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Applied Superconductivity, IEEE Transactions on

Issue 1 • Date March 2002

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Displaying Results 1 - 25 of 403
  • 17th International Conference on Magnet Technology

    Page(s): 1 - 16
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    Freely Available from IEEE
  • Eddy currents and their effects on the mechanical structures of the Dynamic Ergodic Divertor of the TEXTOR 94 tokamak

    Page(s): 1463 - 1466
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (214 KB) |  | HTML iconHTML  

    The Dynamic Ergodic Divertor (DED) of the TEXTOR 94 tokamak will work at the regimes of DC current and AC current at frequencies up to 10 kHz. In order to design the mechanical structures supporting the DED coils and the graphite protective tiles it is necessary to take into account the induced eddy currents, especially at high frequencies. The temperature rise and mechanical forces in the structures should be within acceptable limits. The screening effect of the DED coils in the plasma region should be minimized. The modeling of the DED electromagnetic field is discussed. The problem is solved numerically with the ANSYS code. For comparison, some simplified technique is employed. Two approaches are used for the different types of structures: thin shell approach and infinitely thin skin-layer approach. The eddy currents and energy losses in the structures have been defined. The 2-D and 3-D nonstationary thermal problems have been solved and the temperature rise in the structures has been calculated for the steady state regimes. The evaluation of the static and cyclic strength of the structures has been made. Based on parametric studies, the parameters of the coil and tile supporting structures have been optimized. View full abstract»

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  • An evaluation of mechanical properties of YBaCuO and (Sm,Gd)BaCuO bulk superconductors using Vickers hardness test at cryogenic temperatures

    Page(s): 1755 - 1758
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    Vickers hardness properties of bulk superconductors have been investigated to estimate the mechanical properties of bulk materials. However, the test at cryogenic temperatures had not been conducted at all. Then we conducted Vickers hardness test on (001) plane of YBaCuO and (Sm,Gd)BaCuO bulk superconductors from 40 to 293 K. The hardness of YBaCuO and (Sm,Gd)BaCuO increased with decreasing temperature up to 19 000 MPa and 10 000 MPa, respectively. Furthermore, the cracks caused by the indentation were observed with SEM, and the fracture toughness KIC at cryogenic temperatures was calculated. The KIC of YBaCuO and (Sm,Gd)BaCuO decreased with decreasing temperature to 0.6 MPa√m and 0.8 MPa√m, respectively. View full abstract»

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  • The coil of the MBI bending magnets for the LHC injection transfer lines

    Page(s): 228 - 231
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (253 KB) |  | HTML iconHTML  

    All MBI bending magnets in each of the two LHC injection transfer lines will be powered in series. The limited output voltage of existing power converters lead to an unusual coil design avoiding external return bus-bars by combining two overlapping half-coils, electrically separated, with 3 1/2 turns each in a monolithic structure. The voltage between turns in one coil can reach up-to 3.6 kV. The coil has been designed with particular care for obtaining high interturn and ground insulation. Flux-free soldering of connections with plug-in cone sleeves is applied, allowing to execute water cooled current connections as prolongation of the coil conductor. Epoxy compound polymerization in the impregnation mould is obtained by passing overheated water in regulated cycles through the water circuit of the coil conductor. We describe the design basics as well as various test results of pre-series and series produced coils. View full abstract»

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  • ITER TF conductor insert coil manufacture

    Page(s): 548 - 553
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    A single layer Toroidal Field Conductor Insert (TFCI) coil for testing at 46 kA in the 13 T background magnetic field generated by the Central Solenoid Model Coil (CSMC) of the International Thermonuclear Experimental Reactor (ITER) has been manufactured by a collaboration of Russian scientific-industrial institutions. The report contains a brief description of the technique and tooling used for the 1152 Nb3Sn strand, thin-wall Ti jacket, 45-m length cable-in-conduit conductor manufacturing, its wounding into the coil, end bending, terminal joint preparation, heat treatment in a high-vacuum electrical oven, insulation and transfer into the spiral grooves from inside of a cylindrical stainless steel mandrel, and vacuum-pressure impregnation with epoxy. View full abstract»

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  • Fabrication and mechanical performance of the ATLAS central solenoid

