IPAC2017 - List of Authors (Tang, C.-X.)

Paper	Title	Page
MOPAB075	Measurement of Electron Bunch Length via a Tunable-Gap Undulator	295
	X.L. Su, Y.-C. Du, W.-H. Huang, L. Niu, C.-X. Tang, Q.L. Tian, D. Wang, L.X. Yan TUB, Beijing, People's Republic of China Y.F. Liang Tsinghua University, Beijing, People's Republic of China
	A THz undulator with widely tunable gap is constructed and installed at Tsinghua University beamline, which is applied for narrow-band THz radiation and measurements of electron bunch longitudinal structure. This is a planar electromagnetic device with 8 regular periods, each 10 cm long. The field range B=0.15- 0.99 T peak field on axis while changing the gap from 75mm to 23mm. In the experiments, we scanned the undulator gap to measure the radiation intensity at different resonant frequency, thus we can get the bunch length even form factor of the bunch. The demonstrated experimental results show that the bunch of 220pC compressed by chicane in Tsinghua beamline is about 120fs (rms), which agree well with the simulations. The resolution of bunch length measurement with this method can be attoseconds by optimized undulator. Furthermore, the form factor of electron bunch train can also be measured.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB075
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MOPAB077	Spatial Decoding Electro-Optic Bunch Measurement at Tsinghua Thomson Scattering X-ray Source	302
SUSPSIK075	use link to see paper's listing under its alternate paper code
	W. Wang, Z.J. Chi, Y.-C. Du, W.-H. Huang, C.-X. Tang, L.X. Yan, Z. Zhang TUB, Beijing, People's Republic of China
	Electron bunches with duration of sub-picosecond are essential in ultraviolet and X-ray free electron laser (XFEL) to reach the desired peak current. Electro-optic (EO) technique is suitable for temporal profile measure-ment of these ultrashort bunches which is one of the key diagnostics in FELs. An electro-optic monitor based on spatial sampling has recently been designed and installed for bunch profile diagnostic at Tsinghua Thomson scat-tering X-ray source (TTX). An ultrashort laser pulse is used to detect the field induced birefringence of the bunch Coulomb field in an electro-optic crystal and the monitor allows direct time-resolved single-shot measure-ment of bunch profile with an accuracy of 135 femtosec-onds for a 40 MeV electron bunch in a non-destructive way, which can simultaneously record the relative time jitter between probe laser and electron bunch. This paper performs the layout of the setup and presents the current measurement results.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB077
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MOPVA027	Measurement of High Power Terahertz with Dielectric Loaded Waveguide at Tsinghua University	914
	D. Wang, Y.-C. Du, W. Gai, W.-H. Huang, X.L. Su, C.-X. Tang, Q.L. Tian, L.X. Yan TUB, Beijing, People's Republic of China S.P. Antipov Euclid Beamlabs LLC, Bolingbrook, USA Y.F. Liang Tsinghua University, Beijing, People's Republic of China
	Funding: Work supported by the National Nature Science Foundation of China (NSFC Grants No.11475097) and the National Key Scientific Instrument and Equipment Development Project of China (Grants No. 2013YQ12034504) We have measured an intense THz radiation produced by a sub-picosecond, relativistic electron bunch passing through a dielectric loaded waveguide (DLW) at Tsinghua University accelerator beamline. The DLW was 3 cm long quartz tube with 900 'm inner diameter and 100 'm wall thickness metallized on the outside. Radiated energy of the THz pulse was measured to be proportional to the square of the effective charge. The end of the DLW was cut at an angle for efficient THz pulse extraction. Tens of 'J THz energy per pulse were measured outside the vacuum chamber with a calibrated Golay cell in the experiment. wangdan16@mail.tsinghua.edu.cn yanlx@mail.tsinghua.edu.cn
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPVA027
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MOPVA031	Low Energy Compact Storage Ring Design for Compton Gamma-Ray Light Source	921
	Z. Pan, J.M. Byrd, C. Sun LBNL, Berkeley, California, USA H. Hao, Y.K. Wu FEL/Duke University, Durham, North Carolina, USA W.-H. Huang, C.-X. Tang TUB, Beijing, People's Republic of China
	Gamma-ray sources with high flux and spectral densities are highly demanded by many nuclear experiments. We design a low energy compact storage ring to produce gamma-ray with energy in the range of 4-20 MeV based on Compton backscattering technique. The storage ring energy is 500-800 MeV with the circumference of about 59 m and natural emittance of about 3 nmrad at 500 MeV. In this paper, we present the storage ring lattice design and propose two collision configurations for Compton gamma-ray generation. Intrabeam scattering has been investigated which can increase emittance from 3 nmrad to 6 nmrad horizontally for 500 MeV ring. We also discuss how Compton scattering affects longitudinal and transverse beam dynamics by tracking macro particles using our parallel simulation code. Based on this study, we can further optimize our storage ring lattice design for the higher gamma-ray flux production.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPVA031
