Author: Mainaud Durand, H.
Paper Title Page
WEPME045 Development and Validation of a Multipoint Based Laser Alignment System for CLIC 3028
 
  • G. Stern, J. Kemppinen, F. Lackner, H. Mainaud Durand, D. Piedigrossi, J. Sandomierski, M. Sosin
    CERN, Geneva, Switzerland
  • A. Geiger, S. Guillaume
    ETH, Zurich, Switzerland
 
  Alignment is one of the major challenges within CLIC study, since all accelerator components have to be aligned with accuracy up to 10 μm over sliding windows of 200 m. So far, the straight line reference concept has been based on stretched wires coupled with Wire Positioning Sensors. This concept should be validated through inter-comparison with an alternative solution. This paper proposes an alternative concept where laser beam acts as straight line reference and optical shutters coupled with cameras visualise the beam. The principle was first validated by a series of tests using low-cost components. Yet, in order to further decrease measurement uncertainty in this validation step, a high-precision automatised micrometric table and reference targets have been added to the setup. The paper presents the results obtained with this new equipment, in terms of measurement precision. In addition, the paper gives an overview of first tests done at long distance (up to 53 m), having emphasis on beam divergence.  
 
WEPME046 Alignment Challenges for a Future Linear Collider 3031
 
  • H. Mainaud Durand, D.P. Missiaen, G. Stern
    CERN, Geneva, Switzerland
 
  The preservation of ultra-low emittances in the main linac and Beam Delivery System area is one of the main challenges for linear colliders. This requires alignment tolerances never achieved before at that scale, down to the micrometre level. As a matter of fact, in the LHC, the goal for the smoothing of the components was to obtain a 1σ deviation with respect to a smooth curve of 0.15 mm in a 150 m long sliding window, while for the CLIC project for example, it corresponds to 10 micrometres over a sliding window of 200m in the Beam Delivery System area. Two complementary strategies are being studied to fulfill these requirements: the development and validation of long range alignment systems to propagate precision and accuracy over a few hundreds of metres and short range alignment systems over a few metres. The studies undertaken, with associated test setups and the latest results will be detailed, as well as their application for the alignment of both CLIC and ILC colliders.