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The Engineering Design of the 1.5 m Diameter Solenoid for the MICERFCC Modules

Description: The RF coupling coil (RFCC) module of MICE is where muonsthat have been cooled within the MICE absorber focus (AFC) modules arere-accelerated to their original longitudinal momentum. The RFCC moduleconsists of four 201.25 MHz RF cavities in a 1.4 meter diameter vacuumvessel. The muons are kept within the RF cavities by the magnetic fieldgenerated by a superconducting coupling solenoid that goes around the RFcavities. The coupling solenoid will be cooled using a pair of 4 K pulsetube cooler that will generate 1.5 W of cooling at 4.2 K. The magnet willbe powered using a 300 A two-quadrant power supply. This report describesthe ICST engineering design of the coupling solenoid forMICE.
Date: August 27, 2007
Creator: Wang, L.; Green, M.A.; Xu, F.Y.; Wu, H.; Li, L.K.; Gou, C.S. et al.
Partner: UNT Libraries Government Documents Department

The Helium Cooling System and Cold Mass Support System for theMICE Coupling Solenoid

Description: The MICE cooling channel consists of alternating threeabsorber focus coil module (AFC) and two RF coupling coil module (RFCC)where the process of muon cooling and reacceleration occurs. The RFCCmodule comprises a superconducting coupling solenoid mounted around fourconventional conducting 201.25 MHz closed RF cavities and producing up to2.2T magnetic field on the centerline. The coupling coil magnetic fieldis to produce a low muon beam beta function in order to keep the beamwithin the RF cavities. The magnet is to be built using commercialniobium titanium MRI conductors and cooled by pulse tube coolers thatproduce 1.5 W of cooling capacity at 4.2 K each. A self-centering supportsystem is applied for the coupling magnet cold mass support, which isdesigned to carry a longitudinal force up to 500 kN. This report willdescribe the updated design for the MICE coupling magnet. The cold masssupport system and helium cooling system are discussed indetail.
Date: August 27, 2007
Creator: Wang, L.; Wu, H.; Li, L.K.; Green, M.A.; Liu, C.S.; Li, L.Y. et al.
Partner: UNT Libraries Government Documents Department

Liquid Cryogen Absorber for MICE

Description: The Muon Ionization Cooling Experiment (MICE) will test ionization cooling of muons. In order to have effective ionization cooling, one must use an absorber that is made from a low-z material. The most effective low z materials for ionization cooling are hydrogen, helium, lithium hydride, lithium and beryllium, in that order. In order to measure the effect of material on cooling, several absorber materials must be used. This report describes a liquid-hydrogen absorber that is within a pair of superconducting focusing solenoids. The absorber must also be suitable for use with liquid helium. The following absorber components are discussed in this report; the absorber body, its heat exchanger, the hydrogen system, and the hydrogen safety. Absorber cooling and the thin windows are not discussed here.
Date: August 20, 2005
Creator: Baynham, D.E.; Bish, P.; Bradshaw, T.W.; Cummings, M.A.; Green,M.A.; Ishimoto, S. et al.
Partner: UNT Libraries Government Documents Department

The Development of 6061-Aluminum Windows for the MICE LiquidAbsorber

Description: The thin windows for the Muon Ionization Cooling Experiment (MICE) liquid Absorber will be fabricated from 6061-T6-aluminum. The absorber and vacuum vessel thin windows are 300-mm in diameter and are 180 mm thick at the center. The windows are designed for an internal burst pressure of 0.68 MPa (100 psig) when warm. The MICE experiment design calls for changeable windows on the absorber, so a bolted window design was adopted. Welded windows offer some potential advantages over bolted windows when they are on the absorber itself. This report describes the bolted window and its seal. This report also describes an alternate window that is welded directly to the absorber body. The welded window design presented permits the weld to be ground off and re-welded. This report presents a thermal FEA analysis of the window seal-weld, while the window is being welded. Finally, the results of a test of a welded-window are presented.
Date: August 24, 2005
Creator: Lau, W.; Yang, S.Q.; Green, M.A.; Ishimoto, S. & Swanson, J.
Partner: UNT Libraries Government Documents Department

