IPAC2018 - List of Authors (He, Z.G.)

Paper	Title	Page
THPMK018	Design of a rotationally symmetric S-band photocathode RF gun	4336
	Zh. X. Tang USTC, Hefei, Anhui, People's Republic of China Z.G. He, W.W. Li, Y.J. Pei, L. Wang USTC/NSRL, Hefei, Anhui, People's Republic of China
	The photocathode RF gun is one of the most critical components for high quality electron beam sources. The asymmetric multi-pole field contributes to the transverse emittance growth and degrades the beam quality. In order to overcome the problem, we propose a novel rotationally symmetric 1.6 cell RF gun to construct the symmetric field in this paper. The concrete proposal is that a coaxial cell with a symmetrical distribution of four grooves is concatenated to the first 0.6 cell at the photocathode end to form a new resonant cell (NRC) to mantain the symmetric multi-pole field in 1.6 cell. Our simulations indicate that 3D multi-pole fields of NRC are with the perfect symmetry. After that, the profile of the RF gun is optimized to improve the shunt impedance and mode separation and make the surface peak electric field at the photocathode end. Our simulations demonstrate promising outlook of using coaxial cell for photocathode RF guns with various applications.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK018
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPMK123	Initial Design on the High Quality Electron Beam for the Hefei Advanced Light Source	4605
	R. Huang, Z.G. He, Q.K. Jia, Y. Lu, L. Wang USTC/NSRL, Hefei, Anhui, People's Republic of China
	Funding: Work is supported by China Postdoctoral Science Foundation (Grant No. 51627901) and Chinese Universities Scientific Fund (Contract WK2310000063) The Hefei Advanced Light Source (HALS) was proposed as a future soft X-ray diffraction-limited storage ring with a Free Electron Laser (FEL) at National Synchrotron Radiation Laboratory (NSRL). We present a design for a high brightness electron source as an injector of a 2.4 GeV linac-based diffraction limited storage ring and a free electron laser. The electron beams with low emittance and high peak current will be generated from a photoinjector and designed to fulfill the requirement of the HALS. To compress the bunch length and enhance the pulse current, velocity bunching scenario by a deceleration injection phase is designed. Owing to a linear compression, the electron beam is expected to be extremely short with a further magnetic compression.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK123
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPMK124	The Radiation Source for a Pre-Bunched THz Free Electron Laser	4608
	R. Huang, Z.G. He, Q.K. Jia, H.T. Li, W.W. Li, Y. Lu, L. Wang, Z. Zhao USTC/NSRL, Hefei, Anhui, People's Republic of China
	Funding: Work is supported by National Natural Science Foundation of China (Grant No. 51627901) Electron beam, generated in a photoinjector and bunched at terahertz (THz) frequency, will excite the coherent THz radiation when entering an undulator. We present a scheme of the radiation source for the pre-bunched THz free electron laser (FEL). The physical design of electron source is described in detail. The radiation frequency is widely tunable by both the pulse train tuning and the undulator gap tuning. It is simulation proved that the radiation power is greatly enhanced in our scheme.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK124
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPMK126	Numerical Method for Longitudinal Dynamics of a Terahertz Cherenkov Free Electron Laser Driven by a Mev Picosecond Electron Beam	4614
	W.W. Li, Z.G. He, Q.K. Jia, S.M. Jiang, L. Wang USTC/NSRL, Hefei, Anhui, People's Republic of China D. He Anhui Electrical Engineering Professional Technique College, Hefei, People's Republic of China
	Funding: Natural Science Foundation of China (11705198, 11775216) China Postdoctoral Science Foundation (2017M622023) Fundamental Research Funds for the Central Universities (WK2310000061) Corrugated or dielectric structures have been widely used for producing electron bunch train or THz radiation source. Recently, a novel scheme of sub-terahertz free electron laser (FEL) from a metallic pipe with corrugated walls driven by a non-ultra-relativistic (<10 MeV) picosecond electron beam was proposed and analyzed using the Vlasov-Maxwell equations. In this paper, we use the dielectric loaded waveguide instead, and a numerical method for the longitudinal beam dynamics and electromagnetics of the FEL interaction is presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK126
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPMK127	Terahertz Smith-Purcell Radiation From the High-Harmonic Component of Modulated Electron Beam From Dielectric Structure	4617
	S.M. Jiang, Z.G. He, Q.K. Jia, W.W. Li, L. Wang USTC/NSRL, Hefei, Anhui, People's Republic of China D. He Anhui Electrical Engineering Professional Technique College, Hefei, People's Republic of China
	Funding: Supported by National Nature Science Foundation of China(11705198, 11775216) In this paper, a new radiation scheme, which adopts the high order harmonic of modulated electron beam from dielectric loaded waveguide to excite the Smith-Purcell terahertz (THz) radiation, is proposed and in-vestigated by numerical simulations. The results show that the radiation with frequency close to 1.0 THz is generated, while, the fundamental bunching frequency of electron beam is 0.28 THz. Thus, this scheme offer a new method to get the higher frequency THz radiation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK127
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Design of a rotationally symmetric S-band photocathode RF gun

