Laser Wire Scanner Compton Scattering Techniques for the Measurement of the Transverse Beam Size of Particle Beams at Future Linear Colliders

This archive summarizes a working paper and conference proceedings related to laser wire scanner development for the Future Linear Collider (FLC) in the years 2001 to 2006. In particular the design, setup and data taking for the laser wire experiments at PETRA II and CT2 are described. The material is focused on the activities undertaken by Royal Holloway University of London (RHUL).Comment: 61 page

Planck-scale Gravity test at PETRA - Letter of Intent

Quantum or torsion gravity models predict unusual properties of space-time at very short distances. In particular, near the Planck length, around $10^{-35}m$, empty space may behave as a crystal, singly or doubly refractive. This hypothesis, however, remains uncheckable for any direct measurement since the smallest distance accessible in experiment is about $10^{-19}m$ at the LHC. Here we propose a laboratory test to measure space birefringence or refractivity induced by gravity. A sensitivity $10^{-31}m$ for doubly and $10^{-28}m$ for singly refractive vacuum could be reached with PETRA 6 GeV beam exploring UV laser Compton scattering

Dispersion and Beam Optic Parameter Measurements in the Transport Line (E-Weg) from DESY II To PETRA III

The transport line E-Weg extends from the extraction septum in DESY II to the injection septum in PETRA III, and transports electrons at a beam energy of 6.0 GeV. It consists of 3 parts. The first part is in the DESY tunnel, the second part is a long drift space in a slanted tube and the third part is in the PETRA III tunnel. The vertical plane difference between the accelerators is 1.28 m. The optics was derived from initial values at Übergabepunkt (UGP) from a previous optics. The total length of the transfer line is about 203 m. Ten screen monitors are used to estimate the profiles of the beam spot for the optics measurements, while 8 BPMs, mostly adjacent to the screens, are used to compare and control the orbits. Two scrapers are installed on either side of the long drift space to trim the beam dimensions in transverse plane. Two FCTs are used to measure the beam current and the transfer efficiency. The transverse dispersion and beta functions are measured by extracting the beam from DESY at different energies and analysing the beam profiles at the screen as well as positions at BPMs. The details of such measurements are reported in this paper

Beam Profile Measurements at PETRA with the Laserwire Compton Scattering Monitor

The vertical beam profile at the PETRA positron storage ring has been measured using a laserwire scanner. A laser- wire monitor is a device which can measure high brilliant beam profiles by scanning a finely focused laser beam non- invasively across the charged particle beam. Evaluation of the Compton scattered photon flux as a function of the laser beam position yields the transverse beam profile. The aim of the experiment at PETRA is to obtain the profile of the positron beam at several GeV energy and several nC bunch charge. Key elements of laserwire systems are currently being studied and are described in this paper such as laser beam optics, a fast scanning system and a photon calorime- ter. Results are presented from positron beam profile scans using orbit bumps and a fast scanning scheme

Compton scattering techniques for the measurement of the transverse beam size of particle beams at future linear colliders

At several locations of the beam delivery system (BDS) of a future linear collider (FLC),beam spot sizes ranging from several hundreds to a fewmicrometers have to be measured.The large demagnification of the beam in the BDS and the high beam power puts extremeconditions on any measuring device. With conventional techniques at their operational limit inFLC scenarios, newmetho ds for the detection of the transverse beam size have to be developed.Laser based techniques are capable of measuring high power beams with sizes in the micrometerrange. General aspects and critical issues of a generic device based on Compton scattering areoutlined and specific solutions proposed