IPAC2016 - List of Authors (Petrushina, I.)

Paper	Title	Page
WEPMR040	HOM Absorber Study by Photon Diffraction Model	2360
	C. Xu, I. Ben-Zvi, V. Ptitsyn, P. Takas, W. Xu BNL, Upton, Long Island, New York, USA I. Petrushina SUNY SB, Stony Brook, New York, USA B. P. Xiao SBU, Stony Brook, New York, USA
	Photon diffraction model (PDM) is one of the most promising candidates to study High Order Mode (HOM) power absorption on absorbing materials for high current SRF cavities. Because at very high frequency (>10GHz), the wavelengths of HOMs are much smaller compared with accelerators dimension, the phase of those HOM will be negligible. Meanwhile, Finite Element Method (FEM) cannot lend a high resolution on evaluation the HOM field patterns due to limited meshing capability. This PDM model utilizes Monte Carlo simulation to trace the ray diffusive reflection in a cavity. This method can directly estimate the power absorption on the cavity and absorber wall. This method will help design the HOM damper setup for eRHIC HOM damper. In this report, we evaluate HOM absorption on the cavity wall with different absorber setup and give a possible solution for power damping scheme for high frequency HOMs.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMR040
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WEPMW042	Trapped Modes Study and BBU Analysis in the 5-Cell 650 MHz Cavity	2529
	C. Xu, I. Ben-Zvi, Y. Hao, V. Ptitsyn, W. Xu BNL, Upton, Long Island, New York, USA I. Petrushina SUNY SB, Stony Brook, New York, USA
	Funding: This work is supported by LDRD program of Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. DOE. #chenxu@bnl.gov eRHIC project is a future electron-hadron collider proposed at BNL. The proposed electron accelerator will generate up to 20 GeV polarized electrons which will collide with proton beams with energy up to 250 GeV. The proposed collider will deliver electron-nucleon luminosity of 10³³- 10³⁴ cm^-2 ses⁻¹. A superconducting RF (SRF) 5-cell elliptical cavity will be utilized in electron accelerator. This paper presents a study of higher-order modes (HOM) for this 647 MHz SRF cavity. Different types of HOM modes and their BBU instabilities were investigated for frequencies up to 3.2 GHz. Threshold current values of beam breakup are estimated by GBBU code. Further improvement on this threshold current has been explored and discussed.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMW042
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

HOM Absorber Study by Photon Diffraction Model

2360

C. Xu, I. Ben-Zvi, V. Ptitsyn, P. Takas, W. Xu
BNL, Upton, Long Island, New York, USA
I. Petrushina
SUNY SB, Stony Brook, New York, USA
B. P. Xiao
SBU, Stony Brook, New York, USA

Photon diffraction model (PDM) is one of the most promising candidates to study High Order Mode (HOM) power absorption on absorbing materials for high current SRF cavities. Because at very high frequency (>10GHz), the wavelengths of HOMs are much smaller compared with accelerators dimension, the phase of those HOM will be negligible. Meanwhile, Finite Element Method (FEM) cannot lend a high resolution on evaluation the HOM field patterns due to limited meshing capability. This PDM model utilizes Monte Carlo simulation to trace the ray diffusive reflection in a cavity. This method can directly estimate the power absorption on the cavity and absorber wall. This method will help design the HOM damper setup for eRHIC HOM damper. In this report, we evaluate HOM absorption on the cavity wall with different absorber setup and give a possible solution for power damping scheme for high frequency HOMs.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMR040

Export •

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

WEPMW042

Trapped Modes Study and BBU Analysis in the 5-Cell 650 MHz Cavity

2529

C. Xu, I. Ben-Zvi, Y. Hao, V. Ptitsyn, W. Xu
BNL, Upton, Long Island, New York, USA
I. Petrushina
SUNY SB, Stony Brook, New York, USA

Funding: This work is supported by LDRD program of Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. DOE. #chenxu@bnl.gov
eRHIC project is a future electron-hadron collider proposed at BNL. The proposed electron accelerator will generate up to 20 GeV polarized electrons which will collide with proton beams with energy up to 250 GeV. The proposed collider will deliver electron-nucleon luminosity of 10³³- 10³⁴ cm^-2 ses⁻¹. A superconducting RF (SRF) 5-cell elliptical cavity will be utilized in electron accelerator. This paper presents a study of higher-order modes (HOM) for this 647 MHz SRF cavity. Different types of HOM modes and their BBU instabilities were investigated for frequencies up to 3.2 GHz. Threshold current values of beam breakup are estimated by GBBU code. Further improvement on this threshold current has been explored and discussed.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMW042

Export •

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