23 Matching Results

Search Results

Advanced search parameters have been applied.

Design Issues for the Superconducting Magnet that Goes Around theLiquid Hydrogen Absorber for the Muon Ionization Cooling Experiment(MICE)

Description: This report describes the design issues that are associated with a superconducting focusing solenoid that goes around a liquid hydrogen absorber for the Muon Ionization Cooling Experiment (MICE) proposed for the Rutherford Appleton Laboratory. The solenoid consists of two superconducting coils that may operated at the same polarity or at opposite polarities. As a result, the coils and their support structure must be designed to carry a 360-ton inter-coil force that is forcing the coils apart along their axis. The basic design parameters for the focusing magnet are discussed. The magnet and its cryostat are designed so that the absorber can be assembled and tested before installation into the pre-tested focusing solenoid. Safety requirements for MICE dictate that the insulating vacuum for the superconducting magnet be separated from the insulating vacuum for the absorber and that both vacuum be separated from the experiment vacuum and the vacuum within adjacent RF cavities. The safety issues associated with the arrangement of the various vacuums in the MICE focusing modules are presented. The effect of magnet operation and magnet quench on the liquid hydrogen absorber is also discussed.
Date: June 15, 2004
Creator: Barr, G.; Cobb, J.H.; Green, M.A.; Lau, W.; R.S., Senanayake; Yang, S.Q. et al.
Partner: UNT Libraries Government Documents Department

Progress on the Design and Fabircation of the MICE SpectrometerSolenoids

Description: The Muon Ionization Cooling Experiment (MICE) willdemonstrate ionization cooling in a short section of a realistic coolingchannel using a muon beam at Rutherford Appleton Laboratory (RAL) in theUK. A five-coil, superconducting spectrometer solenoid magnet at each endof the cooling channel will provide a 4 T uniform field region for thescintillating fiber tracker within the magnet bore tubes. The trackermodules are used to measure the muon beam emittance as it enters andexits the cooling channel. The cold mass for the 400 mm warm bore magnetconsists of two sections: a three-coil spectrometer magnet and a two-coilmatching section that matches the uniform field of the solenoid into theMICE cooling channel. The spectrometer solenoid detailed designandanalysis has been completed, and the fabrication of the magnets is wellunder way. The primary features of the spectrometer solenoid magnet andmechanical designs are presented along with a summary of key fabricationissues and photos of the construction.
Date: June 20, 2007
Creator: Virostek, S.P.; Green, M.A.; Lia, D. & Sizman, M.S.
Partner: UNT Libraries Government Documents Department

Progress on the Design of the Coupling coils for MICE andMUCOOL

Description: The Muon Ionization Cooling Experiment (MICE) [1]willdemonstrate ionization cooling in a short section of a realistic coolingchannel using a muon beam at Rutherford Appleton Laboratory (RAL) in theUK. The MICE RF and Coupling Coil (RFCC) Module consists of asuperconducting solenoid mounted around four normal conducting 201.25-MHzRF cavities. The coil package that surrounds the RF cavities is to bemounted in a 1.4 m diameter vacuum vessel. The coupling coil confines thebeam in the RFCC module within the radius of the RF cavity beam windows.Each coupling magnet will be powered by a 300 A, 10 V power supply. Themaximum design longitudinal force that will be carried by the cold masssupport system is 0.5 MN. The detailed design and analysis of thecoupling magnet has been completed by ICST. The primary magnetic andmechanical design features of the coils are presented in thispaper.
Date: June 20, 2007
Creator: Green, M.A.; Li, D.; Virostek, Steve P.; Wang, L.; Wu, H.; Li,L.K. et al.
Partner: UNT Libraries Government Documents Department

Progress Report on the g-2 Storage Ring Magnet System

Description: The 3.1 GeV muon storage ring for the g-2 experiment at Brookhaven National Laboratory has three large solenoid magnets that form a continuous 1.451 tesla storage ring dipole with an average beam bend radius of 7.1 meters. In addition to the three storage ring solenoids, there is an inflector dipole with nested dipole coils that create very little stray magnetic field. A superconducting shield on the inflector gets rid of most of the remaining stray flux. This paper reports on the progress made on the storage ring solenoid magnet system and the inflector as of June 1995. The results of cryogenic system tests are briefly reported.
Date: June 1, 1995
Creator: Bunce, G.A.; Cullen, J.; Danby, G.; Green, M.A.; Jackson, J.; Jia, L. et al.
Partner: UNT Libraries Government Documents Department

