 out of the 32 Front End crates are being read out, amounting to about 35000 channels. cool down, few little typos --> After a 6-week cool down, the barrel cryostat was filled with Liquid Argon in May. The presence of a few shorts (~1MΩ) at the edges of the modules was indicating the possibility of conducting dust having entered into the calorimeter with the flowing liquid. In order to try to improve this situation, the calorimeter was emptied and filled again, but this time by condensating the argon instead of flowing it in liquid phase. The new High Voltage tests are not showing any significant improvement but the situation is statisfactory for ATLAS runn...

  12. Performance of a Rain Barrel Sharing Network under Climate Change

    Directory of Open Access Journals (Sweden)

    Seong Jin Noh

    2015-07-01

    Full Text Available Rain barrels can be technically shared through social practices or mutual agreement between individual households. This study proposes the evaluation system for a rain barrel sharing network (RBSN considering three performance criteria of reliability, resiliency, and vulnerability, under plausible climate change scenarios. First, this study shows how the system can be improved in terms of the performance criteria using historical daily rainfall data based on the storage-reliability-yield relationship. This study then examined how the benefits from RBSN are affected by climate change after 100 years. Three climate change scenarios (A1B, A2 and B2 and three global circulation models were used for this purpose. The results showed that the reliability and vulnerability are improved due to sharing and their improvements become larger under climate change conditions. In contrast, the resiliency reduces slightly due to sharing and its reduction is attenuated under climate change conditions. In particular, vulnerability will be reduced significantly under climate change. These results suggest that the sharing of various water resources systems can be an effective climate change adaptation strategy that reduces vulnerability and increases the reliability of the system.

  13. Toroidal Momentum Pinch Velocity due to the Coriolis Drift Effect on Small Scale Instabilities in a Toroidal Plasma

    International Nuclear Information System (INIS)

    In this Letter, the influence of the ''Coriolis drift'' on small scale instabilities in toroidal plasmas is shown to generate a toroidal momentum pinch velocity. Such a pinch results because the Coriolis drift generates a coupling between the density and temperature perturbations on the one hand and the perturbed parallel flow velocity on the other. A simple fluid model is used to highlight the physics mechanism and gyro-kinetic calculations are performed to accurately assess the magnitude of the pinch. The derived pinch velocity leads to a radial gradient of the toroidal velocity profile even in the absence of a torque on the plasma and is predicted to generate a peaking of the toroidal velocity profile similar to the peaking of the density profile. Finally, the pinch also affects the interpretation of current experiments

  14. Principles of Superconductivity

    OpenAIRE

    Mourachkine, A.

    2004-01-01

    The purpose of this chapter is to discuss the main principles of superconductivity as a phenomenon, valid for every superconductor independently of its characteristic properties and material. The underlying mechanisms of superconductivity can be different for various materials, but certain principles must be satisfied. The chapter introduces four principles of superconductivity. (The chapter is slightly nodified from the original one in order to be self-contained.)

  15. Heavy Fermion Superconductivity

    OpenAIRE

    Heffner, Robert H.; Norman, Michael R.

    1995-01-01

    A brief review is given on the current state of experimental and theoretical work in the field of heavy fermion superconductivity. Particular emphasis is placed on those experiments which demonstrate the presence of an unconventional order parameter, as well as the intricate interplay of magnetism and superconductivity in these metals. On the theoretical front, current phenomenological models of the superconductivity are reviewed along with potential pairing mechanisms.

  16. Frontiers in Superconducting Materials

    CERN Document Server

    Narlikar, Anant V

    2005-01-01

    Frontiers in Superconducting Materials gives a state-of-the-art report of the most important topics of the current research in superconductive materials and related phenomena. It comprises 30 chapters written by renowned international experts in the field. It is of central interest to researchers and specialists in Physics and Materials Science, both in academic and industrial research, as well as advanced students. It also addresses electronic and electrical engineers. Even non-specialists interested in superconductivity might find some useful answers.

  17. Fundamentals of Superconducting Nanoelectronics

    CERN Document Server

    Sidorenko, Anatolie

    2011-01-01

    This book demonstrates how the new phenomena in superconductivity on the nanometer scale (FFLO state, triplet superconductivity, Crossed Andreev Reflection, synchronized generation etc.) serve as the basis for the invention and development of novel nanoelectronic devices and systems. It demonstrates how rather complex ideas and theoretical models, like odd-pairing, non-uniform superconducting state, pi-shift etc., adequately describe the processes in real superconducting nanostructues and novel devices based on them. The book is useful for a broad audience of readers, researchers, engineers, P

  18. Superconductivity and its application

    International Nuclear Information System (INIS)

    This paper, after a short introduction to superconductivity and to multifilamentary superconducting composites is aiming to review the state of the art and the future perspective of some of the applications of the superconducting materials. The main interest is focussed to large scale applications like, for istance, magnets for accelerators or fusion reactors, superconducting system for NMR thomography, etc. A short paragraph is dedicated to applications for high sensitivity instrumentation. The paper is then concluded by some considerations about the potentialities of the newly discovered high critical temperature materials

  19. Superconducting wind turbine generators

    DEFF Research Database (Denmark)

    Abrahamsen, Asger Bech; Mijatovic, Nenad; Seiler, Eugen;

    2010-01-01

    We have examined the potential of 10 MW superconducting direct drive generators to enter the European offshore wind power market and estimated that the production of about 1200 superconducting turbines until 2030 would correspond to 10% of the EU offshore market. The expected properties of future...... main challenge of the superconducting direct drive technology is to prove that the reliability is superior to the alternative drive trains based on gearboxes or permanent magnets. A strategy of successive testing of superconducting direct drive trains in real wind turbines of 10 kW, 100 kW, 1 MW and 10...

  20. An analysis of increasing the size of the strategic petroleum reserve to one billion barrels

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    The Department of Energy's Office of Energy Emergency Policy and Evaluation requested that the Energy Information Administration complete an analysis of the proposed expansion in the Strategic Petroleum Reserve (SPR) from its currently planned size of 750 million barrels to 1000 million barrels. Because the SPR contains only 580 million barrels at this point in time, the benefits and costs of increasing the SPR from 600 to 750 million barrels were also estimated. This report documents the assumptions, methodology, and results of the analysis. 17 figs., 15 tabs.

  1. Installation of CMS EB (ECAL Barrel) Supermodules 5 and 13 inside HB+ (HCAL Barrel) on 26/27 April 2006

    CERN Multimedia

    Ken Bell, RAL

    2006-01-01

    The first two barrel "supermodules" of the CMS Electromagnetic Calorimeter (ECAL) have been inserted into the barrel hadron calorimeter (HCAL) in the CMS experimental hall (called SX5) in Cessy in preparation for the forthcoming magnet test and cosmic challenge (MTCC). Each of the two supermodules contains 1700 lead tungstate crystals in glass-fibre alveolar support structures, with associated avalanche photodiodes (APDs, for scintillation light detection), electronics and cooling system. See also the document CMS-PHO-OREACH-2006-019. The first two pictures show the two supermodules in their final position. Fig. 3: the "enfourneur" in position on the HB Cradle. Fig. 4: supermodule n. 5 and extension rails being lifted to the enforneur. Figs. 5-6: supermodule approaching the enforneur. Fig. 7: rotating the Enfourneur to the correct phi direction Figs. 8-9: aligning the extension rails with the rails inside HB and view from inside HB, once the rails are aligned. Figs. 10-12: insertion of supermodule n. 5. Fig. ...

  2. A radiation-resistant epoxy resin system for toroidal field and other superconducting coil fabrication

    International Nuclear Information System (INIS)

    A liquid-epoxy resin system with high resistance to 4-K reactor radiation (neutron plus gamma) has been developed that meets all ITER and BPX requirements: pot life longer than 12 h at ambient temperatures; viscosity less than 1000 cP over its entire pot life; cure below 150 degrees C; low shrinkage; no volatiles upon curing; excellent penetration; and good wetting of fibers, stainless steels, and nickel-based steels. The strength of the epoxy resin system, CTD-101, was tested with and without S-2 Glass fiber reinforcement at 295, 76 and 4 K. Specimens were then irradiated at two dose levels (2.9 x 107 and 1.6 x 108 Gy) at temperatures below 6 K. Virtually no deterioration in interlaminar shear strength at 76 K was observed after the lower dose level, which is the end-of-life dose level for ITER. After the higher dose level, the material had degraded, but its strength was still well above the BPX requirement (14 MPa in shear) at the end-of-life dose level of 1 x 108 Gy

  3. Simulation of chain of quenches on toroidal HTS-SMES taking account of thermal and electromagnetic characteristics

    Science.gov (United States)

    Oga, Y.; Noguchi, S.; Igarashi, H.

    When a temperature rise occurs at a local area inside a coil of toroidal HTS-SMES by any reason, a temperature hotspot which results in a thermal runaway appears at the local area. Subsequently, after appearing the local normal zone in the HTS coil, the transport current of the HTS coil decrease since the resistance of HTS coil appears and the current partially flows into a parallel-connecting shunt resistance. However, if the transport current of the normal-transitioned HTS coil is hardly changed, the temperature on the hotspot would rise more and then the normal zone would spread rapidly. It may cause a serious accident due to high stored energy. Therefore, using the numerical simulation, we have investigated the behaviors of the coil current, the critical current, and the temperature in the superconducting element coils of HTS-SMES. Consequently, the temperature of the superconducting element coils rises up extremely when a large heat is generated at a certain area of one of them by any reason. Moreover, there is a possibility that the shunt resister hardly functions for protection since the coil is burned out due to high inductances and low resistance of the superconducting element coil.

  4. Academic training: Applied superconductivity

    CERN Multimedia

    2007-01-01

    LECTURE SERIES 17, 18, 19 January from 11.00 to 12.00 hrs Council Room, Bldg 503 Applied Superconductivity : Theory, superconducting Materials and applications E. PALMIERI/INFN, Padova, Italy When hearing about persistent currents recirculating for several years in a superconducting loop without any appreciable decay, one realizes that we are dealing with a phenomenon which in nature is the closest known to the perpetual motion. Zero resistivity and perfect diamagnetism in Mercury at 4.2 K, the breakthrough during 75 years of several hundreds of superconducting materials, the revolution of the "liquid Nitrogen superconductivity"; the discovery of still a binary compound becoming superconducting at 40 K and the subsequent re-exploration of the already known superconducting materials: Nature discloses drop by drop its intimate secrets and nobody can exclude that the last final surprise must still come. After an overview of phenomenology and basic theory of superconductivity, the lectures for this a...

  5. High temperature superconductivity

    International Nuclear Information System (INIS)

    This book contains the proceedings of a conference on high temperature superconductivity. The papers presented include: Microstructural considerations in polycrystalline YBa2Cu3O7 and The role of the metallic orbital and of crest and trough superconduction in high temperature superconductors

  6. High temperature superconductivity

    International Nuclear Information System (INIS)

    This book covers the proceedings of the 3rd National Meeting on High Temperature Superconductivity Topics includes: Crystal growth of superconductors; thermodynamic stability of superconducting materials; spectroscopy of High Tc Superconductors; synchrotron radiation investigation of superconductors; density state determination; measurements of current density; preparation and characterization of superconductors

  7. Non-Abelian Superconductivity

    OpenAIRE

    Cho, Y. M.

    2001-01-01

    We establish a non-Abelian superconductivity and a non-Abelian Meissner effect by constructing an effective field theory of superconductivity in which a genuine SU(2) gauge symmetry governs the dynamics. We show that the magnetic flux is quantized in the unit of $4\\pi/g$, not $2\\pi/g$, in the non-Abelian superconductor.

