A novel Mixed Axial and Radial field System (MARS) seeks to enhance the B fields inside the plasma chamber within the limits of a given conductor, thereby making it possible to raise the operating fields for Electron Cyclotron Resonance Ion Sources (ECRISs). The MARS concept consists of a hexagonally shaped closed-loop coil and a set of auxiliary solenoids. The application of MARS will be combined with a hexagonal plasma chamber to maximize the use of the radial fields at the chamber inner surfaces. Calculations using Opera's TOSCA-3D solver have shown that MARS can potentially generate up to 50% higher fields and use of only about one half of the same superconducting wire, as compared with existing magnet designs in ECRISs. A MARS magnet system built with Nb 3 Sn coils could generate a high strength minimum-B field of maxima of ≥ 10 T on axis and ~6 T radially in an ECRIS plasma chamber. Following successful development, the MARS magnet system will be the best magnet scheme for the next generation of ECRISs. This paper will present the MARS concept, magnet design, prototyping a copper closed-loop coil, and discussions.

To demonstrate a Mixed Axial and Radial field System (MARS) as the best magnet scheme for future ECRISs, MARS-D, a demonstrative ECRIS using a NbTi MARS magnet is progressing at Lawrence Berkeley National Laboratory. An optimized MARS design can use either NbTi or Nb3Sn coils with reduced engineering complexities to construct the needed high-field magnets. The optimized magnet design could enhance MARS-D to a next generation ECRIS by producing minimum-B field maxima of 5.6 T axially and 3.2 T radially for operating frequencies up to 45 GHz. In-progress test winding has achieved a milestone demonstrating the fabrication feasibility of a MARS closed-loop coil.

The design and results of an upgraded cyclotron center region in which a mirror field type inflector was replaced by a spiral inflector is described. The main goals of the design were to facilitate injection at higher energies in order to improve transmission efficiency and to reduce down-time due to the need of replacing mirror inflector wires which rapidly break when exposed to high beam currents. The design was based on a detailed model of the spiral inflector and matching center region electrodes using AMaze, a 3D finite element suite of codes. The spiral inflector was used to extract a 2.0 pμA 250 MeV Ca beam from the cyclotron thus meeting design goals. Furthermore, the inflector was utilized during an eight week experiment without any issues delivering around 1 pμA Ca as requested by the users.

The complex 3-D magnetic field structure of the 88-Inch Cyclotron combined with the large number of tuning parameters such as trim coils, valley coils, the main field itself and the injection/extraction components makes it challenging to tune the Cyclotron. Furthermore, beam diagnostic devices to help tuning were limited to a stationary Faraday cup at the exit of the machine and a so-called Dee-probe which allowed for beam current measurements as a function of the turn radius. Motivated to improve the transmission of the Cyclotron due to misalignment of the ion beam in the center region and insufficient beam diagnostics, we have developed an optical beam viewer which we can move radially in and out of the machine. It allows us to image the beam cross section and its axial position with high spatial resolution as a function of radius. In this paper, we describe the mechanical development of the device which consists of a KBr scintillator disc, a fiber bundle and a digital camera and we present data from its initial commissioning.

The low energy beam transport system and the inflector of the 88-Inch Cyclotron have been improved to provide more intense heavy-ion beams, especially for experiments requiring 48 Ca beams. In addition to a new spiral inflector [1] and increased injection voltage, the injection line beam transport and beam orbit dynamics in the cyclotron have been analyzed, new diagnostics have been developed, and extensive measurements have been performed to improve the transmission efficiency. By coupling diagnostics, such as emittance scanners in the injection line and a radially-adjustable beam viewing scintillator within the cyclotron, with computer simulations we have been able to identify loss mechanisms. The diagnostics used and their findings will be presented. We will discuss the solutions we have employed to address losses, such as changing our approach to tuning VENUS and running the cyclotron's central trim coil asymmetrically.

Lawrence Berkeley National Laboratory develops high-field Nb3Sn magnets for HEP applications. In. the past few years, this experience has been extended to the design and fabrication of undulator magnets. Some undulator applications require devices that can operate in the presence of a heat load from a beam. The use of Nb3Sn permits operation of a device at both a marginally higher temperature (5-8 K) and a higher J(c), compared to NbTi devices, without requiring a larger magnetic gap. A half-undulator device consisting of 6 periods (12 coil packs) of 14.5 mm period was designed, wound, reacted, potted and tested. It reached the short sample current limit of 717 A in 4 quenches. The non-Cu J(c) of the strand was over 7,600 A/mm(2) and the Cu current density at quench was over 8,000 A/mm(2). Magnetic field models show that if a complete device was fabricated with the same parameters one could obtain beam fields of 1.1 T and 1.6 T for pole gaps of 8 mm and 6 mm, respectively.

