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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

Progress on the superconducting magnet for the time projection chamber experiment (TPC) at PEP

Description: The TPC (Time Projection Chamber) experiment at PEP will have a two meter inside diameter superconducting magnet which creatests a 1.5 T uniform solenoidal field for the TPC. The superconducting magnet coil, cryostat, cooling system, and the TPC gas pressure vessel (which operatests at 11 atm) were designed to be about two thirds of a radiation length thick. As a result, a high current density coil design was chosen. The magnet is cooled by forced flow two phase helium. The TPC magnet is the largest adiabatically stable superconducting magnet built to date. The paper presents the parameters of the TPC thin solenoid and its subsystems. Tests results from the Spring 1980 cryogenic tes are presented. The topics to be dealt with in the paper are cryogenic services and the tests of magnet subsystems such as the folded current leads. Large thin superconducting magnet technology will be important to large detectors to be used on LEP.
Date: January 1, 1980
Creator: Green, M.A.; Eberhard, P.H. & Burns, W.A.
Partner: UNT Libraries Government Documents Department

Forced two phase helium cooling of large superconducting magnets

Description: A major problem shared by all large superconducting magnets is the cryogenic cooling system. Most large magnets are cooled by some variation of the helium bath. Helium bath cooling becomes more and more troublesome as the size of the magnet grows and as geometric constraints come into play. An alternative approach to cooling large magnet systems is the forced flow, two phase helium system. The advantages of two phase cooling in many magnet systems are shown. The design of a two phase helium system, with its control dewar, is presented. The paper discusses pressure drop of a two phase system, stability of a two phase system and the method of cool down of a two phase system. The results of experimental measurements at LBL are discussed. Included are the results of cool down and operation of superconducting solenoids.
Date: August 1, 1979
Creator: Green, M.A.; Burns, W.A. & Taylor, J.D.
Partner: UNT Libraries Government Documents Department

The Mechanical and Thermal Design for the MICE Detector SolenoidMagnet System

Description: The detector solenoid for MICE surrounds a scintillating fiber tracker that is used to analyze the muon beam within the detector. There are two detector magnets for measuring the beam emittance entering and leaving the cooling channel that forms the central part of the experiment. The field in the region of the fiber detectors must be from 2.8 to 4 T and uniform to better than 1 percent over a volume that is 300 mm in diameter by 1000 mm long. The portion of the detector magnet that is around the uniform field section of the magnet consists of two short end coils and a long center coil. In addition, in the direction of the MICE cooling channel, there are two additional coils that are used to match the muon beam in the cooling channel to the beam required for the detectors. Each detector magnet module, with its five coils, will have a design stored-energy of about 4 MJ. Each detector magnet is designed to be cooled using three 1.5 W coolers. This report presents the mechanical and electrical parameters for the detector magnet system.
Date: September 26, 2004
Creator: Fabbricatore, P.; Farinon, S.; Perrella, M.; Bravar, U. & Green,M.A.
Partner: UNT Libraries Government Documents Department

The Mice Focusing Solenoids and their Cooling System

Description: This report describes the focusing solenoid for the proposed Muon Ionization Cooling Experiment (MICE) [1]. The focusing solenoid consists of a pair of superconducting solenoids that are on a common bobbin. The two coils, which have separate leads, may be operated in the same polarity or at opposite polarity. This report discusses the superconducting magnet design and the cryostat design for the MICE focusing module. Also discussed is how this superconducting magnet can be integrated with a pair of small 4.2 K coolers.
Date: May 7, 2004
Creator: Green, M.A.; Barr, G.; Lau, W.; Senanayake, R.S. & Yang, S.Q.
Partner: UNT Libraries Government Documents Department