  8. Large superconducting magnets

    CERN Document Server

    Pérot, J

    1981-01-01

    Discusses the use of large superconducting magnets in the areas of particle physics, thermonuclear fusion, and magnetohydrodynamics. In addition to considering the physics of the superconducting state, the article considers machines such as BEBC (Big European Bubble Chamber) at CERN, the LINAC at SLAC and possible Tokamak applications. The future application of superconductors to high speed trains is discussed. (0 refs).

  9. Superconducting RF cavities

    CERN Document Server

    Bernard, Philippe

    1999-01-01

    It was 20 years ago when the research and development programme for LEP superconducting cavities was initiated. It lasted about 10 years. Today, my aim is not to tell you in great detail about the many innovations made thanks to our research, but I would like to point out some milestones in the development of superconducting cavities where Emilio's influence was particularly important.

  10. Superconducting cavities for LEP

    CERN Multimedia

    1983-01-01

    Above: a 350 MHz superconducting accelerating cavity in niobium of the type envisaged for accelerating electrons and positrons in later phases of LEP. Below: a small 1 GHz cavity used for investigating the surface problems of superconducting niobium. Albert Insomby stays on the right. See Annual Report 1983 p. 51.

  11. Fast granular superconducting bolometer

    International Nuclear Information System (INIS)

    A granular superconducting thin film bolometer made by anodizing a thin film of such materials as niobium nitride to form a thin granular film separated by and covered with the anodized oxide. The bolometer is cooled to its superconducting state and electrically connected to a biasing and detecting network. Its temporal response is better than 1 ns

  12. Superconducting photonic crystals

    OpenAIRE

    Berman, Oleg L.; Lozovik, Yurii E.; Eiderman, Sergey L.; Coalson, Rob D.

    2006-01-01

    The band structure of a novel type of photonic crystal with superconducting constituent elements is calculated numerically via a plane wave expansion. The density of states and the dependence of the width of the photonic gap on the filling factor is analyzed for a two-dimensional photonic crystal consisting of an infinite array of parallel superconducting cylinders.

  13. Performance of the ATLAS electromagnetic calorimeter barrel module 0

    International Nuclear Information System (INIS)

    The construction and performance of the barrel pre-series module 0 of the future ATLAS electromagnetic calorimeter at the LHC is described. The signal reconstruction and performance of ATLAS-like electronics has been studied. The signal to noise ratio for muons has been found to be 7.11±0.07. An energy resolution of better than 9.5% GeV1/2/√E (sampling term) has been obtained with electron beams of up to 245 GeV. The uniformity of the response to electrons in an area of ΔηxΔphi=1.2x0.075 has been measured to be better than 0.8%

  14. Functional diversity of supragranular GABAergic neurons in the barrel cortex

    Directory of Open Access Journals (Sweden)

    Luc J Gentet

    2012-08-01

    However, recent technological advances in microscopy and mouse genetics have fostered a renewed interest in neocortical interneurons by putting them within “visible” reach of experimenters. The anatomically well-defined whisker-to-barrel pathway of the rodent is particularly amenable to studies attempting to link cortical circuit dynamics to behavior. To each whisker corresponds a discrete cortical unit equivalent to a single column, specialized in the encoding and processing of the sensory information it receives. In this review, we will focus on the functional role that each subtype of supragranular GABAergic neuron embedded within such a single neocortical unit may play in shaping the dynamics of the local circuit during somatosensory integration.

  15. Alcohol dehydrogenase polymorphism in barrel cactus populations of Drosophila mojavensis.

    Science.gov (United States)

    Cleland, S; Hocutt, G D; Breitmeyer, C M; Markow, T A; Pfeiler, E

    1996-07-01

    Starch gel electrophoresis revealed that the alcohol dehydrogenase (ADH-2) locus was polymorphic in two populations (from Agua Caliente, California and the Grand Canyon, Arizona) of cactophilic Drosophila mojavensis that utilize barrel cactus (Ferocactus acanthodes) as a host plant. Electromorphs representing products of a slow (S) and a fast (F) allele were found in adult flies. The frequency of the slow allele was 0.448 in flies from Agua Caliente and 0.659 in flies from the Grand Canyon. These frequencies were intermediate to those of the low (Baja California peninsula, Mexico) and high (Sonora, Mexico and southern Arizona) frequency Adh-2S populations of D. mojavensis that utilize different species of host cacti. PMID:8765684

  16. Charged Pion Energy Reconstruction in the ATLAS Barrel Calorimeter

    CERN Document Server

    Bosman, M; Nessi, Marzio

    2000-01-01

    The intrinsic performance of the ATLAS barrel and extended barrelcalorimeters for the measurement of charged pions is presented. Pion energyscans (E = 20, 50, 200, 400 and 1000 GeV) at two pseudo-rapidity points ($\\eta$= 0.3 and 1.3) and pseudorapidity scans ($-0.2 < \\eta < 1.8$) with pions ofconstant transverse energy ($E_T = 20$ and 50 GeV) are analysed. A simpleapproach, that accounts in first order for non-compensation and dead materialeffects, is used for the pion energy reconstruction. The intrinsic performancesof the calorimeter are studied: resolution, linearity, effect of dead material,tails in the energy distribution. The effect of electronic noise, cell energycuts and restricted cone size are investigated.

  17. Modeling of gun barrel surface erosion: Historic perspective

    Energy Technology Data Exchange (ETDEWEB)

    Buckingham, A.C.

    1996-08-01

    Results and interpretations of numerical simulations of some dominant processes influencing gun barrel propellant combustion and flow-induced erosion are presented. Results include modeled influences of erosion reduction techniques such as solid additives, vapor phase chemical modifications, and alteration of surface solid composition through use of thin coatings. Precedents and historical perspective are provided with predictions from traditional interior ballistics compared to computer simulations. Accelerating reactive combustion flow, multiphase and multicomponent transport, flow-to-surface thermal/momentum/phase change/gas-surface chemical exchanges, surface and micro-depth subsurface heating/stress/composition evolution and their roles in inducing surface cracking, spall, ablation, melting, and vaporization are considered. Recognition is given to cyclic effects of previous firing history on material preconditioning. Current perspective and outlook for future are based on results of a US Army-LLNL erosion research program covering 7 y in late 1970s. This is supplemented by more recent research on hypervelocity electromagnetic projectile launchers.

  18. Performance of the ATLAS electromagnetic calorimeter barrel module 0

    CERN Document Server

    Aubert, Bernard; Alexa, C; Astesan, F; Augé, E; Aulchenko, V M; Ballansat, J; Barreiro, F; Barrillon, P; Battistoni, G; Bazan, A; Beaugiraud, B; Beck-Hansen, J; Belhorma, B; Belorgey, J; Belymam, A; Ben-Mansour, A; Benchekroun, D; Benchouk, C; Bernard, R; Bertoli, W; Boniface, J; Bonivento, W; Bourdarios, C; Bremer, J; Breton, D; Bán, J; Camard, A; Canton, B; Carminati, L; Cartiglia, N; Cavalli, D; Chalifour, M; Chekhtman, A; Chen, H; Cherkaoui, R; Chevalley, J L; Chollet, F; Citterio, M; Clark, A; Cleland, W; Clément, C; Colas, Jacques; Collot, J; Costa, G; Cros, P; Cunitz, H; de Saintignon, P; Del Peso, J; Delebecque, P; Delmastro, M; Di Ciaccio, Lucia; Dinkespiler, B; Djama, F; Dodd, J; Driouichi, C; Dumont-Dayot, N; Duval, P Y; Dzahini, D; Efthymiopoulos, I; Egdemir, J; El-Kacimi, M; El-Mouahhidi, Y; Engelmann, R; Ernwein, J; Falleau, I; Fanti, M; Farrell, J; Fassnacht, P; Ferrari, A; Fichet, S; Fournier, D; Gallin-Martel, M L; Gara, A; García, G; Gaumer, O; Ghazlane, H; Ghez, P; Gianotti, F; Girard, C; Gordon, H; Gouanère, M; Guilhem, G; Hackenburg, B; Hakimi, M; Hassani, S; Henry-Coüannier, F; Hervás, L; Hinz, L; Hoffman, A; Hoffman, J; Hostachy, J Y; Hoummada, A; Hubaut, F; Idrissi, A; Imbault, D; Jacquier, Y; Jérémie, A; Jevaud, M; Jézéquel, S; Kambara, H; Karst, P; Kazanin, V; Kierstead, J A; Kolachev, G M; Kordas, K; de La Taille, C; Labarga, L; Lacour, D; Lafaye, R; Laforge, B; Lanni, F; Le Coroller, A; Le Dortz, O; Le Maner, C; Le Van-Suu, A; Le Flour, T; Leite, M; Leltchouk, M; Lesueur, J; Lissauer, D; Lund-Jensen, B; Lundqvist, J M; Ma, H; Macé, G; Makowiecki, D S; Malychev, V; Mandelli, L; Mansoulié, B; Marin, C P; Martin, D; Martin, L; Martin, O; Martin, P; Maslennikov, A L; Massol, N; Mazzanti, M; McCarthy, R; McDonald, J; Megner, L; Merkel, B; Mirea, A; Moneta, L; Monnier, E; Moynot, M; Muraz, J F; Nagy, E; Negroni, S; Neukermans, L; Nicod, D; Nikolic-Audit, I; Noppe, J M; Ohlsson-Malek, F; Olivier, C; Orsini, F; Pailler, P; Parrour, G; Parsons, J A; Pearce, M; Perini, L; Perrodo, P; Perrot, G; Pétroff, P; Poggioli, Luc; Pospelov, G E; Pralavorio, Pascal; Prast, J; Przysiezniak, H; Puzo, P; Radeka, V; Rahm, David Charles; Rajagopalan, S; Raymond, M; Renardy, J F; Repetti, B; Rescia, S; Resconi, S; Riccadona, X; Richer, J P; Rijssenbeek, M; Rodier, S; Rossel, F; Rousseau, D; Rydström, S; Saboumazrag, S; Sauvage, D; Sauvage, G; Schilly, P; Schwemling, P; Schwindling, J; Seguin-Moreau, N; Seidl, W; Seman, M; Serin, L; Shousharo, A; Simion, S; Sippach, W; Snopkov, R; Steffens, J; Stroynowski, R; Stumer, I; Taguet, J P; Takai, H; Talyshev, A A; Tartarelli, F; Teiger, J; Thion, J; Tikhonov, Yu A; Tisserant, S; Tocut, V; Tóth, J; Veillet, J J; Vossebeld, Joost Herman; Vuillemin, V; Wielers, M; Willis, W J; Wingerter-Seez, I; Ye, J; Yip, K; Zerwas, D; Zitoun, R; Zolnierowski, Y

    2003-01-01

    The construction and performance of the barrel pre-series module 0 of the future ATLAS electromagnetic calorimeter at the LHC is described. The signal reconstruction and performance of ATLAS-like electronics has been studied. The signal to noise ratio for muons has been found to be 7.11+-0.07. An energy resolution of better than 9.5% GeV^1/2/sqrt{E} (sampling term) has been obtained with electron beams of up to 245GeV. The uniformity of the response to electrons in an area of Delta_eta x Delta_phi = 1.2 x 0.075 has been measured to be better than 0.8%.