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TUPAB070	S-Band Accelerating Structure for High-Gradient Upgrade of TTX	1485
	D.Z. Cao, H.B. Chen, Y.-C. Du, W. Gai, W.-H. Huang, X.C. Meng, J. Shi, C.-X. Tang, X.W. Wu, H. Zha TUB, Beijing, People's Republic of China
	Thomson scattering x-ray source is an indispensable scientific X-ray imaging tool in various research fields. The 3-meter S-band linac in Tsinghua Thomson scatter-ing X-ray source (TTX) has been running at an accelerat-ing gradient of 15 MV/m so far. The gradient will be upgraded to 30MV/m by replacing the old structure with a shorter linac. Detailed optimization of the RF design of the new S-band linac structure is presented in this paper. Finally, further research on energy upgrade with X-band structures are also discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB070
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TUPAB071	Experimental Results on THz Superradiation From the Undulator in Tsinghua University Beamline	1488
SUSPSIK024	use link to see paper's listing under its alternate paper code
	X.L. Su, Y.-C. Du, W.-H. Huang, L. Niu, C.-X. Tang, Q.L. Tian, D. Wang, L.X. Yan TUB, Beijing, People's Republic of China Y.F. Liang Tsinghua University, Beijing, People's Republic of China
	In this paper, the first operation of a widely tunable 8-period undulator at terahertz (THz) frequency in Tsinghua University beamline was reported. Superradiate undulator radiation from sub-picosecond electron bunches compressed by chicane was observed. The measured radiation curve shows clearly that the radiation energy is proportional to the charge square, and the THz frequency can be changed from 0.4 THz to 10 THz with narrow-band spectrums. Our results demonstrate a high power and tunable coherent THz source, which could be useful for many applications in the future.
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TUPAB074	Measurements of Thermal Emittance for Cesium Telluride Photocathodes in an L-Band RF Gun	1491
	L.M. Zheng, W. Gai, C.-X. Tang TUB, Beijing, People's Republic of China W. Gai, C.-J. Jing, W. Liu, N.R. Neveu, J.G. Power, J.H. Shao, E.E. Wisniewski ANL, Argonne, Illinois, USA W. Liu Euclid TechLabs, LLC, Solon, Ohio, USA
	The thermal emittance is a major contributor to the final emittance of an electron beam in a photocathode RF gun. In this paper we present measurement results of thermal emittance for the cesium telluride photocathode at the Argonne Wakefield Accelerator (AWA) facility using the quadrupole scan method. Measurements of the thermal emittance vs. the laser spot size are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB074
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TUPAB075	Compact High Energy Electron Radiography System Based on Permanent Magnet Quadrupole	1494
	Z. Zhou, Y.-C. Du, W. Gai, W.-H. Huang, F. Li, T. Rui, C.-X. Tang TUB, Beijing, People's Republic of China W. Gai ANL, Argonne, Illinois, USA
	High energy electron radiography(HEER) is a promising diagnostic method for High Energy Density Physics (HEDP) or Inertial Confinement Fusion (ICF) owing to its capability of picosecond-nanometer spatio-temporal resolution, and is cost-effective in the meantime. A Compact HEER (CHEER) system based on Permanent Magnet Quadrupoles (PMQ) instead of conventional electromagnetic quadrupole is proposed. Its lattice design and beam optics optimization is finished, and experiment is to be carried out on Tsinghua Thomson X-ray source (TTX) beamline after PMQs fabrication and installation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB075
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TUPAB076	Design of an X-Band Photocathode for Tsinghua Thomson Scattering X-Ray Source	1497
	L.Y. Zhou, H.B. Chen, Y.-C. Du, W. Gai, W.-H. Huang, J. Shi, C.-X. Tang, D. Wang, Z. Zhang, Z. Zhou TUB, Beijing, People's Republic of China
	Compared with S-band and C-band accelerating structures, X-band structures can run at a higher accelerating gradient and are more compact in size. In order to obtain higher electron energy in a limited space, a new X-band photo-injector operating at 11.424GHz has been designed at the Accelerator Laboratory of Tsinghua University. The structural design of the X-band photo-cathode RF gun and the accelerating structures as well as the beam dynamics simulation are presented in this paper, followed by the optimization of the structure based on the dispersed optimization experiment method(DOE). The results show that the design satisfies the working requirements with a small space occupied and a high beam quality.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB076
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TUPVA104	RF and Primary Beam Dynamics Design of a 325 MHz IH-DTL	2332
	Y. Lei, X. Guan, C.-X. Tang, R. Tang, X.W. Wang, Q.Z. Xing, S.X. Zheng TUB, Beijing, People's Republic of China
	An interdigital H-mode drift tube linac (IH-DTL), which is aimed at proton medical facilities, has been proposed and developing at Tsinghua University. Considering following 3 MeV RFQ in the platform of CPHS (Compact Pulse Hadron Source at Tsinghua University) and XiPAF (Xi‘an Proton Application Facility) project, the input energy of IH-DTL is 3 MeV and the RF frequency is 325 MHz. The proton beam can be accelerated from 3 MeV to 7 MeV and the peak current of the beam at the exit of the cavity is about 15 mA. In order to simplify the fabrication, A KONUS structure without focusing element in the cavity is chosen. The RF design of single CELL and the primary dynamics design is done. The co-iteration of dynamics simulation and RF calculation of whole cavity is undergoing.
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TUPVA105	Development Progress of the 7MeV Linac Injector for the 200MeV Synchrotron of Xi'an Proton Application Facility	2336
	Q.Z. Xing, C.B. Bi, C. Cheng, D. Dan, C.T. Du, T.B. Du, X. Guan, Q.K. Guo, Y. Lei, K.D. Man, C.-X. Tang, R. Tang, D. Wang, X.W. Wang, H.Y. Zhang, S.X. Zheng TUB, Beijing, People's Republic of China W.Q. Guan, Y. He, J. Li NUCTECH, Beijing, People's Republic of China E.Y. Qu, B.C. Wang, Z.M. Wang, Y. Yang, C. Zhao State Key Laboratory of Intense Pulsed Radiation Simulation and Effect, Northwest Institute of Nuclear Technology, Shannxi, People's Republic of China
	We present, in this paper, the development progress of the 7MeV Linac for the 200MeV synchrotron of the Xi'an Proton Application Facility (XiPAF). The 7 MeV linac injector is composed of the 50 keV negative hydrogen ion source, Low Energy Beam Transport line (LEBT), 3 MeV four-vane type Radio Frequency Quadrupole (RFQ) accelerator, 7 MeV Alvarez-type Drift Tube Linac (DTL), and the corresponding RF power source system. The 2.45 GHz microwave-driven Cesium-free Electron Cyclotron Resonance (ECR) source and LEBT will be commissioned in this year, and the peak current of the extracted H⁻ beam at the exit of the LEBT is expected to be 6 mA, with the output energy of 50 keV, maximum repetition rate of 0.5 Hz, beam pulse width of 10~40 microseconds and normalized RMS emittance of less than 0.2 PI mm mrad. Furthermore, the construction status of the RFQ accelerator and DTL accelerator will be presented in this paper.
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WEPVA067	Preliminary Results on the Resonant Excitation of THz Wakefield in a Multi-Mode Dielectric Loaded Waveguide by Bunch Train	3426
	D. Wang, Y.-C. Du, W. Gai, W.-H. Huang, L. Niu, X.L. Su, C.-X. Tang, Q.L. Tian, L.X. Yan TUB, Beijing, People's Republic of China S.P. Antipov Euclid TechLabs, LLC, Solon, Ohio, USA Y.F. Liang Tsinghua University, Beijing, People's Republic of China
	Funding: Work supported by the National Nature Science Foundation of China (NSFC Grants No.11475097) and the National Key Scientific Instrument and Equipment Development Project of China (Grants No. 2013YQ12034504) We report the preliminary experimental results on the resonant excitation of THz wakefield in a multi-mode dielectric loaded waveguide (DLW) by electron bunch train at the Tsinghua University accelerator beamline. The bunch train with certain longitudinal periodicity was generated based on nonlinear longitudinal space charge oscillation [1]. By passing such bunch train through a multi-mode DLW, we observed selective excitation of the fifth longitudinal mode (TM05 mode) was resonantly excited. Future experiment plan is to tune the bunch train interval with a chicane in the beamline in order to selectively excite arbitrary mode for tunable THz radiation source with multi-mode DLWs. wangdan16@mail.tsinghua.edu.cn yanlx@mail.tsinghua.edu.cn
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THPVA055	The Preliminary Performance of the Timing and Synchronization System at Tsinghua University	4565
SUSPSIK113	use link to see paper's listing under its alternate paper code
	Z.Y. Lin, Y.-C. Du, W.-H. Huang, W.-H. Huang, C.-X. Tang, C.-X. Tang, J. Yang TUB, Beijing, People's Republic of China J.M. Byrd, L.R. Doolittle, G. Huang, Q. Qiang, R.B. Wilcox, Y.L. Xu LBNL, Berkeley, California, USA
	A precise timing and synchronization system is developed in Tsinghua University(THU). The whole system scheme includes fiber-based CW carrier phase reference distribution system (PRDS) for delivering stabilized RF phase reference to multiple receiver clients, Low Level RF (LLRF) control system to stabilized the accelerating mi-crowave field and laser-RF synchronization system for high precise synchronization of optical and RF signals. The system test and the demonstration experiment of each subsystem are carried on to evaluate the system and the phase error jitter resources are analysed.
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Paper