Quench Protection for the MICE Cooling Channel CouplingMagnet

Description: The MICE coupling coil is fabricated from Nb-Ti, which hashigh quench propagation velocities within the coil in all directionscompared to coils fabricated with other superconductors such as niobiumtin. The time for the MICE coupling coil to become fully normal throughnormal region propagation in the coil is shorter than the time needed fora safe quench (as defined by a hot-spot temperature that is less than 300K). A MICE coupling coil quench was simulated using a code written at theInstitute of Cryogenics and Superconductive Technology (ICST) at theHarbin Institute of Technology (HIT). This code simulates quench backfrom the mandrel as well as normal region propagation within the coil.The simulations included sub-division of the coil. Each sub-division hasa back to back diodes and resistor across the coil. Current flows in theresistor when there is enough voltage across the coil to cause current toflow through the diodes in the forward direction. The effects of thenumber of coil sub-divisions and the value of the resistor across thesub-division on the quench were calculated with and without quench back.Sub-division of the coupling coil reduces the peak voltage to ground, thelayer-to-layer voltage and the magnet hot-spot temperature. Quench backreduces the magnet hot-spot temperature, but the peak voltage to groundand layer-to-layer voltage are increased, because the magnet quenchesfaster. The resistance across the coil sub-division affects both thehot-spot temperature and the peak voltage to ground.
Date: November 20, 2007
Creator: Green, M.A.; Wang, L. & Guo, X.L.
Partner: UNT Libraries Government Documents Department

Three dimensional field calculations for a Short Superconducting Dipole for the UCLA Ultra Compact Synchrotron

Description: The Ultra Compact Synchrotron (UCS), proposed for UCLA, is a compact 1.5 GeV electron light source with superconducting magnets to produce X rays with a critical energy of about 10 keV. The design physical length (cold length) for the dipole is 418 mm. The synchrotron requires that a uniform field be produced in a region that is 180 mm wide by 40 mm high by about 380 mm long. The end regions of the dipole should be short compared to the overall length of the dipole field region. A Vobly H type of dipole was selected for the synchrotron bending magnets. In order for each dipole to bend a 1.5 GeV electron beam 30 degrees, the central induction must be in the range of 6.4 to 6.9 T (depending on the dipole magnetic length). The pole width for the dipole was set so that over 90% of the X rays generated by the magnet can be extracted. The three dimensional field calculations were done using TOSCA. This report shows that a Vobly type of dipole will behave magnetically as a conventional water cooled iron dominated dipole. The uniformity of the integrated magnetic field can be controlled by varying the current in the shield coil with respect to the gap and cross-over coils. The two dimensional field in the center of the magnet can be tuned to be very uniform over a width of 110 to 120 mm. The three dimensional calculations show that the magnetic length along a particle track in the dipole is about 29 mm longer than the length of the iron pole pieces. This report will present the three dimensional design of the UCS Vobly dipole and the results of the field calculations for that magnet.
Date: August 1, 1998
Creator: Green, M.A. & Taylor, C.E.
Partner: UNT Libraries Government Documents Department

High field solenoids for muon cooling

Description: The proposed cooling system for the muon collider will consist of a 200 meter long line of alternating field straight solenoids interspersed with bent solenoids. The muons are cooled in all directions using a 400 mm long section liquid hydrogen at high field. The muons are accelerated in the forward direction by about 900 mm long, 805 MHz RF cavities in a gradient field that goes from 6 T to -6 T in about 300 mm. The high field section in the channel starts out at an induction of about 2 T in the hydrogen. As the muons proceed down the cooling channel, the induction in the liquid hydrogen section increases to inductions as high as 30 T. The diameter of the liquid hydrogen section starts at 750 mm when the induction is 2 T. As the induction in the cooling section goes up, the diameter of the liquid hydrogen section decreases. When the high field induction is 30 T, the diameter of the liquid hydrogen section is about 80 mm. When the high field solenoid induction is below 8.5 T or 9T, niobium titanium coils are proposed for generating .the magnetic field. Above 8.5 T or 9 T to about 20 T, graded niobium tin and niobium titanium coils would be used at temperatures down to 1.8 K. Above 20 T, a graded bybrid magnet system is proposed, where the high field magnet section (above 20 T) is either a conventional water cooled coil section or a water cooled Bitter type coil. Two types of superconducting coils have been studied. They include; epoxy impregnated intrinsically stable coils, and cable in conduit conductor (CICC) coils with helium in the conduit.
Date: September 8, 1999
Creator: Green, M.A.; Eyssa, Y.; Kenny, S.; Miller, J.R. & Prestemon, S.
Partner: UNT Libraries Government Documents Department