  19. The CMS Level-1 Trigger Barrel Track Finder

    CERN Document Server

    Ero, Janos; Ioannis Flouris; Fountas, Konstantinos; Guiducci, Luigi; Loukas, Nikitas; Manthos, Nikolaos; Papadopoulos, Ioannis; Paradas, Evangelos; Triossi, Andrea; Wulz, Claudia

    2015-01-01

    The design and performance of the upgraded CMS Level-1 Trigger Barrel Muon Track Finder (BMTF) is presented. Monte Carlo simulation data as well as cosmic ray and pp data from a CMS muon detector slice test have been used to study in detail the performance of the new track finder. The design architecture is based on twelve MP7 cards which use a Xilinx Virtex-7 FPGA and can receive and transmit data at 10 Gbps from 72 input and 72 output fibers. According to the CMS Trigger Upgrade TDR the BMTF receives trigger primitive data which are computed using both RPC and DT data and transmits data from a number of muon candidates to the upgraded Global Muon Trigger. Results from detailed studies of comparisons between the BMTF algorithm results and the results of a C++ emulator are also presented. The new BMTF will be commissioned for data taking in 2016.

  20. Superconducting Graphene Nanoelectronic Devices

    Science.gov (United States)

    Wang, Joel; Zaffalon, Michele; Jarillo-Herrero, Pablo

    2010-03-01

    Graphene, a single atom-thick sheet of graphite discovered in recent years, has attracted tremendous attention due to its exotic electronic properties. At low energy, its gapless linear band structure results in transport properties described by the Dirac equation, making it an ideal system for the study of exotic quantum phenomena and other new physics. Graphene may also exhibit many novel transport characteristics in the superconducting regime. New phenomena, such as pseudo-diffusive dynamics of ballistic electrons, the relativistic Josephson effect, and specular Andreev reflection are predicted by theoretical models combining relativistic quantum mechanics and superconductivity. We study these phenomena experimentally with superconductor-graphene-superconductor junctions. The supercurrent in graphene is induced by the superconducting contacts through proximity effect. Various superconducting materials are considered for different explorations. Preliminary tests indicate clean electrical contact with graphene and superconducting properties as expected.

  1. Physics models in the toroidal transport code PROCTR

    Energy Technology Data Exchange (ETDEWEB)

    Howe, H.C.

    1990-08-01

    The physics models that are contained in the toroidal transport code PROCTR are described in detail. Time- and space-dependent models are included for the plasma hydrogenic-ion, helium, and impurity densities, the electron and ion temperatures, the toroidal rotation velocity, and the toroidal current profile. Time- and depth-dependent models for the trapped and mobile hydrogenic particle concentrations in the wall and a time-dependent point model for the number of particles in the limiter are also included. Time-dependent models for neutral particle transport, neutral beam deposition and thermalization, fusion heating, impurity radiation, pellet injection, and the radial electric potential are included and recalculated periodically as the time-dependent models evolve. The plasma solution is obtained either in simple flux coordinates, where the radial shift of each elliptical, toroidal flux surface is included to maintain an approximate pressure equilibrium, or in general three-dimensional torsatron coordinates represented by series of helical harmonics. The detailed coupling of the plasma, scrape-off layer, limiter, and wall models through the neutral transport model makes PROCTR especially suited for modeling of recycling and particle control in toroidal plasmas. The model may also be used in a steady-state profile analysis mode for studying energy and particle balances starting with measured plasma profiles.

  2. Physics models in the toroidal transport code PROCTR

    International Nuclear Information System (INIS)

    The physics models that are contained in the toroidal transport code PROCTR are described in detail. Time- and space-dependent models are included for the plasma hydrogenic-ion, helium, and impurity densities, the electron and ion temperatures, the toroidal rotation velocity, and the toroidal current profile. Time- and depth-dependent models for the trapped and mobile hydrogenic particle concentrations in the wall and a time-dependent point model for the number of particles in the limiter are also included. Time-dependent models for neutral particle transport, neutral beam deposition and thermalization, fusion heating, impurity radiation, pellet injection, and the radial electric potential are included and recalculated periodically as the time-dependent models evolve. The plasma solution is obtained either in simple flux coordinates, where the radial shift of each elliptical, toroidal flux surface is included to maintain an approximate pressure equilibrium, or in general three-dimensional torsatron coordinates represented by series of helical harmonics. The detailed coupling of the plasma, scrape-off layer, limiter, and wall models through the neutral transport model makes PROCTR especially suited for modeling of recycling and particle control in toroidal plasmas. The model may also be used in a steady-state profile analysis mode for studying energy and particle balances starting with measured plasma profiles

  3. Active toroidal field ripple reduction system in FAST

    International Nuclear Information System (INIS)

    The fusion advanced studies torus (FAST) has been proposed as a flexible and cost effective machine that is able to support the development of ITER and DEMO operating scenarios exploiting some innovative technology solutions and to investigate the physics of high-performance plasmas in a dimensionless parameter range close to ITER. The FAST magnet consists of 18 coils, spaced by 20o in the toroidal angle, each made up of 14 copper plates, suitably arranged in order to realise 3 turns in the radial direction, with 89.2 kA per coil (in the H-mode plasma scenario 6.5 MA at 7.5 T). The finite number and toroidal extension of the toroidal field coils (TFCs) cause a periodic variation of the toroidal field from its nominal value called toroidal field ripple (TFR). An active ripple reduction system has been comprehensively investigated, by using proper 3D finite elements models, to provide an efficient and flexible system able to minimize the TFR in the region of interest. An optimization study of position and size of the coils required to reduce to an acceptable level for the operations the maximum ripple on the plasma (well below 0.3%), feeding them with currents sustainable during the whole scenario (∼1/10 of the current flowing in TFCs), is presented in this paper.

  4. Computer simulations of compact toroid formation and acceleration

    International Nuclear Information System (INIS)

    Experiments to form, accelerate, and focus compact toroid plasmas will be performed on the 9.4 MJ SHIVA STAR fast capacitor bank at the Air Force Weapons Laboratory during the 1990. The MARAUDER (magnetically accelerated rings to achieve ultrahigh directed energy and radiation) program is a research effort to accelerate magnetized plasma rings with the masses between 0.1 and 1.0 mg to velocities above 10 8 cm/sec and energies above 1 MJ. Research on these high-velocity compact toroids may lead to development of very fast opening switches, high-power microwave sources, and an alternative path to inertial confinement fusion. Design of a compact toroid accelerator experiment on the SHIVA STAR capacitor bank is underway, and computer simulations with the 2 1/2-dimensional magnetohydrodynamics code, MACH2, have been performed to guide this endeavor. The compact toroids are produced in a magnetized coaxial plasma gun, and the acceleration will occur in a configuration similar to a coaxial railgun. Detailed calculations of formation and equilibration of a low beta magnetic force-free configuration (curl B = kB) have been performed with MACH2. In this paper, the authors discuss computer simulations of the focusing and acceleration of the toroid

  5. Toroidal linear force-free magnetic fields with axial symmetry

    Science.gov (United States)

    Vandas, M.; Romashets, E.

    2016-01-01

    Aims: Interplanetary magnetic flux ropes are often described as linear force-free fields. To account for their curvature, toroidal configurations must be used. The aim is to find an analytic description of a linear force-free magnetic field of the toroidal geometry in which the cross section of flux ropes can be controlled. Methods: The solution is found as a superposition of fields given by linear force-free cylinders tangential to a generating toroid. The cylindrical field is expressed in a series of terms that are not all cylindrically symmetric. Results: We found the general form of a toroidal linear force-free magnetic field. The field is azimuthally symmetric with respect to the torus axis. It depends on a set of coefficients that enables controlling the flux rope shape (cross section) to some extent. By varying the coefficients, flux ropes with circular and elliptic cross sections were constructed. Numerical comparison suggests that the simple analytic formula for calculating the helicity in toroidal flux ropes of the circular cross section can be used for flux ropes with elliptic cross sections if the minor radius in the formula is set to the geometric mean of the semi-axes of the elliptic cross section.

  6. Optical toroidal dipolar response by an asymmetric double-bar metamaterial

    CERN Document Server

    Dong, Zheng-Gao; Rho, Junsuk; Li, Jia-Qi; Lu, Changgui; Yin, Xiaobo; Zhang, X; 10.1063/1.4757613

    2012-01-01

    We demonstrate that the toroidal dipolar response can be realized in the optical regime by designing a feasible nanostructured metamaterial, comprising asymmetric double-bar magnetic resonators assembled into a toroid-like configuration. It is confirmed numerically that an optical toroidal dipolar moment dominates over other moments. This response is characterized by a strong confinement of an E-field component at the toroid center, oriented perpendicular to the H-vortex plane. The resonance-enhanced optical toroidal response can provide an experimental avenue for various interesting optical phenomena associated with the elusive toroidal moment.

  7. Design and development of a work robot to place ATLAS SCT modules onto barrel cylinders

    CERN Document Server

    Terada, S; Honma, F; Ikegami, Y; Iwata, Y; Kato, Y; Kobayashi, H; Kohriki, T; Kondo, T; Nakano, I; Sengoku, H; Takashima, R; Tanaka, R; Ujiie, N; Unno, Y; Yasuda, S

    2005-01-01

    More than 2000 silicon modules need to be placed and fastened on the ATLAS SCT barrel tracker. A semi-automatic pick-and-place work robot was designed and developed to cope with the module placement for the SCT barrel assembly. We found that this robot could place modules to a mechanical precision of better than 25 mum.

  8. ATF [Advanced Toroidal Facility]-2 studies

    International Nuclear Information System (INIS)

    Design studies for a low-aspect-ratio, large next-generation stellarator, ATF-II, with high-current-density, high-field, stable NbTi/Cu helical windings are described. The design parameters are an average plasma radius of 0.52 m, a major radius of 2 m, and a field on axis of 4-5 T, with 10 to 15 MW of heating power. Such a device would be comparable in scope to other next-generation stellarators but would have roughly the same aspect ratio as the tokamaks without, however, the need for current drive to sustain steady-state operation. A number of low-aspect-ratio physics issues need to be addressed in the design of ATF-II, primarily compromises between high-beta capability and good confinement properties. A six-field-period Compact Torsatron is chosen as a reference design for ATF-II, and its main features and performance predictions are discussed. An integrated (beta capability and confinement) optimization approach and optimization of superconducting windings are also discussed. 36 refs., 13 figs., 2 tabs

  9. Superconductivity in aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Kubozono, Yoshihiro, E-mail: kubozono@cc.okayama-u.ac.jp [Research Laboratory for Surface Science, Okayama University, Okayama 700-8530 (Japan); Research Center of New Functional Materials for Energy Production, Storage and Transport, Okayama University, Okayama 700-8530 (Japan); Japan Science and Technology Agency, ACT-C, Kawaguchi 332-0012 (Japan); Goto, Hidenori; Jabuchi, Taihei [Research Laboratory for Surface Science, Okayama University, Okayama 700-8530 (Japan); Yokoya, Takayoshi [Research Laboratory for Surface Science, Okayama University, Okayama 700-8530 (Japan); Research Center of New Functional Materials for Energy Production, Storage and Transport, Okayama University, Okayama 700-8530 (Japan); Kambe, Takashi [Department of Physics, Okayama University, Okayama 700-8530 (Japan); Sakai, Yusuke; Izumi, Masanari; Zheng, Lu; Hamao, Shino; Nguyen, Huyen L.T. [Research Laboratory for Surface Science, Okayama University, Okayama 700-8530 (Japan); Sakata, Masafumi; Kagayama, Tomoko; Shimizu, Katsuya [Center of Science and Technology under Extreme Conditions, Osaka University, Osaka 560-8531 (Japan)