The Cooling of a Liquid Absorber using a Small Cooler

Description: This report discusses the use of small cryogenic coolers for cooling the Muon Ionization Cooling Experiment (MICE) liquid cryogen absorbers. Since the absorber must be able contain liquid helium as well liquid hydrogen, the characteristics of the available 4.2 K coolers are used here. The issues associated with connecting two-stage coolers to liquid absorbers are discussed. The projected heat flows into an absorber and the cool-down of the absorbers using the cooler are presented. The warm-up of the absorber is discussed. Special hydrogen safety issues that may result from the use of a cooler on the absorbers are also discussed.
Date: August 24, 2005
Creator: Baynham, D.E.; Bradshaw, T.W.; Green, M.A.; Ishimoto, S. & Liggins, N.
Partner: UNT Libraries Government Documents Department

The Effect of Magnetic Field on the Position of HTS Leads and theCooler in the Services Tower of the MICE Focusing Magnet

Description: The MICE focusing solenoids have three 4 K coolers (two forthe superconducting magnet and one for the liquid absorber) and four HTSleads that feed the current to the focusing coils. The focusing solenoidsproduce large radial external fields when they operate with the polarityof the two coils in opposition (the gradient or flip mode). When the MICEfocusing coils operate at the same polarity (the solenoid or non-flipmode), the fields are much smaller and parallel to the axis of thesolenoid. The worst-case magnetic field affects the selection of thecooler and the HTS leads. This magnetic field can also determine theheight of the service towers that house the three coolers and the fourHTS leads. This paper shows the criteria used for Cooler selection, HTSlead selection, and the position of both the cooler and leads withrespect to the solenoid axis of rotation.
Date: August 27, 2007
Creator: Green, M.A.; Yang, S.Q.; Cobb, J.; Lau, P.; Lau, W.W.; Witte,H. et al.
Partner: UNT Libraries Government Documents Department

The Cost of Superconducting Magnets as a Function of Stored Energy and Design Magnetic Induction Times the Field Volume

Description: By various theorems one can relate the capital cost of superconducting magnets to the magnetic energy stored within that magnet. This is particularly true for magnet where the cost is dominated by the structure needed to carry the magnetic forces. One can also relate the cost of the magnet to the product of the magnetic induction and the field volume. The relationship used to estimate the cost the magnet is a function of the type of magnet it is. This paper updates the cost functions given in two papers that were published in the early 1990 s. The costs (escalated to 2007 dollars) of large numbers of LTS magnets are plotted against stored energy and magnetic field time field volume. Escalated costs for magnets built since the early 1990 s are added to the plots.
Date: August 27, 2007
Creator: Green, Mike; Green, M.A. & Strauss, B.P.
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

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

Multiparameter Optimization Studies on Geothermal Energy Cycles

Description: Various standard geothermal power cycles are modeled and optimized with program GEOTHM. The results are displayed in 3-D isometric form. These graphical plots vividly display the sensitivity of energy cost and other performance criteria as a result of departures from the design operating point. For example, we will present the mutual interaction of energy cost, resource utilization efficiency, and resource temperature as an EC-RUE-RT surface for a range of temperatures between 100 C and 300 C. Calculation results will be presented for subcritical and supercritical binary cycles with several pure fluids, and on two stage flashed steam cycles for practical non-condensable gas levels.
Date: August 1, 1977
Creator: Pope, W.L.; Pines, H.S.; Silvester, L.F.; Green, M.A. & Williams, J.D.
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

