MAIN MAGNETIC FIELD AND SLOW EXTRACTION CONTROL SYSTEM OF NUCLOTRON

The bending (BM), focusing (QF) and defocusing (QD) magnets of Nuclotron - superferric heavy ion synchrotron - 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 required ratio IQF/IQD. The BM magnetic field shape is set by a pulse function generator which produces a reference burst (B0-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 the 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 supplies is described as well. The extracted beam spill is used as the reference function for feedback loop of extraction quadrupole supply.