    2015-07-15

    Highlights: • Aromatic superconductor is one of core research subjects in superconductivity. Superconductivity is observed in certain metal-doped aromatic hydrocarbons. Some serious problems to be solved exist for future advancement of the research. This article shows the present status of aromatic superconductors. - Abstract: ‘Aromatic hydrocarbon’ implies an organic molecule that satisfies the (4n + 2) π-electron rule and consists of benzene rings. Doping solid aromatic hydrocarbons with metals provides the superconductivity. The first discovery of such superconductivity was made for K-doped picene (K{sub x}picene, five benzene rings). Its superconducting transition temperatures (T{sub c}’s) were 7 and 18 K. Recently, we found a new superconducting K{sub x}picene phase with a T{sub c} as high as 14 K, so we now know that K{sub x}picene possesses multiple superconducting phases. Besides K{sub x}picene, we discovered new superconductors such as Rb{sub x}picene and Ca{sub x}picene. A most serious problem is that the shielding fraction is ⩽15% for K{sub x}picene and Rb{sub x}picene, and it is often ∼1% for other superconductors. Such low shielding fractions have made it difficult to determine the crystal structures of superconducting phases. Nevertheless, many research groups have expended a great deal of effort to make high quality hydrocarbon superconductors in the five years since the discovery of hydrocarbon superconductivity. At the present stage, superconductivity is observed in certain metal-doped aromatic hydrocarbons (picene, phenanthrene and dibenzopentacene), but the shielding fraction remains stubbornly low. The highest priority research area is to prepare aromatic superconductors with a high superconducting volume-fraction. Despite these difficulties, aromatic superconductivity is still a core research target and presents interesting and potentially breakthrough challenges, such as the positive pressure dependence of T{sub c} that is clearly

  10. Dynamics of the Disruption Halo Current Toroidal Asymmetry in NSTX

    Energy Technology Data Exchange (ETDEWEB)

    S.P. Gerhardt

    2012-09-27

    This paper describes the dynamics of disruption halo current non-axisymmetries in the lower divertor of the National Spherical Torus Experiment [M. Ono, et al. Nuclear Fusion 40, 557 (2000)]. While. The halo currents typically have a strongly asymmetric structure where they enter the divertor floor, and this asymmetry has been observed to complete up to 7 toroidal revolutions over the duration of the halo current pulse. However, the rotation speed and toroidal extend of the asymmetry can vary significantly during the pulse. The rotation speed, halo current pulse duration, and total number of revolutions tend to be smaller in cases with large halo currents. The halo current pattern is observed to become toroidally symmetric at the end of the halo current pulse. It is proposed that this symmeterization is due to the loss of most or all of the closed field line geometry in the final phase of the vertical displacement event.

  11. Toroidal drift waves with an equilibrium velocity field

    International Nuclear Information System (INIS)

    The author investigated the effect of a radially sheared poloidal velocity field on the toroidal drift wave which is well known to escape magnetic shear damping through toroidal coupling between different poloidal harmonics centered on individual rational surfaces. He endeavored to model the velocity profile according to that observed at the plasma edge during H-mode shots. The resultant wave formed by the interference of different poloidal harmonics now sees an antiwell created by the H-mode type velocity profile in the radial direction (in contrast to a well formed by the diamagnetic frequency in the absence of velocity fields). The wave, therefore, convects energy outward and hence undergoes damping. Outgoing wave boundary condition then introduces a negative imaginary contribution to the global eigenvalue -- once again confirming the stabilizing role of H-mode type velocity profiles. On the other hand, L-mode type velocity profiles have destabilizing action on toroidal drift waves

  12. Axion Haloscopes with Toroidal Geometry at CAPP/IBS

    CERN Document Server

    Ko, B R

    2016-01-01

    The present state of the art axion haloscope employs a cylindrical resonant cavity in a solenoidal field. We, the Center for Axion and Precision Physics Research (CAPP) of the Institute for Basic Science (IBS) in Korea, are also pursuing halo axion discovery using this cylindrical geometry. However, the presence of end caps of cavities increases challenges as we explore higher frequency regions for the axion at above 2 GHz. To overcome these challenges we exploit a toroidal design of cavity and magnetic field. A toroidal geometry offers several advantages, two of which are a larger volume for a given space and greatly reduced fringe fields which interfere with our preamps, in particular the planned quantum-based devices. We introduce the concept of toroidal axion haloscopes and present ongoing research activities and plans at CAPP/IBS.

  13. Reduction of toroidal ripple by using high Tc superconductors

    International Nuclear Information System (INIS)

    In this paper we present a new method to reduce the toroidal ripple with use of high Tc superconductors. High Tc superconductors can behave as ferromagnetic or diamagnetic materials depending on their magnetic hysteresis. If they are appropriately arranged and magnetized between the toroidal field coils, they possibly decrease the toroidal field ripple. Here, the preliminary design of ITER is taken as an example, and the effect of the high Tc superconductors on the ripple is evaluated. The magnetic induction due to the superconductors is calculated by the current vector potential method based on the critical state model. Several arrangements of the high Tc superconductors were quantitatively examined in order to reduce the ripple. The results obtained by the calculation show that the maximum ripple value can be reduced to be the required value. (orig.)

  14. Vlasov tokamak equilibria with shearad toroidal flow and anisotropic pressure

    Science.gov (United States)

    Throumoulopoulos, George; Kuiroukidis, Apostolos; Tasso, Henri

    2015-11-01

    By choosing appropriate deformed Maxwellian ion and electron distribution functions depending on the two particle constants of motion, i.e. the energy and toroidal angular momentum, we reduce the Vlasov axisymmetric equilibrium problem for quasineutral plasmas to a transcendental Grad-Shafranov-like equation. This equation is then solved numerically under the Dirichlet boundary condition for an analytically prescribed boundary possessing a lower X-point to construct tokamak equilibria with toroidal sheared ion flow and anisotropic pressure. Depending on the deformation of the distribution functions these steady states can have toroidal current densities either peaked on the magnetic axis or hollow. These two kinds of equilibria may be regarded as a bifurcation in connection with symmetry properties of the distribution functions on the magnetic axis. This work has received funding from (a) the National Programme for the Controlled Thermonuclear Fusion, Hellenic Republic, (b) Euratom research and training programme 2014-2018 under grant agreement No 633053.

  15. Vlasov tokamak equilibria with shearad toroidal flow and anisotropic pressure

    CERN Document Server

    Kuiroukidis, Ap; Tasso, H

    2015-01-01

    By choosing appropriate deformed Maxwellian ion and electron distribution functions depending on the two particle constants of motion, i.e. the energy and toroidal angular momentum, we reduce the Vlasov axisymmetric equilibrium problem for quasineutral plasmas to a transcendental Grad-Shafranov-like equation. This equation is then solved numerically under the Dirichlet boundary condition for an analytically prescribed boundary possessing a lower X-point to construct tokamak equilibria with toroidal sheared ion flow and anisotropic pressure. Depending on the deformation of the distribution functions these steady states can have toroidal current densities either peaked on the magnetic axis or hollow. These two kinds of equilibria may be regarded as a bifurcation in connection with symmetry properties of the distribution functions on the magnetic axis.

  16. Vlasov tokamak equilibria with sheared toroidal flow and anisotropic pressure

    Energy Technology Data Exchange (ETDEWEB)

    Kuiroukidis, Ap, E-mail: kouirouki@astro.auth.gr [Technological Education Institute of Serres, 62124 Serres (Greece); Throumoulopoulos, G. N., E-mail: gthroum@uoi.gr [Department of Physics, University of Ioannina, GR 451 10 Ioannina (Greece); Tasso, H., E-mail: het@ipp.mpg.de [Max-Planck-Institut für Plasmaphysik, D-85748 Garching (Germany)

    2015-08-15

    By choosing appropriate deformed Maxwellian ion and electron distribution functions depending on the two particle constants of motion, i.e., the energy and toroidal angular momentum, we reduce the Vlasov axisymmetric equilibrium problem for quasineutral plasmas to a transcendental Grad-Shafranov-like equation. This equation is then solved numerically under the Dirichlet boundary condition for an analytically prescribed boundary possessing a lower X-point to construct tokamak equilibria with toroidal sheared ion flow and anisotropic pressure. Depending on the deformation of the distribution functions, these steady states can have toroidal current densities either peaked on the magnetic axis or hollow. These two kinds of equilibria may be regarded as a bifurcation in connection with symmetry properties of the distribution functions on the magnetic axis.

  17. Linear wave propagation in a hot axisymmetric toroidal plasma

    International Nuclear Information System (INIS)

    Kinetic effects on the propagation of the Alfven wave are studied for the first time in a toroidal plasma relevant for experiments. This requires the resolution of a set of coupled partial differential equations whose coefficients depend locally on the plasma parameters. For this purpose, a numerical wave propagation code called PENN has been developed using either a bilinear or a bicubic Hermite finite element discretization. It solves Maxwell's equations in toroidal geometry, with a dielectric tensor operator that takes into account the linear response of the plasma. Two different models have been implemented and can be used comparatively to describe the same physical case: the first treats the plasma as resistive fluids and gives results which are in good agreement with toroidal fluid codes. The second is a kinetic model and takes into account the finite size of the Larmor radii; it has successfully been tested against a kinetic plasma model in cylindrical geometry. New results have been obtained when studying kinetic effects in toroidal geometry. Two different conversion mechanisms to the kinetic Alfven wave have been described: one occurs at toroidally coupled resonant surfaces and is the kinetic counterpart of the fluid models' resonance absorption. The other has no such correspondence and results directly from the toroidal coupling between the kinetic Alfven wave and the global wavefield. An analysis of a heating scenario suggests that it might be difficult to heat a plasma with Alfven waves up to temperatures that are relevant for a tokamak reactor. Kinetic effects are studied for three types of global Alfven modes (GAE, TAE, BAE) and a new class of kinetic eigenmodes is described which appear inside the fluid gap: it could be related to recent observations in the JET (Joint European Torus) tokamak. (author) 56 figs., 6 tabs., 58 refs

  18. On rotation of multi-species plasmas in toroidal systems

    International Nuclear Information System (INIS)

    This paper describes the poloidal and toroidal spin-up of an isothermal plasma in toroidal equilibria. The mechanism is the Stringer spin-up mechanism which will be generalized to an arbitrary toroidal equilibrium using the Hamada coordinate system. Viscous damping or magnetic pumping balances the accelerating forces and determines the threshold of spin-up. The accelerating forces arise from the Coriolis forces which couple the radial flow to the poloidal flow velocity. The theory presented here is a continuation of a previous paper and applies to a multi-species plasma with impurities. In the two-fluid model - or including impurities - in a multi-fluid model, the flux-friction relations derived on every magnetic surface are the basic equations for computing the poloidal and toroidal flow velocities of the particle species. Futhermore, the effect of turbulent forces on the mean flow is analysed. The Reynolds stresses resulting from anisotropic turbulence provide a force in the tangential direction and thus contribute to the poloidal and toroidal spin-up. Furthermore, turbulence increases the Stringer spin-up mechanism and introduces enhanced plasma losses. The final result is a set of differential equations describing the poloidal and toroidal flow on every magnetic surface. The formalism is valid in every regime of collisionality; however, to obtain specific results, appropriate appoximations must be found for every regime. This will be outlined for the collisional regime where the viscous forces are given by Braginskii's equations. The relation between plasma rotation and the zonal circulation in planetary atmospheres will be discussed. (Author)

  19. Development of superconducting electromagnets

    International Nuclear Information System (INIS)

    The contribution of superconduction techniques to high energy physics has increased recently, and the experiment on high energy physics is no more possible if superconduction techniques are neglected. The development of superconducting magnets for a proton ring in the phase 2 of TRISTAN project of KEK, the superconducting proton synchrotron in Fermi National Accelerator Laboratory already in operation, the superconducting supercollider of 20TeV x 20TeV proton-proton in USA, and the JSC project of 30TeV x 30TeV proton-antiproton collision type accelerator are the examples. For the superconducting electromagnets of the SSC project, the full scale mass production lines will be completed. The intensity of their magnetic field is from 3T to 8T. As to the electromagnets for the JSC project, the intensity of magnetic field as high as 9T is required. The material of wires, two-layer shell type structure, cold iron and cold bore type, self correction coil and so on are discussed. The problems of electromagnetic force acting on coils and stored electromagnetic energy at the time of quenching are described. The present status and the project of superconducting electromagnet development in KEK are explained. (Kako, I.)

