IPAC2018 - List of Authors (Chang, F.Y.)

Paper	Title	Page
WEPAL053	Dynamic Signal Analysis Based on FPGA for NSRRC DLLRF	2295
	F.Y. Chang, L.-H. Chang, M.H. Chang, S.W. Chang, L.J. Chen, F.-T. Chung, Y.T. Li, M.-C. Lin, Z.K. Liu, C.H. Lo, Ch. Wang, M.-S. Yeh, T.-C. Yu NSRRC, Hsinchu, Taiwan
	As DLLRF control system designs for SRF cavities have greatly matured and the FPGA technology has im-proved as well, it is possible now to think about incorporating dynamic signal analysis (DSA). Implementation of a DSA in the FPGA is desired to study the frequency response of the open/closed loop gain in a SRF system. Open loop gain is useful to observe the stability of a SRF system while closed loop gain can be applied to investi-gate the operational bandwidth of the system feedback and also to configure the performance of a PID controller. The DSA function was confirmed by analyzing the frequency response of a digital filter and the results of the analysis will be compared with MATLAB simulations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL053
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WEPAL054	Digital Low Level Radio Frequency System for the Booster Ring of the Taiwan Photon Source	2298
	Z.K. Liu, F.Y. Chang, L.-H. Chang, M.H. Chang, S.W. Chang, L.J. Chen, F.-T. Chung, Y.T. Li, M.-C. Lin, C.H. Lo, Ch. Wang, M.-S. Yeh, T.-C. Yu NSRRC, Hsinchu, Taiwan
	The purpose of a Low-Level Radio Frequency (LLRF) system is to control the accelerating cavity field amplitude and phase. For the Taiwan Photon Source (TPS) at NSRRC, the currently operating LLRF systems are based on analog technology. To have better RF field stability, precise con-trol and high noise reduction, a digital LLRF control sys-tems based on Field Programmable Gate Arrays (FPGA) was developed. We replaced the analog LLRF system with the digital version for the TPS booster ring at the beginning of 2018, and we will replace those in the storage rings in the future. Test results and operational performance of the TPS booster DLLRF system are reported here.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL054
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WEPAL055	TPS Beam Trip Analysis and Dose Distribution	2302
	B.Y. Chen, F.Y. Chang, S. Fann, C.S. Huang, C.H. Kuo, T.Y. Lee, C.C. Liang, W.Y. Lin, Y.C. Lin, Y.-C. Liu NSRRC, Hsinchu, Taiwan
	Failure analysis during TPS users operation is im-portant to improve the performance of the TPS storage ring. In this report, we discuss the particular radiation dose patterns, relevant to different beam trips, and the development of a tool to help us analyse this dose distri-bution. We will use this analysing tool to train our ability for future failure analysis to shorten the time it takes to find the problem.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL055
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THPAL045	Determination of the Electron Bunch Length With Third Harmonic Cavity for the Taiwan Photon Source	3745
	Z.K. Liu, F.Y. Chang, L.-H. Chang, M.H. Chang, S.W. Chang, L.J. Chen, F.-T. Chung, M.-C. Lin, C.H. Lo, Ch. Wang, M.-S. Yeh, T.-C. Yu NSRRC, Hsinchu, Taiwan
	The Taiwan Photon Source (TPS) is a modern 3 GeV low emittance light source with RMS bunch lengths of about 3 mm at a beam current of 500 mA and operating gap voltage of 3.2 MV. With a higher harmonic cavity, we could increase the Touschek lifetime and lower the heat load of in-vacuum undulators by lengthening the bunch lengths. Preliminary studies show that for full and uni-form fill patterns, the bunch lengths could be increased by a factor of four. However, this calculation ignores phase transient effects and may overestimate the effect of harmonic cavities. A multi-bunch, multi-particle tracking method has been developed to determine the bunch lengths for non-uniform fill patterns, which also takes phase transient effects into account and the expected maximum bunch lengthening factor for different TPS operation conditions are discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL045
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THPAL046	Energy-Savings for the TPS Booster RF System at the NSRRC in Taiwan	3748
	F.-T. Chung, F.Y. Chang, L.-H. Chang, M.H. Chang, S.W. Chang, L.J. Chen, Y.T. Li, M.-C. Lin, Z.K. Liu, C.H. Lo, Ch. Wang, M.-S. Yeh, T.-C. Yu NSRRC, Hsinchu, Taiwan
	In this paper, we discuss an energy-savings control sys-tem for the Taiwan Photon Source (TPS) booster RF sys-tem. During top-up storage ring operation, a timing con-trol is activated to reduce the booster RF transmitter en-ergy consumption when no injection is required. When-ever injection into the TPS storage ring is needed, the booster RF transmitter is immediately adjusted to operat-ing conditions. This timing-control system will save an energy of 380, 000 kWh annually.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL046
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THPAL049	Power Supply Decoupling Design	3751
	Y.T. Li, F.Y. Chang NSRRC, Hsinchu, Taiwan
	After an actual operation of the phase-shifted magnet's power supply was conducted, it was found that the currents in the two modules of magnets would be coupled each other. In order to solve this mutual coupling current, a decoupling controller is designed. From the experiment results indicate that it does not only solve the issue of coupling current but also shorten the rising time of the power supply current. This helps to increase the power supply bandwidth.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL049
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Paper

