Spear3 Intermediate Dc Magnet Power Supplies

P. Bellomo, A. de Lira (SLAC) Menlo Park, CA 94025-7015, USA Abstract The Stanford Synchrotron Radiation Laboratory (SSRL) has successfully commissioned SPEAR3, its newly upgraded 3-GeV synchrotron light source. First stored beam occurred December 15, 2003 and 100mA operation was reached on January 20, 2004. This paper describes the specification, design, and performance of the SPEAR3 DC magnet intermediate power supplies (IPS) that consist of tightly-regulated (better than ±10ppm) current sources ranging from 60 A to 500 A and output powers ranging from 2.4kW to 22.5kW. A total of 69 IPS are in successful operation. The SPEAR 3 upgrade performance and reliability requirements mandated new power supplies for both the SPEAR3 storage ring, and for the booster-to-SPEAR3 transport line. IPS are widely used at SPEAR3 to power single quadrupoles, dipoles, families of quadrupoles and sextupoles, and also Titanium sublimation pumps. IPS topology allows them to be series operated for those magnet strings requiring higher voltages. A compact 19" standard rack-mounted design is common to all the units. These are off-line, switch-mode, operating at 16 kHz to reduce space and provide for fast output response and high efficiency.