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Title: Overview of Top-up Injection at Taiwan Light Source

Abstract

During the last two years, a series of beam parameters measurement, subsystem checkout, installation of various sensors, control program modification and hardware upgrade made the top-up injection possible in practical routine operation. Top-up injection is an operation mode in which the beam current in the storage ring is maintained above certain level by frequent injections. The routine current stability is in the range of 10-3 for long period of operation. The Top-up injection provides advantages in operation such as lower emittance, higher current, smaller coupling, smaller ID gaps, exotic bunch filling patterns, and higher bunch charge. It also provides constant thermal loading on all components in the storage ring and the optics components of beamlines, as well as constant signal to the beam position monitor. Discussions on the results of some measurements of booster and storage ring, the requirement of hardware upgrade and the summary of routine Top-up operation will be presented in this paper.

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ; ;  [1]
  1. National Synchrotron Radiation Research Center, No. 101, Hsin-Ann Road, Hsin-chu, Taiwan (China)
Publication Date:
OSTI Identifier:
21049291
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 879; Journal Issue: 1; Conference: 9. international conference on synchrotron radiation instrumentation, Daegu (Korea, Republic of), 28 May - 2 Jun 2006; Other Information: DOI: 10.1063/1.2435994; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; BEAM CURRENTS; BEAM INJECTION; BEAM MONITORING; BEAM MONITORS; BEAM OPTICS; BEAM POSITION; CONTROL; LIGHT SOURCES; LOADING; MODIFICATIONS; OPERATION; PARTICLE BEAMS; SENSORS; STORAGE RINGS; TAIWAN

Citation Formats

Luo, G. H., Chang, H. P., Chang, J. C., Chen, C. T., Chen, Jenny, Chen, J. R., Fann, C. S., Hsu, K. T., Hwang, C. S., Kuo, C. C., Liu, K. B., Liu, Y. C., Sheu, R. J., Ueng, T. S., Wang, D. J., and Wang, M. H. Overview of Top-up Injection at Taiwan Light Source. United States: N. p., 2007. Web. doi:10.1063/1.2435994.
Luo, G. H., Chang, H. P., Chang, J. C., Chen, C. T., Chen, Jenny, Chen, J. R., Fann, C. S., Hsu, K. T., Hwang, C. S., Kuo, C. C., Liu, K. B., Liu, Y. C., Sheu, R. J., Ueng, T. S., Wang, D. J., & Wang, M. H. Overview of Top-up Injection at Taiwan Light Source. United States. doi:10.1063/1.2435994.
Luo, G. H., Chang, H. P., Chang, J. C., Chen, C. T., Chen, Jenny, Chen, J. R., Fann, C. S., Hsu, K. T., Hwang, C. S., Kuo, C. C., Liu, K. B., Liu, Y. C., Sheu, R. J., Ueng, T. S., Wang, D. J., and Wang, M. H. Fri . "Overview of Top-up Injection at Taiwan Light Source". United States. doi:10.1063/1.2435994.
@article{osti_21049291,
title = {Overview of Top-up Injection at Taiwan Light Source},
author = {Luo, G. H. and Chang, H. P. and Chang, J. C. and Chen, C. T. and Chen, Jenny and Chen, J. R. and Fann, C. S. and Hsu, K. T. and Hwang, C. S. and Kuo, C. C. and Liu, K. B. and Liu, Y. C. and Sheu, R. J. and Ueng, T. S. and Wang, D. J. and Wang, M. H.},
abstractNote = {During the last two years, a series of beam parameters measurement, subsystem checkout, installation of various sensors, control program modification and hardware upgrade made the top-up injection possible in practical routine operation. Top-up injection is an operation mode in which the beam current in the storage ring is maintained above certain level by frequent injections. The routine current stability is in the range of 10-3 for long period of operation. The Top-up injection provides advantages in operation such as lower emittance, higher current, smaller coupling, smaller ID gaps, exotic bunch filling patterns, and higher bunch charge. It also provides constant thermal loading on all components in the storage ring and the optics components of beamlines, as well as constant signal to the beam position monitor. Discussions on the results of some measurements of booster and storage ring, the requirement of hardware upgrade and the summary of routine Top-up operation will be presented in this paper.},
doi = {10.1063/1.2435994},
journal = {AIP Conference Proceedings},
number = 1,
volume = 879,
place = {United States},
year = {Fri Jan 19 00:00:00 EST 2007},
month = {Fri Jan 19 00:00:00 EST 2007}
}
  • After three years of upgrading work, PLS-II (S. Shin, Commissioning of the PLS-II, JINST, January 2013) is now successfully operating. The top-up operation of the 3 GeV linear accelerator had to be delayed because of some challenges encountered, and PLS-II was run in decay mode at the beginning in March 2012. The main difficulties encountered in the top-up operation of PLS-II are different levels between the linear accelerator and the storage ring, the 14 narrow gap in-vacuum undulators in operation, and the full energy injection by 3 GeV linear accelerator. Large vertical emittance and energy jitter of the linac weremore » the major obstacles that called for careful control of injected beam to reduce beam loss in the storage ring during injection. The following measures were taken to resolve these problems: (1) The high resolution Libera BPM (see http://www.i-tech.si ) was implemented to measure the beam trajectory and energy. (2) Three slit systems were installed to filter the beam edge. (3) De-Qing circuit was applied to the modulator system to improve the energy stability of injected beam. As a result, the radiation by beam loss during injection is reduced drastically, and the top-up mode has been successfully operating since 19th March 2013. In this paper, we describe the experimental results of the PLS-II top-up operation and the improvement plan.« less
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  • An intermediate energy synchrotron light source has been proposed. The goal is to construct a high performance light source in complementary to the existing 1.5 GeV synchrotron ring in Taiwan to boost the research capabilities. A 3 GeV machine with 518.4 m and 24-cell DBA lattice structure is considered and other options are also investigated. We report the 24-cell design considerations and its performances.
  • Top-up operation was successfully demonstrated at UVSOR-II, which will remove the short beam-lifetime problem caused by strong Touschek effect due to the small emittance, 27 nm-rad, and the low electron energy, 750 MeV. In these years, we have improved the accelerators, step by step, towards top-up operation. The radiation shielding wall was reconstructed. The energy of the booster synchrotron and the beam transport line were successfully upgraded from 600 MeV to 750 MeV, by replacing the magnet power supplies in 2006. Soon after, we succeeded in injecting the electron beam at the full energy. We improved the radiation safety systemmore » and constructed a injection control system. In autumn, 2008, we succeeded in operating the ring for 12 hours as keeping the beam current quasi-constant at 300 mA. Currently, we operated the ring in the top-up mode for 12 hours on every Thursday night, to check the effects on the users' experiments. In 2009, we have succeeded in the top-up operation in single bunch mode. Free electron laser oscillation with the top-up mode was also successfully demonstrated.« less