Measurement and adjustment of the differential positions of colliding bunches at CESR

Author

Billing, M. ; Codner, G. ; Meller, R. ; Sikora, J.

Author_Institution

Lab. of Nucl. Studies, Cornell Univ., Ithaca, NY, USA

Volume

2

fYear

2001

fDate

6/23/1905 12:00:00 AM

Firstpage

1240

Abstract

In CESR, 9 trains of 4 or 5 bunches of electrons and positrons collide at the interaction point, but bypass each other in the arcs of the storage ring using electrostatically separated orbits (pretzels). The parasitic bunch crossings resulting from the use of pretzel separation causes the bunches to have different orbits and, thus, the luminosity to be sensitive to the relative transverse positions of colliding bunches. We measure the bunch-by-bunch position projected to the interaction point from information available from the transverse feedback systems used for beam stabilisation. Some modification of the feedback systems has permitted the application of a bunch-by-bunch deflection designed to adjust the relative positions of colliding bunches. Observation of bunch-by-bunch position during collisions and the effect of relative position adjustments will be presented

Keywords

colliding beam accelerators; electron accelerators; feedback; particle beam bunching; particle beam diagnostics; storage rings; CESR; bunch-by-bunch deflection; bunch-by-bunch position; colliding bunches; electrostatically separated orbits; parasitic bunch crossings; position adjustments; pretzels; storage ring; Colliding beam accelerators; Electrons; Electrostatic measurements; Extraterrestrial measurements; Feedback; Filtering; Orbits; Particle beams; Position measurement; Positrons;

fLanguage

English

Publisher

ieee

Conference_Titel

Particle Accelerator Conference, 2001. PAC 2001. Proceedings of the 2001

Print_ISBN

0-7803-7191-7

Type

conf

DOI

10.1109/PAC.2001.986640

Filename

986640