IPAC2015 - List of Authors (Crittenden, J.A.)

Paper	Title	Page
TUPTY079	Initial Modeling of Electron Cloud Buildup in the Final-focus Quadrupole Magnets of the SuperKEKB Positron Ring	2218
	J.A. Crittenden Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Funding: US National Science Foundation contracts PHY-0734867, PHY-1002467, and PHY-1068662, US Department of Energy contract DE-FC02-08ER41538 and the Japan/US Cooperation Program We present modeling results for electron cloud buildup in the final-focus quadrupole magnet nearest the interaction point in the SuperKEKB positron storage ring. The calculations employ as input recently obtained estimates of synchrotron radiation absorption rates on the vacuum chamber wall including the effect of photon scattering. While the effect both adds to and subtracts from photoelectron production at the points in the ring where unscattered photons strike the wall, it also produces cloud in the other regions. Results for beam-pipe-averaged and beam-averaged cloud densities are presented, as are estimates for the contribution to the fractional vertical coherent tune shift. The effect of the strong magnetic fields is studied and the dependence on the vacuum chamber surface secondary yield characteristics is considered. Cloud buildup is modeled with a 2D particle-in-cell macroparticle tracking code validated using recent measurements of electron trapping in a quadrupole magnet at the Cornell Electron Storage Ring Test Accelerator.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPTY079
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TUPTY080	Synchrotron Radiation Analysis of the SuperKEKB Positron Storage Ring	2222
	J.A. Crittenden, D. Sagan Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA T. Ishibashi, Y. Suetsugu KEK, Ibaraki, Japan
	Funding: US National Science Foundation contracts PHY-0734867, PHY-1002467, and PHY-1068662, US Department of Energy contract DE-FC02-08ER41538 and the Japan/US Cooperation Program. We report on modeling results for synchrotron radiation absorption in the SuperKEKB positron storage ring vacuum chamber including the effects of photon scattering on the interior walls. A detailed model of the geometry of the inner vacuum chamber profile has been developed and used as input to a photon tracking code. Particular emphasis is placed on the photon absorption rates in the electron-positron interaction region.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPTY080
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Initial Modeling of Electron Cloud Buildup in the Final-focus Quadrupole Magnets of the SuperKEKB Positron Ring

2218

J.A. Crittenden
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Funding: US National Science Foundation contracts PHY-0734867, PHY-1002467, and PHY-1068662, US Department of Energy contract DE-FC02-08ER41538 and the Japan/US Cooperation Program
We present modeling results for electron cloud buildup in the final-focus quadrupole magnet nearest the interaction point in the SuperKEKB positron storage ring. The calculations employ as input recently obtained estimates of synchrotron radiation absorption rates on the vacuum chamber wall including the effect of photon scattering. While the effect both adds to and subtracts from photoelectron production at the points in the ring where unscattered photons strike the wall, it also produces cloud in the other regions. Results for beam-pipe-averaged and beam-averaged cloud densities are presented, as are estimates for the contribution to the fractional vertical coherent tune shift. The effect of the strong magnetic fields is studied and the dependence on the vacuum chamber surface secondary yield characteristics is considered. Cloud buildup is modeled with a 2D particle-in-cell macroparticle tracking code validated using recent measurements of electron trapping in a quadrupole magnet at the Cornell Electron Storage Ring Test Accelerator.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPTY079

Export •

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

TUPTY080

Synchrotron Radiation Analysis of the SuperKEKB Positron Storage Ring

2222

J.A. Crittenden, D. Sagan
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
T. Ishibashi, Y. Suetsugu
KEK, Ibaraki, Japan

Funding: US National Science Foundation contracts PHY-0734867, PHY-1002467, and PHY-1068662, US Department of Energy contract DE-FC02-08ER41538 and the Japan/US Cooperation Program.
We report on modeling results for synchrotron radiation absorption in the SuperKEKB positron storage ring vacuum chamber including the effects of photon scattering on the interior walls. A detailed model of the geometry of the inner vacuum chamber profile has been developed and used as input to a photon tracking code. Particular emphasis is placed on the photon absorption rates in the electron-positron interaction region.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPTY080

Export •

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