  20. The superconducting spin valve and triplet superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Garifullin, I.A., E-mail: ilgiz_garifullin@yahoo.com [Zavoisky Physical-Technical Institute, Kazan Scientific Center of Russian Academy of Sciences, 420029 Kazan (Russian Federation); Leksin, P.V.; Garif' yanov, N.N.; Kamashev, A.A. [Zavoisky Physical-Technical Institute, Kazan Scientific Center of Russian Academy of Sciences, 420029 Kazan (Russian Federation); Fominov, Ya.V. [L. D. Landau Institute for Theoretical Physics RAS, 119334 Moscow (Russian Federation); Moscow Institute of Physics and Technology, 141700 Dolgoprudny (Russian Federation); Schumann, J.; Krupskaya, Y.; Kataev, V.; Schmidt, O.G. [Leibniz Institute for Solid State and Materials Research IFW Dresden, D-01171 Dresden (Germany); Büchner, B. [Leibniz Institute for Solid State and Materials Research IFW Dresden, D-01171 Dresden (Germany); Institut für Festkörperphysik, Technische Universität Dresden, D-01062 Dresden (Germany)

    2015-01-01

    A review of our recent results on the spin valve effect is presented. We have used a theoretically proposed spin switch design F1/F2/S comprising a ferromagnetic bilayer (F1/F2) as a ferromagnetic component, and an ordinary superconductor (S) as the second interface component. Based on it we have prepared and studied in detail a set of multilayers CoO{sub x}/Fe1/Cu/Fe2/S (S=In or Pb). In these heterostructures we have realized for the first time a full spin switch effect for the superconducting current, have observed its sign-changing oscillating behavior as a function of the Fe2-layer thickness and finally have obtained direct evidence for the long-range triplet superconductivity arising due to noncollinearity of the magnetizations of the Fe1 and Fe2 layers. - Highlights: • We studied a spin switch design F1/F2/S. • We prepared a set of multilayers CoOx/Fe1/Cu/Fe2/S (S=In or Pb). • The full spin switch effect for the superconducting current was realized. • We observed its oscillating behavior as a function of the Fe2-layer thickness. • We obtained direct evidence for the long-range triplet superconductivity.

  1. Toroidal vortices as a solution to the dust migration problem

    CERN Document Server

    Loren-Aguilar, Pablo

    2015-01-01

    In an earlier letter, we reported that dust settling in protoplanetary discs may lead to a dynamical dust-gas instability that produces global toroidal vortices. In this letter, we investigate the evolution of a dusty protoplanetary disc with two different dust species (1 mm and 50 cm dust grains), under the presence of the instability. We show how toroidal vortices, triggered by the interaction of mm grains with the gas, stop the radial migration of metre-sized dust, potentially offering a natural and efficient solution to the dust migration problem.

  2. Experiments with a fully toroidal Extrap Z-pinch

    International Nuclear Information System (INIS)

    In the Extrap plasma confinement scheme, a Z-pinch is produced along the null of an octupole field generated by currents in external conductors. In the paper, studies of the discharge startup process in a fully toroidal configuration are described. Startup involves first breaking down a toroidal discharge and then driving up the current in order to reach the pinch parameter regime. Current densities of 2x106 A·m-2 have been achieved. The estimated plasma density is 6x1020m-3, and the temperature is about 4 eV. These parameters correspond to pinch conditions. (author)

  3. Low frequency wave propagation in hot toroidal plasma

    International Nuclear Information System (INIS)

    The equation for low frequency wave propagation in full toroidal geometry with arbitrary cross section is derived. It is mainly shown that, when including self consistently the various absorption terms from Vlasov equation in the dielectric tensor, the global wave structure is described by a fourth order system, which even reduces to a second order Helmoltz type equation when neglecting toroidal corrections. Close to the singular ion ion conversion layer, the structure of the wave is strongly affected. Finite Larmor radius conversion effects there compete with simple absorption mechanisms via Landau or cyclotron Landau damping making the FLR effects not likely to dominate nor even occur

  4. Toroidal equilibrium of plasma with concentrated relativistic electron beam

    International Nuclear Information System (INIS)

    A simplified model has been given for toroidal equilibrium of a tokamak-type plasma with high-current concentrated electron beam. The plasma has a thermal pressure, and the electron beam has effective inertial pressure. Strong deformations of tokamak equilibria have been simulated by numerical calculations. Toroidal equilibria with relatively large vertical field are obtained when we consider high-energy intense electron beam. The beam orbit, which is shifted outward from the magnetic axis of the plasma, is closed by the sum of the externally applied relatively large vertical field and the poloidal magnetic field of the plasma. (author)

  5. Development and verification of printed circuit board toroidal transformer model

    DEFF Research Database (Denmark)

    Pejtersen, Jens; Mønster, Jakob Døllner; Knott, Arnold

    2013-01-01

    comparing calculated parameters with 3D finite element simulations and experimental measurement results. The developed transformer model shows good agreement with the simulated and measured results. The model can be used to predict the parameters of printed circuit board toroidal transformer configurations......An analytical model of an air core printed circuit board embedded toroidal transformer configuration is presented. The transformer has been developed for galvanic isolation of very high frequency switch-mode dc-dc power converter applications. The theoretical model is developed and verified by...

  6. Development and verification of printed circuit board toroidal transformer model

    DEFF Research Database (Denmark)

    Pejtersen, Jens; Mønster, Jakob Døllner; Knott, Arnold

    comparing calculated parameters with 3D finite element simulations and experimental measurement results. The developed transformer model shows good agreement with the simulated and measured results. The model can be used to predict the parameters of printed circuit board toroidal transformer configurations......An analytical model of an air core printed circuit board embedded toroidal transformer configuration is presented. The transformer has been developed for galvanic isolation of very high frequency switch-mode dc-dc power converter applications. The theoretical model is developed and verified by...

  7. Compact toroid theory issues and approaches: a panel report

    International Nuclear Information System (INIS)

    In the six years since the initiation of the compact toroid program by the Office of Fusion Energy, remarkable scientific advances have occurred on both field-reversed configurations (FRC) and spheromaks. This progress has been stimulated by a diverse experimental program with facilities at six laboratories, and by a small but nevertheless broad theoretical research effort encompassing more than a dozen institutions. The close coupling between theoretical and experimental programs has contributed immeasurably to this progress. This document offers guidance for future compact toroid theory by identifying and discussing the key physics issues. In most cases promising approaches to these issues are offered

  8. Comparative study between toroidal coordinates and the magnetic dipole field

    CERN Document Server

    Chávez-Alarcón, Esteban

    2012-01-01

    There is a similar behaviour between the toroidal coordinates and the dipole magnetic field produced by a circular loop. In this work we evaluate up to what extent the former can be used as a representation of the latter. While the tori in the toroidal coordinates have circular cross sections, those of the circular loop magnetic field are nearly elliptical ovoids, but they are very similar for large aspect ratios.The centres of the latter displace from the axis faster than the former. By making a comparison between tori of similar aspect ratios, we find quantitative criteria to evaluate the accuracy of the approximation.

  9. Self-interference of a toroidal Bose–Einstein condensate

    International Nuclear Information System (INIS)

    We demonstrate the self-interference of a single Bose–Einstein condensate on a non-simply connected geometry, focussing on a toroidally trapped ring-shaped condensate. First, we show how the opposite parts of the ring can interfere using the Wigner function representation. Then, using analytical expressions for the time-evolution of a freely expanding ring-shaped condensate with and without a persistent current, we show that the self-interference of the ring-shaped condensate is possible only in the absence of the persistent current. We conclude by proposing an experimental protocol for the creation of ring dark solitons using the toroidal self-interference

  10. Ion temperature gradient modes in toroidal helical systems

    International Nuclear Information System (INIS)

    Linear properties of ion temperature gradient (ITG) modes in helical systems are studied. The real frequency, growth rate, and eigenfunction are obtained for both stable and unstable cases by solving a kinetic integral equation with proper analytic continuation performed in the complex frequency plane. Based on the model magnetic configuration for toroidal helical systems like the Large Helical Device (LHD), dependences of the ITG mode properties on various plasma equilibrium parameters are investigated. Particularly, relative effects of ∇B-curvature drifts driven by the toroidicity and by the helical ripples are examined in order to compare the ITG modes in helical systems with those in tokamaks. (author)

  11. Toroidal Spiral Strings in Higher-dimensional Spacetime

    OpenAIRE

    Igata, Takahisa; Ishihara, Hideki

    2010-01-01

    We report on our progress in research of separability of the Nambu-Goto equation for test strings with a symmetric configuration in a shape of toroidal spiral in a five-dimensional Kerr-AdS black hole. In particular, for a Hopf loop string which is a special class of the toroidal spirals, we show the complete separation of variables occurs in two cases, Kerr background and Kerr-AdS background with equal angular momenta. We also obtain the dynamical solution for the Hopf loop around a black ho...

  12. Reevaluation of the Braginskii viscous force for toroidal plasma

    CERN Document Server

    Johnson, Robert W

    2009-01-01

    The model by Braginskii for the viscous stress tensor is used to determine the shear and gyroviscous forces acting within a toroidally confined plasma. Comparison is made to previous evaluations which contain an inconsistent treatment of the radial derivative and neglect the effect of the pitch angle. A radial gyroviscous force is found to survive the limit of constant density and rigid toroidal rotation of the flux surface, and a radial shear viscous force may develop for sufficient vertical asymmetry to the ion velocity profile.

  13. Induction Motor with Switchable Number of Poles and Toroidal Winding

    Directory of Open Access Journals (Sweden)

    MUNTEANU, A.

    2011-05-01

    Full Text Available This paper presents a study of an induction motor provided with toroidal stator winding. The ring-type coils offer a higher versatility in obtaining a different number of pole pairs by means of delta/star and series/parallel connections respectively. As consequence, the developed torque can vary within large limits and the motor can be utilized for applications that require, for example, high load torque values for a short time. The study involves experimental tests and FEM simulation for an induction machine with three configurations of pole pairs. The conclusions attest the superiority of the toroidal winding for certain applications such as electric vehicles or lifting machines.

  14. Technology development and mass production of Nb3Sn conductors for ITER toroidal field coils in Japan

    International Nuclear Information System (INIS)

    The design and manufacture of Nb3Sn conductors for ITER toroidal field (TF) coils have many technical challenges. Although it was demonstrated in the ITER model coil project that the conductors have a sufficiently high performance and the engineering design is valid, unexpected issues arose. Through both theoretical and experimental efforts improved conductors were developed. The Japan Atomic Energy Agency started to procure improved conductors for TF coils as part of the ITER project. Because the required tonnage of Nb3Sn strands is quite large compared with past experience and the required superconducting performance is higher than that of the model coils, quality control techniques are very important for the successful manufacture of the strands. Approximately 60 ton of Nb3Sn strands have been successfully completed under a severe quality control regimen and all strands meet ITER specifications. This paper summarizes the technical developments leading to the first successful mass production of ITER TF conductors.

