IBIC2017 - List of Authors (Lai, L.W.)

Paper	Title	Page
WEPCF01	Beam Charge Measurement Using the Method of Double-Cavity Mixing	411
	J. Chen, S.S. Cao, L.W. Lai, Y.B. Leng, R.X. Yuan SINAP, Shanghai, People's Republic of China N. Zhang SSRF, Shanghai, People's Republic of China
	The measurement of beam charge is a fundamental re-quirement to all particle accelerators facility. In this paper, using the TM010 mode of the cavity BPM to measure the beam charge will be introduced. The data processing methods including harmonic analysis, time domain analysis and principle component analysis (PCA) are used and compared in evaluating the resolution of the beam charge. On the basis of this, the results of the evaluation at a ultra-low charge are also given and indicates the superiority of the cavity probe in the measurement of lower beam charge. In addition, the use of double-cavity mixing method to measure the beam charge will be proposed as well.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2017-WEPCF01
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TH2AB2	Bunch-by-Bunch Beam Length Measurement Using Two-Frequency System at SSRF	499
	H.J. Chen, L.W. Duan, B. Gao, L.W. Lai, Y.B. Leng SINAP, Shanghai, People's Republic of China N. Zhang SSRF, Shanghai, People's Republic of China
	A Two-frequency method has been implemented for bunch length measurement at Shanghai Synchrotron Radiation Facility (SSRF). It is based on the information from two harmonic frequencies of Flourier Transformation of longitudinal charge distribution. We select 500MHz and 3GHz as working frequency and the system consists of power splitters, band-pass filters and a mixer. Raw data are acquired by a digital oscilloscope and analyzed by MATLAB code. The system has been calibrated by Streak Camera in single-bunch experiment environment with bunch charge from 0.23nC to 6.05nC. The paper also shows bunch length synchronous oscillation phenomenon during injection period.
	Slides TH2AB2 [3.638 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2017-TH2AB2
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TUPWC01	The Application of Direct RF Sampling System on Cavity BPM Signal Processing	278
	L.W. Lai, F.Z. Chen, Y.B. Leng, T. Wu, L.Y. Yu, R.X. Yuan SSRF, Shanghai, People's Republic of China S.S. Cao, J. Chen, J. Chen, Y.B. Leng, T.J. Shen, L.Y. Yu, R.X. Yuan SINAP, Shanghai, People's Republic of China
	Cavity BPM signal processing system normally consists of two modules, first one is RF conditioning module to down convert the BPM signal to IF, second one is IF signal digitizer and digital signal processing module. The conditioning module complicates the system and introduce noise. A direct RF sampling system has been constructed to process the cavity BPM signal, which structure is more concise and performance is more stable compared to the conventional system. The platform and test results will be introduced in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2017-TUPWC01
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TUPWC03	Design of A New Type of Beam Charge Monitor Based on Bunch by Bunch DAQ System	284
	F.Z. Chen, L.W. Lai, Y.B. Leng SSRF, Shanghai, People's Republic of China Y.B. Yan SINAP, Shanghai, People's Republic of China
	Beam current is one of the fundamental parameters to be measured in storage ring. The Shanghai Synchrotron Radiation Facility (SSRF), a third generation light source with the RF frequency of 499.68MHz, used adopt com-mercial product to monitor beam charge. However, the maintain and upgrade is not always straightforward. Thus, a new type of beam charge monitor (BCM) based on beam positon monitor (BPM) sum signals has been de-veloped for the online beam current measurement on SSRF storage ring. This system has been convincingly validated by mathematical analysis and has been demonstrated with beam experiments during machine study time.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2017-TUPWC03
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Beam Charge Measurement Using the Method of Double-Cavity Mixing

411

J. Chen, S.S. Cao, L.W. Lai, Y.B. Leng, R.X. Yuan
SINAP, Shanghai, People's Republic of China
N. Zhang
SSRF, Shanghai, People's Republic of China

The measurement of beam charge is a fundamental re-quirement to all particle accelerators facility. In this paper, using the TM010 mode of the cavity BPM to measure the beam charge will be introduced. The data processing methods including harmonic analysis, time domain analysis and principle component analysis (PCA) are used and compared in evaluating the resolution of the beam charge. On the basis of this, the results of the evaluation at a ultra-low charge are also given and indicates the superiority of the cavity probe in the measurement of lower beam charge. In addition, the use of double-cavity mixing method to measure the beam charge will be proposed as well.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2017-WEPCF01

Export •

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

TH2AB2

Bunch-by-Bunch Beam Length Measurement Using Two-Frequency System at SSRF

499

H.J. Chen, L.W. Duan, B. Gao, L.W. Lai, Y.B. Leng
SINAP, Shanghai, People's Republic of China
N. Zhang
SSRF, Shanghai, People's Republic of China

A Two-frequency method has been implemented for bunch length measurement at Shanghai Synchrotron Radiation Facility (SSRF). It is based on the information from two harmonic frequencies of Flourier Transformation of longitudinal charge distribution. We select 500MHz and 3GHz as working frequency and the system consists of power splitters, band-pass filters and a mixer. Raw data are acquired by a digital oscilloscope and analyzed by MATLAB code. The system has been calibrated by Streak Camera in single-bunch experiment environment with bunch charge from 0.23nC to 6.05nC. The paper also shows bunch length synchronous oscillation phenomenon during injection period.

Slides TH2AB2 [3.638 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2017-TH2AB2

Export •

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

TUPWC01

The Application of Direct RF Sampling System on Cavity BPM Signal Processing

278

L.W. Lai, F.Z. Chen, Y.B. Leng, T. Wu, L.Y. Yu, R.X. Yuan
SSRF, Shanghai, People's Republic of China
S.S. Cao, J. Chen, J. Chen, Y.B. Leng, T.J. Shen, L.Y. Yu, R.X. Yuan
SINAP, Shanghai, People's Republic of China

Cavity BPM signal processing system normally consists of two modules, first one is RF conditioning module to down convert the BPM signal to IF, second one is IF signal digitizer and digital signal processing module. The conditioning module complicates the system and introduce noise. A direct RF sampling system has been constructed to process the cavity BPM signal, which structure is more concise and performance is more stable compared to the conventional system. The platform and test results will be introduced in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2017-TUPWC01

Export •

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

TUPWC03

Design of A New Type of Beam Charge Monitor Based on Bunch by Bunch DAQ System

284

F.Z. Chen, L.W. Lai, Y.B. Leng
SSRF, Shanghai, People's Republic of China
Y.B. Yan
SINAP, Shanghai, People's Republic of China

Beam current is one of the fundamental parameters to be measured in storage ring. The Shanghai Synchrotron Radiation Facility (SSRF), a third generation light source with the RF frequency of 499.68MHz, used adopt com-mercial product to monitor beam charge. However, the maintain and upgrade is not always straightforward. Thus, a new type of beam charge monitor (BCM) based on beam positon monitor (BPM) sum signals has been de-veloped for the online beam current measurement on SSRF storage ring. This system has been convincingly validated by mathematical analysis and has been demonstrated with beam experiments during machine study time.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2017-TUPWC03

Export •

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