IPAC2018 - List of Authors (Zhao, H.W.)

Paper	Title	Page
TUPAL011	Low Power Test and Tuning of the LEAF RFQ	1028
	L. Lu, T. He, Y. He, W. Ma, L.B. Shi, L.P. Sun, C.C. Xing, X.B. Xu, L. Yang, H.W. Zhao IMP/CAS, Lanzhou, People's Republic of China
	A continuous wave (CW) four-vane radio frequency quadrupole (RFQ) accelerator is under construction for the Low Energy Accelerator Facility (LEAF) at Institute of Modern Physics (IMP). The 5.96 m RFQ will operate with the capability of accelerating all ion species from proton to uranium from 14 keV/u up to 500 keV/u. In this paper, the low power test and tuning results of the RFQ accelerator, including the test of the separate sections and the whole cavity, will be presented. After the final tuning, the relative error of the quadrupole field is within 2% and the admixture of the dipole modes are below 4% of the quadrupole mode.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL011
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TUPAL069	Experimental Demonstration of Ion Beam Cooling with Pulsed Electron Beam	1174
	Y. Zhang, A. Hutton, K. Jordan, T. Powers, R.A. Rimmer, M. F. Spata, H. Wang, S. Wang, H. Zhang JLab, Newport News, Virginia, USA J. Li, X.M. Ma, L.J. Mao, M.T. Tang, J.C. Yang, X.D. Yang, H. Zhao, H.W. Zhao IMP/CAS, Lanzhou, People's Republic of China
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. Cooling ion beams at high energy is presently considered for several ion colliders, in order to achieve high luminosities by enabling a significant reduction of emittance of hadron beams. Electron beam at cooling channel in a few to tens MeV can be accelerated by a RF/SRF linac, and thus using bunched electrons to cool bunched ions. To study such cooling process, the DC electron gun of EC35 cooler at the storage ring CSRm, IMP was modified by pulsing the grid voltage. A 0.07-3.5 micro-second pulse length with a repetition frequency of less than 250 kHz and synchronized with the ion revolution frequency was obtained. The first experimental demonstration of cooling of a coasting and bunched ion beam by a pulsed electron beam was carried out. Data analysis indicates the bunch length shrinkage and the momentum spread reduction of bunched 12C+6 ion beam as evidence of cooling. A longitudinal grouping effect of the coasting ion beam by the electron pulses has also been observed. In this paper, we will present experimental results and comparison to the simulation modelling, particularly on the bunched electron cooling data after carefully analyzing the beam diagnostic signals. L.J. Mao et al., Experimental Demonstration of Electron Cooling with Bunched Electron Beam, TUP15, Proceedings of COOL2017, Bonn, Germany
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL069
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TUPML070	Laser Ablation Plasma with Solenoid Field Confinement	1706
SUSPF048	use link to see paper's listing under its alternate paper code
	G.C. Wang, Q. Jin, L.T. Sun, J. Zhang, X.Z. Zhang, H.W. Zhao, H. Zhao IMP/CAS, Lanzhou, People's Republic of China
	Funding: This work is supported by National Natural Science Foundation of China (Grant Nos. 11722547, 11605263 and 11505257) and West Light Foundation of The Chi-nese Academy of Sciences (Grant Nos. 29Y637020) A Laser Ion Source (LIS) can produce high charge state and high intensity ion beams (~emA), especially refracto-ry metallic ion beams, which makes it a promising candi-date as an ion source for heavy ion cancer therapy facili-ties and future accelerator complexes, where pulsed high intensity and high charged heavy ion beams are required. However, it is difficult for LIS to obtain a long pulse width while ensuring high current intensity, thus limiting the application of LIS. To solve the conflict, magnetic fields are proposed to confine the expansion of the laser produced plasma. With a solenoid along the normal direc-tion to the target surface, the lateral adiabatic expansion of the laser ablation plasma is suppressed which extends the pulse width of the ion beam effectively.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPML070
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THPAL002	RF System Operation of High Current RFQ in ADS Project	3613
	L.P. Sun, R. Huang, C.X. Li, L. Lu, A. Shi, L.B. Shi, W.B. Wang, X.B. Xu, H.W. Zhao IMP/CAS, Lanzhou, People's Republic of China Y. Hu TUB, Beijing, People's Republic of China
	Funding: Work supported by Natural Science Foundation of China， No.11505253 New RF system has been upgraded several times for high-current operation, especially for extra beam power and detuning angle. The current was increased gradually resulting in more and more frequency detuning, and an effective method is to tune the temperature of cavity to compromise detuning. Of course, the power dissipated in cavity and high intensity beam are approximately 120kW resulting in too many power modules operated in the high risk of failure. The specific analysis and simulation were introduced in detail.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL002
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Paper

