Development of Nuclotron magnet power supply control system

The magnetic field control subsystem of the Nuclotron - a superferric ion synchrotron - is described. The bending (BM), focusing (QF) and defocusing (QD) magnets are powered by three supplies. The BMs are driven by the supply of a 6.3 kA nominal current. The QFs and QDs are connected in series and powered by the 6 kA supply. An additional supply of 200 A for the QFs is used to keep the reqired ratio I(QF)/I(QD). The BM magnetic field shape is set by a pulse function generator which produceds a reference burst (Bo-train) with a 0.1 Gs resolution. A real B-train of the bending magnet field with the same (0.1 Gs) resolution is used for feedback loop and as reference function for QD and QF supplies. The QD and QF trains are utilized for feedback loop in the QD and QF supplies. The control of slow extraction system suppllies is described as well.