IPAC2017 - List of Authors (Liu, W.)

Paper	Title	Page
TUPAB080	Considerations of the HALS Injection System and a New Non-linear Kicker Design	1503
	L. Shang, W. Liu, Y. Lu, F.L. Shang, Z.B. Sun USTC/NSRL, Hefei, Anhui, People's Republic of China
	Funding: Work supported by The National Key Research and Development Program of China No. 2016YFA0402000(2016YFA0402002) Hefei Advanced Light Source (HALS) is a newly designed diffraction-limited synchrotron radiation source with an energy of 2GeV and a natural emittance of 18.4 pm. A project to build test facility of this new light source has been approved and funded in 2017. Among many key subsystems, the injection system of HALS is a very important one. Both on-axis swap out, on-axis longitudinal accumulation and off-axis single multipole kicker injection are considered. For on-axis fast kicker injection, basic parameters of the system are given. Layout of kickers and septums are presented. For off-axis multipole injection, non-linear kickers (NLK) draw much attention in recent years, various studies have been carried out in many laboratories. But it suffered from low injection efficiency and has not been used in routine operation. In this paper, we propose a new ferrite-loaded non-linear kicker (FNLK) and a prototype FNLK has been developed and tested. Compared to the air bus design of NLK, the FNLK not only improves the flat region of magnetic field but also reduce the error sensitivity of bars' position.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB080
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WEPVA075	Labview-Based Software for Electron Gun Controller	3439
	Z.X. Shao, H. Gao, W. Liu, C.Y. Pan USTC/NSRL, Hefei, Anhui, People's Republic of China
	Funding: Supported by the National Science Foundation of China (No: 21327901) Instrument control can improve measurement level of automation. In the actual control of the accelerator electron gun, we need to obtain a voltage with different amplitudes for the filament. Boost and voltage regulator modules should be used in the 220V AC input conditions. In order to adjust the filament voltage and stabilize the filament current more convenient, we developed a control software based on LabVIEW.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPVA075
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THPAB123	Low Level RF Control System Architecture OF IR-FEL	4014
	B. Du, G. Huang, L. Lin, W. Liu, Z.R. Zhou USTC/NSRL, Hefei, Anhui, People's Republic of China
	Infrared free electron laser (IR-FEL) is one type of laser driven by accelerator and generated by undulator. It is built by National Synchrotron Radiation Laboratory (NSRL). Compared to synchrotron radiation light source, it have much higher demand of beam quality. Low level RF control system (LLRF) need to reach higher controlled accuracy corresponded to the demand. Accelerating structure which contains one pre-buncher, one buncher and two accelerating tube can accelerate beam to 60MeV. Frequency distribution system use direct digital synthesizer technology to generate 5 signal of different frequency. LLRF system detect 8 channels signal, one for control loop, and the others for monitor and interlock. The hardware contain MTCA.4 architecture which is advanced in global; RF board for downconverter and IQ modulation output; DSP board for sampling, controller and transmission.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB123
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THPAB124	DSP Frame and Algorithm of LLRF of IR-FEL	4017
	B. Du, G. Huang, L. Lin, W. Liu, Z.R. Zhou USTC/NSRL, Hefei, Anhui, People's Republic of China
	Infrared Free Electron Laser (IR-FEL) use linear accelerator to accelerate electron to relative speed and then generate simulated radiation of infrared wavelength by periodic magnetic field of undulator. The amplitude and phase of microwave field need to be controlled precisely by low level RF control system (LLRF) to meet the high quality demand of electron from undulator. This paper mainly introduce the digital signal processing frame and feedback algorithm. Four times frequency sampling can realize IQ demodulation precisely and reduce DC offset, amplitude sampling error is less than 0.075% and phase sampling error is less than 0.1°. Pipeline CORDIC can calculate amplitude and phase by parallel processing and shift operation. Phase calculating accuracy reach 0.0005° when iteration count is 18. FIR filter is used to improve frequency selected performance. Feedback loop use digital PI controller to adjust system output.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB124
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THPAB127	Development of 1.3 GHz Cavity Combiner for 24 kW CW SSA	4020
SUSPSIK107	use link to see paper's listing under its alternate paper code
	W. Liu, B. Du, G. Huang, L. Lin, L. Shang, W.B. Song USTC/NSRL, Hefei, Anhui, People's Republic of China
	The 24KW CW SSA (Solid-State Amplifier) is being developed to drive the 1.3GHz SC Linac used in a THz light source. The SSA adopts the compact all-in-one combining method ' cavity combiner, which is proposed and developed in recent years. This paper reports the R&D of the cavity combiner. The cavity combiner resonates in TM010 mode, coupling with 24 coaxial-connected 1kW amplifier modules. The cavity's electromagnetic characteristic is calculated by CST, and the mechanical structure including the input and output coupler has been designed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB127
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THPVA104	Design of New Spectrum Data Acquisition System	4707
	Z.X. Shao, H. Gao, W. Liu, C.Y. Pan USTC/NSRL, Hefei, Anhui, People's Republic of China
	Funding: Project supported by the National Basic Research Program of China, the National Key Scientific Instrument and Equipment Development Projects, China (2014YQ120351). To solve the problem of spectrum acquisition in LIBS (Laser-Induced Breakdown Spectroscopy), a real-time data acquisition system was designed based on PSoC (Programmable System-On-Chip). First, the linear array CCD with electronic shutter function TCD1304DG has been used as detector .And then, the AD7621, a 16-bit analog-to-digital converter, was used to convert signal from the AFE (Analog Front End). After that, a high-integrated, low-power PSoC5LP was used as core controller, it works to complete the driver and data communication, including CCD , ADC, FIFO, the USB interface, etc. At last, a WIFI module has been added to the system for the convenience of users as well as follow-up research. The result through board-level testing indicates that the system in the spectrum acquisition is stable and accurate, and the indicators meet the LIBS project requirements.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPVA104
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Paper

