Neutronics Engineer

Proxima Fusion

WHO WE ARE At Proxima Fusion, we're driven by a bold mission – to redefine the future of sustainable energy. Our unique concept, built upon the ground breaking W7-X stellarator and the latest advances in technology, paves the way for commercially viable fusion power plants. What’s more, our work in stellarator optimization, powered by cutting-edge computation and machine learning, is propelling us into uncharted territories of fusion technology. New higher performance design points are unlocked by high temperature superconducting magnets. To fully grasp this huge opportunity, we’re building a team of extremely dedicated and passionate people who come together driving something extraordinary, radically transforming technology in the world. WHY JOIN PROXIMA FUSION * You will get to work on some of the most complex tech challenges to bring abundant, safe, clean energy to the world * You'll get to join and learn from an exceptional selection of accomplished and driven individuals * Do your life’s best work and enjoy the journey * Get to show that big things are possible in Europe when you assemble the best talent YOUR IMPACT This design-focused role aims to steer the stellarator design and facilitate choices that ensure radiological safety is prioritized. Work across teams to ensure that component designers are informed of relevant nuclear safety implications. Review the existing design and propose changes that improve safety, mitigate accident scenarios, and strengthen compliance with regulatory standards. See the impact of your nuclear analysis directly influencing the design of stellarator demonstrator machines and first-of-a-kind power plants. In this role, you will have a significant impact on design safety and help set the path toward regulatory approval. WHAT YOU WILL DO * Review designs with nuclear safety in mind. * Engage with engineering and physics teams, early in the design process to ensure components and systems are developed with nuclear safety considerations. * Collaborate with the neutronics experts, material scientists, and manufacturers to define limits for impurities in materials exposed to intense neutron irradiation. * Analyze accident scenarios and propose mitigations. * Support licensing activities, safety case development, and regulatory submissions. * Develop and maintain procedures for tritium handling, activated material management, and waste minimization. * Train and inform staff on radiation safety practices (e.g., nuclear-qualified welding). * Provide clear justification for design changes to fulfil risk analysis requirements. * Translate complex analysis outputs (e.g., neutronics dose maps) into actionable design guidance. * Conduct supporting analyses (e.g., neutronics activation simulations with OpenMC) to evidence the benefits of safety-driven design decisions. * Lead the development of operational procedures that are compatible with regulatory and inspection requirements. * Perform detailed Failure Modes and Effects Analyses (FMEA) to identify potential component and system failures, evaluate their safety implications, assess risk significance, and recommend design or procedural mitigations to ensure compliance with nuclear safety standards. WHO YOU ARE * Experienced nuclear safety engineer or a similar role, designing nuclear reactors or reactor components. * Experienced in engaging with German regulators. * Operating in radioactive environments with both gamma and neutron dose. * Relevant education, such as a nuclear engineering degree (desirable). * German speaker (desirable) * Able to quantify the risk of material activation due to neutron irradiation with OpenMC. * Able to program in Python to interface with the design and simulation capabilities. * Understanding of tritium-related risks and associated design mitigation strategies. INTERVIEW PROCESS * Recruiter Interview (30-60 min) * Technical Screening (30 min) * Technical Panel (3x60 min) * CEO call (30 min) *This role sits at L3 of our framework, please inquire during the recruitment process for further information* At Proxima Fusion, our mission is bold: making limitless clean energy a reality. To get there, we need a high-performing, diverse team that brings different perspectives, challenges assumptions, and builds together with purpose. We know that diversity of thought and experience leads to better ideas, stronger execution, and a more resilient team. We don’t look at how you identify, what you look like, who you choose to worship or what ethnicity you are. We care about what you can bring to the table.

