IBIC2017 - List of Authors (Leng, Y.B.)

Paper	Title	Page
TUPCC18	Beam Arrival Time Measurement at SXFEL	193
	S.S. Cao, J. Chen, Y.B. Leng SINAP, Shanghai, People's Republic of China R.X. Yuan SSRF, Shanghai, People's Republic of China
	Shanghai Soft X-ray Free Electron Laser (SXFEL) is a fourth-generation light source which could provide coherent X-rays for various scientific researches. One of the key issues of its operation is the measurement of bunch arrival time which is important for the synchronization of a bunch and seeded laser. The measurement utilized a newly designed beam arrival time monitor (BAM) which contains two cavities at a different frequency. Thus a new way, dual-cavities mixing method, is applied in this experiment to evaluate the beam arrival time resolution. In this paper, we presented the scheme and different measured resolution of various measurement methods and evaluated the stability of the new monitor.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2017-TUPCC18
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)

TUPWC02	Three-Dimensional Bunch-by-Bunch Position Measurement at SSRF	281
	Y.M. Zhou, N. Zhang SSRF, Shanghai, People's Republic of China L.W. Duan, Y.B. Leng SINAP, Shanghai, People's Republic of China
	Measurement of the bunch-by-bunch particle beam position related to dynamic instability is a useful input to accelerator optimization. And the bunch-by-bunch information has been contained in the BPM signals, including bunch charge, transverse position and longitudinal phase information. This paper reports a 3D beam position monitor system based on a high speed digital oscilloscope, which has been used to capture three-dimensional position information during the injection transient at the Shanghai Synchrotron Radiation Facility. With this information the traces of stored bunch and refilled bunch, and the mismatch of energy, transverse position and longitudinal phase between them can be precisely retrieved. The progress of this work and several particular experimental results will be discussed in this paper. The details of data processing method so-called software re-sampling technique will be discussed as well.
	Poster TUPWC02 [0.924 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2017-TUPWC02
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPCC21	Beam Size Monitor Based on Multi-Silt Interferometer at SSRF	408
	B. Gao, H.J. Chen, J. Chen, Y.B. Leng, K.R. Ye SINAP, Shanghai, People's Republic of China
	Double-silt synchrotron radiation interferometer is a common and useful tool to measure transverse beam size around the world. In order to satisfy the requirement of high speed measurement and improve the accuracy of BSM (beam size monitor), multi-silt interferometers have been designed and tested at SSRF. Multi-silt mask pattern has characteristics of high flux throughput and high SNR of the interferogram, which is very useful at high-speed beam size measurement. This technique has a relative complex algorithm to deconvolve the result image and figure out the beam size. Principle of the multi-silt SR interferometer, mask design and experiment will be present detailed in this paper.
	Poster WEPCC21 [1.081 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2017-WEPCC21
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

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

WEPCF02	A Study on the Resolution of Bunch Length Measurement System Using Harmonic Method	415
	Q. Wang, Q. Luo, B.G. Sun USTC/NSRL, Hefei, Anhui, People's Republic of China B. Gao, Y.B. Leng SINAP, Shanghai, People's Republic of China B. Gao University of Chinese Academy of Sciences, Beijing, People's Republic of China
	Funding: Supported by The National Key Research and Development Program of China (2016YFA0401900), NSFC (11575181, 11375178) and the Fundamental Research Funds for the Central Universities (WK2310000046) Harmonic method is very useful when we try to obtain the bunch length, while its resolution is always influenced by many factors. In this paper, the relations between resolution and working frequencies of two cavities are given by mathematical deduction. The laws of resolution change caused by some decisive factors such as beam position, working frequency, electromagnetic mode and probe position are obtained through simulation on computer. An improved measurement method utilizing TM020 mode is presented based on the theory above. The simulation results show that the improved method can enhance the resolution capability of the bunch length monitor and these analyses can provide references for the design of cavity bunch length monitor.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2017-WEPCF02
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)

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 Arrival Time Measurement at SXFEL

193

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

Shanghai Soft X-ray Free Electron Laser (SXFEL) is a fourth-generation light source which could provide coherent X-rays for various scientific researches. One of the key issues of its operation is the measurement of bunch arrival time which is important for the synchronization of a bunch and seeded laser. The measurement utilized a newly designed beam arrival time monitor (BAM) which contains two cavities at a different frequency. Thus a new way, dual-cavities mixing method, is applied in this experiment to evaluate the beam arrival time resolution. In this paper, we presented the scheme and different measured resolution of various measurement methods and evaluated the stability of the new monitor.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2017-TUPCC18

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)

TUPWC02

Three-Dimensional Bunch-by-Bunch Position Measurement at SSRF

281

Y.M. Zhou, N. Zhang
SSRF, Shanghai, People's Republic of China
L.W. Duan, Y.B. Leng
SINAP, Shanghai, People's Republic of China

Measurement of the bunch-by-bunch particle beam position related to dynamic instability is a useful input to accelerator optimization. And the bunch-by-bunch information has been contained in the BPM signals, including bunch charge, transverse position and longitudinal phase information. This paper reports a 3D beam position monitor system based on a high speed digital oscilloscope, which has been used to capture three-dimensional position information during the injection transient at the Shanghai Synchrotron Radiation Facility. With this information the traces of stored bunch and refilled bunch, and the mismatch of energy, transverse position and longitudinal phase between them can be precisely retrieved. The progress of this work and several particular experimental results will be discussed in this paper. The details of data processing method so-called software re-sampling technique will be discussed as well.

Poster TUPWC02 [0.924 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2017-TUPWC02

Export •

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

WEPCC21

Beam Size Monitor Based on Multi-Silt Interferometer at SSRF

408

B. Gao, H.J. Chen, J. Chen, Y.B. Leng, K.R. Ye
SINAP, Shanghai, People's Republic of China

Double-silt synchrotron radiation interferometer is a common and useful tool to measure transverse beam size around the world. In order to satisfy the requirement of high speed measurement and improve the accuracy of BSM (beam size monitor), multi-silt interferometers have been designed and tested at SSRF. Multi-silt mask pattern has characteristics of high flux throughput and high SNR of the interferogram, which is very useful at high-speed beam size measurement. This technique has a relative complex algorithm to deconvolve the result image and figure out the beam size. Principle of the multi-silt SR interferometer, mask design and experiment will be present detailed in this paper.

Poster WEPCC21 [1.081 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2017-WEPCC21

Export •

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

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

Export •

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

WEPCF02

A Study on the Resolution of Bunch Length Measurement System Using Harmonic Method

415

Q. Wang, Q. Luo, B.G. Sun
USTC/NSRL, Hefei, Anhui, People's Republic of China
B. Gao, Y.B. Leng
SINAP, Shanghai, People's Republic of China
B. Gao
University of Chinese Academy of Sciences, Beijing, People's Republic of China

Funding: Supported by The National Key Research and Development Program of China (2016YFA0401900), NSFC (11575181, 11375178) and the Fundamental Research Funds for the Central Universities (WK2310000046)
Harmonic method is very useful when we try to obtain the bunch length, while its resolution is always influenced by many factors. In this paper, the relations between resolution and working frequencies of two cavities are given by mathematical deduction. The laws of resolution change caused by some decisive factors such as beam position, working frequency, electromagnetic mode and probe position are obtained through simulation on computer. An improved measurement method utilizing TM020 mode is presented based on the theory above. The simulation results show that the improved method can enhance the resolution capability of the bunch length monitor and these analyses can provide references for the design of cavity bunch length monitor.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2017-WEPCF02

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)

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)