Cargando…

A Method for Determining the Roll Angle of the CLIC Accelerating Structures From the Beam Shape Downstream of the Structure

The Compact Linear Collider (CLIC) accelerating structures have a four-fold symmetry from the radial waveguides for damping higher order modes. This symmetry allows for an octupole component of the rf fields to co-propagate with the main accelerating field. The effect of this octupole mode has been...

Descripción completa

Detalles Bibliográficos
Autores principales: Ögren, Jim, Farabolini, Wilfrid, Ziemann, Volker
Lenguaje:eng
Publicado: 2017
Materias:
Acceso en línea:https://dx.doi.org/10.18429/JACoW-IPAC2017-MOPAB107
http://cds.cern.ch/record/2674351
Descripción
Sumario:The Compact Linear Collider (CLIC) accelerating structures have a four-fold symmetry from the radial waveguides for damping higher order modes. This symmetry allows for an octupole component of the rf fields to co-propagate with the main accelerating field. The effect of this octupole mode has been observed at the CLIC test facility 3. In CLIC the accelerating structures are mounted together on a moveable girders. There are four vertical and four horizontal actuators on the girder, which allows for 5D control in a limited range and for instance we can roll the girder. By observing the beam shape perturbed by the octupole field on a screen downstream from the structure we can determine the roll angle and thus align the structure azimuthally. Here we discuss a possible method and show some preliminary results.