    Page(s): 416 - 419
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    Fabrication of the central solenoid for ATLAS detector in the CERN-LHC project was completed, and the performance test has been successfully carried out in Japan. The solenoid has arrived at CERN to be assembled with the LAr calorimeter. This paper describes the fabrication and mechanical, performance of the ATLAS central solenoid. View full abstract»

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  • Effect of γ-irradiation on silver-sheathed Bi1.6Pb0.4Ba2Ca2Cu3O10 tapes

    Page(s): 1121 - 1123
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    Specimens with nominal composition Bi1.6Pb0.4Ba2Ca2Cu3O10 were prepared using the powder-in tube technique. The effect of γ-irradiation at room temperature on the superconducting properties have been investigated using x-ray diffraction, resistivity measurements and I-V characteristics. The intensities of the main diffraction peaks decrease by about 25%, however, the peak positions do not change with γ-irradiation up to a dose of 400 MR. The normal state resistance R(T) increases gradually up to a dose of 100 MR, whereas at higher doses, the effect of irradiation becomes rather negligible. The transition temperature Tc decrease slightly and the transition temperature width ΔT broadens at doses below 100 MR with almost no change at higher doses up to 400 MR. At relatively low magnetic fields and low γ doses, the critical current densities Jc(B) increase with γ-irradiation, while the effect of γ-irradiation at relatively high magnetic fields is hardly observable. These results are discussed and explained in terms of the effect of γ-rays on the weak links grain boundaries and Josephson junctions between the grains. View full abstract»

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  • Magnetic field error analysis of a low-β quadrupole magnet

    Page(s): 215 - 218
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    A good field quality is always requested to achieve for the low-β quadrupole magnet being used in the accelerator projects. To meet the requirement, people are always managing to reduce the field errors from its magnetic design and construction. In order to obtain a basic understanding for various known multipolar field errors, some calculation evaluations have been performed. Based on the results, the possible origins and corresponding correction methods of the deviation were briefly discussed in the paper. View full abstract»

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  • Superconducting coil system for a stellarator fusion reactor

    Page(s): 558 - 561
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    A superconducting coil system has been developed for the stellarator fusion reactor. The distributions of the magnetic field and the forces are calculated. In order to support the magnetic forces a scheme of mutual support of the coils is applied. The pancakes of the coil winding pack of each individual coil are embedded in a strong coil housing of stainless steel. Linear and nonlinear finite element computations are done with half a field period, taking into account the stellarator symmetry. The mechanical stress and strain distributions inside the winding pack and the coil structure are analyzed. Furthermore, for the superconducting coil system the quench protection system is addressed. View full abstract»

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  • Correction multipoles for the high current operation of the Heavy Ion Synchrotron SIS

    Page(s): 166 - 169
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (243 KB) |  | HTML iconHTML  

    An upgrade program is under way to fill the Heavy Ion Synchrotron SIS up to the space charge limit at injection energy (e.g., 2·1011 Ne10+ ions and 4·1010 U73+ ions). One part of the program entails the construction of corrector multipoles for fine tuning of the synchrotron. Four normal quadrupoles are foreseen to compensate gradient errors of the 36 main quadrupoles in the ring, while eight skew quadrupoles will be used for the correction of tilt errors of the main quadrupoles. The skew quadrupoles will also be used to improve the multiturn injection efficiency, by linear coupling of the horizontal and vertical phase spaces. Two skew sextupoles will be provided to compensate sextupole components of the short, large aperture vertical steering magnets in the ring. Two technical restrictions had to be fulfilled. First, the space occupied by the correctors must be minimal. Therefore, the correction magnets will be constructed with a number of concentrically arranged multipole correction windings in the same magnet housing. Second, these magnets must be mounted around the beam line vacuum chamber, to avoid breaking the vacuum during their installation. Different possible configurations were investigated by computer simulation with respect to their field quality. Installation of the magnets is planned for the winter shut down of 2001/2002. View full abstract»

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  • High gradient magnetic separation for weakly magnetized fine particles [for geothermal water treatment]