LUX - A recirculating linac-based ultrafast X-ray source

Description: We describe the design of a proposed source of ultra-fast synchrotron radiation x-ray pulses based on a recirculating superconducting linac, with an integrated array of ultrafast laser systems. The source produces x-ray pulses with duration of 10-50 fs at a 10 kHz repetition rate, with tunability from EUV to hard x-ray regimes, and optimized for the study of ultra-fast dynamics. A high-brightness rf photocathode provides electron bunches. An injector linac accelerates the beam to the 100 MeV range, and is followed by four passes through a 700 MeV recirculating linac. Ultrafast hard x-ray pulses are obtained by a combination of electron bunch manipulation, transverse temporal correlation of the electrons, and x-ray pulse compression. EUV and soft x-ray pulses as short as 10 fs are generated in a harmonic-cascade free electron laser scheme.
Date: August 1, 2003
Creator: Corlett, J. N.; Barletta, W. A.; DeSantis, S.; Doolittle, L.; Fawley, W. M.; Green, M. A. et al.
Partner: UNT Libraries Government Documents Department

Two phase cooling for superconducting magnets

Description: A closed circuit tubular cooling system for superconducting magnets offers advantages of limiting boiloff and containing high pressures during quenches. Proper location of automatic valves to lower pressures and protect the refrigerator in the event of quenches is described. Theoretical arguments and exprimental evidence are given against a previously suggested method to determine He two phase flow regimes. If loss of flow occurs due to some types of refrigeration failure and transfer lines have enough heat leak to warm up, quenches are induced when the flow is restored. Examples are taken from experience with the TPC magnet.
Date: August 1, 1985
Creator: Eberhard, P.H.; Gibson, G.A.; Green, M.A.; Ross, R.R.; Smits, R.G.; Taylor, J.D. et al.
Partner: UNT Libraries Government Documents Department

Magnetic field decay in model SSC dipoles

Description: We have observed that some of our model SSC dipoles have long time constant decays of the magnetic field harmonics with amplitudes large enough to result in significant beam loss, if they are not corrected. The magnets were run at constant current at the SSC injection field level of 0.3 tesla for one to three hours and changes in the magnetic field were observed. One explanation for the observed field decay is time dependent superconductor magnetization. Another explanation involves flux creep or flux flow. Data are presented on how the decay changes with previous flux history. Similar magnets with different Nb-Ti filament spacings and matrix materials have different long time field decay. A theoretical model using proximity coupling and flux creep for the observed field decay is discussed. 10 refs., 5 figs., 2 tabs.
Date: August 1, 1988
Creator: Gilbert, 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

Reduced mass persistent switches for large superconducting magnets in space

Description: Superconducting magnets in space must operate in the persistent mode. This paper describes the characteristics of low mass niobium titanium persistent switches for low mass superconducting magnets which are designed to quench protect themselves through the quench back process. (The whole coil is driven normal shortly after the quench has started and the magnet stored energy is taken up by the coil and the persistent switch.) The concept Of using a resistor and diode in parallel with the persistent switch to reduce the overall mass of the persistent switch system and the helium consumption during magnet charging is discussed in the report. A 1.4 meter diameter free-flyer version of the 11.6 Mi stored energy ASTROMAG magnet and its persistent switch is presented as an example.
Date: August 1, 1992
Creator: Green, M.A.
Partner: UNT Libraries Government Documents Department

Magnetic measurements at Lawrence Berkeley Laboratory

Description: Recent magnetic measurement activities at LBL have been concentrated in two separate areas, electro-magnets and permanent magnets for the Advanced Light Source (ALS), and superconducting magnets for the Superconducting Super Collider Laboratory (SSCL). A survey of the many different measurement systems is presented. These include: AC magnetic measurements of an ALS booster dipole engineering model magnet, dipole moment measurements of permanent magnet blocks for ALS wigglers and undulators, permeability measurements of samples destined for wiggler and undulator poles, harmonic error analysis of SSC one meter model dipoles and quadrupoles and five meter long SSC prototype quadrupoles, harmonic error analysis of ALS dipoles, quadrupoles, and sextupoles, precision Hall probe mapping of ALS storage ring combined function magnets, and the design of the ALS insertion device magnets mapping system. We also describe a new UNIX based data acquisition system that is being developed for the SSC. Probes used for magnetic measurements include Helmholtz coils, integral coils, point coils, and bucking harmonic analysis coils, several different types of Hall probes, and nuclear magnetic resonance magnetometers. Both analog and digital integrators are used with the coils. Some problems that occurred and their rectification is described. The mechanisms used include rotating systems with optical encoders, X-Y mapping systems with optical encoders and a laser position measuring device. 10 refs., 3 figs., 1 tab.
Date: August 1, 1991
Creator: Green, M.I.; Barale, P.; Callapp, L.; Case-Fortier, M.; Lerner, D.; Nelson, D. et al.
Partner: UNT Libraries Government Documents Department