Nb3Sn Magnets for a Muon Collider

Description: High field dipole and quadrupole magnet designs with racetrack coils are investigated. The design option is particularly attractive for a muon collider dipole magnet using the Nb{sub 3}Sn superconductor. A conceptual design of {approx} 15 T single aperture dipole magnet is presented where the coils maintain a simple 2-d structure through the ends. The use of racetrack coils in quadrupole magnets is also discussed. It appears that the racetrack coils are less attractive for high gradient quadrupole magnets.
Date: June 20, 1998
Creator: Gupta, R.C.; Green, M.A.; Scanlan, R.M. & Palmer, R.
Partner: UNT Libraries Government Documents Department

Estimating the Cost of Superconducting Magnets and the Refrigerators Needed to Keep Them Cold

Description: The cost of superconducting magnets and the refrigerators needed to keep them cold can be estimated if one knows the magnet stored energy and the amount of refrigeration needed. This report updates the cost data collected over 20 years ago by Strobridge and others. Early cost data has been inflated into 1991 dollars and data on newer superconducting magnets has been added to the old data. The cost of superconducting magnets has been correlated with stored energy and field-magnetic volume product. The cost of the helium refrigerator cold box and the compressors needed to keep the magnet cold can be correlated with the refrigeration generated at 4.5K. The annual cost of 4.5K refrigeration can be correlated with 4.5K refrigeration and electrical energy cost.
Date: June 1, 1991
Creator: Green, M. A.; Byrns, R. & St. Lorant, S. J.
Partner: UNT Libraries Government Documents Department

Over Voltage in a Multi-sectioned Solenoid during a Quenching

Description: Accurate analysis of over voltage in the superconducting solenoid during a quench is one of the bases for quench protection system design. Classical quench simulation methods can only give rough estimation of the over voltage within a magnet coil. In this paper, for multi-sectioned superconducting solenoid, based on the classical assumption of ellipsoidal normal zone, three-dimension al temperature results are mapped to the one-dimension of the wire, the temperature distribution along the wire and the resistances of each turn are obtained. The coil is treated as circuit comprised of turn resistances, turn self and mutual inductances. The turn resistive voltage, turn inductive voltage, and turn resultant voltage along the wire are calculated. As a result, maximum internal voltages, the layer-to-layer voltages and the turn-to-turn voltages are better estimated. Utilizing this method, the over voltage of a small solenoid and a large solenoid during quenching have been studied. The result shows that this method can well improve the over voltage estimate, especially when the coil is larger.
Date: June 21, 2009
Creator: Guo, Xinglong; Wang, Li; Pan, Heng; Wu, Hong; Liu, Xiaokun; Chen, Anbin et al.
Partner: UNT Libraries Government Documents Department

Measurements of Retractable Gas-Cooled 6061 Aluminum ElectricalLeads Operating in a Vacuum

Description: To charge and discharge the ASTROMAG superconducting magnet in space requires retractable gas-cooled leads which must operate in a vacuum. This report describes the design and test of 500 ampere retractable gas-cooled leads made from 6061-T4 aluminum tubes. Aluminum is attractive for gas-cooled electrical leads in space because of its low mass density and the desire for short leads. Initial tests showed that retractable gas-cooled leads could operate in a vacuum from a source of normal helium. The pressure drop through the leads was low enough to permit a superconducting magnet to be charged and discharged while the leads vent into space. The leads were stable at currents above 700 amperes. The voltage drop across the contact between the upper and lower leads was as low as 1.2 mV per lead out of a total voltage drop of 42 mV per lead when the leads carried 714 amperes. The gas required for cooling was comparable to the more conventional copper gas-cooled current leads. In a second test seven months later. The contact resistance between the lead sections had increased considerably. In the second test, the contact resistance was repeatable for one lead but not for the other.
Date: June 1, 1991
Creator: Green, M.A.; Aguiar, H.; Bensadoun, M.J.; Gibson, J.H.; Heine,D.L.; Levin, S. et al.
Partner: UNT Libraries Government Documents Department