At the ALS there had been an increasing demand for additional high brightness hard x-ray beamlines in the 7 to 40 KeV range. In response to that demand, the ALS storage ring was modified in August 2001. Three 1.3 Tesla normal conducting bending magnets were removed and replaced with three 5 Tesla superconducting magnets (Superbends). The radiation produced by these Superbends is an order of magnitude higher in photon brightness and flux at 12 keV than the 1.3 Tesla bends, making them excellent sources of hard x-rays for protein crystallography and other hard x-ray applications. At the same time the Superbends do not compromise the performance of the facility in the UV and Soft X-ray regions of the spectrum. The Superbends will eventually feed 12 new beam lines greatly enhancing the facility’s capacity in the hard x-ray region. The Superbend project is the biggest upgrade to the ALS storage ring since it was commissioned in 1993. In this paper we present a history of the project, as well as the installation, commissioning, and resulting performance of the ALS with Superbends.

ALS Superbend Magnet Performance S. Marks, J. Zbasnik, W. Byrne, D. Calais, M . Chin, R. DeMarco, M . Fahmie, A . Geyer, J. Krupnick, F. Ottens, J. A . Paterson, P. Pipersky, D. A . Robin, R. D. Schlueter, C. Steier, A . Wandesforde results; Section III will summarize cryogenic test results. The design, requirements, and Superbend project have been 'Abstract— The Lawrence Berkeley National Laboratory has discussed elsewhere [3], [4], [5]. been engaged in the design, construction and testing of four superconducting dipoles (Superbends) that are installed in three arcs of the Advanced Light Source (ALS), with the fourth magnet as a spare. This represents a major upgrade to the A L S providing an enhanced flux and brightness at photon energies above 10 keV. In preparation for installation, an extensive set of tests and measurements have been conducted to characterize the magnetic and cryogenic performance of the Superbends and to fiducialize them for accurate placement in the A L S storage ring. The magnets are currently installed, and the storage ring is undergoing final commissioning. This paper will present the results of magnetic and cryogenic testing. i. INTRODUCTION II. MAGNETIC PERFORMANCE A. Magnetic Measurement Setup Figure 1 below, shows a picture of Superbend #1 installed around an alignment fixture on the test stand. Both the cryostat and the alignment fixture are mounted with six struts allowing for adjustment in all degrees of freedom. he Advanced Light Source (ALS) at the Lawrence Berkeley National Laboratory (LBNL) is a national user facility producing high brightness synchrotron radiation, primarily in the vacuum ultraviolet and soft x-ray regimes (6 eV to 10 keV). The A L S has engaged in a major upgrade to meet the growing demand for bright hard x-ray sources with photon energies above 10 keV. The upgrade consists of replacing three of the total of 36 conventional storage ring bending magnets with three superconducting bend magnets (Superbends). The increase in peak field from 1.34 T, corresponding to the conventional bend magnets, to 5.74 T, for the Superbends, results in almost an order of magnitude increase in both flux and brightness at 10 keV, and nearly two orders of magnitude at 20 keV for an electron beam energy of 1.9 GeV. Experimental uses for the new sources will include protein crystallography, x-ray tomography and powder diffraction. In the initial R & D phase of the Superbend project a conceptual design of a magnet that could be incorporated into the A L S was developed, and a robust superconducting coil was produced and tested[l], [2]. The second phase of the project, a joint venture between L B N L and Wang N M R , involved detailed design and fabrication of four magnets. Following fabrication, each magnet underwent extensive magnetic and cryogenic testing. This paper will report the results of the tests. Section II will summarize magnetic test Manuscript received September 24, 2001. This work was supported by the Director, Office of Energy Research, Office of Basic Energy Sciences, Materials Sciences Division, of the U . S. Department of Energy, under Contract No. DE-AC03-76F00098. Authors are with Larwence Berkeley National Laboratory, 1 Cyclotron Rd., Berkeley, California, U S A . T Fig. 1 Magnet #1 installed on the test stand. The alignment fixture serves several important functions in the testing process [4]. A cylindrical bore coincident with the

The Lawrence Berkeley National Laboratory is preparing to upgrade the Advanced Light Source (ALS) with three superconducting dipoles (Superbends). In this paper we present the final magnet system design which incorporates R&D test results and addresses the ALS operational concerns of alignment, availability, and economy. The design incorporates conduction-cooled Nb-Ti windings and HTS current leads, epoxy-glass suspension straps, and a Gifford-McMahon cryocooler to supply steady state refrigeration. We also present the current status of fabrication and testing

Utility load management programs, including direct load control and interruptible load programs, constitute a large installed base of controllable loads that are employed by utilities as system reliability resources. In response to energy supply shortfalls expected during the summer of 2001, the California Public Utilities Commission in spring 2001 authorized new utility load management programs as well as revisions to existing programs. This report provides an independent review of the designs of these new programs for a large utility (Southern California Edison) and suggests possible improvements to enhance the “price responsiveness” of the customer actions influenced by these programs. The report also proposes a new program to elicit a mass-market demand response to utility price signals.

