PhD position: Investigating fuel ion trapping and removal in liquid lithium using high flux plasma with operando ion beam analysis

DIFFER (Dutch Institute for Fundamental Energy Research) is one of the Netherlands Organisation for Scientific Research (NWO) institutes and focuses on a multidisciplinary approach to energy research, combining physics, chemistry, engineering and materials science. The institute is based on two main strands, solar fuels for the conversion and storage of renewable energy and fusion-energy as clean and unlimited source of energy. DIFFER is developing and supporting a national network on fundamental energy research and is closely collaborating with academic institutions, research institutes and industry. As of 2015 the institute is located in a new building at the campus of Eindhoven University of Technology (TU/e).

PhD position: Investigating fuel ion trapping and removal in liquid lithium using high flux plasma with operando ion beam analysis
Scientific aim: 

Developing nuclear fusion power would create a zero-CO2, safe and continuous energy source with no long-lived radioactive waste. This is highly desirable for society, but a great challenge is to control the waste heat which arrives in the exhaust region, known as the divertor. This must be reduced to manageable levels before it reaches the wall, so that the reactor operates reliably over long timescales. Recent developments have opened a new path to power exhaust: to use a liquid metal (lithium) based wall which strongly evaporates, forming a vapour cloud in front of the wall which cools and redirects the heat, ultimately preventing any damage.

A big challenge for the use of lithium is the strong interaction with the hydrogen fuel ions  (HI, deuterium and tritium), which can be trapped in the lithium, which is undesirable as they must be continually recycled to be burnt in the fusion reaction and tritium is not naturally occurring and must be made in the reactor. However, recent analysis of the interplay between lithium and HI indicated an operational regime where fuel trapping should be minimized but also emphasizes the large role that impurities such as oxygen and carbon play in the trapping of HI chemically as compounds. This underlines the importance of in-vacuo approaches to surface analysis. A newly developed linear plasma device at DIFFER, Upgraded Pilot-PSI, is capable of using ion beam analysis to study this problem without breaking vacuum. The goal of the PhD is to investigate how the fuel ions are trapped, the dynamics of the reaction and interaction with different seeded impurity plasma species as well as how the fuel ions can most effectively be removed. This would have a big impact in determining the operational space such a divertor design can occupy.

Responsibilities and tasks: 

You will:

  • Develop hypotheses and experiments to study the physics of hydrogen fuel trapping of lithium in vacuo and in operando (i.e. simultaneous to plasma exposure).
  • Study how isotope exchange, lithium flow and impurity gases can change the trapping dynamics to investigate how best to overcome the challenges presented in this approach.
  • Produce and publish scientific publications and present your work at national and international conferences.
  • Produce and defend a doctoral thesis at the Eindhoven University of Technology.
  • You should have (or very soon will have) a recent Master’s degree in physics, engineering or materials science.
  • You should be able to work well both independently and as part of a team in an experimental setting
  • You can produce outstanding academic results and can work with originality and high scientific quality.
  • Prior experience in plasma physics, atomic physics, chemistry and/or ion beam analysis will be considered a plus but not an essential requirement.
  • You should have excellent English language proficiency.
Employment conditions: 

DIFFER is the Dutch Institute for Fundamental Energy Research, one of the nine research institutes of the Netherlands Organization for Scientific Research (NWO). In our institute we focus on a multidisciplinary approach to energy research, combining physics, chemistry, engineering and materials science. DIFFER's research takes place in two main themes: Solar Fuels for the conversion and storage of renewable energy and Fusion Energy as a clean and unlimited source of energy. At DIFFER we develop and support a national network on fundamental energy research and collaborate closely with the academic community and industrial partners.

Our institute offers a first class and international research environment with various interdisciplinary but related research topics and projects. When fulfilling a PhD position at DIFFER, you will have an employee status as junior scientist at NWO. You can participate in all the employee benefits NWO offers. NWO and DIFFER have number of regulations that support employees in finding a good work-life balance. Such as conditions for teleworking, partly paid parental leave, the possibility to purchase and sell holiday leave, and a mentoring program. You will get a contract for four years. Your salary will be up to a maximum of 3,085 euro gross per month. The salary is supplemented with a holiday allowance of 8 percent and an end-of-year bonus of 8.33 percent. A training program is part of the agreement: you and your supervisor will design a plan for the additional education and supervising that you specifically need, for example through several courses offered by NWO (see The doctoral degree will be awarded by the Eindhoven University of Technology (TU/e, General information on working at NWO can also be found at the NWO-I website (

Further information: 

The Plasma Material Interactions group

The PMI group works to solve the challenges of power exhaust for ITER and for future fusion reactors, and also applies its expertise in extreme plasma conditions for industrial problems and novel materials processing. Our main foci are on

1. Understanding the expected performance of the ITER divertor.
2. Exploring new approaches for heat exhaust in fusion reactors, such as liquid metal walls.
3. Understanding the impact of impurities on the performance of mirrors in Extreme Ultraviolet plasma sources.

The NWO Recruitment code applies to this position. At DIFFER we believe that a workforce diverse in gender, age and cultural background is key to performing excellent research. We therefore strongly encourage applications from women and minorities. In our institute physicists, chemists, engineers and other specialists work together in multidisciplinary teams to accelerate the transition to a sustainable society. DIFFER’s workforce is currently composed of ~160 scientists (of which 60 are guests and interns), supported by ~40 technicians and ~30 support staff members. The global nature of the energy challenge is apparent from the international representation of our employees, who originate from over 30 different countries. Further information on the vacancy is available through Dr. Thomas Morgan (t [368] w [368] morgan [28] differ [368] nl).

Application procedure: 

You can apply by submitting the following three/four documents, in pdf format, to vacancies [28] differ [368] nl:

  • Your curriculum vitae, including contact details of at least two persons willing to provide references;
  • A cover letter addressed to dr. Thomas Morgan of maximum 1 page, summarizing the aspects in your curriculum that fit with the current opening and describing your motivation to apply to this position;
  • A list of relevant grades/proof of MsC or equivalent diploma
  • If available, evidence of English proficiency (e.g. IELTS Academic, TOEFL or an equivalent certificate)

Please use the format: lastname_CV.pdf, lastname_motivation.pdf, lastname_gradelist.pdf and lastname_english.pdf.  Please use ‘Application to vacancy number 20-017’ as the email subject. Please be aware that only applications in this format will be taken into account.

Closing date: 
Monday, January 4, 2021
Vacacany number: 

Go to the Vacancies page.