Title

Page

Measurement of Electron Bunch Length via a Tunable-Gap Undulator

295

X.L. Su, Y.-C. Du, W.-H. Huang, L. Niu, C.-X. Tang, Q.L. Tian, D. Wang, L.X. Yan
TUB, Beijing, People's Republic of China
Y.F. Liang
Tsinghua University, Beijing, People's Republic of China

A THz undulator with widely tunable gap is constructed and installed at Tsinghua University beamline, which is applied for narrow-band THz radiation and measurements of electron bunch longitudinal structure. This is a planar electromagnetic device with 8 regular periods, each 10 cm long. The field range B=0.15- 0.99 T peak field on axis while changing the gap from 75mm to 23mm. In the experiments, we scanned the undulator gap to measure the radiation intensity at different resonant frequency, thus we can get the bunch length even form factor of the bunch. The demonstrated experimental results show that the bunch of 220pC compressed by chicane in Tsinghua beamline is about 120fs (rms), which agree well with the simulations. The resolution of bunch length measurement with this method can be attoseconds by optimized undulator. Furthermore, the form factor of electron bunch train can also be measured.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB075

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MOPAB077

Spatial Decoding Electro-Optic Bunch Measurement at Tsinghua Thomson Scattering X-ray Source

302

SUSPSIK075

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

W. Wang, Z.J. Chi, Y.-C. Du, W.-H. Huang, C.-X. Tang, L.X. Yan, Z. Zhang
TUB, Beijing, People's Republic of China

Electron bunches with duration of sub-picosecond are essential in ultraviolet and X-ray free electron laser (XFEL) to reach the desired peak current. Electro-optic (EO) technique is suitable for temporal profile measure-ment of these ultrashort bunches which is one of the key diagnostics in FELs. An electro-optic monitor based on spatial sampling has recently been designed and installed for bunch profile diagnostic at Tsinghua Thomson scat-tering X-ray source (TTX). An ultrashort laser pulse is used to detect the field induced birefringence of the bunch Coulomb field in an electro-optic crystal and the monitor allows direct time-resolved single-shot measure-ment of bunch profile with an accuracy of 135 femtosec-onds for a 40 MeV electron bunch in a non-destructive way, which can simultaneously record the relative time jitter between probe laser and electron bunch. This paper performs the layout of the setup and presents the current measurement results.

