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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. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

The plan for beamlines in Phase II at Taiwan Photon Source is to construct two new BioSAXS and nano- ARPES beamlines. A highly brilliant light source can be produced with a cryogenic undulator, and many synchrotron facilities have been developed and operated with these in their storage rings. The development of a cryogenic undulator became a target for a light source in TPS phase II. A cryogenic undulator with period of length 15 mm will be made in a hybrid magnetic structure, and use PrFeB permanent-magnet materials. A maximum magnetic field 1.31 T is estimated at gap 4 mm and temperature about 100 K. The spectral performance of a TPS cryogenic undulator is presented in this paper. [ABSTRACT FROM AUTHOR]

The Taiwan Light Source (TLS) is the first dedicated synchrotron light source facility that used a superconducting RF cavity to upgrade its existing RF system. More then one year has passed since the superconducting RF cavity was successfully integrated with the existing RF subsystem for routine operation. The operating status shows that the superconducting RF (SRF) system has effectively suppressed the instabilities of the beam that are caused by the interaction of the electron beam with the higher-order-modes of the cavity. The original goal of doubling the photon intensity has been reached by applying top-up mode injection at the beam current of 300 mA. However, compared to the original RF system, the beam loading is much higher, and the frequency of the superconducting cavity is also more easily perturbed by the mechanical vibrations. Those make the operation of the SRF system facing the challenge on the machine reliability, especially for a dedicated synchrotron light source facility. Here we report the operating status of the SRF system, analyze the trip sources, and present our efforts to improve the machine reliability and performance since the SRF system began routine operation. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

The 1.5 GeV Taiwan Light Source (TLS) has been upgraded, subsequently increasing the beam current from 200 mA to 300 mA. Additionally, the operational mode changed from decay mode to the top-up mode in 2006 after the cavities were replaced by a superconducting RF cavity and the chambers in the injection straight section with new ones in 2005. The operation at 400 mA has been tested to ensure regular operations of a stored beam at 300 mA. Efforts have been made to replace the interlock systems, spare parts, utility systems and signal archiving systems to ensure the reliable operation of the storage ring and ultimately avoid damage incurred to the system. The beam test at a high current and the performance of the vacuum system will be described. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

An FPGA based transverse bunch-by-bunch feedback system was implemented and commissioned to replace the existing analog transverse feedback system in order to suppress more effectively multi-bunch instabilities caused by the resistive wall of the vacuum chamber, cavity-like structures and ions related instability. This system replaces existing analog transverse feedback system to enlarge the tunability of the working point. Lower chromaticity is possible with feedback system that is very helpful for injection efficiency improvement. Top-up and high current operation is benefit for this upgrade. One feedback loop suppresses horizontal and vertical multi-bunch instabilities simultaneously. The clean and simple structure makes the system simple and reliable. This study also presents the preliminary result of commissioning the new transverse feedback system. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

The synchrotron radiation monitor provides useful information to support routine operation and physics experiments using the beam. Precisely knowing the profile of the beam helps to improve machine performance. The synchrotron radiation monitor at the Taiwan Light Source (TLS) was recently upgraded. The optics and modeling were improved to increase the accuracy of measurement in the small beam size. A high-performance IEEE-1394 digital CCD camera was used to improve the quality of images and extend the dynamic range of measurement. The image analysis is also improved. This report summarizes status and results. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

The beam position monitoring system is an important part of a synchrotron light source that supports its routine operation and studies of beam physics. The Taiwan light source is equipped with 59 BPMs. Highly precise closed orbits are measured by multiplexing BPMs. Data are acquired using multi-channel 16-bit ADC modules. Orbit data are sampled every millisecond. Fast orbit data are shared in a reflective memory network to support fast orbit feedback. Averaged data were updated to control database at a rate of 10 Hz. A few new generation digital BPMs were tested to evaluate their performance and functionality. This report summarizes the system structure, the software environment and the preliminary beam test of the BPM system. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]