The Astromag Superconducting Magnet Facility Configured for a FreeFlying Satellite

Description: ASTROMAG is a particle astrophysics facility that was originally configured for the Space Station. The heart of the ASTROMAG facility is a large superconducting magnet which is cooled using superfluid helium. The task of resizing the facility so that it will fly in a satellite in. a high angle of inclination orbit is driven by the launch weight capability of the launch rocket and the desire to be able to do nearly the same physics as the Space Station version of ASTROMAG. In order to reduce the launch weight, the magnet and its cryogenic system had to be downsized, yet the integrated field generated by the magnet in the particle detectors has to match the Space Station version of the magnet. The use of aluminum matrix superconductor and oriented composite materials in the magnet insulation permits one to achieve this goal. The net magnetic dipole moment from the ASTROMAG magnet must be small to minimize the torque due to interaction with the earth's magnetic field. The ASTROMAG magnet consists of identical two coils 1.67 meters apart. The two coils are connected in series in persistent mode. Each coil is designed to carry 2.34 million ampere turns. Both coils are mounted on the same magnetic axis and they operate at opposite polarity. This reduces the dipole moment by a factor of more than 1000. This is tolerable for the Space Station version of the magnet. A magnet operating on a free flying satellite requires additional compensation. This report presents the magnet parameters of a free flying version of ASTROMAG and the parameters of the space cryogenic system for the magnet.
Date: June 1, 1991
Creator: Green, M.A. & Smoot, George F.
Partner: UNT Libraries Government Documents Department

Thermal Stability Analysis for Superconducting Coupling Coil in MICE

Description: The superconducting coupling coil to be used in the Muon Ionization Cooling Experiment (MICE) with inner radius of 750 mm, length of 285 mm and thickness of 110.4 mm will be cooled by a pair of 1.5 W at 4.2 K cryo-coolers. When the coupling coil is powered to 210 A, it will produce about 7.3 T peak magnetic field at the conductor and it will have a stored energy of 13 MJ. A key issue for safe operation of the coupling coil is the thermal stability of the coil during a charge and discharge. The magnet and its cooling system are designed for a rapid discharge where the magnet is to be discharged in 5400 seconds. The numerical simulation for the thermal stability of the MICE coupling coil has been done using ANSYS. The analysis results show that the superconducting coupling coil has a good stability and can be charged and discharged safely.
Date: June 28, 2010
Creator: Wu, Hong; Wang, Li; Pan, Heng; Guo, XingLong & Green, M.A.
Partner: UNT Libraries Government Documents Department

Progress on Design and Construction of a MuCool Coupling Solenoid Magnet

Description: The MuCool program undertaken by the US Neutrino Factory and Muon Collider Collaboration is to study the behavior of muon ionization cooling channel components. A single superconducting coupling solenoid magnet is necessary to pursue the research and development work on the performance of high gradient, large size RF cavities immersed in magnetic field, which is one of the main challenges in the practical realization of ionization cooling of muons. The MuCool coupling magnet is to be built using commercial copper based niobium titanium conductors and cooled by two cryo-coolers with each cooling capacity of 1.5 W at 4.2 K. The solenoid magnet will be powered by using a single 300A power supply through a single pair of binary leads that are designed to carry a maximum current of 210A. The magnet is to be passively protected by cold diodes and resistors across sections of the coil and by quench back from the 6061 Al mandrel in order to lower the quench voltage and the hot spot temperature. The magnet is currently under construction. This paper presents the updated design and fabrication progress on the MuCool coupling magnet.
Date: June 28, 2010
Creator: Wang, L.; Liu, Xiao Kun; Xu, FengYu; Li, S.; Pan, Heng; Wu, Hong et al.
Partner: UNT Libraries Government Documents Department