  15. High temperature superconductivity

    International Nuclear Information System (INIS)

    New superconducting oxides and physical basis of the high-temperature superconductivity developed from 1979 till 1986 are reviewed. The analysis is based upon the concept of exchange amplification of electron-phonon interaction put forward by the author in 1964. Using the high-temperature superconductivity theory an approach to increasing the critical temperature of high-temperature superconductors (HTSC) is proposed along with the means for synthesis of HTSC with higher critical fields. The feasibility of HTSC implementation in the modern physical experiment technology is also considered, e.g. for detecting the magnetic monopoles. 35 refs.; 2 figs

  16. Superconductivity in doped insulators

    International Nuclear Information System (INIS)

    It is shown that many synthetic metals, including high temperature superconductors are ''bad metals'', with such a poor conductivity that the usual mean-field theory of superconductivity breaks down because of anomalously large classical and quantum fluctuations of the phase of the superconducting order parameter. It is argued that the supression of a first order phase transition (phase separation) by the long-range Coulomb interaction leads to high temperature superconductivity accompanied by static or dynamical charge inhomogeneity. Evidence in support of this picture for high temperature superconductors is described. (orig.)

  17. Superconducting accelerator magnets

    International Nuclear Information System (INIS)

    In the near future, a large number of high quality superconducting dipole and quadrupole magnets will be required for construction of the next generation multi-TeV high energy hadron accelerator-colliders. To establish the construction technology of such accelerator- colliders, extensive and world-wide R and D programs are now carrying out at several laboratories. In this paper the important issues in superconducting accelerator magnets such as cables, design, fabrication, testing and cryogenic system are discussed together with some details on coil cross- sectional current configurations, quality control of materials, quench protections, radiation heating and etc. The key technology in superconducting accelerator magnets is summarized

  18. Tunneling in superconducting structures

    Science.gov (United States)

    Shukrinov, Yu. M.

    2010-12-01

    Here we review our results on the breakpoint features in the coupled system of IJJ obtained in the framework of the capacitively coupled Josephson junction model with diffusion current. A correspondence between the features in the current voltage characteristics (CVC) and the character of the charge oscillations in superconducting layers is demonstrated. Investigation of the correlations of superconducting currents in neighboring Josephson junctions and the charge correlations in neighboring superconducting layers reproduces the features in the CVC and gives a powerful method for the analysis of the CVC of coupled Josephson junctions. A new method for determination of the dissipation parameter is suggested.

  19. Superconducting materials and magnets

    International Nuclear Information System (INIS)

    The Technical Committee Meeting on Superconducting Materials and Magnets was convened by the IAEA and held by invitation of the Japanese government on September 4-6, 1989 in Tokyo. The meeting was hosted by the National Research Institute for Metals. Topics of the conference related to superconducting magnets and technology with particular application to fusion and the superconducting supercollider. Technology using both high and low-temperature superconductors was discussed. This document is a compendium of the papers presented at the meeting. Refs, figs and tabs

  20. Effects of Toroidal Rotation Shear on Toroidicity-induced Alfven Eigenmodes in the National Spherical Torus Experiment

    International Nuclear Information System (INIS)

    The effects of a sheared toroidal rotation on the dynamics of bursting Toroidicity-induced Alfven eigenmodes are investigated in neutral beam heated plasmas on the National Spherical Torus Experiment (NSTX) (M. Ono et al., Nucl. Fusion 40 557 (2000)). The modes have a global character, extending over most of the minor radius. A toroidal rotation shear layer is measured at the location of maximum drive for the modes. Contrary to results from other devices, no clear evidence of increased damping is found. Instead, experiments with simultaneous neutral beam and radio-frequency auxiliary heating show a strong correlation between the dynamics of the modes and the instability drive. It is argued that kinetic effects involving changes in the mode drive and damping mechanisms other than rotation shear, such as continuum damping, are mostly responsible for the bursting dynamics of the modes.

  1. Effects of Toroidal Rotation Sshear on Toroidicity-induced Alfven Eigenmodes in the National Spherical Torus Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Podesta, M; Fredrickson, E D; Gorelenkov, N N; LeBlanc, B P; Heidbrink, W W; Crocker, N A; Kubota, S

    2010-08-19

    The effects of a sheared toroidal rotation on the dynamics of bursting Toroidicity-induced Alfven eigenmodes are investigated in neutral beam heated plasmas on the National Spherical Torus Experiment (NSTX) [M. Ono et al., Nucl. Fusion 40 557 (2000)]. The modes have a global character, extending over most of the minor radius. A toroidal rotation shear layer is measured at the location of maximum drive for the modes. Contrary to results from other devices, no clear evidence of increased damping is found. Instead, experiments with simultaneous neutral beam and radio-frequency auxiliary heating show a strong correlation between the dynamics of the modes and the instability drive. It is argued that kinetic effects involving changes in the mode drive and damping mechanisms other than rotation shear, such as continuum damping, are mostly responsible for the bursting dynamics of the modes.

  2. Safety analysis of superconducting poloidal magnets for a JAERI experimental fusion reactor

    International Nuclear Information System (INIS)

    The design of superconducting poloidal magnets was restudied concerning safety. The magnetmotive force of the superconducting air core transformer was reduced from 60 MAT to 48 MAT by shortening the operation period of reactor, so that the maximum repeated tensile stress of structural material (304SS) caused by electromagnetic force was lowered to the level of 24 kg/mm2 and stability margin of the superconductor was increased. The deterioration of thermal insulation in the vacuum jacket was studied, and safety valves were designed to cope with it. For repair, dissasembling the poloidal magnet was also studied in relation of the toroidal magnet. Analysis of general failure of the superconducting poloidal magnet was made by event tree and fault tree techniques. (author)

  3. Design and development of the SDC barrel electromagnetic calorimeter

    International Nuclear Information System (INIS)

    In fulfillment of contract SSC92-W-17743, Argonne National Laboratory is required to closeout and document all work performed in the design and development of the central calorimeter for the Solenoidal Detector Collaboration (SDC) Detector at the Superconducting Super Collider Laboratory (SSCL). This report will summarize the work performed, and identify all documents (technical reports, memo's, drawings, etc.) that resulted from that effort. The work under this contract was shared in collaboration with the Westinghouse Science and Technology Center (WSTC) of Pittsburgh, Pennsylvania. It is the intent of this report to provide information that can be useful in the development of future detectors for high energy physics particle research

  4. The Investigation on Welding Processes for SUS316LN Tubes Used in Superconducting Magnetic System of EAST

    Institute of Scientific and Technical Information of China (English)

    Wu Jiefeng; Chen Siyue; Weng Peide; Gao Daming

    2005-01-01

    The force flow cooled superconducting cable-in-conduit conductor (CICC) is used in both of EAST toroidal field (TF) and poloidal field (PF) coils. The conductor consists of multi-stage NbTi superconducting cable and 1.5 mm thick square jacket. The cable is pulled through in a thin wall circular jacket and then compacted to square cross-section conductor. The jacket material is SUS316LN austenitic stainless steel seamless tubes (about 10 m each), which is assembled by butt-welding up to 600 m. The results of the welding procedure investigation and quality assurance procedures carrying out are described in this paper.

  5. The Investigation on Welding Processes for SUS316LN Tubes Used in Superconducting Magnetic System of EAST

    Science.gov (United States)

    Wu, Jiefeng; Chen, Siyue; Weng, Peide; Gao, Daming

    2005-08-01

    The force flow cooled superconducting cable-in-conduit conductor (CICC) is used in both of EAST toroidal field (TF) and poloidal field (PF) coils. The conductor consists of multi-stage NbTi superconducting cable and 1.5 mm thick square jacket. The cable is pulled through in a thin wall circular jacket and then compacted to square cross-section conductor. The jacket material is SUS316LN austenitic stainless steel seamless tubes (about 10 m each), which is assembled by butt-welding up to 600 m. The results of the welding procedure investigation and quality assurance procedures carrying out are described in this paper.

  6. Superconductivity in the thirties

    International Nuclear Information System (INIS)

    The author discusses the theoretical advances made in understanding superconductivity by the introduction of new quantum mechanics. He concludes with a few comments on the present theory, BCS theory. (G.T.H.)

  7. Magnetic and superconducting nanowires

    DEFF Research Database (Denmark)

    Piraux, L.; Encinas, A.; Vila, L.;

    2005-01-01

    magnetic and superconducting nanowires. Using different approaches entailing measurements on both single wires and arrays, numerous interesting physical properties have been identified in relation to the nanoscopic dimensions of these materials. Finally, various novel applications of the nanowires are also...

  8. Superconductivity of magnesium diboride

    International Nuclear Information System (INIS)

    Highlights: • Over the past 14 years MgB2 has gone from a startling discovery to a promising, applied superconductor. • In this article we present a brief overview of the synthesis and the basic superconducting properties of this remarkable compound. • In particular, the effects of pressure, substitutions and neutron irradiation on superconducting properties are discussed. - Abstract: Over the past 14 years MgB2 has gone from a startling discovery to a promising, applied superconductor. In this article we present a brief overview of the synthesis and the basic superconducting properties of this remarkable compound. In particular, the effect of pressure, substitutions and neutron irradiation on superconducting properties are discussed

  9. Superconductivity: materials and applications

    International Nuclear Information System (INIS)

    This digest paper presents the different types of superconducting materials: 1 - the low-TC superconductors: the multi-filament composite as elementary constituent, the world production of NbTi, the superconducting cables of the LHC collider and of the ITER tokamak; 2 - the high-TC superconductors: BiSrCaCuO (PIT 1G) ribbons and wires, deposited coatings; 3 - application to particle physics: the the LHC collider of the CERN, the LHC detectors; 4 - applications to thermonuclear fusion: Tore Supra and ITER tokamaks; 5 - NMR imaging: properties of superconducting magnets; 6 - applications in electrotechnics: cables, motors and alternators, current limiters, transformers, superconducting energy storage systems (SMES). (J.S.)

  10. Dynamics of inner ear pressure release, measured with a double-barreled micropipette in the guinea pig

    NARCIS (Netherlands)

    Wit, HP; Thalen, EO; Albers, FWJ

    1999-01-01

    The inner ear, fluid pressure was measured in scala media of the guinea pig through one barrel of a double-barreled micropipette after a sudden volume increase or decrease, caused by injection or withdrawal of artificial endolymph through the other barrel. During injection or withdrawal, the inner e

  11. Structural insight into the biogenesis of β-barrel membrane proteins.

    Science.gov (United States)

    Noinaj, Nicholas; Kuszak, Adam J; Gumbart, James C; Lukacik, Petra; Chang, Hoshing; Easley, Nicole C; Lithgow, Trevor; Buchanan, Susan K

    2013-09-19

    β-barrel membrane proteins are essential for nutrient import, signalling, motility and survival. In Gram-negative bacteria, the β-barrel assembly machinery (BAM) complex is responsible for the biogenesis of β-barrel membrane proteins, with homologous complexes found in mitochondria and chloroplasts. Here we describe the structure of BamA, the central and essential component of the BAM complex, from two species of bacteria: Neisseria gonorrhoeae and Haemophilus ducreyi. BamA consists of a large periplasmic domain attached to a 16-strand transmembrane β-barrel domain. Three structural features shed light on the mechanism by which BamA catalyses β-barrel assembly. First, the interior cavity is accessible in one BamA structure and conformationally closed in the other. Second, an exterior rim of the β-barrel has a distinctly narrowed hydrophobic surface, locally destabilizing the outer membrane. And third, the β-barrel can undergo lateral opening, suggesting a route from the interior cavity in BamA into the outer membrane. PMID:23995689

  12. Photoemission, Correlation and Superconductivity:

    Science.gov (United States)

    Abrecht, M.; Ariosa, D.; Cloëtta, D.; Pavuna, D.; Perfetti, L.; Grioni, M.; Margaritondo, G.

    We review some of the problems still affecting photoemission as a probe of high-temperature superconductivity, as well as important recent results concerning their solution. We show, in particular, some of the first important results on thin epitaxial films grown by laser ablation, which break the monopoly of cleaved BCSCO in this type of experiments. Such results, obtained on thin LSCO, may have general implications on the theory of high-temperature superconductivity.

