IPAC2019 - List of Authors (Tang, Y.G.)

Paper	Title	Page
MOPRB033	Preliminary Research of HOM for 100MHz Superconducting Cavity in the Pre-Research Project of HALS	649
SUSPFO070	use link to see paper's listing under its alternate paper code
	Y.G. Tang, L. Wang, C.-F. Wu USTC/NSRL, Hefei, Anhui, People’s Republic of China
	A 100MHz QWR superconducting cavity is researched in the pre-research project of Hefei Advanced Light Source (HALS). Higher order modes (HOM) damping is a big challenge for synchrotron radiation light source. In this paper, we first apply the novel choke mode structure to the 100MHz QWR (quarter wave resonator) cavity in order to damp the HOM. We identify the main harmful higher order modes. The HOMs in the QWR cavity are suppressed by optimizing the choke dimensions. The broadband HOM impedance spectrum of the cavity was also evaluated by calculating the beam induced wake potential in time domain. The results show that choke mode structure has a good HOM damping effect on the QWR cavity.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB033
About •	paper received ※ 25 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPRB052	Design of Two Types of X-Band High Power Directional Coupler	2928
	G. Wang, X. Lin, Y.G. Tang, C.-F. Wu USTC/NSRL, Hefei, Anhui, People’s Republic of China
	The directional coupler is one of the most widely used components in many microwave systems, which is used to distribute the power of the input microwave signal according to a desired ratio. Directional coupler may be a three-port component or a four-port component with certain specification such as frequencies, bandwidth and structure. To meet the requirements of stable coupling degree and high directivity, we designed two types of directional coupler working at 11.424 GHz with high power handling capacity. One consists of two parallel rectangular waveguides with four holes drilled along the central line of the narrow-wall for coupling the electromagnetic power from the main-waveguide to the sub-waveguide which is called H-plane directional coupler. Simulations show that the coupling degree of H-face directional coupler is 49.9 dB and the directivity is 54.5 dB .The peak electric field is about 29MV/m while operating at 200 MW peak power. The other consists of a circular main-waveguide transmitting TM01 mode and a rectangular sub-waveguide transmitting TE10 mode, called circular-rectangle waveguide directional coupler. These two waveguide are connected by six holes drilled on the side of the circular main-waveguide and along the central line of the wide-wall of the sub-waveguide. The coupling degree of this directional coupler is 50.14 dB and the directivity is 37.93 dB due to the simulation. The bandwidth is about 800MHz. The peak electric field is 404.5V/m while operating at 200 MW peak power. Comparing with the H-plane directional coupler, peak electric field of this directional coupler is lower. Low peak electric field can reduce the risk of RF breakdown and the Multipactor effect, which ensures the stable high power operation of the directional coupler.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB052
About •	paper received ※ 27 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPRB054	Design of the Multiplexing Optical Measurement System for a Pre-bunched THz Free Electron Laser	2931
	Y.K. Zhao, W. Li, B.G. Sun, Y.G. Tang, F.F. Wu, T.Y. Zhou USTC/NSRL, Hefei, Anhui, People’s Republic of China
	Funding: Work supported by the the Fundamental Research Funds for the Central Universities (WK2310000080, WK2310000057), and the National Science Foundation of China (11705203, 11575181) A new and compact a pre-bunched terahertz (THz) free electron laser (FEL) at the National Synchrotron Radiation Laboratory, University of Science and Technology of China is being constructed and aims to generate the tunable radiation frequency ranges from 0.5 THz to 5 THz at 11-18 Mev electron energy. This system is expected to use for imaging, basic researches as well as industrial applications as a result of the significant merits of simple, compact and cost-effective. Due to the THz laser measurement system plays an important part in the pre-bunched THz FEL facility. Therefore, a multiplexing THz laser sensing measurement system model is developed for measuring the output laser power and the optical spectrum of THz radiation with the excellent advantages of robustness, high sensitivity and low-cost in this paper. Corresponding author (email: tiany86@ustc.edu.cn) Corresponding author (email: wufangfa@ustc.edu.cn)
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB054
About •	paper received ※ 14 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