A Four Cell Lattice for the UCLA Compact Light Source Synchrotron

Description: The 1.5 GeV compact light source UCS proposed for UCLA must fit into a shielded vault that is 9.144 meters (30 feet) wide. In order for the machine to fit into the allowable space, the ring circumference must be reduced 36 meters, the circumference of the six cell lattice, to something like 26 or 27 meters. The four cell lattice described in this report has a ring circumference of 27.0 meters.
Date: March 12, 1999
Creator: Garren, A.A. & Green, M.A.
Partner: UNT Libraries Government Documents Department

The design and construction of a gradient solenoid for the high powered RF cavity experiment for the muon collider

Description: This report describes the construction and test of a split solenoid that has a warm bore of 440 mm and a cryostat length of 1088 mm. (A 750 mm section contains the magnetic field.) When the coils are hooked so the fields are additive, the central induction is 5.0 T at its design current. When the coils are hooked so that the fields are in opposition, the induction at the center of the solenoid is zero and the peak induction on the solenoid axis is {+-}3.7 T. The on-axis induction gradient is 25 T per meter when the coils are hooked in opposition. When the coils are operated at their design currents in opposition, the force pushing the two coils apart is about 3 MN. The force pushing the coils apart is carried by the aluminum coil mandrel and a solid aluminum sheath outside of the superconducting winding. The coil was wound as a wet lay-up coil using alumina filled epoxy (Stycast). A layer of hard aluminum wire wound on the outside of the superconducting coil carries some of the hoop forces and limits the strain so that training does not occur. At design current, at both polarities, the peak induction in the windings is about 7 T. This report describes the solenoid magnet system and its construction.
Date: September 5, 1999
Creator: Green, M.A.; Chen, J.Y. & Wang, S.T.
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

Bent solenoid simulations for the muon cooling experiment

Description: The muon collider captures pions using solenoidal fields. The pion are converted to muons as they are bunched in an RF phase rotation system. Solenoids are used to focus the muons as their emitance is reduced during cooling. Bent solenoids are used to sort muons by momentum. This report describes a bent solenoid system that is part of a proposed muon cooling experiment. The superconducting solenoid described in this report consists of a straight solenoid that is 1.8 m long, a bent solenoid that is 1.0 m to 1.3 m long and a second straight solenoid that is 2.6 m long. The bent solenoid bends the muons over an angle of 57.3 degrees (1 radian). The bent solenoid has a minor coil radius (to the center of the coil) that is 0.24 m and a major radius (of the solenoid axis) of 1.0 m. The central induction along the axis is 3.0 T There is a dipole that generates an induction of 0.51 T, perpendicular to the plane of the bend, when the induction on the bent solenoid axis is 3.0 T.
Date: July 9, 1999
Creator: Green, M.A.; Eyssa, Y.M.; Kenney, S.; Miller, J.R. & Prestemon, S.
Partner: UNT Libraries Government Documents Department

A heat exchanger between forced flow helium gas at 14 to 18 K andliquid hydrogen at 20 K circulated by natural convection

Description: The Muon Ionization Cooling Experiment (MICE) has three 350-mm long liquid hydrogen absorbers to reduce the momentum of 200 MeV muons in all directions. The muons are then re-accelerated in the longitudinal direction by 200 MHz RF cavities. The result is cooled muons with a reduced emittance. The energy from the muons is taken up by the liquid hydrogen in the absorber. The hydrogen in the MICE absorbers is cooled by natural convection to the walls of the absorber that are in turn cooled by helium gas that enters at 14 K. This report describes the MICE liquid hydrogen absorber and the heat exchanger between the liquid hydrogen and the helium gas that flows through passages in the absorber wall.
Date: September 15, 2003
Creator: Green, M. A.; Ishimoto, S.; Lau, W. & Yang, S.
Partner: UNT Libraries Government Documents Department

Modeling the Thermal Mechanical Behavior of a 300 K Vacuum Vesselthat is Cooled by Liquid Hydrogen in Film Boiling