Title

Page

Dynamic Signal Analysis Based on FPGA for NSRRC DLLRF

2295

F.Y. Chang, L.-H. Chang, M.H. Chang, S.W. Chang, L.J. Chen, F.-T. Chung, Y.T. Li, M.-C. Lin, Z.K. Liu, C.H. Lo, Ch. Wang, M.-S. Yeh, T.-C. Yu
NSRRC, Hsinchu, Taiwan

As DLLRF control system designs for SRF cavities have greatly matured and the FPGA technology has im-proved as well, it is possible now to think about incorporating dynamic signal analysis (DSA). Implementation of a DSA in the FPGA is desired to study the frequency response of the open/closed loop gain in a SRF system. Open loop gain is useful to observe the stability of a SRF system while closed loop gain can be applied to investi-gate the operational bandwidth of the system feedback and also to configure the performance of a PID controller. The DSA function was confirmed by analyzing the frequency response of a digital filter and the results of the analysis will be compared with MATLAB simulations.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL053

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPAL054

Digital Low Level Radio Frequency System for the Booster Ring of the Taiwan Photon Source

2298

Z.K. Liu, F.Y. Chang, L.-H. Chang, M.H. Chang, S.W. Chang, L.J. Chen, F.-T. Chung, Y.T. Li, M.-C. Lin, C.H. Lo, Ch. Wang, M.-S. Yeh, T.-C. Yu
NSRRC, Hsinchu, Taiwan

The purpose of a Low-Level Radio Frequency (LLRF) system is to control the accelerating cavity field amplitude and phase. For the Taiwan Photon Source (TPS) at NSRRC, the currently operating LLRF systems are based on analog technology. To have better RF field stability, precise con-trol and high noise reduction, a digital LLRF control sys-tems based on Field Programmable Gate Arrays (FPGA) was developed. We replaced the analog LLRF system with the digital version for the TPS booster ring at the beginning of 2018, and we will replace those in the storage rings in the future. Test results and operational performance of the TPS booster DLLRF system are reported here.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL054

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPAL055

TPS Beam Trip Analysis and Dose Distribution

2302

B.Y. Chen, F.Y. Chang, S. Fann, C.S. Huang, C.H. Kuo, T.Y. Lee, C.C. Liang, W.Y. Lin, Y.C. Lin, Y.-C. Liu
NSRRC, Hsinchu, Taiwan

Failure analysis during TPS users operation is im-portant to improve the performance of the TPS storage ring. In this report, we discuss the particular radiation dose patterns, relevant to different beam trips, and the development of a tool to help us analyse this dose distri-bution. We will use this analysing tool to train our ability for future failure analysis to shorten the time it takes to find the problem.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL055

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPAL045

Determination of the Electron Bunch Length With Third Harmonic Cavity for the Taiwan Photon Source

3745

Z.K. Liu, F.Y. Chang, L.-H. Chang, M.H. Chang, S.W. Chang, L.J. Chen, F.-T. Chung, M.-C. Lin, C.H. Lo, Ch. Wang, M.-S. Yeh, T.-C. Yu
NSRRC, Hsinchu, Taiwan

The Taiwan Photon Source (TPS) is a modern 3 GeV low emittance light source with RMS bunch lengths of about 3 mm at a beam current of 500 mA and operating gap voltage of 3.2 MV. With a higher harmonic cavity, we could increase the Touschek lifetime and lower the heat load of in-vacuum undulators by lengthening the bunch lengths. Preliminary studies show that for full and uni-form fill patterns, the bunch lengths could be increased by a factor of four. However, this calculation ignores phase transient effects and may overestimate the effect of harmonic cavities. A multi-bunch, multi-particle tracking method has been developed to determine the bunch lengths for non-uniform fill patterns, which also takes phase transient effects into account and the expected maximum bunch lengthening factor for different TPS operation conditions are discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL045

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THPAL046

Energy-Savings for the TPS Booster RF System at the NSRRC in Taiwan

3748

F.-T. Chung, F.Y. Chang, L.-H. Chang, M.H. Chang, S.W. Chang, L.J. Chen, Y.T. Li, M.-C. Lin, Z.K. Liu, C.H. Lo, Ch. Wang, M.-S. Yeh, T.-C. Yu
NSRRC, Hsinchu, Taiwan

In this paper, we discuss an energy-savings control sys-tem for the Taiwan Photon Source (TPS) booster RF sys-tem. During top-up storage ring operation, a timing con-trol is activated to reduce the booster RF transmitter en-ergy consumption when no injection is required. When-ever injection into the TPS storage ring is needed, the booster RF transmitter is immediately adjusted to operat-ing conditions. This timing-control system will save an energy of 380, 000 kWh annually.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL046

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPAL049

Power Supply Decoupling Design

3751

Y.T. Li, F.Y. Chang
NSRRC, Hsinchu, Taiwan

After an actual operation of the phase-shifted magnet's power supply was conducted, it was found that the currents in the two modules of magnets would be coupled each other. In order to solve this mutual coupling current, a decoupling controller is designed. From the experiment results indicate that it does not only solve the issue of coupling current but also shorten the rising time of the power supply current. This helps to increase the power supply bandwidth.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL049

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)