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MOPVA027

Measurement of High Power Terahertz with Dielectric Loaded Waveguide at Tsinghua University

914

D. Wang, Y.-C. Du, W. Gai, W.-H. Huang, X.L. Su, C.-X. Tang, Q.L. Tian, L.X. Yan
TUB, Beijing, People's Republic of China
S.P. Antipov
Euclid Beamlabs LLC, Bolingbrook, USA
Y.F. Liang
Tsinghua University, Beijing, People's Republic of China

Funding: Work supported by the National Nature Science Foundation of China (NSFC Grants No.11475097) and the National Key Scientific Instrument and Equipment Development Project of China (Grants No. 2013YQ12034504)
We have measured an intense THz radiation produced by a sub-picosecond, relativistic electron bunch passing through a dielectric loaded waveguide (DLW) at Tsinghua University accelerator beamline. The DLW was 3 cm long quartz tube with 900 'm inner diameter and 100 'm wall thickness metallized on the outside. Radiated energy of the THz pulse was measured to be proportional to the square of the effective charge. The end of the DLW was cut at an angle for efficient THz pulse extraction. Tens of 'J THz energy per pulse were measured outside the vacuum chamber with a calibrated Golay cell in the experiment.
*wangdan16@mail.tsinghua.edu.cn
*yanlx@mail.tsinghua.edu.cn

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MOPVA031

Low Energy Compact Storage Ring Design for Compton Gamma-Ray Light Source

921

Z. Pan, J.M. Byrd, C. Sun
LBNL, Berkeley, California, USA
H. Hao, Y.K. Wu
FEL/Duke University, Durham, North Carolina, USA
W.-H. Huang, C.-X. Tang
TUB, Beijing, People's Republic of China

Gamma-ray sources with high flux and spectral densities are highly demanded by many nuclear experiments. We design a low energy compact storage ring to produce gamma-ray with energy in the range of 4-20 MeV based on Compton backscattering technique. The storage ring energy is 500-800 MeV with the circumference of about 59 m and natural emittance of about 3 nmrad at 500 MeV. In this paper, we present the storage ring lattice design and propose two collision configurations for Compton gamma-ray generation. Intrabeam scattering has been investigated which can increase emittance from 3 nmrad to 6 nmrad horizontally for 500 MeV ring. We also discuss how Compton scattering affects longitudinal and transverse beam dynamics by tracking macro particles using our parallel simulation code. Based on this study, we can further optimize our storage ring lattice design for the higher gamma-ray flux production.

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TUPAB070

S-Band Accelerating Structure for High-Gradient Upgrade of TTX

1485

D.Z. Cao, H.B. Chen, Y.-C. Du, W. Gai, W.-H. Huang, X.C. Meng, J. Shi, C.-X. Tang, X.W. Wu, H. Zha
TUB, Beijing, People's Republic of China

Thomson scattering x-ray source is an indispensable scientific X-ray imaging tool in various research fields. The 3-meter S-band linac in Tsinghua Thomson scatter-ing X-ray source (TTX) has been running at an accelerat-ing gradient of 15 MV/m so far. The gradient will be upgraded to 30MV/m by replacing the old structure with a shorter linac. Detailed optimization of the RF design of the new S-band linac structure is presented in this paper. Finally, further research on energy upgrade with X-band structures are also discussed.

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TUPAB071

Experimental Results on THz Superradiation From the Undulator in Tsinghua University Beamline

1488

SUSPSIK024

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

X.L. Su, Y.-C. Du, W.-H. Huang, L. Niu, C.-X. Tang, Q.L. Tian, D. Wang, L.X. Yan
TUB, Beijing, People's Republic of China
Y.F. Liang
Tsinghua University, Beijing, People's Republic of China

In this paper, the first operation of a widely tunable 8-period undulator at terahertz (THz) frequency in Tsinghua University beamline was reported. Superradiate undulator radiation from sub-picosecond electron bunches compressed by chicane was observed. The measured radiation curve shows clearly that the radiation energy is proportional to the charge square, and the THz frequency can be changed from 0.4 THz to 10 THz with narrow-band spectrums. Our results demonstrate a high power and tunable coherent THz source, which could be useful for many applications in the future.