Description: This report discusses the results from the rupture of a thin window that is part of a 20-liter liquid hydrogen vessel. This rupture will spill liquid hydrogen onto the walls and bottom of a 300 K cylindrical vacuum vessel. The spilled hydrogen goes into film boiling, which removes the thermal energy from the vacuum vessel wall. This report analyzes the transient heat transfer in the vessel and calculates the thermal deflection and stress that will result from the boiling liquid in contact with the vessel walls. This analysis was applied to aluminum and stainless steel vessels.
Date: May 7, 2004
Creator: Yang, S.Q.; Green, M.A. & Lau, W.
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

Comparison of elementary geothermal-brine power-production processes

Description: From applied technology geothermal committee meeting; Idaho Falls, Idaho, USA (7 Aug 1973). A comparison of three simple geothermal power- production systems shows that the flashed steam and the compound systems are favored for use with high-temperature brines. The binary system becomes economically competitive only when used on low-temperature brines (enthalpies less than 350 Btu/lb). Geothermal power appears to be economically attractive even when low-temperature brines are used. (auth)
Date: August 1, 1973
Creator: Green, M.A. & Laird, A.D.K.
Partner: UNT Libraries Government Documents Department

Sampling and Analysis Plan for canister liquid and gas sampling at 105-KW fuel storage basin

Description: This Sampling and Analysis Plan (SAP) details the sampling and analyses to be performed on fuel canisters transferred to the Weasel Pit of the 105-KW fuel storage basin. The radionuclide content of the liquid and gas in the canisters must be evaluated to support the shipment of fuel elements to the 300 Area in support of the fuel characterization studies (Abrefah, et al. 1994, Trimble 1995). The following sections provide background information and a description of the facility under investigation, discuss the existing site conditions, present the constituents of concern, outline the purpose and scope of the investigation, outline the data quality objectives (DQO), provide analytical detection limit, precision, and accuracy requirements, and address other quality assurance (QA) issues.
Date: March 1, 1995
Creator: Harris, R.A.; Green, M.A.; Makenas, B.J. & Trimble, D.J.
Partner: UNT Libraries Government Documents Department

Scaling laws for modeling large superconducting solenoids

Description: The neutrino factory cooling system will consist of a long series of superconducting solenoids with a warm bore of 1.2 meters. In order to minimize the cost of the 200 to 300-meter long solenoid muon-cooling channel, the solenoids must be fabricated so that their mass is minimized. This report discusses how one can model the stress, strain and quench behavior of these large solenoid sections by building one-third to one-half scale models of the magnets. The cost of building and engineering the scale model magnets is a small fraction of the cost of fabricating a full-scale magnet section. This report discusses the limitations of the scaling approach as well as the types of superconducting solenoids for which the modeling technique is suitable.
Date: August 16, 2000
Creator: Green, M.A. & McInturff, A.D.
Partner: UNT Libraries Government Documents Department

Superconducting magnets for induction linac phase-rotation in a neutrino factory

Description: The neutrino factory[1-3] consists of a target section where pions are produced and captured in a solenoidal magnetic field. Pions in a range of energies from 100 Mev to 400 MeV decay into muons in an 18-meter long channel of 1.25 T superconducting solenoids. The warm bore diameter of these solenoids is about 600 mm. The phase rotation section slows down the high-energy muon and speeds up the low energy muons to an average momentum of 200 MeV/c. The phase-rotation channel consists of three induction linac channels with a short cooling section and a magnetic flux reversal section between the first and second induction linacs and a drift space between the second and third induction linacs. The length of the phase rotation channel will be about 320 meters. The superconducting coils in the channel are 0.36 m long with a gap of 0.14 m between the coils. The magnetic induction within the channel will be 1.25. For 260 meters of the 320-meter long channel, the solenoids are inside the induction linac. This paper discusses the design parameters for the superconducting solenoids in the neutrino factory phase-rotation channel.
Date: May 9, 2001
Creator: Green, M.A. & Yu, S.
Partner: UNT Libraries Government Documents Department