English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

The beam lifetime in an electron storage ring is also limited by the lossrate of the stored electrons due to the elastic coulomb scattering of electronswith the nuclei of residual gas atoms. The contribution to the beam lifetimedue to this elastic scattering depends upon the shape factor which is governedby the shape of the vacuum chamber. In this paper, analytical expressions forthe shape factor for a rectangular and an elliptical vacuum chamber as afunction of longitudinal position along the circumference in a storage ring arederived using an approach in which the position of electrons at the focusingquadrupole is transformed to the location of defocusing quadrupole and viceversa to define the parts of the vacuum chamber, where the loss of electronstakes place at the location of quadrupoles. The expressions available in theliterature are for the average shape factors. The expression of shape factorfor a rectangular chamber derived in this paper are similar to the expressionfor average shape factor quoted in the literature, whereas a new expression forelliptical shape of vacuum chamber having no resemblance with the availableexpression for average shape factor is obtained. A comparative study of shapefactors at each scattering location in the ring obtained from derivedexpressions and with the existing expressions are reported using Indus-2lattice parameters for rectangular and elliptical shapes of the chamber. Acomparison of average shape factors for these two shapes using derived as wellas existing expressions is also reported. These studies indicate that theeffect of the rectangular and elliptical shape of vacuum chamber on beamlifetime due to elastic coulomb scattering between electrons and nuclei ofresidual gas molecules is nearly same.

Dependence of loss rate of electrons due to elastic gas scattering on the shape of the vacuum chamber in an electron storage ring