  13. Introduction to Color Superconductivity

    OpenAIRE

    Nardulli, G.

    2006-01-01

    At high nuclear density and small temperature, due to the asymptotic freedom property of Quantum ChromoDynamics and to the existence of an attractive channel in the color interaction, diquark condensates might be formed. Since these condensates break the color gauge symmetry, this phenomenon has the name of color superconductivity. In the last few years this has become a very active field of research. While a direct experimental test is still missing, color superconductivity might have implic...

  14. Relativistic Theory of Superconductivity

    OpenAIRE

    Capelle, K.; Marques, M. A. L.; Gross, E. K. U.

    2001-01-01

    The relativistic generalization of the theory of superconductivity is reviewed with respect to its conceptual basis and first applications. The construction of relativistically covariant order parameters for superconductors is outlined and the generalization of the Dirac equation for the superconducting state is presented. A weakly relativistic expansion of this equation leads to the Pauli equation for superconductors, which describes the lowest-order relativistic corrections to the conventio...

  15. Superconducting crab cavity

    International Nuclear Information System (INIS)

    Complete overlapping of the electron and positron bunches at colliding point can be attained by using the strong time-depending electromagnetic RF field in the superconducting crab cavity. Commissioning of the crab cavities started in February 2007 at KEKB. Effective head-on collision of electron and positron has been achieved successfully. After introduction of crab crossing and crab cavity, the structure and the fabrication of the KEKB superconducting crab cavity are discussed. (author)

  16. Charged Pion Energy Reconstruction in the ATLAS Barrel Calorimeter

    CERN Document Server

    Bosman, Martine; Nessi, Marzio

    1999-01-01

    Intrinsic performance of the ATLAS calorimeters in the barrel region with respect to charged pions was studied. For this the following simulated data were used: pion energy scans ($E = 20, 50, 200, 400$ and $1000$ GeV) at two pseudo-rapidity points ($eta = 0.3$ and $1.3$) and pseudo-rapidity scans ($-0.2 < eta < 1.8$) with pions of constant transverse energy ($E_T = 20$ and $50$ GeV). For pion energy reconstruction the benchmark approach was used. Performance was estimated for cases, when energy and rapidity dependent and independent calibration parameters were applied. The best results were obtained with energy and rapidity dependent parameters. Studies done for pions enabled optimization of the cone size and of the cut to obtain the best energy resolution. Energy dependence of the resolution can be parameterized as: $(50pm4)%/sqrt{E} oplus (3.4pm0.3)% oplus 1.0/E$ at $eta = 0.3$ and $(68pm8)%/sqrt{E} oplus (3.0pm0.7)% oplus 1.5/E$ at $eta = 1.3$. Larger constant term at $eta=0.3$ can be explained by l...

  17. Erosion measurement techniques for plasma-driven railgun barrels

    Energy Technology Data Exchange (ETDEWEB)

    Jamison, K.A.; Niiler, A.

    1987-04-01

    Plasma-driven railguns are now in operation at several locations throughout the world. All share common problems in barrel erosion arising from the fact that the bore surface must contain a high temperature plasma armature which transmits the acceleration force to a projectile. The plasma temperature at the core of the armature is estimated to be 30 000 K or higher. Such conditions are erosive to most materials even when the exposure time is 100 s or less. We have adapted two accelerator based techniques to aid in the study of this erosion. The first technique involves the collection and analysis of material ablated and left behind by the plasma. This analysis is baded on the unfolding of the Rutherford backscattered (RBS) spectra of 1 MeV deuterons incident on residue collected from a railgun bore. The second technique is an erosion measurement involving thin layer activation (TLA) of surfaces. In this process, the copper rail surface is activated by 2.4 MeV protons creating a relatively thin (3 m) layer sparsely seeded with a long lived zinc isotope. Monitoring the decay of the activated sample before and after a firing can detect surface wear of about 0.1 m. Results from the RBS and TLA experiments on the BRL plasma driven railgun are described.

  18. Erosion measurement techniques for plasma-driven railgun barrels

    Energy Technology Data Exchange (ETDEWEB)

    Jamison, K.A.; Niiler, A.

    1987-04-01

    Plasma-driven railguns are now in operation at several locations throughout the world. All share common problems in barrel erosion arising from the fact that the bore surface must contain a high temperature plasma armature which transmits the acceleration force to a projectile. The plasma temperature at the core of the armature is estimated to be 30 000 K or higher. Such conditions are erosive to most materials even when the exposure time is 100 ..mu..s or less. We have adapted two accelerator based techniques to aid in the study of this erosion. The first technique involves the collection and analysis of material ablated and left behind by the plasma. This analysis is baded on the unfolding of the Rutherford backscattered (RBS) spectra of 1 MeV deuterons incident on residue collected from a railgun bore. The second technique is an erosion measurement involving thin layer activation (TLA) of surfaces. In this process, the copper rail surface is activated by 2.4 MeV protons creating a relatively thin (3 ..mu..m) layer sparsely seeded with a long lived zinc isotope. Monitoring the decay of the activated sample before and after a firing can detect surface wear of about 0.1 ..mu..m. Results from the RBS and TLA experiments on the BRL plasma driven railgun are described.

  19. Performance of prototypes for the PANDA barrel EMC

    Science.gov (United States)

    Bremer, D. A.; Eissner, T.; Drexler, P.; Moritz, M.; Novotny, R. W.; PANDA Collaboration

    2015-02-01

    The PANDA experiment will be part of the future Facility for Antiproton and Ion Research (FAIR) and aims for the study of strong interaction within the charm sector via antiproton proton collisions up to antiproton momenta of 15 GeV/c. Reflecting the variety of the physics program the PANDA detector is designed as a multi-purpose detector able to perform tracking, calorimetry and particle identification with nearly complete coverage of the solid angle. The Electromagnetic Calorimeter (EMC) contained inside its Target Spectrometer is based on cooled PbWO4 scintillator crystals. In order to ensure an excellent performance throughout the large dynamic range of photon/electron energies ranging from a few MeV up to 15 GeV an extensive prototyping phase is mandatory. This contribution describes the measured response of the EMC barrel part prototype PROTO60 at the largest design energy to secondary beams provided by the SPS at CERN. In addition to PROTO60 a tracking station was deployed, providing precise position information of the 15 GeV/c positrons. For calibration purposes a 150 GeV/c muon beam and cosmic radiation, in combination with estimations from GEANT4 simulations were used. The obtained performance concerning energy, position and time information is presented.

  20. Supramolecular barrels from amphiphilic rigid-flexible macrocycles

    Science.gov (United States)

    Yang, Won-Young; Ahn, Jong-Hyun; Yoo, Yong-Sik; Oh, Nam-Keun; Lee, Myongsoo

    2005-05-01

    Precise control of supramolecular objects requires the rational design of molecular components, because the information determining their specific assembly should be encoded in their molecular architecture. In this context, diverse self-assembling molecules including liquid crystals, dendrimers, block copolymers, hydrogen-bonded complexes and rigid macrocycles are being created as a means of manipulating supramolecular structure. Incorporation of a stiff rod-like building block into an amphiphilic molecular architecture leads to another class of self-assembling molecules. Aggregation of rod building blocks can generate various nanoscale objects including bundles, ribbons, tubules and vesicles, depending on the molecular structure and/or the presence of a selective solvent. We present here an unusual example of supramolecular barrels in the solid and in aqueous solution, based on the self-assembly of amphiphilic rigid-flexible macrocycles driven by non-covalent interactions. Preliminary experiments show that these amphiphilic macrocycles are membrane-active. The amphiphilic macrocycles might thus lead to an excellent model system for exploring biological processes in supramolecular materials.

  1. Study of the EM Barrel Module 0 with muons

    CERN Document Server

    Camard, A; Laforge, B; Schwemling, P

    2001-01-01

    Muons contaminating the high energy electron beam have been used to study the EM barrel module~0 response to ''minimum ionising'' particles. The ratio between the muon signal and the noise reaches 7.11$\\pm$0.07 when only the middle sampling information are used and reconstructed with an optimal filtering method. The latter increases this ratio by a factor 1.8 with respect to a raw conversion between ADC counts and GeV. From an absolute energy measurement, a $\\left( \\frac{\\mathrm{e}}{\\mathrm{\\mu}} \\right)$ ratio of $0.75\\pm0.02$ is derived. As muons deposit their energy in a smaller cluster than the electrons, they can provide cleaner or complementary information on the calorimeter. For example, the modulation of a cell response with~$\\Phi$ is larger than with electrons, the modulation in the latter case being smoothed out by the transverse size of the electromagnetic showers. Unlike electrons, muons provide also a mean to test the crosstalk measurements done with calibration runs. A good agreement is found. A...

  2. Modal analysis of an ECC duct for APR+ reactor barrel

    International Nuclear Information System (INIS)

    Advanced Power Reactor Plus (APR+) provides four Direct Vessel Injection (DVI) ducts on the reactor barrel to enhance the performance of Emergency Core Cooling System (ECCS). Several studies on safety analysis have verified the excellent performance of the DVI duct. In this study, from the viewpoint of mechanical integrity, modal analyses of two full-scaled DVI ducts have been presented; both numerical analysis and modal tests have been performed in air and water. It was found that the numerical simulation and modal test coincide with each other. The DVI duct is a thin shell of 5 mm thickness, so that harmonic responses to RCP blade passing frequencies should be checked. The dominant passing frequencies are known to be 20, 40, 60, 120 and 240 Hz. In addition, an interesting thing in this study is that added mass effect by coolant seems to be so significant that the natural frequency of the ducts under water could be considerably low as compared with those in air; the natural frequency under water is 60 % lower than that in air. (author)

  3. High Stimulus-Related Information in Barrel Cortex Inhibitory Interneurons.

    Directory of Open Access Journals (Sweden)

    Vicente Reyes-Puerta

    2015-06-01

    Full Text Available The manner in which populations of inhibitory (INH and excitatory (EXC neocortical neurons collectively encode stimulus-related information is a fundamental, yet still unresolved question. Here we address this question by simultaneously recording with large-scale multi-electrode arrays (of up to 128 channels the activity of cell ensembles (of up to 74 neurons distributed along all layers of 3-4 neighboring cortical columns in the anesthetized adult rat somatosensory barrel cortex in vivo. Using two different whisker stimulus modalities (location and frequency we show that individual INH neurons--classified as such according to their distinct extracellular spike waveforms--discriminate better between restricted sets of stimuli (≤6 stimulus classes than EXC neurons in granular and infra-granular layers. We also demonstrate that ensembles of INH cells jointly provide as much information about such stimuli as comparable ensembles containing the ~20% most informative EXC neurons, however presenting less information redundancy - a result which was consistent when applying both theoretical information measurements and linear discriminant analysis classifiers. These results suggest that a consortium of INH neurons dominates the information conveyed to the neocortical network, thereby efficiently processing incoming sensory activity. This conclusion extends our view on the role of the inhibitory system to orchestrate cortical activity.

  4. Compact-Toroid development: status and technical needs

    International Nuclear Information System (INIS)

    This document contains the description, goals, status, plans, and strategy for the technical development of a class of magnetic confinement configurations collectively identified as Compact Toroids. This component of the magnetic fusion development program has been characterized by its potential for physical compactness and range of output power

  5. Theory of the M = 1 Kink Mode in Toroidal Plasma

    NARCIS (Netherlands)

    de Blank, H. J.; Schep, T. J.

