COOL2015 - List of Authors (Wang, H.)

Paper

Title

Page

Taper and Tuner Scheme of a Multi-Frequency Cavity for the Fast Kicker Resonator in MEIC Electron Circular Cooler Ring

63

Y.L. Huang
IMP/CAS, Lanzhou, People's Republic of China
R.A. Rimmer, H. Wang, S. Wang
JLab, Newport News, Virginia, USA

An ultra-fast harmonic kicker consisted of normal conducting resonators with high transverse shunt impedance thus less RF power consumption was designed for the proposed Medium energy Electron Ion Collider (MEIC). In the prototype design, four quarter wave resonator (QWR) based deflecting cavities are used to generate ten cosine harmonic waveforms, the electron bunches passing through these cavities will experience an integral effect of all the harmonic fields, thus every 10th bunch in a continues bunch train of 10th harmonic bunch frequency will be kicked while all the other bunches un-kicked. Ten harmonic waves are distributed in the four cavities with the proportion of 5:3:1:1. For the multi-frequency cavities, a great challenge is to tune each harmonic to be exact frequency. In this paper, the taper and tuning scheme for the 5-modes cavity is presented. Five taper points in the inner conductor are chosen to make the five frequencies to be odd harmonics. Five stub tuners on the outer conductor are used to tune every harmonic back to its target frequency from the manufacturing errors.
Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.

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TUXAUD03

ERL Cooling Ring Concepts for the MEIC

S.V. Benson, Y.S. Derbenev, D. Douglas, F.E. Hannon, F. Marhauser, R.A. Rimmer, C. Tennant, H. Wang, H. Zhang, Y. Zhang
JLab, Newport News, Virginia, USA

Funding: This work was supported by U.S. DOE Contract No. DE-AC05-84-ER40150
The MEIC design at Jefferson Lab will collide electrons in a storage ring with ions in a separate ring. In order to enhance the luminosity, the ions must be cooled in a cooling channel. The required current and charge necessary to cool the ions is on the order of 200 mA and 420 pC at an electron energy as high as 55 MeV. This is too high for a DC accelerator such as a pelletron and so the electron beam must be provided by an Energy Recovery Linac (ERL). This presentation will discuss two options for such an ERL and show some early results of modeling and simulation for these designs. At least at the highest energy, the beam quality seems to be good enough to provide a reasonable cooling rate for the ions.

Slides TUXAUD03 [3.763 MB]

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TUPF10

Harmonic Stripline Kicker for MEIC Bunched Beam Cooler

120

J. Guo, H. Wang
JLab, Newport News, Virginia, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177
In the current MEIC design, the ion collider ring needs to be cooled by a bunched electron beam of up to 200 mA 55 MeV, with the possibility to upgrade to 1.5 A. Although it's not impossible to design and build an ERL to provide such a beam, the technical risk and cost associated with such an ERL will be very high. An alternative is to recirculate the electron bunches in a ring for up to 25 turns until the bunch's quality is degraded, reducing the beam current in the ERL by a factor of 25. This scheme requires a pair of fast kickers that kick one in every 25 bunches. In this paper, we will analyze the electrodynamics of a harmonic stripline kicker for this application, and compare it to a harmonic resonator kicker.

Poster TUPF10 [1.081 MB]

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TUPF11

Progress in Experimental Demonstration of Cooling of Ions by a Bunched Electron Beam

L.J. Mao, X.M. Ma, M.T. Tang, H. Zhao
IMP/CAS, Lanzhou, People's Republic of China
A. Hutton, H. Wang, H. Zhang, Y. Zhang
JLab, Newport News, Virginia, USA
V.V. Parkhomchuk, V.B. Reva
BINP SB RAS, Novosibirsk, Russia

Electron cooling is essential for achieving high luminosities for hadron colliders by enabling a reduction of emittance of hadron beams in storage rings. For several future projects such as low energy RHIC cooling program (LEReC) at BNL, a low energy electron-ion collider based on HIAF at IMP and a Medium energy Electron-Ion Collider (MEIC) at JLab, since the hadron beam energies are in a range from several GeV to 100 GeV, the required electron energy is up to 55 MeV. Such high energy electron beams can only be provided by a RF/SRF linac. As a result, the electron beam is highly bunched. Cooling of ions by a bunched electron beam has never been realized before, thus it becomes a critical R&D to these projects. Recently we proposed a proof-of-concept experiment to demonstrate cooling by a bunched electron beam utilizing an existing DC cooler at IMP. Here we present a progress report of this experiment. We briefly describe the experiment and show the design parameters. We then report hardware installation and results of the bench tests. We also summarize the results of the cooling simulation studies and discuss the required beam measurement capability.

