Comparative Study of Tracking Error for Booster Synchrotron Power Supply: Effects of Reference Profile Variations and Feedforward Compensation in Fast-Ramped Power Supply

The Booster Synchrotron (BS) at the Indus Accelerator Complex (IAC), Raja Ramanna Centre for Advanced Technology (RRCAT), Indore, has been operating for three decades. In its present configuration, the Quadrupole (QP) and Dipole (DP) electromagnets are connected in series and powered by a main Power Supply (PS) following a ramped current reference. During beam injection at low current levels, limited beam rigidity increases sensitivity to tracking errors in the magnet currents, which can induce beta-beat oscillations and lead to beam loss. Ramping current profiles driving magnet loads inherently demand step changes in load voltage. While ideal tracking requires an instantaneous voltage response, practical limitations introduced by filtering in the power circuit, control loop delays, and switching constraints prevents such behavior. To investigate these limitations, a 15A/50V prototype Fast-Ramped Power Supply (FRPS) was developed, and a comparative study was conducted to assess tracking accuracy improvements through enhanced dynamic response and reference corner shaping. The study further identifies the key challenges and areas for advancement in FRPS performance. These findings provide valuable insights for the future development of high-power (5–10 MVA) BS magnet PS required for the proposed 6 GeV High-Brilliance Synchrotron Radiation Source (HBSRS).