IPAC2018 - List of Authors (Chen, J.)

Paper	Title	Page
THPML062	A Beam Based Method to Optimize the SBPM System	4780
SUSPF095	use link to see paper's listing under its alternate paper code
	J. Chen SINAP, Shanghai, People's Republic of China L.W. Lai, Y.B. Leng, T. Wu, R.X. Yuan SSRF, Shanghai, People's Republic of China
	For the electron accelerator, it is hoped that the trajec-tory of the beam can pass through the magnetic center of the quadrupole to minimize the orbital motion caused by the instability of the power supply. The relative deviation between the magnetic center of quadrupole and the elec-tric center of adjacent BPM is measured by electron beam usually in various accelerator facilities. But for the stripline BPM (SBPM) system, in order to achieve the best performance, the beam trajectory should also need to pass through the electrical center of the SBPM system. In this paper, a beam based method to optimize the SBPM system was proposed, the intensity of the magnet power was scanned to change the beam position in two-dimension and combine the change trend of the sum signal of adjacent SBPM to find out the relative deviation of BPM electric center and mechanical center. Relevant beam experiment work on the Shanghai Soft X-ray free electron laser (SXFEL) and the benefit of this method will be addressed as well.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML062
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THPML067	SXFEL Linac BPM System Development and Performance Evaluation	4794
SUSPF094	use link to see paper's listing under its alternate paper code
	F.Z. Chen, T. Wu SSRF, Shanghai, People's Republic of China J. Chen, L.W. Lai, Y.B. Leng, L.Y. Yu, R.X. Yuan SINAP, Shanghai, People's Republic of China
	Shanghai Soft X-ray Free Electron Laser (SXFEL) is a test facility to study key technologies and new FEL physics. In order to deliver high quality electron beams to the undulator section, a high resolution (better than 10 microns with 200pC beam) Linac beam position monitor system has been developed. The system consists of stripline pickup and custom designed DBPM processor. The hardware and software architecture will be introduced in this paper. The online performance evaluation results will be presented as well.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML067
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THPML071	Upgrade of Digital BPM Processor at DCLS and SXFEL	4807
	L.W. Lai, F.Z. Chen, Y.B. Leng, T. Wu, Y.B. Yan SSRF, Shanghai, People's Republic of China J. Chen SINAP, Shanghai, People's Republic of China
	A digital BPM processor has been developed at 2016 in SINAP for DCLS and SXFEL, which are FEL facilities built in China. The stripline BPM and cavity BPM processors share the same hardware platform and firmware, but the processing algorithms implemented in EPICS IOC on the ARM CPU are different. The capability of the ARM limits the processing speed to 10 bunches per second. Now the bunch rate of DCLS and SXFEL are going to increase from 10Hz to 50Hz. To meet the higher processing speed requirements, the processor firmware and software are upgraded in 2017. All BPM signal processing algorithms are implemented in FPGA, and EPICS IOC reads results only. After the upgrade, the processing speed reach 120 bunches per second. And this is also a good preparation for future Shanghai Hard-X ray FEL, which bunch rate is about 1MHz.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML071
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Paper

Title

Page

THPML062

A Beam Based Method to Optimize the SBPM System

4780

SUSPF095

use link to see paper's listing under its alternate paper code

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

For the electron accelerator, it is hoped that the trajec-tory of the beam can pass through the magnetic center of the quadrupole to minimize the orbital motion caused by the instability of the power supply. The relative deviation between the magnetic center of quadrupole and the elec-tric center of adjacent BPM is measured by electron beam usually in various accelerator facilities. But for the stripline BPM (SBPM) system, in order to achieve the best performance, the beam trajectory should also need to pass through the electrical center of the SBPM system. In this paper, a beam based method to optimize the SBPM system was proposed, the intensity of the magnet power was scanned to change the beam position in two-dimension and combine the change trend of the sum signal of adjacent SBPM to find out the relative deviation of BPM electric center and mechanical center. Relevant beam experiment work on the Shanghai Soft X-ray free electron laser (SXFEL) and the benefit of this method will be addressed as well.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML062

Export •

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

THPML067

SXFEL Linac BPM System Development and Performance Evaluation

4794

SUSPF094

use link to see paper's listing under its alternate paper code

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

Shanghai Soft X-ray Free Electron Laser (SXFEL) is a test facility to study key technologies and new FEL physics. In order to deliver high quality electron beams to the undulator section, a high resolution (better than 10 microns with 200pC beam) Linac beam position monitor system has been developed. The system consists of stripline pickup and custom designed DBPM processor. The hardware and software architecture will be introduced in this paper. The online performance evaluation results will be presented as well.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML067

Export •

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

THPML071

Upgrade of Digital BPM Processor at DCLS and SXFEL

4807

L.W. Lai, F.Z. Chen, Y.B. Leng, T. Wu, Y.B. Yan
SSRF, Shanghai, People's Republic of China
J. Chen
SINAP, Shanghai, People's Republic of China

A digital BPM processor has been developed at 2016 in SINAP for DCLS and SXFEL, which are FEL facilities built in China. The stripline BPM and cavity BPM processors share the same hardware platform and firmware, but the processing algorithms implemented in EPICS IOC on the ARM CPU are different. The capability of the ARM limits the processing speed to 10 bunches per second. Now the bunch rate of DCLS and SXFEL are going to increase from 10Hz to 50Hz. To meet the higher processing speed requirements, the processor firmware and software are upgraded in 2017. All BPM signal processing algorithms are implemented in FPGA, and EPICS IOC reads results only. After the upgrade, the processing speed reach 120 bunches per second. And this is also a good preparation for future Shanghai Hard-X ray FEL, which bunch rate is about 1MHz.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML071

Export •

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