European Spallation Source ERIC

The European Spallation Source (ESS) will soon be the world’s most powerful source of neutrons, providing researchers with unique opportunities to explore the structure of materials at the atomic level. Neutron scattering at ESS will address critical questions in physics, chemistry, geology, materials science and life science.   The Science Directorate at the European Spallation Source (ESS) invites applications for an instrument scientist for the dedicated Test beamline (TBL).   The Diffraction and Imaging Division is home to the instrument scientists and instrument operational engineers responsible for designing, constructing, and operating the DREAM, MAGiC, BEER, HEIMDAL, ODIN, and TBL instruments at ESS. New designs for a wide range of neutron instruments are being implemented to fully leverage the unique long-pulse time structure of the ESS neutron source.   The primary purpose of TBL is characterizing the target-reflector-moderator system and verifying the performance of the neutron source based on operating parameters such as proton beam energy, stability, pulse length, and beam rastering, as well as the moderator conditions. An important aspect of this work will be comparing the measured and simulated neutronic performance of the moderator, providing a crucial reference for various neutron scattering instruments. Additionally, the TBL will contribute to optimizing instruments and methods to fully exploit the unique long-pulse time structure of the ESS neutron source. The TBL will function as a local characterization station, supporting technical developments in areas such as neutron optics, polarization, and novel detectors. It is designed to support the user program by performing exploratory imaging experiments, neutron diffraction studies, and single-crystal alignment. Due to the flexibility of the instrument, a variety of detectors and sample environments can be fitted inside the experimental cave, allowing multipurpose measurements on not only thermal neutrons but also epithermal/fast neutrons and gamma rays. This includes but is not limited to a well-established technique such as time-of-flight transmission measurements, neutron tomography, neutron activation analysis, grating interferometry, etc. As the facility evolves, the modular design of the TBL will allow for modifications to meet new objectives, ensuring its continued relevance and utility in advancing neutron science. The construction of TBL is completed and the team prepares the instrument for the first neutrons.   About the role:  As the instrument scientist for TBL you will: Work closely with another scientist and the instrument operations engineer, forming the core instrument team. Participate in commissioning of the TBL beamline with neutrons. Develop a diagnostic plan for ESS Operation via the utilization of TBL Develop and implement new experimental methods using the TBL, including (but not limited to) spectroscopic imaging, diffractive imaging, polarized neutron imaging, grating interferometry, neutron depth profiling, prompt-gamma neutron activation analysis (PGNAA), and advanced sample environments, etc. Develop synergies with other neutron facilities and build links with universities.   The position is a 3-year fixed term role and the workplace will be situated in Lund, Sweden. ESS will support and encourage the candidate to take up an adjunct position at a university in an ESS partner country, in order to facilitate their own research.    Please read about the qualifications and experience needed for this position in the full job advertisement on ESS webpage: https://europeanspallationsource.se/careers/vacancies?rmpage=job&rmjob=2026&rmlang=UK   To apply: A career at ESS gives you the opportunity to contribute to the future discoveries within neutron science at a stunning, brand-new workplace filled with innovative minds and brilliant people from across the globe. We offer market competitive, individualised compensation which is differentiated according to role, responsibilities, individual skills, abilities and achievements as well as monthly pension contributions on top of your salary.   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, so submit your application as soon as you can. The last date for receiving applications is August 16th 2026.   For further information regarding the position, please contact Talent Acquisition Specialist Sofie Berg on sofie.berg@ess.eu or Hiring Manager Head of Diffraction & Imaging Division, Mikhail Feygenson on Mikhail.Feygenson@ess.eu   Please note that it might take longer than normal to answer questions due to vacation period.      This role requires enhanced security screening processes which will be performed during the recruitment and onboarding processes.For more information regarding the ESS recruitment process in general, please follow this link: https://europeanspallationsource.se/careers. For trade union information, please contact Unionen representative Nerusha Naicker on Nerusha.Naicker@ess.eu or SACO/Swedish Association of Graduate Engineers representative Marc Kickulies at Marc.Kickulies@ess.eu

European Spallation Source ERIC

The European Spallation Source (ESS) will soon be the world’s most powerful source of neutrons, providing researchers with unique opportunities to explore the structure of materials at the atomic level. Neutron scattering at ESS will address critical questions in physics, chemistry, geology, materials science and life science.  About the Role:  ESS is at an exciting turning point, transitioning from a construction site to an operating facility. To help us achieve our goal of becoming the world’s most powerful neutron source, we are seeking a Process Engineer for the Plant & Process Engineering Function, part of the Design & Engineering Division.  The team is responsible for maintaining state-of-the-art process activities across ESS. The group will first specify and design process systems such as cooling systems, instrument air and deionized water distribution, in accordance with PED, European harmonized codes, ESS rules and AFS regulations. They will then design the associated piping systems and mechanical supports to prepare for manufacturing, purchasing and installation phases. Finally, the group will help finalize the as-built documentation. Additional tasks include configuring and supporting the AVEVA tool suite, providing engineering review support, and offering technical advice.  Day-to-Day you will:  Perform system/project preliminary design based on design descriptions and requirements:   Prepare specifications and reports,  Review design projects,  Prepare for and present at preliminary design reviews.  Participate in critical process reviews,  Document design and group development:   Write and/or review process quality requirements,  Write and/or review processing licensing requirements,  Support standardization activities (components, best practices, and attributes),  Propose and implement improvements to procedures, best practices, and policies.  Follow up on post-design stages:   Support manufacturing phases,  Support installation and testing of equipment,  Support as-built activities,  Stay current with state-of-the-art technology.  This is a full-time/permanent position based at the brand new https://www.youtube.com/watch?v=d5h4bIEfM5Q. About you:  Required:  Higher vocational education or university degree in engineering (e.g. a bachelor’s degree), or an equivalent combination of education and experience,  Knowledge of components and system dimensioning for requirement and system/function descriptions,  Proficiency in the AVEVA tool suite,  Proficiency in written and spoken English.  Desirable:  Knowledge of normative constrained environments,  Knowledge of EN harmonized codes, preferably EN 13445 and EN 13480,  Knowledge of the Pressurized Equipment Directive (PED),  Knowledge of fluid distribution system installation.  We’re looking for someone who is self-motivated, has a problem-solving mindset, is structured, takes responsibility, and adheres to instructions and procedures.  To apply:  A career at ESS gives you the opportunity to contribute to the future discoveries within neutron science at a stunning, brand-new workplace filled with innovative minds and brilliant people from across the globe. We offer market competitive, individualised compensation which is differentiated according to role, responsibilities, individual skills, abilities and achievements as well as monthly pension contributions on top of your salary.  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, so submit your application as soon as you can. The last date for receiving applications is 2026-07-26.  For further information regarding the position, please contact Talent Acquisition Specialist Sofie Berg on mailto:sofie.berg@ess.eu or Hiring Manager Xavier Roy on mailto:xavier.roy@ess.eu Due to summer vacations questions will be answered after last application day, and first interviews will be conducted during week 34.   This role requires enhanced security screening processes which will be performed during the recruitment and onboarding processes. For more information regarding the ESS recruitment process in general, please follow this link: https://europeanspallationsource.se/careers   For trade union information, please contact Unionen representative Nerusha Naicker on mailto:Nerusha.Naicker@ess.eu or SACO/Swedish Association of Graduate Engineers representative Marc Kickulies at mailto:Marc.Kickulies@ess.eu