CERN, the European Organisation for Nuclear Research, is one of the largest and most important scientific research centres in the world. Located along the French/Swiss border near Geneva, researchers from over 100 countries are attempting to recreate the fundamental structure of the universe using large, exceptionally complex instruments.
The Large Hadron Collider (LHC) is situated 100 meters below ground at CERN and is considered the biggest single machine on the planet. It is also the location of one of the most important scientific achievements of this century, the Higgs boson.
Earlier this year, with support from the UK Engineering Research Council and CERN, a team from the University of Glasgow (Dr Aidan Robson, Dr Paul Soler, Douglas Pritchard), with support from Autodesk (Dennis Martin) and Zoller + Fröhlich (Chris Held), precisely documented the LHC experiment using the latest terrestrial scanning equipment.
The initial justification for the project was to document LHC as a scientific heritage site. Given the international significance of CERN, the associated research achievements, and that the facility will be significantly modified in the near future, it was important to create a dimensional record for more than pragmatic survey reasons. With this in mind, this meant moving the scanners and cameras throughout the cavern to capture as much surface coverage as possible, not just overall dimensions.
Over 160 laser scans, as well as 360-degree images for enhanced photogrammetry, were taken over 5 days. All of the scanning was done with two Zoller + Fröhlich 5016 terrestrial scanners at a high-resolution setting (3mm @10m point spacing/resolution) and associated HDR imagery (80 MPixel).
Three features of the 5016 proved to be exceptionally beneficial for this type of project: the quality of HDR imagery, having a camera at the same nodal point as the laser sensor, and the built-in LED lighting system. This provided the team with the ability to position the scanners throughout the cavern, to capture both point and RGB data, including features that were dark or in poor light.
Critically, this configuration allowed the team to position and remotely operate the scanner within the focal point of the LHC experiment, the Beryllium beam pipe area. The heart of LHC consists of a long beryllium metal pipe that is surrounded by huge magnets and an array of sensors – the exact collision point of the subatomic particles.
Beryllium metal is ideally suited for the CERN experiments due to its low atomic number and low density, but it did pose a challenge to scan. Beryllium is an exceptionally rare element, difficult to manufacture and highly toxic if broken, therefore the area is highly restricted and accessible to only highly trained CERN staff. With the scanner carefully positioned, three high-resolution scans were taken within this area – apparently a world’s first.
With the imagery and point data currently registered, the idea is that it will provide CERN with a precise three-dimensional CAD survey, but also the foundation for the development of visually engaging, multimedia content for educators, engineers, researchers and visitors.
Douglas Pritchard
dpritch5@jh.edu
Research Fellow (Honorary),
University of Glasgow
Lecturer,
Advanced Academic Programs
Johns Hopkins University
