SCF Interview Series: Engineering design of a prototype permanent magnet for Ion Beam Analysis
04 Nov 2021



Olli Tarvainen (ISIS) and Ben Shepherd (ASTeC) have collaborated to design a prototype of a permanent magnet for Ion Beam Analysis.

We recently spoke to Olli and Ben to understand more about their time at STFC, future plans, and passion for environmental sustainability.

Ben Shepherd began his career at STFC in 2002, after completing his Master's degree in Physics with Astrophysics at the University of Leeds. Ben has been a member of ASTeC's Magnetics and Radiation Sources (MaRS) group since 2002. His primary research interests are magnet systems for accelerators, and high-level software for accelerator control room operations. Ben is responsible for the magnetic measurement laboratory at Daresbury Laboratory, where many of the magnetic devices used on STFC's accelerators are built and tested.

Olli Tarvainen, a Physicist and Researcher at STFC's ISIS Neutron and Muon Source based at the Rutherford Appleton Laboratory, joined STFC in 2018. His role at STFC is somewhere between physics and engineering, trying to improve the Ion Source. Olli's background is in nuclear physics, completing his PhD in Nuclear Physics at the University of Jyvaskyla in Finland . After completing his PhD, Olli went on to complete his Post Doctorate at Los Alamos National Lab, this was his first introduction to neutron facilities.

What do you see yourself doing in the future and why?

BS: I am becoming increasingly interested in sustainability and as an organisation; STFC is starting to get this as well. In the ASTeC department, we've just started a Sustainable Accelerators Task Force, so I certainly see myself being more involved in that in the future.  We do a lot of really good science in our facilities, but they do take a lot of energy to run. What we want to do is to try and make accelerator technology as green as possible. I want to be able to say in the future, I played a part in reducing the impact of climate change.

OT: My thoughts actually align very well with what Ben says. For me, it's important that the work that I do has some real world applications. So that's why I enjoy trying to develop new ideas for how to use accelerators for the common good.

Can you tell us about your ESCF project?

BS: To change the direction of a charged particle beam you need a magnetic field and the magnets we usually use to steer and focus particle beams are usually electromagnets. So essentially, for an electromagnet, you've got a set of coils wrapped around a steel pole and that produces a strong magnetic field that can change the path of a beam of charged particles.

OT: The difference between this magnet within this project and previous ones is the application; we intend to make this magnet suitable for a technique called Ion Beam Analysis (IBA). IBA facilities use electrostatic accelerators with high terminal voltage (several MV) that require SF6-insulation. IBA facilities also use electromagnets that require huge amounts of electrical power as well as cooling in order for them to function. IBA facilities therefore have a significant environmental impact.

We developed a new IBA facility concept that removes the need for SF6 – a potent greenhouse gas – and uses zero-emission permanent magnets (PMs) to replace electromagnets for the ion source and variable field M/Q-selection dipole.

What prompted you to do your ESCF project?

BS: My team at ASTeC were introduced to Olli and his team through a colleague in the Vacuum Solutions Group at ASTeC. We thought Olli's project to develop a more environmentally friendly version of an Ion Source sounded great, something that would fit in with the expertise we have on our side from a project we've been developing over the past few years. That is when the collaboration began and then a year or so later, we heard about the ESCF funding and jumped at the chance to further this collaboration and project.

What would you like to happen to the outputs of your project?

BS: This ESCF project enabled us to produce the engineering design of the PM dipole and to investigate the size, shape, and required grade of PM material to use. We are now ready to go to tender for components to develop the design further.

OT: Over the summer, we've successfully applied for more funding from STFC, allowing our team and five others to explore ways to turn research into real-world solutions and technologies to help to reach net zero.

The ESCF allowed us to more work on paper to develop the mechanical design, so this new funding from STFC's net zero grant will allow us to finalise the engineering design, plan how to assemble the magnet safely, buy materials, build the magnet and complete the assembly!

What would you say to others who may have ideas for improving environmental sustainability? 

BS: If you have an idea for improving environmental sustainability, speak up. We're an organisation that thrives on ideas. There are several groups around the organisation to discuss and promote ideas to make us a more environmentally friendly organisation. For instance, the Daresbury Green Group, which I am a member of, it's a great group to share ideas and implement changes relating to the environment and sustainability.

OT: I think STFC should take the lead in this country to develop prototypes for sustainable technologies. It is exactly what STFC has the expertise and know-how on! I would like to see STFC being more aggressive at enabling prototype development.

Contact: Diakun, Joseph (STFC,DL,AST)