4336

Zh. X. Tang
USTC, Hefei, Anhui, People's Republic of China
Z.G. He, W.W. Li, Y.J. Pei, L. Wang
USTC/NSRL, Hefei, Anhui, People's Republic of China

The photocathode RF gun is one of the most critical components for high quality electron beam sources. The asymmetric multi-pole field contributes to the transverse emittance growth and degrades the beam quality. In order to overcome the problem, we propose a novel rotationally symmetric 1.6 cell RF gun to construct the symmetric field in this paper. The concrete proposal is that a coaxial cell with a symmetrical distribution of four grooves is concatenated to the first 0.6 cell at the photocathode end to form a new resonant cell (NRC) to mantain the symmetric multi-pole field in 1.6 cell. Our simulations indicate that 3D multi-pole fields of NRC are with the perfect symmetry. After that, the profile of the RF gun is optimized to improve the shunt impedance and mode separation and make the surface peak electric field at the photocathode end. Our simulations demonstrate promising outlook of using coaxial cell for photocathode RF guns with various applications.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK018

Export •

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

THPMK123

Initial Design on the High Quality Electron Beam for the Hefei Advanced Light Source

4605

R. Huang, Z.G. He, Q.K. Jia, Y. Lu, L. Wang
USTC/NSRL, Hefei, Anhui, People's Republic of China

Funding: Work is supported by China Postdoctoral Science Foundation (Grant No. 51627901) and Chinese Universities Scientific Fund (Contract WK2310000063)
The Hefei Advanced Light Source (HALS) was proposed as a future soft X-ray diffraction-limited storage ring with a Free Electron Laser (FEL) at National Synchrotron Radiation Laboratory (NSRL). We present a design for a high brightness electron source as an injector of a 2.4 GeV linac-based diffraction limited storage ring and a free electron laser. The electron beams with low emittance and high peak current will be generated from a photoinjector and designed to fulfill the requirement of the HALS. To compress the bunch length and enhance the pulse current, velocity bunching scenario by a deceleration injection phase is designed. Owing to a linear compression, the electron beam is expected to be extremely short with a further magnetic compression.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK123

Export •

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

THPMK124

The Radiation Source for a Pre-Bunched THz Free Electron Laser

4608

R. Huang, Z.G. He, Q.K. Jia, H.T. Li, W.W. Li, Y. Lu, L. Wang, Z. Zhao
USTC/NSRL, Hefei, Anhui, People's Republic of China

Funding: Work is supported by National Natural Science Foundation of China (Grant No. 51627901)
Electron beam, generated in a photoinjector and bunched at terahertz (THz) frequency, will excite the coherent THz radiation when entering an undulator. We present a scheme of the radiation source for the pre-bunched THz free electron laser (FEL). The physical design of electron source is described in detail. The radiation frequency is widely tunable by both the pulse train tuning and the undulator gap tuning. It is simulation proved that the radiation power is greatly enhanced in our scheme.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK124

Export •

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

THPMK126

Numerical Method for Longitudinal Dynamics of a Terahertz Cherenkov Free Electron Laser Driven by a Mev Picosecond Electron Beam

4614

W.W. Li, Z.G. He, Q.K. Jia, S.M. Jiang, L. Wang
USTC/NSRL, Hefei, Anhui, People's Republic of China
D. He
Anhui Electrical Engineering Professional Technique College, Hefei, People's Republic of China

Funding: Natural Science Foundation of China (11705198, 11775216) China Postdoctoral Science Foundation (2017M622023) Fundamental Research Funds for the Central Universities (WK2310000061)
Corrugated or dielectric structures have been widely used for producing electron bunch train or THz radiation source. Recently, a novel scheme of sub-terahertz free electron laser (FEL) from a metallic pipe with corrugated walls driven by a non-ultra-relativistic (<10 MeV) picosecond electron beam was proposed and analyzed using the Vlasov-Maxwell equations. In this paper, we use the dielectric loaded waveguide instead, and a numerical method for the longitudinal beam dynamics and electromagnetics of the FEL interaction is presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK126

Export •

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

THPMK127

Terahertz Smith-Purcell Radiation From the High-Harmonic Component of Modulated Electron Beam From Dielectric Structure

4617

S.M. Jiang, Z.G. He, Q.K. Jia, W.W. Li, L. Wang
USTC/NSRL, Hefei, Anhui, People's Republic of China
D. He
Anhui Electrical Engineering Professional Technique College, Hefei, People's Republic of China

Funding: Supported by National Nature Science Foundation of China(11705198, 11775216)
In this paper, a new radiation scheme, which adopts the high order harmonic of modulated electron beam from dielectric loaded waveguide to excite the Smith-Purcell terahertz (THz) radiation, is proposed and in-vestigated by numerical simulations. The results show that the radiation with frequency close to 1.0 THz is generated, while, the fundamental bunching frequency of electron beam is 0.28 THz. Thus, this scheme offer a new method to get the higher frequency THz radiation.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK127

Export •

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