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Paper	Title	Page
MOPF13	Taper and Tuner Scheme of a Multi-Frequency Cavity for the Fast Kicker Resonator in MEIC Electron Circular Cooler Ring	63
	Y.L. Huang IMP/CAS, Lanzhou, People's Republic of China R.A. Rimmer, H. Wang, S. Wang JLab, Newport News, Virginia, USA
	An ultra-fast harmonic kicker consisted of normal conducting resonators with high transverse shunt impedance thus less RF power consumption was designed for the proposed Medium energy Electron Ion Collider (MEIC). In the prototype design, four quarter wave resonator (QWR) based deflecting cavities are used to generate ten cosine harmonic waveforms, the electron bunches passing through these cavities will experience an integral effect of all the harmonic fields, thus every 10th bunch in a continues bunch train of 10th harmonic bunch frequency will be kicked while all the other bunches un-kicked. Ten harmonic waves are distributed in the four cavities with the proportion of 5:3:1:1. For the multi-frequency cavities, a great challenge is to tune each harmonic to be exact frequency. In this paper, the taper and tuning scheme for the 5-modes cavity is presented. Five taper points in the inner conductor are chosen to make the five frequencies to be odd harmonics. Five stub tuners on the outer conductor are used to tune every harmonic back to its target frequency from the manufacturing errors. Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
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TUXAUD03	ERL Cooling Ring Concepts for the MEIC
	S.V. Benson, Y.S. Derbenev, D. Douglas, F.E. Hannon, F. Marhauser, R.A. Rimmer, C. Tennant, H. Wang, H. Zhang, Y. Zhang JLab, Newport News, Virginia, USA
	Funding: This work was supported by U.S. DOE Contract No. DE-AC05-84-ER40150 The MEIC design at Jefferson Lab will collide electrons in a storage ring with ions in a separate ring. In order to enhance the luminosity, the ions must be cooled in a cooling channel. The required current and charge necessary to cool the ions is on the order of 200 mA and 420 pC at an electron energy as high as 55 MeV. This is too high for a DC accelerator such as a pelletron and so the electron beam must be provided by an Energy Recovery Linac (ERL). This presentation will discuss two options for such an ERL and show some early results of modeling and simulation for these designs. At least at the highest energy, the beam quality seems to be good enough to provide a reasonable cooling rate for the ions.
	Slides TUXAUD03 [3.763 MB]
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TUPF10	Harmonic Stripline Kicker for MEIC Bunched Beam Cooler	120
	J. Guo, H. Wang JLab, Newport News, Virginia, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177 In the current MEIC design, the ion collider ring needs to be cooled by a bunched electron beam of up to 200 mA 55 MeV, with the possibility to upgrade to 1.5 A. Although it's not impossible to design and build an ERL to provide such a beam, the technical risk and cost associated with such an ERL will be very high. An alternative is to recirculate the electron bunches in a ring for up to 25 turns until the bunch's quality is degraded, reducing the beam current in the ERL by a factor of 25. This scheme requires a pair of fast kickers that kick one in every 25 bunches. In this paper, we will analyze the electrodynamics of a harmonic stripline kicker for this application, and compare it to a harmonic resonator kicker.
	Poster TUPF10 [1.081 MB]
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TUPF11	Progress in Experimental Demonstration of Cooling of Ions by a Bunched Electron Beam
	L.J. Mao, X.M. Ma, M.T. Tang, H. Zhao IMP/CAS, Lanzhou, People's Republic of China A. Hutton, H. Wang, H. Zhang, Y. Zhang JLab, Newport News, Virginia, USA V.V. Parkhomchuk, V.B. Reva BINP SB RAS, Novosibirsk, Russia
	Electron cooling is essential for achieving high luminosities for hadron colliders by enabling a reduction of emittance of hadron beams in storage rings. For several future projects such as low energy RHIC cooling program (LEReC) at BNL, a low energy electron-ion collider based on HIAF at IMP and a Medium energy Electron-Ion Collider (MEIC) at JLab, since the hadron beam energies are in a range from several GeV to 100 GeV, the required electron energy is up to 55 MeV. Such high energy electron beams can only be provided by a RF/SRF linac. As a result, the electron beam is highly bunched. Cooling of ions by a bunched electron beam has never been realized before, thus it becomes a critical R&D to these projects. Recently we proposed a proof-of-concept experiment to demonstrate cooling by a bunched electron beam utilizing an existing DC cooler at IMP. Here we present a progress report of this experiment. We briefly describe the experiment and show the design parameters. We then report hardware installation and results of the bench tests. We also summarize the results of the cooling simulation studies and discuss the required beam measurement capability.
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)