    Page(s): 967 - 970
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    We measured the removal efficiency of hematite (Fe2O3) and iron (III) hydroxide (Fe(OH)3) fine particles suspended in water in a high gradient magnetic separation (HGMS) system. Fe2O3 and Fe(OH)3 have relatively small magnetic relative susceptibilities (MKS) near 10-3 and average particle diameters near 1 μm. We demonstrated that HGMS is able to effectively separate weakly magnetized particles. View full abstract»

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  • Status of the CMS magnet (MT17)

    Page(s): 385 - 390
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (270 KB) |  | HTML iconHTML  

    The CMS experiment (Compact Muon Solenoid) is a general-purpose detector designed to run at the highest luminosity at the CERN Large Hadron Collider (LHC). Its distinctive features include a 4 T superconducting solenoid with a free bore of 6 m diameter and 12.5-m length, enclosed inside a 10 000-ton return yoke. The magnet will be assembled and tested in a surface hall at Point 5 of the LHC at the beginning of 2004 before being transferred by heavy lifting means to an experimental hall 90 m below ground level. The design and construction of the magnet is a common project of the CMS Collaboration. The task is organized by a CERN based group with strong technical and contractual participation from CEA Saclay, ETH Zurich, Fermilab, INFN Genova, ITEP Moscow, University of Wisconsin and CERN. The magnet project will be described, with emphasis on the present status of the fabrication. View full abstract»

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  • The short circuit analysis of integrated three phase superconducting fault current limiter with two phase superconducting circuits

    Page(s): 854 - 858
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    The integrated three-phase superconducting fault current limiter (SFCL) using two superconducting circuits was conceptually designed and analyzed. The integrated three-phase SFCL system is an upgrade version of inductive single-phase SFCL systems. It uses one magnetic core having three legs, like a three phase transformer. Each leg has a copper winding as a primary winding but, as a secondary winding, only two legs have superconducting tubes and the other leg has no secondary winding. It has the same characteristics with inductive single-phase SFCL. Moreover it has other merits in stability, expense, and mechanical stress. View full abstract»

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  • Status of the ALICE magnet system

    Page(s): 432 - 437
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (283 KB) |  | HTML iconHTML  

    ALICE is the LHC experiment dedicated to heavy ion (Pb, Ca) physics. ALICE will be installed in point 2 of LHC, the former point 2 of LEP. The luminosity at the interaction point will be in the order of 1027 (1031 for p-p). Consequently, the radiation level in ALICE will be comparatively low. We will use the existing infrastructure. Therefore, no noticeable civil engineering work will be necessary. Minor modifications will be made to gain a second access to the experiment cavern-mainly for the union arm spectrometer. ALICE will reuse the L3 solenoid, which is already installed and has been used in LEP as spectrometer magnet. A dipole magnet with a very large aperture is in addition required for the Dimuon Arm spectrometer and will be installed next to the L3 solenoid. The detectors in ALICE are concentrated around the IP inside L3 (Barrel) and along the muon arm. Some small forward detectors will be located toward the injection area at a larger distance from IP (∼100 m). After a review of the present status of both projects some important milestones will be highlighted in the conclusion. View full abstract»

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  • Magnetic system of the installation for plasma separation process

    Page(s): 955 - 958
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    The magnetic system of the installation for plasma separation process (IPSP) by ion cyclotron resonance (ICR) heating method is presented. The requirements on the spatial uniformity and time stability of the magnetic field are realized by the high precision manufacture and mechanical adjustment of the solenoid coils. The influence of various inaccuracies of the magnetic field on the efficiency of the selective ICR heating are discussed. The design of the coils is considered. View full abstract»

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  • A tool for simulating rotating coil magnetometers

    Page(s): 1680 - 1683
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (222 KB) |  | HTML iconHTML  

    When investigating the quality of a magnetic measurement system, one observes difficulties to identify the "trouble maker" of such a system as different effects can yield similar influences on the measurement results. We describe a tool in this paper that allows to investigate numerically the effects produced by different imperfections of components of such a system, including, but not limited to: vibration and movements of the rotating coil, influence of electrical noise on the system, angular encoder imperfections. This system can simulate the deterministic and stochastic parts of those imperfections. We outline the physical models used that are generally based on experience or first principles. Comparisons to analytical results are shown. The modular structure of the general design of this tool permits to include new modules for new devices and effects. View full abstract»

