The Advanced Light Source (ALS) is a third generation synchrotron light source at Lawrence Berkeley National Laboratory (LBNL). There was an increasing demand for additional high brightness hard X-ray beamlines in the 7–40 keV range, so in August 2001, three 1.3 T normal conducting bending magnets were removed from the storage ring and replaced with 5 T superconducting magnets (Superbends). The radiation produced by these Superbends is an order of magnitude higher in photon brightness and flux at 12 keV, making them excellent sources of hard X-rays for protein crystallography and other hard X-ray applications. The Superbends did not compromise the performance of the facility in the VUV and soft X-ray regions of the spectrum. The Superbends will eventually feed 12 new beam lines, greatly enhancing the facility's capability and capacity in the hard X-ray region. The Superbend project is the biggest upgrade since the ALS storage ring was commissioned in 1993. In this paper we present an overview of the Superbend project, its challenges and the resulting impact on the ALS.

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