Title

Page

Considerations of the HALS Injection System and a New Non-linear Kicker Design

1503

L. Shang, W. Liu, Y. Lu, F.L. Shang, Z.B. Sun
USTC/NSRL, Hefei, Anhui, People's Republic of China

Funding: Work supported by The National Key Research and Development Program of China No. 2016YFA0402000(2016YFA0402002)
Hefei Advanced Light Source (HALS) is a newly designed diffraction-limited synchrotron radiation source with an energy of 2GeV and a natural emittance of 18.4 pm. A project to build test facility of this new light source has been approved and funded in 2017. Among many key subsystems, the injection system of HALS is a very important one. Both on-axis swap out, on-axis longitudinal accumulation and off-axis single multipole kicker injection are considered. For on-axis fast kicker injection, basic parameters of the system are given. Layout of kickers and septums are presented. For off-axis multipole injection, non-linear kickers (NLK) draw much attention in recent years, various studies have been carried out in many laboratories. But it suffered from low injection efficiency and has not been used in routine operation. In this paper, we propose a new ferrite-loaded non-linear kicker (FNLK) and a prototype FNLK has been developed and tested. Compared to the air bus design of NLK, the FNLK not only improves the flat region of magnetic field but also reduce the error sensitivity of bars' position.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB080

Export •

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

WEPVA075

Labview-Based Software for Electron Gun Controller

3439

Z.X. Shao, H. Gao, W. Liu, C.Y. Pan
USTC/NSRL, Hefei, Anhui, People's Republic of China

Funding: Supported by the National Science Foundation of China (No: 21327901)
Instrument control can improve measurement level of automation. In the actual control of the accelerator electron gun, we need to obtain a voltage with different amplitudes for the filament. Boost and voltage regulator modules should be used in the 220V AC input conditions. In order to adjust the filament voltage and stabilize the filament current more convenient, we developed a control software based on LabVIEW.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPVA075

