Simulation of LiCAS Error Propagation

TL;DR

This paper presents detailed simulations demonstrating that the LiCAS system, using Laser Straightness Monitors and Frequency Scanning Interferometry, can achieve the required tunnel alignment accuracy for future linear colliders.

Contribution

The paper introduces a comprehensive simulation study of the LiCAS system within a Rapid Tunnel Reference Surveyor, validating its potential to meet collider alignment specifications.

Findings

Achieves 200 microns vertical accuracy over 600 meters

Validates LiCAS system design for TESLA collider requirements

Demonstrates feasibility of automated tunnel alignment measurement

Abstract

Linear Collider Alignment and Survey (LiCAS) R&D group is proposing a novel automated metrology instrument dedicated to align and monitor the mechanical stability of a future linear high energy e+e- collider. LiCAS uses Laser Straightness Monitors (LSM) and Frequency Scanning Interferometry (FSI) for straightness and absolute distance measurements, respectively. This paper presents detailed simulations of a LiCAS system operating inside a Rapid Tunnel Reference Surveyor (RTRS train). With the proposed design it is feasible to achieve the required vertical accuracy of the order of 200 micons over 600 m tunnel sections meeting the specification for the TESLA collider.