IPAC2021 - List of Keywords (ion-effects)

Paper	Title	Other Keywords	Page
TUXA01	Advances in Understanding of Ion Effects in Electron Storage Rings	simulation, emittance, storage-ring, injection	1267
	J.R. Calvey, M. Borland, T.K. Clute, J.C. Dooling, L. Emery, J. Gagliano, J.E. Hoyt, P.S. Kallakuri ANL, Lemont, Illinois, USA
	Ion instability, in which beam motion couples with trapped ions in an accelerator, is a serious concern for high-brightness electron storage rings. For the APS-Upgrade, we plan to mitigate coherent ion instability using a compensated gap scheme. To study incoherent effects (such as emittance growth), an IONEFFECTS element has been incorporated into the particle tracking code ELEGANT. The simulations include multiple ionization, transverse impedance, and charge variation between bunches. Once these effects are included, the simulations show good agreement with measurements at the present APS. We have also installed a gas injection system, which creates a controlled pressure bump of Nitrogen gas in a short section of the APS ring. The resulting ion instability was studied under a wide variety of beam conditions. For cases with no or insufficient train gaps, large emittance growth was observed. IONEFFECTS simulations of the gas injection experiment and APS-U storage ring show the possibility of runaway emittance blowup, where the blown-up beam traps more ions, driving further instability.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUXA01
About •	paper received ※ 24 June 2021 paper accepted ※ 27 July 2021 issue date ※ 10 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

TUXA01

Advances in Understanding of Ion Effects in Electron Storage Rings

simulation, emittance, storage-ring, injection

1267

J.R. Calvey, M. Borland, T.K. Clute, J.C. Dooling, L. Emery, J. Gagliano, J.E. Hoyt, P.S. Kallakuri
ANL, Lemont, Illinois, USA

Ion instability, in which beam motion couples with trapped ions in an accelerator, is a serious concern for high-brightness electron storage rings. For the APS-Upgrade, we plan to mitigate coherent ion instability using a compensated gap scheme. To study incoherent effects (such as emittance growth), an IONEFFECTS element has been incorporated into the particle tracking code ELEGANT. The simulations include multiple ionization, transverse impedance, and charge variation between bunches. Once these effects are included, the simulations show good agreement with measurements at the present APS. We have also installed a gas injection system, which creates a controlled pressure bump of Nitrogen gas in a short section of the APS ring. The resulting ion instability was studied under a wide variety of beam conditions. For cases with no or insufficient train gaps, large emittance growth was observed. IONEFFECTS simulations of the gas injection experiment and APS-U storage ring show the possibility of runaway emittance blowup, where the blown-up beam traps more ions, driving further instability.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUXA01

About •

paper received ※ 24 June 2021 paper accepted ※ 27 July 2021 issue date ※ 10 August 2021

Export •

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