The power supply systems for elliptical multipole wigglers

The elliptical multipole wiggler (EMW; 3.4 meter-long) and its prototype (0.8 m) had been built by the joint team of INP (Novosibirsk, Russia), ANL (Argonne, USA), and BNL (Upton, USA). These wigglers are supplied by the DC or trapezoidal shape AC current with variable frequency. Current is in 200 A to 1200 A range. Two different PSs were developed: for prototype-with the frequency range up to 100 Hz, for EMW-up to 10 Hz. The PSs have the original circuit for current polarity forced switching. These circuits allow us to get the rise/fall time twenty times faster than that determined by magnet time constant: it became 1.5 ms for prototype and 5 ms for EMW. Top of the pulses have the flatness better than 0.01, current difference for both polarities better than 0.001. Prototype is under the operation at the NSLS (BNL) during two years. EMW has been installed, tested and first beam for users would be taken out soon at the APS (ANL)