Energy Storage Inductor for the Low Energy Booster resonant power supply system

Abstract

The Energy Storage Inductor (ESI) is an important part of the Low Energy Booster (LEB) Resonant Power Supply System. The ESI is a 40 mH, 3400 A, two-legged, picture frame, ONAN-cooled, linear inductor. The ESI is currently under construction at the UETM plant in Ekaterinburg (Russia) as a part of an inter-laboratory collaborative agreement between BINP (Russia) and SSCL (USA). This paper gives an overview of the ESI requirements and describes the design approach and testing methods. In trod uctionThe LEB is a conventional magnet booster that accelerates the proton beam from the Linac (momentum 1.2 GeV/c) to an extraction momentum of 12 GeV/c for beam injection into the Medium Energy Booster of the Superconducting Super Collider. The LEB main magnet system contains 96 dipole and 108 quadrupole (F+D) magnets supplied in series from a Power Supply (PS) system (see Figure 1). The main operating cycle of the booster requires a magnetic field variation from 0.12 T to 1.3 T (in dipole magnets) with 10 Hz frequency. The operating cycle PS system must produce a DC current of 2.2 U, and AC current very close to sine form with the same frequency and a 10 Hz sinewave AC current with an amplitude of 1.8 kA.The LEB PS system [l] will contain power supplies connected in series with 1 2 resonant cells, each having a 10 Hz resonance frequency (Figure 1). Each cell consists of several dipole and quadrupole magnets, and a capacitor shunted by the ESI to provide a path for the DC current. Dividing the resonant system into 12 resonant cells permits a notable decrease in the system voltage to ground. The ESIs are equipped with auxiliary windings connected in parallel with each other. This equalizes the resonant cell parameters and, therefore, the voltageto-ground distribution. An off-resonance condition in any resonant cell can be detected by monitoring current in the auxiliary windings. ESI in the Resonant CellThe principal parameters of the PS system determine the essential ESI characteristics. ESI current is determined from the expression: