STARTSLIDE

1. STARTSLIDE CLIC Survey and alignment studies Jean-Pierre QUESNEL, Hélène MAINAUD DURAND

2. Objectives for the feasibility • R & D plan concerning the CLIC active pre-alignment, approved in October 2007 by Daniel Schulte and Jean-Pierre Delahaye. • Reference of the document: edms n° 876803. • 4 objectives to fulfill before 2011: • The mechanical alignment of the elements to the supporting girder with precision of a few microns, in an industrial way. • A method of precise fiducialization must be found • The alignment needs to be very precise over at least 200m (max. amplitude 10 microns over 200m in the main linac (over 400m in the BDS) • an optimization of the cost, as well as an integration of the solutions. • Between 2011 and 2012: consolidation of the solutions foreseen and latest results due for the feasibility study.

4. Ressources • Friedrich LACKNER [15.11.2007 – 14-11-2009] is a Dr-Ing. specialized in mechanics, working as a fellow on the following topics: • - The methods to align the components on the girders • - The fiducialization (study of the interfaces between the pre-alignment sensors and the • object to be aligned, proposal of a method of fiducialization) • - The definition of the technical requirements concerning the movers and the testing of the • compatibility of the solution with stabilization, for the module & MB quad of the TBTS. • - The validation of the WPS prototype. • Thomas TOUZE [01.01.2008 – 31.12.2010] is a surveyor, whose doctorate subject is the following: • “proposition d’une méthode d’alignement de l’accélérateur linéaire CLIC: des réseaux de géodésie • au pré-alignement actif”) and is working on: • - The proposal of a global concept for CLIC alignment in all areas • - The simulations of the corresponding alignment uncertainties • - The determination of these uncertainties on all the facilities  Prolongation / Replacement to foresee • Sébastien GUILLAUME [01.08.2008 – 31.07.2010] is a ETHZ doctorate student who will study the effects of the gravity on the alignment systems, and will undertake special studies concerning the accuracy which can be obtained concerning the determination of the geoïd.

5. Budget • Due to delays concerning: • the doctorate cost (arrival later than foreseen) [20 kCHF] • the associated works on gravimetric effects [20 kCHF] • delays with the optical system developped in collaboration with NIKHEF [30 kCHF] •  carry over of 70 kCHF of 2008 budget to 2009. •  Total cost for 2009 budget: 300 kCHF instead of 230 kCHF. (à vérifier) Collaborations • With NIKHEF concerning the development of a laser based alignment system: • some difficulties encountered with the NIKHEF representative (NIKHEF patent, development of a 3 point alignment system dedicated to seismology) • Jos Engelen should help to redefine clear bases for a real collaboration • With other labs developing WPS and HLS sensors, in order to launch an inter-comparison between sensors. A dedicated mini workshop will be held at CERN on the 2nd and 3rd of April 2009.  Web site: http://clic-pral.web.cern.ch/clic-pral/

6. Objectives for 2009 • Mini workshop on sensors in order to launch the inter-comparison between labs concerning WPS and HLS, in the frame of CLIC (with a common interest ILC) • Results following the upgrade of the TT1 facility • Confirm the radial deviation theory (due to the rotation of the Earth) • Modelize the vertical shape of a wire without the HLS system • Alignment simulations using these results (paper for PAC 2009) • Results of the optical WPS (feasibility of an « absolute » WPS) • First results of a modular laser system based on speckle effects and filters. • Results of astromical and gravimetric measurements to define the geoïd • A proposal concerning the supporting of the main beam quadrupoles (pre-alignment + stabilization) • Design, installation, and first results of a longer facility in the TZ32 tunnel. Web site of the survey and alignment study: http://clic-alignment.web.cern.ch/clic-alignment/