IPAC2017 - List of Authors (Chiu, P.C.)

Paper	Title	Page
MOPAB124	A Fast Gain Calibration Algorithm for Beam Position Monitoring at Taiwan Photon Source	419
	J.Y. Chen, C.H. Chen, M.-S. Chiu, P.C. Chiu, P.J. Chou, S. Fann, K.H. Hu, C.S. Huang, C.-C. Kuo, T.Y. Lee, C.C. Liang, Y.-C. Liu, G.-H. Luo, H.-J. Tsai, F.H. Tseng NSRRC, Hsinchu, Taiwan
	A stable, reliable and well-calibrated beam position monitor (BPM) system is essential for the operation of accelerators. At newly constructed Taiwan Photon Source (TPS), it not only helps us to determine the accelerator parameters, such as Twiss parameters and tune, but also to avoid the damage on accelerator instruments caused by high-energy particle beams or radiation. In this study, we demonstrate a new BPM calibration scheme at TPS storage ring. To excite the electron beams inside accelerator beam pipe by one horizontal or vertical corrector magnet, we measure the response of analog-to-digital converter (ADC) of each BPM pick-up electrodes with different lateral positions and beam currents. Depending on the measured ADC responses, we calibrated the beam position monitor system. Simultaneously, because of limited preparation time after every long shutdown, we are looking for a fast algorithm to ensure the measurement could be done easily and finished as quickly as possible.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB124
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TUPAB103	Orbit Correction With Path Length Compensation Based on Rf Frequency Adjusments in TPS	1553
	P.C. Chiu, K.T. Hsu, K.H. Hu, C.H. Huang, C.-C. Kuo, C.C. Liang, Y.-C. Liu, H.-J. Tsai, F.H. Tseng NSRRC, Hsinchu, Taiwan
	The 3 GeV Taiwan Photon Source has been routinely operated for public users since September 2016. Orbit reproducibility and stability are critical for the quality of user experiments. Ambient temperature variations and earth tides can cause a change in circumference, changing in turn the beam energy, and orbit drift. Therefore both, orbit correction and rf frequency adjustments are necessary to keep the ring circumference constant. A Fast Orbit Feedback (FOFB) system combined with rf frequency correction deduced from the fast corrector strengths is applied to the FOFB routine. The correlation between the measured frequency variation with ambient temperature and earth tides is also reported in this article.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB103
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TUPAB107	Study of 60 Hz Beam Orbit Fluctuations in the Taiwan Photon Source	1566
	C.H. Huang, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, K.H. Hu, C.Y. Liao, C.Y. Wu NSRRC, Hsinchu, Taiwan
	The Taiwan Photon Source is a 3 GeV synchrotron light source at NSRRC. To achieve high quality experimental results, it is important to minimize beam motion. During the installation of insertion devices and front-ends, the beam motion around 60 Hz became significant. The response matrix together with singular value decomposition was used to identify the transmitter of the superconducting radio frequency system as the source for the 60 Hz perturbations. This was subsequently corrected by rerouting the grounding of the mains in the transmitters. Yet, the 60Hz orbit fluctuation became even more serious after the next shutdown. A serious of experiments are performed to dig out that the beam was disturbed by the magnetic field from newly installed fan motors. Shielding the fans with mu-metal and increasing the distance between fan and beam pipe drastically reduced the leakage field and greatly increased beam stability. These errors could be prevented at the design stage in the ideal case. However, these errors happened finally and need to be dug out and eliminated. The method and experiences are summarized in this report. These will benefit others who facing the similar problems.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB107
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Paper

Title

Page

A Fast Gain Calibration Algorithm for Beam Position Monitoring at Taiwan Photon Source

419

J.Y. Chen, C.H. Chen, M.-S. Chiu, P.C. Chiu, P.J. Chou, S. Fann, K.H. Hu, C.S. Huang, C.-C. Kuo, T.Y. Lee, C.C. Liang, Y.-C. Liu, G.-H. Luo, H.-J. Tsai, F.H. Tseng
NSRRC, Hsinchu, Taiwan

A stable, reliable and well-calibrated beam position monitor (BPM) system is essential for the operation of accelerators. At newly constructed Taiwan Photon Source (TPS), it not only helps us to determine the accelerator parameters, such as Twiss parameters and tune, but also to avoid the damage on accelerator instruments caused by high-energy particle beams or radiation. In this study, we demonstrate a new BPM calibration scheme at TPS storage ring. To excite the electron beams inside accelerator beam pipe by one horizontal or vertical corrector magnet, we measure the response of analog-to-digital converter (ADC) of each BPM pick-up electrodes with different lateral positions and beam currents. Depending on the measured ADC responses, we calibrated the beam position monitor system. Simultaneously, because of limited preparation time after every long shutdown, we are looking for a fast algorithm to ensure the measurement could be done easily and finished as quickly as possible.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB124

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

TUPAB103

Orbit Correction With Path Length Compensation Based on Rf Frequency Adjusments in TPS

1553

P.C. Chiu, K.T. Hsu, K.H. Hu, C.H. Huang, C.-C. Kuo, C.C. Liang, Y.-C. Liu, H.-J. Tsai, F.H. Tseng
NSRRC, Hsinchu, Taiwan

The 3 GeV Taiwan Photon Source has been routinely operated for public users since September 2016. Orbit reproducibility and stability are critical for the quality of user experiments. Ambient temperature variations and earth tides can cause a change in circumference, changing in turn the beam energy, and orbit drift. Therefore both, orbit correction and rf frequency adjustments are necessary to keep the ring circumference constant. A Fast Orbit Feedback (FOFB) system combined with rf frequency correction deduced from the fast corrector strengths is applied to the FOFB routine. The correlation between the measured frequency variation with ambient temperature and earth tides is also reported in this article.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB103

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

TUPAB107

Study of 60 Hz Beam Orbit Fluctuations in the Taiwan Photon Source

1566

C.H. Huang, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, K.H. Hu, C.Y. Liao, C.Y. Wu
NSRRC, Hsinchu, Taiwan

The Taiwan Photon Source is a 3 GeV synchrotron light source at NSRRC. To achieve high quality experimental results, it is important to minimize beam motion. During the installation of insertion devices and front-ends, the beam motion around 60 Hz became significant. The response matrix together with singular value decomposition was used to identify the transmitter of the superconducting radio frequency system as the source for the 60 Hz perturbations. This was subsequently corrected by rerouting the grounding of the mains in the transmitters. Yet, the 60Hz orbit fluctuation became even more serious after the next shutdown. A serious of experiments are performed to dig out that the beam was disturbed by the magnetic field from newly installed fan motors. Shielding the fans with mu-metal and increasing the distance between fan and beam pipe drastically reduced the leakage field and greatly increased beam stability. These errors could be prevented at the design stage in the ideal case. However, these errors happened finally and need to be dug out and eliminated. The method and experiences are summarized in this report. These will benefit others who facing the similar problems.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB107

Export •

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