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TUPAB074

Measurements of Thermal Emittance for Cesium Telluride Photocathodes in an L-Band RF Gun

1491

L.M. Zheng, W. Gai, C.-X. Tang
TUB, Beijing, People's Republic of China
W. Gai, C.-J. Jing, W. Liu, N.R. Neveu, J.G. Power, J.H. Shao, E.E. Wisniewski
ANL, Argonne, Illinois, USA
W. Liu
Euclid TechLabs, LLC, Solon, Ohio, USA

The thermal emittance is a major contributor to the final emittance of an electron beam in a photocathode RF gun. In this paper we present measurement results of thermal emittance for the cesium telluride photocathode at the Argonne Wakefield Accelerator (AWA) facility using the quadrupole scan method. Measurements of the thermal emittance vs. the laser spot size are presented.

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TUPAB075

Compact High Energy Electron Radiography System Based on Permanent Magnet Quadrupole

1494

Z. Zhou, Y.-C. Du, W. Gai, W.-H. Huang, F. Li, T. Rui, C.-X. Tang
TUB, Beijing, People's Republic of China
W. Gai
ANL, Argonne, Illinois, USA

High energy electron radiography(HEER) is a promising diagnostic method for High Energy Density Physics (HEDP) or Inertial Confinement Fusion (ICF) owing to its capability of picosecond-nanometer spatio-temporal resolution, and is cost-effective in the meantime. A Compact HEER (CHEER) system based on Permanent Magnet Quadrupoles (PMQ) instead of conventional electromagnetic quadrupole is proposed. Its lattice design and beam optics optimization is finished, and experiment is to be carried out on Tsinghua Thomson X-ray source (TTX) beamline after PMQs fabrication and installation.

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TUPAB076

Design of an X-Band Photocathode for Tsinghua Thomson Scattering X-Ray Source

1497

L.Y. Zhou, H.B. Chen, Y.-C. Du, W. Gai, W.-H. Huang, J. Shi, C.-X. Tang, D. Wang, Z. Zhang, Z. Zhou
TUB, Beijing, People's Republic of China

Compared with S-band and C-band accelerating structures, X-band structures can run at a higher accelerating gradient and are more compact in size. In order to obtain higher electron energy in a limited space, a new X-band photo-injector operating at 11.424GHz has been designed at the Accelerator Laboratory of Tsinghua University. The structural design of the X-band photo-cathode RF gun and the accelerating structures as well as the beam dynamics simulation are presented in this paper, followed by the optimization of the structure based on the dispersed optimization experiment method(DOE). The results show that the design satisfies the working requirements with a small space occupied and a high beam quality.

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TUPVA104

RF and Primary Beam Dynamics Design of a 325 MHz IH-DTL

2332

Y. Lei, X. Guan, C.-X. Tang, R. Tang, X.W. Wang, Q.Z. Xing, S.X. Zheng
TUB, Beijing, People's Republic of China

An interdigital H-mode drift tube linac (IH-DTL), which is aimed at proton medical facilities, has been proposed and developing at Tsinghua University. Considering following 3 MeV RFQ in the platform of CPHS (Compact Pulse Hadron Source at Tsinghua University) and XiPAF (Xi‘an Proton Application Facility) project, the input energy of IH-DTL is 3 MeV and the RF frequency is 325 MHz. The proton beam can be accelerated from 3 MeV to 7 MeV and the peak current of the beam at the exit of the cavity is about 15 mA. In order to simplify the fabrication, A KONUS structure without focusing element in the cavity is chosen. The RF design of single CELL and the primary dynamics design is done. The co-iteration of dynamics simulation and RF calculation of whole cavity is undergoing.

