Numerical Simulation of Underground Structures with Sensitive Experimental Equipment: The CERN CMS Detector

This PhD opportunity will form part of an exciting new collaboration between CERN and the University of Dundee, exploring some of the complex Civil Engineering challenges associated with the operation of the CMS detector, one of the two major detectors within the Large Hadron Collider.

The CMS detector weighs 14,000 tonnes and is situated in a cavern, 100 m below ground level near the Franco-Swiss border. The various parts of the detector are regularly moved to provide access for maintenance and development. As a uniquely sensitive piece of equipment it is critical that exacting standards of alignment are maintained during such operations. This is a significant challenge given the high loading – low deformation performance envelope. This PhD will develop advanced simulation models that will be used to understand the structure-ground interaction during routine operations and also explore the effects of natural hazards including fault movement and earthquakes.

Following an initial period of training at the University of Dundee, the 4 year PhD will begin with 2 years based wholly within the CMS Survey team in Geneva during the shut-down period of the experiment when significant new engineering works will be conducted (calendar years 2019-2020). During this period, 75% of the student’s time will be dedicated to working within the team on the various surveying tasks, as directed by the survey team lead. This will include surveying the detector and cavern using laser trackers, photogrammetry and laser scanners, updating the local survey network and replacement of the beam pipe. Through these tasks the student will collect high quality background data on the CMS cavern that will be used to produce digital simulation models, and collect data relating to the response of the detector and cavern during the various maintenance operations, that will be used to validate the numerical models. The remaining 25% of student time will be dedicated to transferring the survey data (and historical data) into a simulation model and running preliminary simulations of the fatigue response of the cavern floor during detector movement. This will be achieved by remote accessing modelling software at the University of Dundee.

Once the detector is back online, the remainder of the PhD (2 years) will be based wholly at the University of Dundee, refining model parameters using the operational response data measured while at CMS, and then extending the model to assess the effects of natural hazards including fault movement and earthquakes. The construction of the CMS cavern and connecting accelerator-ring tunnels means that the new insights into ground-structure interactions obtained in this phase will be highly transferrable to related civil engineering problems, including effects of station boxes on underground transport systems during earthquakes (building on recent collaborative work between the UK and Chile).

During the work based in Geneva, the student will be funded under the PhD funding model in use at CERN, which will include payment in local currency which will cover the local living costs. This will include a limited amount of travel funding for return travel to the UK. During the work based in Dundee, the student will receive a PhD stipend at EPSRC rates. All of the tuition fee costs (for students from within the EU) will be covered by the University of Dundee.

During the period in Geneva, the student may also be required to undertake some in-situ trials of a new survey target that is being developed for use in the CMS detector in a parallel PhD project.

The supervisory team consists of:

• Dr Jonathan Knappett (University of Dundee)
• Dr Michael Brown (University of Dundee)
• Martin Gastal (CMS Experimental Area Manager)
• Antje Behrens (CERN Experiment Survey and Alignment)

The position would particularly suit a candidate with a first degree in Civil Engineering, particularly if there has been an opportunity to study advanced surveying techniques, involving reduction of measurements, and/or photogrammetry. Candidates with a numerate first degree who can demonstrate surveying skills (e.g. through industrial experience) can also be considered.

This PhD is open to candidates from within the EU (including the UK). Applicants from outside the EU would need to separately fund the difference between overseas and EU rates.

The studentship would need to start no later than 01 November 2018.

For further information or for queries about eligibility, please contact Dr Jonathan Knappett, [Email Address Removed].