Cryogenic testing of the TPC superconducting solenoid

Description: This report describes the results of a series of tests on the TPC superconducting magnet cryogenic system which occurred during the winter and spring of 1983. The tests occurred at interaction region 2 of the PEP colliding beam facility at the Stanford Linear Accelerator Center (SLAC). The TPC Magnet Cryogenic System which was tested includes the following major components: a remote helium compressor with a full flow liquid nitrogen purification station, 400 meters of high pressure supply and low pressure return lines; and locally a CTi Model 2800 refrigerator with two Sulzer gas bearing turbines, the TPC magnet control dewar, 70 meters of transfer lines, and the TPC thin superconducting solenoid magnet. In addition, there is a conditioner (liquid nitrogen heat exchangers and gas heaters) system for cooldown and warmup of the magnet. This report describes the local cryogenic system and describes the various steps in the cooldown and operation of the TPC magnet. The tests were successful in that they showed that the TPC magnet could be cooled down in 24 hours and the magnet could be operated on the refrigerator or a helium pump with adequate cooling margin. The tests identified problems with the cryogenic system and the 2800 refrigerator. Procedures for successful operation and quenching of the superconducting magnet were developed. 19 references.
Date: June 1, 1983
Creator: Green, M.A.; Smits, R.G.; Taylor, J.D.; van Slyke, V.; Barrera, F.; Petersen, H. et al.
Partner: UNT Libraries Government Documents Department

SUPERCONDUCTING SOLENOIDS FOR THE MUON COLLIDER

Description: The muon collider is a new idea for lepton colliders. The ultimate energy of an electron ring is limited by synchrotron radiation. Muons, which have a rest mass that is 200 times that of an electron can be stored at much higher energies before synchrotron radiation limits ring performance. The problem with muons is their short life time (2.1 {micro}s at rest). In order to operate a muon storage ring large numbers of muon must be collected, cooled and accelerated before they decay to an electron and two neutrinos. As the authors see it now, high field superconducting solenoids are an integral part of a muon collider muon production and cooling systems. This report describes the design parameters for superconducting and hybrid solenoids that are used for pion production and collection, RF phase rotations of the pions as they decay into muons and the muon cooling (reduction of the muon emittance) before acceleration.
Date: June 12, 2000
Creator: Green, M. A.; Eyssa, Y.; Kenny, S.; Miller, J. R.; Prestemon, S. & Weggel, R. J.
Partner: UNT Libraries Government Documents Department

High-gradient normal-conducting RF structures for muon cooling channels

Description: We present a status report on the research and development of high-gradient normal-conducting RF structures for the ionization cooling of muons in a neutrino factory or muon collider. High-gradient RF structures are required in regions enclosed in strong focusing solenoidal magnets, precluding the application of superconducting RF technology [1]. We propose using linear accelerating structures, with individual cells electromagnetically isolated, to achieve the required gradients of over 15 MV/m at 201 MHz and 30 MV/m at 805 MHz. Each cell will be powered independently, and cell length and drive phase adjusted to optimize shunt impedance of the assembled structure. This efficient design allows for relatively small field enhancement on the structure walls, and an accelerating field approximately 1.7 times greater than the peak surface field. The electromagnetic boundary of each cell may be provided by a thin Be sheet, or an assembly of thin-walled metal tubes. Use of thin, low-Z materials will allow passage of the muon beams without significant deterioration in beam quality due to scattering. R and D in design and analysis of robust structures that will operate under large electric and magnetic fields and RF current heating are discussed, including the experimental program based in a high-power test laboratory developed for this purpose.
Date: June 12, 2001
Creator: Corlett, J.N.; Green, M.A.; Hartman, N.; Ladran, A.; Li, D.; MacGill, R. et al.
Partner: UNT Libraries Government Documents Department

Optimization of superconducting bending magnets for a 1.0 to 1.5 GeV compact light source

Description: Compact light sources are being proposed for protein crystallography, medical imaging, nano-machining and other areas of study that require intense sources of x rays at energies up to 35 keV. In order for a synchrotron light source to be attractive, its capital cost must, be kept low. The proposed compact light source has superconducting bending elements to bend the stored beam and produce the x rays. Additional focusing for the machine is provided by conventional quadrupoles. An important part of the cost optimization of a compact light source is the cost of the bending magnets. In the case of a machine with superconducting bending elements, the bending magnet system can represent close to half of the storage ring cost. The compact light source storage rings studied here have a range of stored electron energies from 1.0 to 1.5 GeV. For a number of reasons, it is desirable to keep the storage ring circumference below 30 meters. Cost optimization parameters include: (1) the number of superconducting bending elements in the ring, and (2) the central induction of the dipole. A machine design that features two superconducting dipoles in a single cryostat vacuum vessel is also discussed.
Date: June 1, 1995
Creator: Green, M.A. & Garren, A.A.
Partner: UNT Libraries Government Documents Department

