IPAC2015 - List of Authors (Cheng, G.)

Paper	Title	Page
WEPWI029	Cavity Design, Fabrication and Test Performance of 750 MHz, 4-Rod Separators for CEBAF 4-Hall Beam Delivery System	3548
	H. Wang, G. Cheng, L. Turlington, M.J. Wissmann JLab, Newport News, Virginia, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. A short version of the original CEBAF normal conducting 4-rod separator cavity has been developed into a 750MHz one * since the concept of simultaneous 4-hall operation for CEBAF is introduced *. This work has been advanced further based on the EM design optimization, bench measurement and by conducting RF-thermal coupled simulation using CST and ANSYS to confirm the cavity tuning and thermal performance. The cavity fabrication used matured technology like copper plating and machining. The cavity flanges, couplers, tuners and cooling channels adopted consistent/compatible hardware with the existing 500MHz cavities. The electromagnetic and thermal design simulations have greatly reduced the prototyping and bench tuning time of the first prototype. Four production cavities have reached a typical 1.94MV kick voltage or 3.0kW wall loss on each cavity after a minor multipactoring or no processing, 7.5% overhead power than the design specification. R. Kazimi et al., IPAC2013, Shanghai, China, pp 2896-2898. ** R. Kazimi, IPAC2013, Shanghai, China, pp 3502-3504.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPWI029
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WEPWI030	Injector Cavities Fabrication, Vertical Test Performance and Primary Cryomodule Design	3551
	H. Wang, G. Cheng, W.A. Clemens, G.K. Davis, K. Macha, R.B. Overton, D. Spell JLab, Newport News, Virgina, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. After the electromagnetic design * and the mechanical design ** of a β=0.6, 2-cell elliptical SRF cavity, the cavity has been fabricated. Then both 2-cell and 7-cell cavities have been bench tuned to the target values of frequency, coupling external Q and field flatness. After buffer chemistry polishing (BCP) and high pressure rinses (HPR), Vertical 2K cavity test results have been satisfied the specifications and ready for the string assembly. We will report the cavity performance including Lorenz Force Detuning (LFD) and Higher Order Modes (HOM) damping data. Its integration with cavity tuners to the cryomodule design will be reported. * H. Wang, etc., Proceeding of IPAC2013, Shanghai, China, WEPWO073. ** G. Cheng, etc., Proceeding of PAC2013, Pasadena, CA, WEPAC47.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPWI030
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Cavity Design, Fabrication and Test Performance of 750 MHz, 4-Rod Separators for CEBAF 4-Hall Beam Delivery System

3548

H. Wang, G. Cheng, L. Turlington, M.J. Wissmann
JLab, Newport News, Virginia, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
A short version of the original CEBAF normal conducting 4-rod separator cavity has been developed into a 750MHz one * since the concept of simultaneous 4-hall operation for CEBAF is introduced **. This work has been advanced further based on the EM design optimization, bench measurement and by conducting RF-thermal coupled simulation using CST and ANSYS to confirm the cavity tuning and thermal performance. The cavity fabrication used matured technology like copper plating and machining. The cavity flanges, couplers, tuners and cooling channels adopted consistent/compatible hardware with the existing 500MHz cavities. The electromagnetic and thermal design simulations have greatly reduced the prototyping and bench tuning time of the first prototype. Four production cavities have reached a typical 1.94MV kick voltage or 3.0kW wall loss on each cavity after a minor multipactoring or no processing, 7.5% overhead power than the design specification.
* R. Kazimi et al., IPAC2013, Shanghai, China, pp 2896-2898.
** R. Kazimi, IPAC2013, Shanghai, China, pp 3502-3504.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPWI029

Export •

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

WEPWI030

Injector Cavities Fabrication, Vertical Test Performance and Primary Cryomodule Design

3551

H. Wang, G. Cheng, W.A. Clemens, G.K. Davis, K. Macha, R.B. Overton, D. Spell
JLab, Newport News, Virgina, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
After the electromagnetic design * and the mechanical design ** of a β=0.6, 2-cell elliptical SRF cavity, the cavity has been fabricated. Then both 2-cell and 7-cell cavities have been bench tuned to the target values of frequency, coupling external Q and field flatness. After buffer chemistry polishing (BCP) and high pressure rinses (HPR), Vertical 2K cavity test results have been satisfied the specifications and ready for the string assembly. We will report the cavity performance including Lorenz Force Detuning (LFD) and Higher Order Modes (HOM) damping data. Its integration with cavity tuners to the cryomodule design will be reported.
* H. Wang, etc., Proceeding of IPAC2013, Shanghai, China, WEPWO073.
** G. Cheng, etc., Proceeding of PAC2013, Pasadena, CA, WEPAC47.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPWI030

Export •

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