Computational Physicist

Company Description

At CERN, the European Organization for Nuclear Research, physicists and engineers are probing the fundamental structure of the universe. Using the world's largest and most complex scientific instruments, they study the basic constituents of matter - fundamental particles that are made to collide together at close to the speed of light. The process gives physicists clues about how particles interact, and provides insights into the fundamental laws of nature. Find out more on http://home.cern.

Diversity has been an integral part of CERN's mission since its foundation and is an established value of the Organization.

This is your Quest. Deepen your knowledge and expertise faster than anywhere else on earth. Take Part!

Job Description

The High Field Magnets Programme at CERN requires a rigorous R&D into high performance, innovative quench protection systems. An understanding of superconducting strand or cable response to a change of its transport current and/or an external magnetic field is becoming increasingly important as more quench protection systems rely on this response as a key part of the protection method. For quench simulations, understanding a conductor response in heat generation (AC loss) or magnetic field distortion (magnetization) is needed. Examples of applications that rely on this response include magnets protected by CLIQ and/or quench-back and potentially magnets concepts with HTS or LTS‑HTS hybrids. For HTS in particular, Robel or more novel Twisted Stacked Tape Cable (TSTC) and Conductor on Round Core (CORC) are particularly relevant but not extensively studied with relevance for accelerator magnets and quench simulations.

Finite Element models could be used for calculating such a response as all necessary geometry, and physics details could be included. To keep model and simulation time practical, a development of FE formulation to capture physics involved is needed for approaches with 2D conductor models accounting for strand twist pitch and/or cable transposition length or a 3D thin shell approach where the HTS layer is collapsed into a surface. Such conductor level response needs to be included in large scale quench protection models. A potential avenue is a conductor and/or winding level homogenization approach dealing with equivalent material properties. An alternative approach is a multiscale-multimodel simulation, where a detailed conductor level model is coupled and responds to a large-scale, magnet-level quench simulation model.

The selected candidate will:

• Develop Finite Element models at conductor level (LTS and HTS; wires, tapes and cables) to simulate AC loss and magnetization response to transport current and/or an external magnetic field change;
• Develop methodology of coupling conductor-level simulations with full magnet size quench simulations. Homogenization and multi-scale approaches to be studied in detail;
• Where possible, verify developed approaches against analytical solutions and other quench simulation tools;
• Validate simulations with available measured data. Such validation will be done on the conductor or magnet level data depending on availability;
• Develop a methodology for abstracting the complexity involved and integrating with existing quench simulation tools or developing a stand-alone conductor-level simulation tool.

More about the High Field Magnets project can be found at https://hfm.web.cern.ch/

Qualifications

Eligibility criteria:

• You are a national of a CERN Member or Associate Member State;
• You have a Master’s degree and between 2 and 6 years’ experience or PhD with up to 3 years of relevant experience in physics or engineering or other related field;
• You should have a working knowledge of English or French.

Skills and/or knowledge:

Computational methods, Electromagnetic or multiphysics simulations, Finite element method and commercial or open-source tools, Superconducting conductors, Quench phenomena, Python, MATLAB, C, High-performance computing.

Additional Information

What we offer:

• An employment contract of in principle 24 months, with a possible extension up to 36 months;
• On-the-job and formal training at CERN as well as in-house language courses for English and/or French;
• A monthly stipend ranging between 6050 and 6650 Swiss Francs per month (net of tax);
• Coverage by CERN’s comprehensive health scheme (for yourself, your spouse and children), and membership of the CERN Pension Fund;
• Depending on your individual circumstances: installation grant; family, child and infant allowances; payment of travel expenses at the beginning and end of contract;
• 30 days of paid leave per year.

How to Apply:

You will need the following documents to complete your application:

• A CV;
• A scanned PDF of your most recent relevant qualification;
• We recommend to add two recent letters of recommendation, giving an overview of your academic and/or professional achievements. You can upload these letters at the time of application if you have them to hand. You will also be provided with a link as soon as you have submitted your application to forward to your referees to upload their letters confidentially.

The earliest expected start date for selected candidates is May 2023.

Ready to take part? Then please submit your application by 23 January 2023 at  midnight (12.00 AM CEST).