Design parameters for a 7.2 tesla bending magnet for a 1.5 GeV compact light source

Description: This report describes the design for a 7.2 tesla superconducting dipole magnet for a compact synchrotron light source. The proposed magnet is a Vobly type modified picture frame dipole that has the flux returned through unsaturated iron. In this magnet, The iron in the pole pieces is highly saturated, Separately powered coils around the pole pieces are used to direct the flux lines until the flux can be returned through the unsaturated iron. The proposed dipole will develop a uniform field over a region that is 80 mm high by 130 mm wide over a range of central induction from 0.4 T to almost 8 T. Each dipole for the compact light source will have a magnetic length of about 0.38 meters.
Date: June 1, 1995
Creator: Green, M. A. & Madura, D.
Partner: UNT Libraries Government Documents Department

The effect of flux creep on the magnetization field in the SSC diopole magnets

Description: The sextuple fields of model SSC dipole magnets have been observed to change with time when the magnets are held at constant current under conditions similar to injection into the SSC accelerator. The changes in the sextupole component have close to a linear log time dependence, and is felt to be caused by flux creep decay of the magnetization currents in the superconductor filaments. Measurements of this decay have been made under various conditions. The conditions include various central field inductions and changes of field prior to when the decay was measured. The measured field decay in the dipole's sextupole is proportional to the magnitude and sign of the sextupole due to magnetization which was measured at the start of the decay. This suggests that the decay is a bulk superconductivity flux creep. Proximity coupling appears to play only a minor role in the flux creep according to recent LBL measurements with a stable power supply. 4 refs., 6 figs., 3 tabs.
Date: June 1, 1989
Creator: Gilber, W.S.; Althaus, R.F.; Barale, P.J.; Benjegerdes, R.W.; Green, M.A.; Green, M.I. et al.
Partner: UNT Libraries Government Documents Department

Measurements of retractable gas-cooled 6061 aluminum electrical leads operating in a vacuum

Description: To charge and discharge the ASTROMAG superconducting magnet in space requires retractable gas-cooled leads which must operate in a vacuum. This report describes the design and test of 500 ampere retractable gas-cooled leads made from 6061-T4 aluminum tubes. Aluminum is attractive for gas-cooled electrical leads in space because of its low mass density and the desire for short leads. Initial tests showed that retractable gas-cooled leads could operate in a vacuum from a source of normal helium. The pressure drop through the leads was low enough to permit a superconducting magnet to be charged and discharged while the leads vent into space. The leads were stable at currents above 700 amperes. The voltage drop across the contact between the upper and lower leads was as low as 1.2 mV per lead out of a total voltage drop of 42 mV per lead when the leads carried 714 amperes. The gas required for cooling was comparable to the more conventional copper gas-cooled current leads. In a second test seven months later, the contact resistance between the lead sections had increased considerably. In the second test, the contact resistance was repeatable for one lead but not for the other. 6 refs., 2 figs.
Date: June 1, 1991
Creator: Green, M.A.; Aguiar, H.; Bensadoun, M.J.; Gibson, J.H.; Heine, D.L.; Levin, S. et al.
Partner: UNT Libraries Government Documents Department

The ASTROMAG superconducting magnet facility configured for a free flying satellite

