PhD candidate for neutron instrument backgrounds

Reference number ESD-56653

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The European Spallation Source is one of the largest science and technology infrastructure projects being built today. The project includes the most powerful linear proton accelerator ever built, a five-tonne, helium-cooled tungsten target wheel, 15 state-of-the-art neutron instruments, a suite of laboratories, and a supercomputing data management and software development centre. In the context of its history and future as a scientific organisation, however, it is more than the sum of its parts. It is a brand-new Big Science organisation and we are building it from the ground up.

The Operations and Machine Directorate at the European Spallation Source (ESS) in Lund, Sweden, in cooperation with the ESS Science Directorate and Lund University, invites applications for a PhD position in the area of theoretical and experimental radiation transport physics within the ESS Spallation Physics Group.

Come and build the future of Science with us!

About the Spallation Physics Group:
The ESS Target Division, including the ESS Spallation Physics Group, is responsible for designing, developing, procuring, installing, commissioning, and testing the systems required to convert the energetic proton beam from the accelerator into neutron beams used for experiments.

Key features of the ESS Target Station include the target itself, the neutron moderator and reflector system, and the neutron beam-extraction system. However, the ESS Spallation Physics Group's responsibilities extend beyond the target, covering spallation physics topics ESS-wide. These responsibilities include but are not limited to:

• Activation and inventory calculations of radionuclides across the facility.
• Particle transport simulations to optimize the target-moderator-reflector system, assess component lifetimes, and conduct shielding and activation analyses.
• Development of computational tools and thermal and cold neutron scattering cross-sections (scattering kernels) for particle transport simulations.
• Experimental verification and development of new moderator-reflector systems and other spallation physics-related concepts.
• Study of materials relevant to the operation and performance of the facility.
• Supporting neutron scattering instrument teams by providing e. g. source terms for instrument optimization.

Position Description:
The performance of neutron scattering instruments depends critically on the ratio between the desired signal and the unwanted noise. While the importance of the so-called signal-to-noise ratio has been known for decades, the mitigating actions, in reality, have often been based on tribal knowledge and preserved more as an art than science. The reason is that instrument backgrounds usually do not have single/binary roots, but are multidimensional problems in interplay with each other. Furthermore, historically, the simulation tools were only useable for smaller geometries not full scale neutron scattering facilities, like ESS. With advances in computing, variance reductions, and detector technologies, the scientific infrastructure is now developed to take this problem to the next level and transform tribal knowledge/art into scientific methods.

With ESS set to commence operations soon, instrument teams will undergo a commissioning phase, where they will, amongst other things, look at the signal-to-noise ratio. The PhD candidate will work closely with the instrument teams to characterize various background sources using both theoretical and experimental approaches. The findings will be used to develop a scientific model of instrument backgrounds, benefiting current and future instruments at ESS and potentially instruments at other neutron facilities worldwide.

The successful candidate will be part of the ESS Spallation Physics Group, while also collaborating closely with neutron scattering instrument teams.

Qualifications
Required qualifications:

• You must be eligible for the PhD program in physics at Lund University.
• A "Sherlock Holmes" kind of mindset; ready to tackle complex and multi-dimensional challenges.
• Excellent communication skills and ability to work effectively in a multicultural, international environment.
• Proactive and self-motivated, with a willingness to take initiative.
• Team-oriented, but also capable of working independently.
• Fluent in English, both written and spoken.

In addition to the required qualifications, the following experience would considered advantageous:

• Experience with radiation transport codes such as PHITS, MCNP(X), or FLUKA.
• Familiarity with CAD-to-particle transport code conversion tools (e. g. ATTILA4MC).
• Some experience performing experiments.
• Understanding of neutron scattering instruments, their construction and operation.
• Knowledge of neutron ray-tracing codes such as MCSTAS, VITESS, or NISP.
• Prior experience working at spallation sources.
• Experience as a user at neutron sources.

To apply:
If you see yourself in what we’re looking for, please provide your CV and motivation letter in English by clicking on “apply” and following the instructions. Please be aware that we can only accept direct applications made via the ESS website.

Certain roles at ESS require health and safety checks and/or security clearance procedures, which will be performed as part of the recruitment process.

We review applications continuously, so don’t miss out! Submit your application as soon as you can and quote the job reference number ESD-56653.

For more information regarding the ESS recruitment process, please contact Daniel Nordin Baker – Technical recruiter – on [email protected].

For trade union information, please contact Unionen representative Mikael Johansson on [email protected] or SACO/Swedish Association of Graduate Engineers representative Marc Kickulies at [email protected]

We look forward to receiving your application soon!

URL to this pagehttps://europeanspallationsource.se/careers/vacancies?rmpage=job&rmjob=1792&rmlang=UK

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