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TUPVA105

Development Progress of the 7MeV Linac Injector for the 200MeV Synchrotron of Xi'an Proton Application Facility

2336

Q.Z. Xing, C.B. Bi, C. Cheng, D. Dan, C.T. Du, T.B. Du, X. Guan, Q.K. Guo, Y. Lei, K.D. Man, C.-X. Tang, R. Tang, D. Wang, X.W. Wang, H.Y. Zhang, S.X. Zheng
TUB, Beijing, People's Republic of China
W.Q. Guan, Y. He, J. Li
NUCTECH, Beijing, People's Republic of China
E.Y. Qu, B.C. Wang, Z.M. Wang, Y. Yang, C. Zhao
State Key Laboratory of Intense Pulsed Radiation Simulation and Effect, Northwest Institute of Nuclear Technology, Shannxi, People's Republic of China

We present, in this paper, the development progress of the 7MeV Linac for the 200MeV synchrotron of the Xi'an Proton Application Facility (XiPAF). The 7 MeV linac injector is composed of the 50 keV negative hydrogen ion source, Low Energy Beam Transport line (LEBT), 3 MeV four-vane type Radio Frequency Quadrupole (RFQ) accelerator, 7 MeV Alvarez-type Drift Tube Linac (DTL), and the corresponding RF power source system. The 2.45 GHz microwave-driven Cesium-free Electron Cyclotron Resonance (ECR) source and LEBT will be commissioned in this year, and the peak current of the extracted H⁻ beam at the exit of the LEBT is expected to be 6 mA, with the output energy of 50 keV, maximum repetition rate of 0.5 Hz, beam pulse width of 10~40 microseconds and normalized RMS emittance of less than 0.2 PI mm mrad. Furthermore, the construction status of the RFQ accelerator and DTL accelerator will be presented in this paper.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA105

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WEPVA067

Preliminary Results on the Resonant Excitation of THz Wakefield in a Multi-Mode Dielectric Loaded Waveguide by Bunch Train

3426

D. Wang, Y.-C. Du, W. Gai, W.-H. Huang, L. Niu, X.L. Su, C.-X. Tang, Q.L. Tian, L.X. Yan
TUB, Beijing, People's Republic of China
S.P. Antipov
Euclid TechLabs, LLC, Solon, Ohio, USA
Y.F. Liang
Tsinghua University, Beijing, People's Republic of China

Funding: Work supported by the National Nature Science Foundation of China (NSFC Grants No.11475097) and the National Key Scientific Instrument and Equipment Development Project of China (Grants No. 2013YQ12034504)
We report the preliminary experimental results on the resonant excitation of THz wakefield in a multi-mode dielectric loaded waveguide (DLW) by electron bunch train at the Tsinghua University accelerator beamline. The bunch train with certain longitudinal periodicity was generated based on nonlinear longitudinal space charge oscillation [1]. By passing such bunch train through a multi-mode DLW, we observed selective excitation of the fifth longitudinal mode (TM05 mode) was resonantly excited. Future experiment plan is to tune the bunch train interval with a chicane in the beamline in order to selectively excite arbitrary mode for tunable THz radiation source with multi-mode DLWs.
*wangdan16@mail.tsinghua.edu.cn
*yanlx@mail.tsinghua.edu.cn

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPVA067

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THPVA055

The Preliminary Performance of the Timing and Synchronization System at Tsinghua University

4565

SUSPSIK113

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Z.Y. Lin, Y.-C. Du, W.-H. Huang, W.-H. Huang, C.-X. Tang, C.-X. Tang, J. Yang
TUB, Beijing, People's Republic of China
J.M. Byrd, L.R. Doolittle, G. Huang, Q. Qiang, R.B. Wilcox, Y.L. Xu
LBNL, Berkeley, California, USA

A precise timing and synchronization system is developed in Tsinghua University(THU). The whole system scheme includes fiber-based CW carrier phase reference distribution system (PRDS) for delivering stabilized RF phase reference to multiple receiver clients, Low Level RF (LLRF) control system to stabilized the accelerating mi-crowave field and laser-RF synchronization system for high precise synchronization of optical and RF signals. The system test and the demonstration experiment of each subsystem are carried on to evaluate the system and the phase error jitter resources are analysed.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPVA055

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