Description: ASTROMAG is a particle astrophysics facility that was originally configured for the Space Station. The heart of the ASTROMAG facility is a large superconducting magnet which is cooled using superfluid helium. The task of resizing the facility so that it will fly in a satellite in a high angle of inclination orbit is driven by the launch weight capability of the launch rocket and the desire to be able to do nearly the same physics as the Space Station version of ASTROMAG. In order to reduce the launch weight, the magnet and its cryogenic system had to be downsized, yet the integrated field generated by the magnet in the particle detectors has to match the Space Station version of the magnet. The use of aluminum matrix superconductor and oriented composite materials in the magnet insulation permits one to achieve this goal. The net magnetic dipole moment from the ASTROMAG magnet must be small to minimize the torque due to interaction with the earth's magnetic field. The ASTROMAG magnet consists of identical two coils 1.67 meters apart. The two coils are connected in series in persistent mode. Each coil is designed to carry 2.34 million ampere turns. Both coils are mounted on the same magnetic axis and they operate at opposite polarity. This reduces the dipole moment by a factor of more than 1000. This is tolerable for the Space Station version of the magnet. A magnet operating on a free flying satellite requires additional compensation. This report presents the magnet parameters of a free flying version of ASTROMAG and the parameters of the space cryogenic system for the magnet. 12 refs., 6 figs.
Date: June 1, 1991
Creator: Green, M.A. & Smoot, G.F.
Partner: UNT Libraries Government Documents Department

Measurements of magnetization multipoles in four centimeter quadrupoles for the SSC

Description: Higher multipoles due to magnetization of the superconductor in superconducting dipole and quadrupole magnets has been observed in over twenty years. This report presents measurements of the 12 pole and 20 pole multipoles in a model one-meter long four-centimeter bore SSC type quadrupole built at the Lawrence Berkeley Laboratory (LBL). The measurements were compared with calculations of the field structure using magnetization theory. Good agreement was observed between the measured multipoles and the calculated multipoles. Under conditions equivalent to injection into the SSC at an energy of 2 TeV, about 1.0 unit of 12 pole was observed and 0.05 units of 20 pole was observed. (One unit of field error is a field error of one part in ten thousand). Magnetization multipole measurements were also done on the first full length (5 meter) SSC quadrupole prototype. Measurements of flux creep decay were made on three one meter quadrupoles and the first five meter long quadrupole. 7 refs., 9 figs.
Date: June 1, 1991
Creator: Green, M.A.; Barale, P.J.; Benjegerdes, R.W.; Gilbert, W.S.; Green, M.I.; Scanlan, R.M. et al.
Partner: UNT Libraries Government Documents Department

Large high current density superconducting solenoid for the time projection chamber experiment

Description: One of the experiments for the PEP storage rings at the Stanford Linear Accelerator Center uses a superconducting magnet to provide the magnetic field for the Time Projection Chamber detector. This magnet has an inside diameter of 2.04 m and a gap of 3.26 m. The magnet central induction is 1.5 T. This magnetic induction is supplied by a thin high current density superconducting coil which is less than 0.4 radiation lengths thick. The magnet stored energy will be 10.9 MJ; the coil superconductor matrix current density will be about 7.0 x 10/sup 8/ Am/sup -2/. The TPC magnet uses a two-phase forced flow tubular cooling system which combines many of the advantages of single-phase supercritical helium cooling with those of boiling helium bath cooling.
Date: June 1, 1978
Creator: Green, M.A.; Burns, W.A.; Eberhard, P.H.; Gibson, G.H.; Miller, P.B.; Ross, R.R. et al.
Partner: UNT Libraries Government Documents Department

Vacuum impregnation with epoxy of large superconducting magnet structures

Description: The Lawrence Berkeley Laboratory (LBL) has been developing a new generation of superconducting magnets which have the helium cooling system as an integral part of the magnet structure. The LBL technique calls for large sections of the magnet structure to be vacuum impregnated with epoxy. The epoxy was chosen for its impregnation properties. Epoxies which have good impregnation characteristics are often subject to cracking when they are cooled to cryogenic temperatures. The cracking of such an epoxy can be controlled by: (1) minimizing the amount of epoxy in the structure; (2) reducing the size of unfilled epoxy spaces; and (3) keeping the epoxy in compression. The technique for using the epoxy is often more important than the formulation of the epoxy. The LBL vacuum impregnation and curing technique is described. Experimental measurements on small samples of coil sections are presented. Practical experience with large vacuum impregnation superconducting coils (up to two meters in dia) is also discussed.
Date: June 1, 1978
Creator: Green, M.A.; Coyle, D.E.; Miller, P.B. & Wenzel, W.F.
Partner: UNT Libraries Government Documents Department