An elliptically polarizing undulator (EPU) for the Advanced Light Source (ALS) has been designed and is currently under construction. The magnetic design is a moveable quadrant pure permanent magnet structure featuring adjustable magnets to correct phase errors and on-axis field integrals. The device is designed with a 5.0 cm period and will produce variably polarized light of any ellipticity, including pure circular and linear. The spectral range at 1.9 GeV for typical elliptical polarization with a degree of circular polarization greater than 0.8 will be from 100 eV to 1500 eV, using the first, third, and fifth harmonics. The device will be switchable between left and right circular modes at a frequency of up to 0.1 Hz. The 1.95 m long overall length will allow two such devices in a single ALS straight sector

Two 3.4 m long wigglers are being designed and constructed at Lawrence Berkeley Laboratory's (LBL) Advanced Light Source (ALS). A 19 period planar wiggler with 16.0 cm period length is designed to provide photons up to 12.4 keV for protein crystallography. This device features a hybrid permanent magnet structure with tapered poles and designed to achieve 2.0 T at a 1.4 cm magnetic gap. An elliptical wiggler is being designed to provide circularly polarized photons in the energy range of 50 eV to 10 keV for magnetic circular dichroism spectroscopy. This device features vertical and horizontal magnetic structures of 14 and 14 1/2 periods respectively of 20 cm period length. The vertical magnetic structure is a 2.0 T hybrid permanent magnet configuration. The horizontal structure is an iron core electromagnetic design, shifted longitudinally 1/4 period with respect to the vertical magnetic structure. A maximum horizontal peak field of 0.1 T at an oscillating frequency up to 1 Hz will be achieved by excitation of the horizontal poles with a trapezoidal current waveform.

The vertical magnetic structures for the Advanced Light Source 15 cm planar wiggler and 20 cm period elliptical wiggler are of hybrid permanent magnet design. The ends of these structures are characterized by diminishing scalar potential distributions of the poles which control beam trajectories. They incorporate electromagnetic correction coils to dynamically correct for variations in the first integral of the field as a function of gap. A permanent magnet trim mechanism is incorporated to minimize the transverse integrated error field distribution. The ends were designed using analytic and computer modeling techniques. The design and modeling results are presented

The elliptical wiggler is a circularly polarized light source capable of providing very broad spectral coverage and a high degree of circular polarization. The main features of an elliptical wiggler can be understood through analogy to bending magnet radiation. However, some aspects, such as the end structure's influence on the degree of circular polarization, require more elaborate methods to characterize. We present an algorithm based on the stationary-phase method, which allows calculation of radiation properties from an arbitrary electron trajectory, so a non-sinusoidal magnetic field's influence on the radiation performance can be taken into account. We show general radiation properties of an elliptical wiggler and discuss factors affecting the radiation produced. Practical issues encountered during the conceptual design of an elliptical wiggler at the Advanced Light Source are addressed.

At Lawrence Berkeley Laboratory’s Advanced Light Source, three 4.6 m long undulators have been completed, tested, and installed. A fourth is under construction. The completed undulators include two 5.0 cm period length, 89 period devices (U5.0s) which achieve a 0.85 T effective field at a 14 mm minimum gap and a 8.0 cm period length, 55 period device (U8.0) that reaches a 1.2 T effective field at a 14 mm minimum gap. The undulator under construction is a 10.0 cm period length, 43 period device (U10.0) that is designed to achieve 0.98 T at a 23 mm gap. Undulator magnetic gap variation (rms) is within 25 μm over the periodic structure length. Reproducibility of the adjustable magnetic gap has been measured to be within ±5 μm. Gap adjusting range is from 14 to 210 mm, which can be scanned in 1 min. The 5.1 m long vacuum chambers are flat in the vertical direction to within 0.74 mm and straight in the horizontal direction to within 0.08 mm over the 4.6 m magnetic structure sections. Vacuum chamber base pressures after UHV beam conditioning are in the mid-10−11 Torr range and storage ring operating pressures with full current are in the low 10−10 Torr range. Measurements show that the uncorrelated magnetic field errors are 0.23% and 0.20% for the two U5.0s and the U8.0, respectively, and that the field integrals are small over the 1 cm×6 cm beam aperture. Device description, fabrication, and measurements are presented.

Multiple trim magnets (MTMs), also known as ‘‘magic fingers,’’ are an arrangement of magnets for reducing integrated magnetic-field errors in insertion devices. The idea is to use transverse arrays of permanent magnets, hence the name ‘‘multiple trim magnets,’’ above and below the midplane, to correct both normal and skew longitudinal magnetic-field integral errors in a device. MTMs are typically installed at the ends of an ID. Adjustments are made by changing either the size, position, or orientation of each trim magnet. Application of the MTMs to the ALS undulators reduced both the normal and skew longitudinal field integral errors, over the entire 20 mm×60 mm ‘‘good field region,’’ of the beam aperture by as much as an order of magnitude. The requirements included corrections of field and gradients outside the multipole convergence radius. Additionally, these trim magnet arrays provided correction of the linear component of the integrated field gradients for particles with trajectories not parallel to the nominal beam axis. The MTM concept, design, construction, tests that demonstrated feasibility, and magnetic-field integral reduction of ALS undulators are presented.