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  • Annealing effects on the electrical and superconducting properties of a Cu-15vol%Nb composite conductor

    Page(s): 1195 - 1198
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    In this paper, annealing effects on the electrical and superconducting properties of a multifilamentary Cu-Nb composite were investigated. During annealing, noticeable changes in the microstructure take place, in special those related to recovery and recrystallization of copper and niobium followed by spheroidization and further coarsening of the Nb-filaments. Results show that spheroidization becomes significant only above 800°C and, even after annealing at severe conditions, e.g., 1050°C for 32 h, the continuity of the niobium-conducting path is partially preserved. The influence of these microstructural changes on the superconducting and normal properties of the multifilamentary Cu-15vol%Nb composite conductor is discussed. View full abstract»

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  • 20.5 kA current leads for ATLAS Barrel Toroid superconducting magnets

    Page(s): 1289 - 1292
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    Three pairs of 20.5 kA current leads for the ATLAS Toroid Magnets have been designed, manufactured and tested at Kurchatov Institute. The current leads have a high mechanical reliability and the vacuum tightness under 30 bars of internal pressure. The insulation between the current carrying parts and the mounting flange, the hydraulic connections and the temperature gauges withstand the overvoltage of at least 2 kV. The current leads are fully equipped with diagnostics needed for safety and control. The current leads were tested up to 24 kA. According to CERN's specification they were also tested in the absence of any cooling at very slow current discharge rate (5 A/s) from 20.5 kA to zero without any excessive overheating. Nowadays the current leads are successfully used at the ATLAS Magnet Test Facility at CERN. View full abstract»

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  • Fabrication and mechanical behavior of a prototype for the LHC low-beta quadrupole magnets

    Page(s): 174 - 178
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (248 KB) |  | HTML iconHTML  

    Superconducting low-beta quadrupole magnets for the LHC insertion regions are being developed at KEK as part of the collaboration between CERN and KEK. Magnet production technology developed at KEK has been transferred to a manufacturer of production magnets. In order to verify the production technology, fabrication jigs, tools, and procedures, the first full-scale prototype, MQXA-P1, was fabricated. Mechanical characteristics of MQXA-P1 were measured during the magnet assembly process, and it satisfied specifications needed for the production magnets. The validity of the magnet design and fabrication method was confirmed. View full abstract»

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  • Manufacturing experience for the LHC inner triplet quadrupole cables

    Page(s): 1203 - 1206
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (218 KB) |  | HTML iconHTML  

    The design for the U.S. LHC Inner Triplet Quadrupole magnet requires a 37 strand (inner layer) and a 46 strand (outer layer) cable. This represents the largest number of strands attempted to date for a production quantity of Rutherford-type cable. The cable parameters were optimized during the production of a series of short prototype magnets produced at FNAL. These optimization studies focused on critical current degradation, dimensional control, coil winding, and interstrand resistance. After the R&D phase was complete, the technology was transferred to NEEW and a new cabling machine was installed to produce these cables. At present, about 60 unit lengths, out of 90 required for the entire production series of magnets, have been completed for each type of cable. The manufacturing experience with these challenging cables will be reported. Finally, the implications for even larger cables, with more strands, will be discussed. View full abstract»

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  • Design and fabrication of an HTS reciprocating magnetic separator

    Page(s): 971 - 974
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (204 KB) |  | HTML iconHTML  

    The conceptual design and fabrication details of a conduction-cooled high temperature superconducting (HTS) reciprocating magnetic separator are reported. Reciprocating magnetic separators are used in the purification of kaolin clay. The HTS coil is 0.30 m in length and has a 0.25 m inner diameter. The central operating magnetic field is a nominal 3.0 T with a design operating current of 126 A. In terms of combined size and magnetic field strength, this is one of the largest HTS magnets ever fabricated, possessing a stored energy >0.1 MJ. The HTS magnet is conduction cooled via one single-stage G-M cryocooler with a nominal operating temperature of 30 K. The HTS conductor uses a stainless steel reinforced Bi-2223 material. Salient features and results of the electromagnetic, thermal, and quench protection analyses are discussed. View full abstract»

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  • An optimal design method for SMES coils using HTS tapes

    Page(s): 1459 - 1462
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (235 KB) |  | HTML iconHTML  

    This paper describes an optimal design method for SMES coils wound with high temperature superconducting (HTS) tapes (e.g., Bi2223/Ag tapes). Recently, the properties of HTS tapes have advanced and HTS magnets have been constructed and demonstrated. However, the HTS tapes have different thermal characteristics compared with the low temperature superconducting (LTS) wires. Therefore, it is necessary to consider these characteristics of HTS tapes at magnet design stage. We propose an optimal design method for SMES coils using Bi2223/Ag tapes. And the proposed configuration is optimized by using the simulated annealing, which is one of the optimization algorithms, under a lot of constraints such as B-I characteristic, storage energy, and so on. The details of the optimization method and examples of its application to small SMES coils (0.5 MJ) using Bi2223/Ag tape are shown. View full abstract»

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  • Design and test of a 1-MJ SMES system

    Page(s): 391 - 394
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    For several decades researches and developments on superconducting magnetic energy storage (SMES) system have been done for efficient electric power management. Korea Electrotechnology Research Institute (KERI) have developed a 1-MJ 300-kVA SMES System for improving power quality in sensitive electric loads. It consists of an IGBT (Insulated Gate Bipolar Transistor) based power conversion module, NbTi mixed matrix conductor superconducting magnet and a cryostat with HTS current leads. The authors developed the code for design of a SMES magnet, which could find the parameters of the SMES magnet having minimum amount of superconductors for the same stored energy, and designed the 1-MJ SMES magnet by using it. And they have designed and fabricated cryostat with kA class HTS current leads for a 1-MJ SMES System. This paper describes the design, fabrication and experimental results for a 1-MJ SMES System. View full abstract»

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  • Technical innovations for a high-gradient quadrupole electromagnet intended for high power proton drift tube linacs

    Page(s): 43 - 46
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    The IPHI project includes a 352 MHz drift tube linac (DTL) to accelerate a 100 mA cw proton beam from 5 to 10 MeV (1 MW beam power). The main challenge of such a structure is to house a strong gradient quadrupole (QP) in the very reduced space of the first drift tubes (DT). Having chosen not to use permanent magnets, the goal is to design 4.70 T integrated-gradient QP less than 50 mm long with 90 mm maximum outer radius and an aperture as large as possible to minimize beam losses. Two DT have been designed and built with different QP magnets for the low energy end of the IPHI DTL. The first one is based on conventional magnets with hollow conductors and high-permeability cobalt-iron alloy for the poles and yoke. Two separate cooling circuits are used for the DT and the magnet coils. A second design has been done to make profit of the full space available inside the DT and to reduce their manufacturing cost as much as possible. A single water flow is used to cool simultaneously both DT body and QP coils made up of full (nonhollow) conductors. View full abstract»

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  • The Grenoble High Magnetic Field Laboratory as a USER FACILITY

    Page(s): 674 - 677
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (226 KB) |  | HTML iconHTML  

    The Grenoble High Magnetic Field Laboratory (GHMFL), run jointly by the Centre National de la Recherche Scientifique (C.N.R.S, France) and the Max-Planck Gesellschaft (MPG, Germany) is a leading laboratory pursuing research in the highest static magnetic fields technically feasible. The laboratory maintains strong in-house research activities and partly operates as a user facility for qualified external researchers. It has developed highly sophisticated instrumentation for specific use under high magnetic fields, including transport, magnetization, visible and infrared optical measurements at low temperatures and/or high pressures, EPR and NMR investigations in high magnetic fields. The laboratory delivers around 5000 hours of magnet time per year. Access for users to the high magnetic field facility is supported by the European Union, in the framework of the Human Potential Program: "Transnational Access to Major Research Infrastructures". The authors give an overview of the technical aspects of the facility and of the laboratory activities as a facility over the last years. The general organization of the user community and repartition between countries is also reviewed. View full abstract»

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Aims & Scope

IEEE Transactions on Applied Superconductivity contains articles on the applications of superconductivity and other relevant technology.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Britton L. T. Plourde
Syracuse University
bplourde@syr.edu
http://www.phy.syr.edu/~bplourde