Export •

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

THPAB123

Low Level RF Control System Architecture OF IR-FEL

4014

B. Du, G. Huang, L. Lin, W. Liu, Z.R. Zhou
USTC/NSRL, Hefei, Anhui, People's Republic of China

Infrared free electron laser (IR-FEL) is one type of laser driven by accelerator and generated by undulator. It is built by National Synchrotron Radiation Laboratory (NSRL). Compared to synchrotron radiation light source, it have much higher demand of beam quality. Low level RF control system (LLRF) need to reach higher controlled accuracy corresponded to the demand. Accelerating structure which contains one pre-buncher, one buncher and two accelerating tube can accelerate beam to 60MeV. Frequency distribution system use direct digital synthesizer technology to generate 5 signal of different frequency. LLRF system detect 8 channels signal, one for control loop, and the others for monitor and interlock. The hardware contain MTCA.4 architecture which is advanced in global; RF board for downconverter and IQ modulation output; DSP board for sampling, controller and transmission.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB123

Export •

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

THPAB124

DSP Frame and Algorithm of LLRF of IR-FEL

4017

B. Du, G. Huang, L. Lin, W. Liu, Z.R. Zhou
USTC/NSRL, Hefei, Anhui, People's Republic of China

Infrared Free Electron Laser (IR-FEL) use linear accelerator to accelerate electron to relative speed and then generate simulated radiation of infrared wavelength by periodic magnetic field of undulator. The amplitude and phase of microwave field need to be controlled precisely by low level RF control system (LLRF) to meet the high quality demand of electron from undulator. This paper mainly introduce the digital signal processing frame and feedback algorithm. Four times frequency sampling can realize IQ demodulation precisely and reduce DC offset, amplitude sampling error is less than 0.075% and phase sampling error is less than 0.1°. Pipeline CORDIC can calculate amplitude and phase by parallel processing and shift operation. Phase calculating accuracy reach 0.0005° when iteration count is 18. FIR filter is used to improve frequency selected performance. Feedback loop use digital PI controller to adjust system output.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB124

Export •

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

THPAB127

Development of 1.3 GHz Cavity Combiner for 24 kW CW SSA

4020

SUSPSIK107

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

W. Liu, B. Du, G. Huang, L. Lin, L. Shang, W.B. Song
USTC/NSRL, Hefei, Anhui, People's Republic of China

The 24KW CW SSA (Solid-State Amplifier) is being developed to drive the 1.3GHz SC Linac used in a THz light source. The SSA adopts the compact all-in-one combining method ' cavity combiner, which is proposed and developed in recent years. This paper reports the R&D of the cavity combiner. The cavity combiner resonates in TM010 mode, coupling with 24 coaxial-connected 1kW amplifier modules. The cavity's electromagnetic characteristic is calculated by CST, and the mechanical structure including the input and output coupler has been designed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB127

Export •

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

THPVA104

Design of New Spectrum Data Acquisition System

4707

Z.X. Shao, H. Gao, W. Liu, C.Y. Pan
USTC/NSRL, Hefei, Anhui, People's Republic of China

Funding: Project supported by the National Basic Research Program of China, the National Key Scientific Instrument and Equipment Development Projects, China (2014YQ120351).
To solve the problem of spectrum acquisition in LIBS (Laser-Induced Breakdown Spectroscopy), a real-time data acquisition system was designed based on PSoC (Programmable System-On-Chip). First, the linear array CCD with electronic shutter function TCD1304DG has been used as detector .And then, the AD7621, a 16-bit analog-to-digital converter, was used to convert signal from the AFE (Analog Front End). After that, a high-integrated, low-power PSoC5LP was used as core controller, it works to complete the driver and data communication, including CCD , ADC, FIFO, the USB interface, etc. At last, a WIFI module has been added to the system for the convenience of users as well as follow-up research. The result through board-level testing indicates that the system in the spectrum acquisition is stable and accurate, and the indicators meet the LIBS project requirements.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPVA104

Export •

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