Commissioning of the ssrf booster

The SSRF Booster, designed to accelerate the electrons from 150MeV to 3.5GeV, is a FODO structure synchrotron with 180m circumference and 2Hz repetition rate. The commissioning of the SSRF booster from the LTB transfer line started on Sept. 30th evening, 2007, the first turns of beam in the booster was obtained in 20 hours. With about 60 hours effective commissioning effort, the electrons were accelerated to 3.5GeV on October 5th morning, 2007. And then the first 3.5GeV beam was extracted to BTS transfer line on October 30th, 2007. In this paper, the SSRF booster is introduced and its commissioning results are presented. INTRODUCTION Shanghai Synchrotron Radiation Facility (SSRF) is a 3rd generation light source, which consists of a 150MeV LINAC, a full energy booster synchrotron and a 20-DBA storage ring. It will provide 4nm·rad nature emittance electron beam at 3.5GeV [1][2]. SSRF booster is used to accelerate the electron beam from 150MeV to 3.5GeV. It is composed with 2 super periods, 28 standard FODO cells and 180m circumferences. The curvature radius of dipole is 14.515m, which can reduce the eddy currents effectively during the energy ramping. There are also eight 2.9m straight sections, which used for the installation of injection, extraction and radio frequency systems [3]. BOOSTER PARAMETERS Fig.1 shows layout of one standard booster cell. Fig.2 shows lattice functions in one quarter of the ring. Figure1: Layout of one standard booster cell. Figure 2: Twiss parameters of SSRF booster synchrotron. (One fourth of the ring is shown.). There are two modes, single bunch and multi bunch, designed for booster commissioning, which can satisfy both the accumulative rate and the top-up injection requirements of the storage ring. The main parameters of the booster are shown in Table 1. Table 1: Main Parameters of the Booster Parameters Value Energy range (GeV) 0.15~3.5 Single bunch 2 Current (mA) Multi bunch 15 Repetition rate (Hz) 2 Cell length (m) 6.4286 Length of long straight (m) 2.904 RF frequency (MHz) 499.654 Harmonic number 300 Nature emittance (nm·rad) 104 Tune, νH /νV 8.181/5.229 Natural chromaticity, ξH/ξV -9.91/-7.45 Nature energy spread 7.799×10 Momentum compaction, αP 0.01849 Damping time, τH,V,L (ms) 4.77/4.60/2.26 Longitudinal tune, νs 0.019 Bunch length (mm) 21.4 0 5 10 15 20 25 30 35 40 45 -5 0 5 10 15 20 25 30 s [m] β x ,y [m ] Twiss Parameters 0 5 10 15 20 25 30 35 40 45 0 0.2 0.4 0.6 0.8 1