Title

Page

Low Power Test and Tuning of the LEAF RFQ

1028

L. Lu, T. He, Y. He, W. Ma, L.B. Shi, L.P. Sun, C.C. Xing, X.B. Xu, L. Yang, H.W. Zhao
IMP/CAS, Lanzhou, People's Republic of China

A continuous wave (CW) four-vane radio frequency quadrupole (RFQ) accelerator is under construction for the Low Energy Accelerator Facility (LEAF) at Institute of Modern Physics (IMP). The 5.96 m RFQ will operate with the capability of accelerating all ion species from proton to uranium from 14 keV/u up to 500 keV/u. In this paper, the low power test and tuning results of the RFQ accelerator, including the test of the separate sections and the whole cavity, will be presented. After the final tuning, the relative error of the quadrupole field is within 2% and the admixture of the dipole modes are below 4% of the quadrupole mode.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL011

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

TUPAL069

Experimental Demonstration of Ion Beam Cooling with Pulsed Electron Beam

1174

Y. Zhang, A. Hutton, K. Jordan, T. Powers, R.A. Rimmer, M. F. Spata, H. Wang, S. Wang, H. Zhang
JLab, Newport News, Virginia, USA
J. Li, X.M. Ma, L.J. Mao, M.T. Tang, J.C. Yang, X.D. Yang, H. Zhao, H.W. Zhao
IMP/CAS, Lanzhou, People's Republic of China

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
Cooling ion beams at high energy is presently considered for several ion colliders, in order to achieve high luminosities by enabling a significant reduction of emittance of hadron beams. Electron beam at cooling channel in a few to tens MeV can be accelerated by a RF/SRF linac, and thus using bunched electrons to cool bunched ions. To study such cooling process, the DC electron gun of EC35 cooler at the storage ring CSRm, IMP was modified by pulsing the grid voltage. A 0.07-3.5 micro-second pulse length with a repetition frequency of less than 250 kHz and synchronized with the ion revolution frequency was obtained. The first experimental demonstration of cooling of a coasting and bunched ion beam by a pulsed electron beam was carried out. Data analysis indicates the bunch length shrinkage and the momentum spread reduction of bunched 12C+6 ion beam as evidence of cooling. A longitudinal grouping effect of the coasting ion beam by the electron pulses has also been observed*. In this paper, we will present experimental results and comparison to the simulation modelling, particularly on the bunched electron cooling data after carefully analyzing the beam diagnostic signals.
* L.J. Mao et al., Experimental Demonstration of Electron Cooling with Bunched Electron Beam, TUP15, Proceedings of COOL2017, Bonn, Germany

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL069

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TUPML070

Laser Ablation Plasma with Solenoid Field Confinement

1706

SUSPF048

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

G.C. Wang, Q. Jin, L.T. Sun, J. Zhang, X.Z. Zhang, H.W. Zhao, H. Zhao
IMP/CAS, Lanzhou, People's Republic of China

Funding: This work is supported by National Natural Science Foundation of China (Grant Nos. 11722547, 11605263 and 11505257) and West Light Foundation of The Chi-nese Academy of Sciences (Grant Nos. 29Y637020)
A Laser Ion Source (LIS) can produce high charge state and high intensity ion beams (~emA), especially refracto-ry metallic ion beams, which makes it a promising candi-date as an ion source for heavy ion cancer therapy facili-ties and future accelerator complexes, where pulsed high intensity and high charged heavy ion beams are required. However, it is difficult for LIS to obtain a long pulse width while ensuring high current intensity, thus limiting the application of LIS. To solve the conflict, magnetic fields are proposed to confine the expansion of the laser produced plasma. With a solenoid along the normal direc-tion to the target surface, the lateral adiabatic expansion of the laser ablation plasma is suppressed which extends the pulse width of the ion beam effectively.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPML070

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THPAL002

RF System Operation of High Current RFQ in ADS Project

3613

L.P. Sun, R. Huang, C.X. Li, L. Lu, A. Shi, L.B. Shi, W.B. Wang, X.B. Xu, H.W. Zhao
IMP/CAS, Lanzhou, People's Republic of China
Y. Hu
TUB, Beijing, People's Republic of China

Funding: Work supported by Natural Science Foundation of China， No.11505253
New RF system has been upgraded several times for high-current operation, especially for extra beam power and detuning angle. The current was increased gradually resulting in more and more frequency detuning, and an effective method is to tune the temperature of cavity to compromise detuning. Of course, the power dissipated in cavity and high intensity beam are approximately 120kW resulting in too many power modules operated in the high risk of failure. The specific analysis and simulation were introduced in detail.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL002

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