Development of a laser-wire beam profile monitor for PETRA-III and CLIC

• Main Author: Aumeyr, Thomas
• Other Authors: Blair, Grahame
• Published: Royal Holloway, University of London 2013
• Subjects: 539.76; laser based beam size monitor : CLIC : laser-wire
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.589430

The Compact Linear Collider (CUC) is a proposed electron-positron collider with a centre- of-mass energy of 0.5 to 5 TeV, optimised for a nominal centre-of-mass energy of 3 TeV, at high luminosities exceeding 1034 cm-2s-J. The high beam charges in the CUC beams make classical techniques for measuring the transverse beam size such as optical transition radiation (OTR) screens or wire scanners very difficult, which necessitates the use of non-invasive beam- size monitors. The laser-wire is a system that meets these requirements; it uses inverse Compton scattering to determine transverse beam-sizes by scanning a laser beam across the electron beam. This thesis describes how such a laser-wire system was installed and operated at PETRA-III at DESY, which uses an automated mirror to scan a Q-switched laser pulse across the electron beam and is developed from the system previously operated at PETRA-II. The measurements of key performance parameters are described and used in determining the emittance of the PETRA-III beam. The thesis includes a detailed investigation of the laser .' system as well as the collision measurements. Furthermore, simulations were carried out to design a similar system for the proposed transfer line of the CUC Drive-Beam and the necessary baseline characteristics of such a system are described.