Quenches in large superconducting magnets

Description: The development of large high current density superconducting magnets requires an understanding of the quench process by which the magnet goes normal. A theory which describes the quench process in large superconducting magnets is presented and compared with experimental measurements. The use of a quench theory to improve the design of large high current density superconducting magnets is discussed.
Date: August 1, 1977
Creator: Eberhard, P.H.; Alston-Garnjost, M.; Green, M.A.; Lecomte, P.; Smits, R.G.; Taylor, J.D. et al.
Partner: UNT Libraries Government Documents Department

Superconducting magnet system for the SPIRIT cosmic ray space telescope

Description: The SPIRIT (A Superconducting Passive Iron Isotope Telescope) experiment requires a large volume (1m/sup 3/) of 2T field in order to achieve enough resolution to study heavy primary cosmic rays. It is proposed that the SPIRIT superconducting magnet system and its experimental package would be used in one of the space shuttles. The superconducting magnet design is based on Lawrence Berkeley Laboratory thin high current density solenoid technology. The superconducting magnet system consists of a number of coils which generate a 2T induction within the experiment, and at the same time allow free access to the package by cosmic rays. The superconducting magnet system uses high current density conductor which is protected by a shorted secondary circuit. The magnet coils are to be cooled by pumped two phase helium which is circulated through tubes. Refrigeration is supplied from a large liquid helium dewar.
Date: August 1, 1979
Creator: Green, M.A.; DeOlivares, J.M.; Tarle, G.; Price, P.B. & Shirk, E.K.
Partner: UNT Libraries Government Documents Department

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

Description: High energy colliding beam physics often requires large detectors which contain large volumes of magnetic field. The TPC (Time Projection Chamber) experiment at PEP will use a 1.5T magnetic field within a cylindrical volume which is 2.04m in diameter bounded by iron poles which are separated by a gap of 3.25m. The TPC magnet, built in 1979 by the Lawrence Berkeley Laboratory (LBL), is the largest high current density superconducting magnet built to date. It is designed to operate at a current density of 7 x 10/sup 8/Am/sup -2/ and a stored energy of 11MJ, and it is protected by shorted secondary windings during a quench. The paper describes the basic parameters of the TPC magnet and the results of the first subassembly tests at LBL.
Date: August 1, 1979
Creator: Green, M.A.; Eberhard, P.H.; Ross, R.R. & Taylor, J.D.
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

Large superconducting detector magnets with ultra thin coils for use in high energy accelerators and storage rings

Description: The development of a new class of large superconducting solenoid magnets is described. High energy physics on colliding beam machines sometimes require the use of thin coil solenoid magnets. The development of these magnets has proceeded with the substitution of light materials for heavy materials and by increasing the current density in the coils. The Lawrence Berkeley Laboratory has developed a radical approach to the problem by having the coil operate at very high current densities. This approach and its implications are described in detail.
Date: August 1, 1977
Creator: Green, M.A.
Partner: UNT Libraries Government Documents Department

Gas cooled electrical leads for use on forced cooled superconducting magnets

Description: This paper describes the fabrication and testing of a pair of single tube leads which carry one fifth of the time projection chamber magnet current. Since one of the TPC magnet leads is horizontal within the vacuum chamber, the test leads were tested in a near horizontal position. From the tests, one can predict the performance of the composite TPC magnet lead or the performance of other leads built with multiple tube bundles.
Date: August 1, 1981
Creator: Smits, R.G.; Andrews, P.L.; Burns, W.A.; Day, C.T.; Gary, J.W.; Gibson, G.H. et al.
Partner: UNT Libraries Government Documents Department