    1991-01-01

    The energy principle of ideal magnetohydrodynamics (MHD) is used to study the ideal MHD stability of the m = 1 internal kink mode in a toroidal plasma. The equilibrium configurations that are considered allow for a broad region where the safety factor q is close to unity. This region may extend to t

  6. A toroidal inductor integrated in a standard CMOS process

    DEFF Research Database (Denmark)

    Vandi, Luca; Andreani, Pietro; Temporiti, Enrico;

    2007-01-01

    This paper presents a toroidal inductor integrated in a standard 0.13 um CMOS process. Finite-elements preliminary simulations are provided to prove the validity of the concept. In order to extract fundamental parameters by means of direct calculations, two different and well-known approaches...

  7. First studies of plasma confined in a toroidal heliac

    International Nuclear Information System (INIS)

    The first experimental results obtained on plasma confined in a toroidal heliac are reported. A simple method of generating highly ionized, weakly collisional plasma is described. It is found that the geometry of the plasma in general and the measured pressure profiles in particular conform closely with the calculated helical axis magnetic surfaces. Preliminary indications of plasma confinement are favourable

  8. Plasma Heating and Losses in Toroidal Multipole Fields

    International Nuclear Information System (INIS)

    The heating and loss of plasmas have been studied in three pulsed, toroidal multipole devices: a large levitated octupole, a small supported octupole and a very small supported quadrupole. Plasmas are produced by gun injection and heated by electron and ion cyclotron resonance heating and ohmic heating. Electron cyclotron heating rates have been measured over a wide range of parameters, and the results are in quantitative agreement with stochastic heating theory. Electron cyclotron resonance heating produces ions with energies larger than predicted by theory. With the addition of a toroidal field, ohmic heating gives densities as high as 1013cm-3 in the toroidal quadrupole and 1012cm-3 in the small octupole. Plasma losses for n=5 x 109cm-3 plasmas are inferred from Langmuir probe and Fabry-Perot interferometer measurements, and measured with special striped collectors on the wall and rings. The loss to a levitated ring is measured using a modulated light beam telemeter. The confinement is better than Bohm but considerably worse than classical. Low frequency convective cells which are fixed in space are observed. These cells around the ring are diminished when a weak toroidal field is added, and loss collectors show a vastly reduced flux to the rings. Analysis of the spatial density profile shows features of B-independent diffusion. The confinement is sensitive to some kinds of dc field errors, but surprisingly insensitive to perturbations of the ac confining field

  9. Construction and initial operation of the Advanced Toroidal Facility

    International Nuclear Information System (INIS)

    The Advanced Toroidal Facility (ATF) torsatron was designed on a physics basis for access to the second stability regime and on an engineering basis for independent fabrication of high-accuracy components. The actual construction, assembly, and initial operation of ATF are compared with the characteristics expected during the design of ATF. 31 refs., 19 figs., 2 tabs

  10. Plasma Processes : Minimum dissipative relaxed states in toroidal plasmas

    Indian Academy of Sciences (India)

    R Bhattacharyya; M S Janaki; B Dasgupta

    2000-11-01

    Relaxation of toroidal discharges is described by the principle of minimum energy dissipation together with the constraint of conserved global helicity. The resulting Euler-Lagrange equation is solved in toroidal coordinates for an axisymmetric torus by expressing the solutions in terms of Chandrasekhar-Kendall (C-K) eigenfunctions analytically continued in the complex domain. The C-K eigenfunctions are obtained as hypergeometric functions that are solutions of scalar Helmholtz equation in toroidal coordinates in the large aspect-ratio approximation. Equilibria are constructed by assuming the current to vanish at the edge of plasma. For the = 0; = 0 ( and are the poloidal and toroidal mode numbers respectively) relaxed states, the magnetic field, current, (safety factor) and pressure profiles are calculated for a given value of aspect-ratio of the torus and for different values of the eigenvalue 0. The new feature of the present model is that solutions allow for both tokamak as well as RFP-like behaviour with increase in the values of 0, which is related directly to volt-sec in the experiment.

  11. An Overview of Plasma Confinement in Toroidal Systems

    OpenAIRE

    Dini, Fatemeh; Baghdadi, Reza; Amrollahi, Reza; Khorasani, Sina

    2009-01-01

    This overview presents a tutorial introduction to the theory of magnetic plasma confinement in toroidal confinement systems with particular emphasis on axisymmetric equilibrium geometries, and tokamaks. The discussion covers three important aspects of plasma physics: Equilibrium, Stability, and Transport. The section on equilibrium will go through an introduction to ideal magnetohydrodynamics, curvilinear system of coordinates, flux coordinates, extensions to axisymmetric equilibrium, Grad-Sh...

  12. Stationary magnetohydrodynamic equilibrium of toroidal plasma in rotation

    International Nuclear Information System (INIS)

    The stationary equations of classical magnetohydrodynamics are utilized to study the toroidal motion of a thermonuclear magnetically - confined plasma with toroidal symmetry (Tokamak). In the present work, we considered a purely toroidal stationary rotation and te problem is reduced to studing a second order partial differencial equation of eliptic type Maschke-Perrin. Assuming that the temperature remains constant on the magnetic surfaces, an analitic solution, valid for low Mach numbers (M ≤ 0 .4), was obtained for the above-mentioned equation by means of a technique developed by Pantuso Sudano. From the solution found, we traced graphs for the quantities which described the equilibrium state of the plasma, namely: mass density, pressure, temperature, electric current density and toroidal magnetic field. Finally we compare this analitical model with others works which utilized differents analitical models and numerical simulations. We conclude that the solutions obtained are in good agreement with the previos results. In addition, however, our model contains the results of Sudano-Goes with the additional advantage of employing much simple analitical expressions. (author)

  13. Evidence of Inward Toroidal Momentum Convection in the JET Tokamak

    DEFF Research Database (Denmark)

    Tala, T.; Zastrow, K.-D.; Ferreira, J.;

    2009-01-01

    Experiments have been carried out on the Joint European Torus tokamak to determine the diffusive and convective momentum transport. Torque, injected by neutral beams, was modulated to create a periodic perturbation in the toroidal rotation velocity. Novel transport analysis shows the magnitude an...

  14. Theoretical studies of non inductive current drive in compact toroids

    NARCIS (Netherlands)

    Farengo, R; Lifschitz, AF; Caputi, KI; Arista, NR; Clemente, RA

    2002-01-01

    Three non inductive current drive methods that can be applied to compact toroids axe studied. The use of neutral beams to drive current in field reversed configurations and spheromaks is studied using a Monte Carlo code that includes a complete ionization package and follows the exact particle orbit

  15. Stability of toroidal magnetic fields in stellar interiors

    CERN Document Server

    Ibañez-Mejia, Juan C

    2015-01-01

    We present 3D MHD simulations of purely toroidal and mixed poloidal-toroidal magnetic field configurations to study the behavior of the Tayler instability. For the first time the simultaneous action of rotation and magnetic diffusion are taken into account and the effects of a poloidal field on the dynamic evolution of unstable toroidal magnetic fields is included. In the absence of diffusion, fast rotation (rotation rate compared to Alfv\\'en frequency) is able to suppress the instability when the rotation and magnetic axes are aligned and when the radial field strength gradient p 1.5, rapid rotation does not suppress the instability but instead introduces a damping factor to the growth rate in agreement with the analytic predictions. For the mixed poloidal-toroidal fields we find an unstable axisymmetric mode, not predicted analytically, right at the stability threshold for the non-axisymmetric modes; it has been argued that an axisymmetric mode is necessary for the closure of the Tayler-Spruit dynamo loop.

  16. The Quasi-Toroidal Stellarator: An Innovative Confinement Experiment

    International Nuclear Information System (INIS)

    To develop a new class of stellarators that exhibit improved confinement compared to conventional stellarators. This approach generally makes use of a designed symmetry of the magnetic field strength along a particular coordinate axis in the toroidal geometry of the stellarator, and is referred to as quasi-symmetry

  17. Toroidal and poloidal momentum transport studies in JET

    DEFF Research Database (Denmark)

    Tala, T.; Andrew, Y.; Crombe, K.;

    2007-01-01

    This paper reports on the recent studies of toroidal and poloidal momentum transport in JET. The ratio of the global energy confinement time to the momentum confinement is found to be close to tau(E)/tau(phi) = 1 except for the low density or low collisionality discharges where the ratio is tau(E...

  18. High temperature interfacial superconductivity

    Science.gov (United States)

    Bozovic, Ivan; Logvenov, Gennady; Gozar, Adrian Mihai

    2012-06-19

    High-temperature superconductivity confined to nanometer-scale interfaces has been a long standing goal because of potential applications in electronic devices. The spontaneous formation of a superconducting interface in bilayers consisting of an insulator (La.sub.2CuO.sub.4) and a metal (La.sub.1-xSr.sub.xCuO.sub.4), neither of which is superconducting per se, is described. Depending upon the layering sequence of the bilayers, T.sub.c may be either .about.15 K or .about.30 K. This highly robust phenomenon is confined to within 2-3 nm around the interface. After exposing the bilayer to ozone, T.sub.c exceeds 50 K and this enhanced superconductivity is also shown to originate from a 1 to 2 unit cell thick interfacial layer. The results demonstrate that engineering artificial heterostructures provides a novel, unconventional way to fabricate stable, quasi two-dimensional high T.sub.c phases and to significantly enhance superconducting properties in other superconductors. The superconducting interface may be implemented, for example, in SIS tunnel junctions or a SuFET.

  19. Superconducting Fullerene Nanowhiskers

    Directory of Open Access Journals (Sweden)

    Yoshihiko Takano

    2012-04-01

    Full Text Available We synthesized superconducting fullerene nanowhiskers (C60NWs by potassium (K intercalation. They showed large superconducting volume fractions, as high as 80%. The superconducting transition temperature at 17 K was independent of the K content (x in the range between 1.6 and 6.0 in K-doped C60 nanowhiskers (KxC60NWs, while the superconducting volume fractions changed with x. The highest shielding fraction of a full shielding volume was observed in the material of K3.3C60NW by heating at 200 °C. On the other hand, that of a K-doped fullerene (K-C60 crystal was less than 1%. We report the superconducting behaviors of our newly synthesized KxC60NWs in comparison to those of KxC60 crystals, which show superconductivity at 19 K in K3C60. The lattice structures are also discussed, based on the x-ray diffraction (XRD analyses.

  20. Electron pairing without superconductivity

    Science.gov (United States)

    Levy, Jeremy

    Strontium titanate (SrTiO3) is the first and best known superconducting semiconductor. It exhibits an extremely low carrier density threshold for superconductivity, and possesses a phase diagram similar to that of high-temperature superconductors--two factors that suggest an unconventional pairing mechanism. Despite sustained interest for 50 years, direct experimental insight into the nature of electron pairing in SrTiO3 has remained elusive. Here we perform transport experiments with nanowire-based single-electron transistors at the interface between SrTiO3 and a thin layer of lanthanum aluminate, LaAlO3. Electrostatic gating reveals a series of two-electron conductance resonances--paired electron states--that bifurcate above a critical pairing field Bp of about 1-4 tesla, an order of magnitude larger than the superconducting critical magnetic field. For magnetic fields below Bp, these resonances are insensitive to the applied magnetic field; for fields in excess of Bp, the resonances exhibit a linear Zeeman-like energy splitting. Electron pairing is stable at temperatures as high as 900 millikelvin, well above the superconducting transition temperature (about 300 millikelvin). These experiments demonstrate the existence of a robust electronic phase in which electrons pair without forming a superconducting state. Key experimental signatures are captured by a model involving an attractive Hubbard interaction that describes real-space electron pairing as a precursor to superconductivity. Support from AFOSR, ONR, ARO, NSF, DOE and NSSEFF is gratefully acknowledged.