MOPRB033

Preliminary Research of HOM for 100MHz Superconducting Cavity in the Pre-Research Project of HALS

649

SUSPFO070

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

Y.G. Tang, L. Wang, C.-F. Wu
USTC/NSRL, Hefei, Anhui, People’s Republic of China

A 100MHz QWR superconducting cavity is researched in the pre-research project of Hefei Advanced Light Source (HALS). Higher order modes (HOM) damping is a big challenge for synchrotron radiation light source. In this paper, we first apply the novel choke mode structure to the 100MHz QWR (quarter wave resonator) cavity in order to damp the HOM. We identify the main harmful higher order modes. The HOMs in the QWR cavity are suppressed by optimizing the choke dimensions. The broadband HOM impedance spectrum of the cavity was also evaluated by calculating the beam induced wake potential in time domain. The results show that choke mode structure has a good HOM damping effect on the QWR cavity.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB033

About •

paper received ※ 25 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

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

WEPRB052

Design of Two Types of X-Band High Power Directional Coupler

2928

G. Wang, X. Lin, Y.G. Tang, C.-F. Wu
USTC/NSRL, Hefei, Anhui, People’s Republic of China

The directional coupler is one of the most widely used components in many microwave systems, which is used to distribute the power of the input microwave signal according to a desired ratio. Directional coupler may be a three-port component or a four-port component with certain specification such as frequencies, bandwidth and structure. To meet the requirements of stable coupling degree and high directivity, we designed two types of directional coupler working at 11.424 GHz with high power handling capacity. One consists of two parallel rectangular waveguides with four holes drilled along the central line of the narrow-wall for coupling the electromagnetic power from the main-waveguide to the sub-waveguide which is called H-plane directional coupler. Simulations show that the coupling degree of H-face directional coupler is 49.9 dB and the directivity is 54.5 dB .The peak electric field is about 29MV/m while operating at 200 MW peak power. The other consists of a circular main-waveguide transmitting TM01 mode and a rectangular sub-waveguide transmitting TE10 mode, called circular-rectangle waveguide directional coupler. These two waveguide are connected by six holes drilled on the side of the circular main-waveguide and along the central line of the wide-wall of the sub-waveguide. The coupling degree of this directional coupler is 50.14 dB and the directivity is 37.93 dB due to the simulation. The bandwidth is about 800MHz. The peak electric field is 404.5V/m while operating at 200 MW peak power. Comparing with the H-plane directional coupler, peak electric field of this directional coupler is lower. Low peak electric field can reduce the risk of RF breakdown and the Multipactor effect, which ensures the stable high power operation of the directional coupler.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB052

About •

paper received ※ 27 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

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

WEPRB054

Design of the Multiplexing Optical Measurement System for a Pre-bunched THz Free Electron Laser

2931

Y.K. Zhao, W. Li, B.G. Sun, Y.G. Tang, F.F. Wu, T.Y. Zhou
USTC/NSRL, Hefei, Anhui, People’s Republic of China

Funding: Work supported by the the Fundamental Research Funds for the Central Universities (WK2310000080, WK2310000057), and the National Science Foundation of China (11705203, 11575181)
A new and compact a pre-bunched terahertz (THz) free electron laser (FEL) at the National Synchrotron Radiation Laboratory, University of Science and Technology of China is being constructed and aims to generate the tunable radiation frequency ranges from 0.5 THz to 5 THz at 11-18 Mev electron energy. This system is expected to use for imaging, basic researches as well as industrial applications as a result of the significant merits of simple, compact and cost-effective. Due to the THz laser measurement system plays an important part in the pre-bunched THz FEL facility. Therefore, a multiplexing THz laser sensing measurement system model is developed for measuring the output laser power and the optical spectrum of THz radiation with the excellent advantages of robustness, high sensitivity and low-cost in this paper.
Corresponding author (email: tiany86@ustc.edu.cn)
Corresponding author (email: wufangfa@ustc.edu.cn)

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB054

About •

paper received ※ 14 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

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