KIT Summer School 2022

In September, the grads visited Germany to attend the 14th International School on Fusion Technologies at KIT in the beautiful Karlsruhe. This was the first time the school had run since before the pandemic, so grad scheme alumni from the 2019 cohort joined the 2020 and 2021 cohorts as we journeyed together for the long-anticipated summer school.

In total there were 31 of us, making up about half of the conference attendees! Our grads represented a variety of departments: CED (Central Engineering), RACE (our Robotics facility), H3AT (our Tritium lab), H&CD (Heating & Current Drive), OCE (Office of the Chief Engineer), Technology, and myself in Advanced Computing.

We met attendees from all over the world, representing both academic and industrial backgrounds, all congregated together to learn more about the technology and engineering that is making fusion energy a reality. After two years largely working in our bedrooms during lockdown, or otherwise focussed on our own projects, it was a refreshing reminder of the context which each of our own day-to-day work fits into, and the global nature of our quest.

KIT Summer School Group Photo 2022 ~ Credit: Mihaela Ionescu-Bujor

The school covered twelve key fusion technology topics over five days:

• Monday opened with an introduction to fusion and plasma physics, by guest lecturers from EUROfusion, the CEA, and our own UKAEA, followed by a lecture on neutronics. 
  
  These topics comprise the core physics of fusion energy: the coupling of magnetohydrodynamic and nuclear considerations that make the magnetically confined deuterium-tritium reaction a viable route to the decarbonised future of energy generation.
  
  
• Tuesday ramped things up by delving into the various plasma heating technologies, plasma diagnostics, and the fusion power plant fuel cycle with guest lectures from UKAEA and the CEA. Tuesday also featured a tour of the gyrotron test stand and was rounded off by tours of KIT’s fusion materials and tritium laboratories.
  
  Developing technologies to efficiently heat and fuel a fusion power plant are very much the sort of practical engineering challenges that define the modern stage of fusion R&D, as distinct from the theoretical physics groundwork solved in the preceding decades.
  
  
• Wednesday covered two major fusion technologies: breeder blankets (required for providing tritium to the fuel cycle), and superconductive magnets (required for plasma confinement).
  
  Breeder blankets are a technology unique to fusion, and a personal favourite of mine, so it was very interesting to learn about the designs being tested in ITER with a guest lecture from F4E (the ITER organisation's European contribution). Tritium is the rarest and most expensive fusion fuel, so a commercial fusion power plant will need to breed tritium in-situ to sustain its fuel cycle and provide a tritium inventory. An elegant solution to this challenge lies in lithium, which emits tritium upon capture of a high energy neutron: exactly the kind of neutron emitted by the main fusion reaction. Thus, a breeder blanket sits snuggly around the vacuum vessel performing two functions: absorbing high energy neutrons and turning their energy into electricity while returning the produced tritium to the power plant fuel cycle.
  
  Superconductive magnets are another fascinating technology used in only a handful of modern applications (including MRI scanners and maglev trains). They are crucial to the design of most fusion power plants, because confining a fusion plasma in a tokamak requires a strong magnetic field. The field strength of an electromagnet grows in line with the current applied, which in a conductor leads to resistive heating as electrons collide with atomic nuclei in the material. Superconductors, however, quite literally have zero resistance, allowing for strong magnetic fields to be produced without melting the magnet in the process.
  
  
• Thursday discussed the materials for fusion devices, including the tungsten divertors. Fusion materials require special properties, capable of withstanding exposure to high heat flux and neutron irradiation for extended periods of time. Neutrons become embedded in these materials, causing microscopic impurities in the lattice which act to embrittle them. At the same time, the high temperatures involved act to soften the materials. Understanding the complex interplay between these phenomena is crucial to engineering a fusion power plant from materials capable of operation throughout its lifetime.
  
  We also discussed the safety, socioeconomics, and waste considerations of fusion with guest lectures from F4E and ENEA. I was glad to see the inclusion of this topic, as the positive socioeconomic impact of fusion is what drew so many of us into the field. The potential to decarbonise the energy supply, while avoiding the waste and safety issues of fossil fuels and nuclear fission is attractive, but it doesn’t come for free; the only way to realise that goal is to integrate safety and waste considerations directly into the design processes in a transparent way, and I’m proud to see that that is exactly how it’s being done.
  
  
• Friday closed with remote handling and maintenance, something my robotics colleagues in RACE are very experienced with, all topped off with guest lectures from the Max Planck Institute on the ASDEX Upgrade and Wendelstein 7-X stellerator facilities. It was great to hear how much progress had been achieved in stellarator technology, especially since it's not something that gets researched much at UKAEA. It was another reminder of how fusion is a collaborative worldwide effort with many organisations and countries involved in bringing the future closer, and a great topic for the final day of KIT.

Of course, we couldn’t visit Karlsruhe without sampling some of their world-famous beer. Luckily, we were honoured to be provided an excellent evening meal at the Badisch Brauhaus (“Badisch Brewery”) which was enjoyed by all.

Evening Meal at the Badisch Brauhaus ~ Credit: Luke Humphrey

On behalf of the graduate scheme, I’d like to thank the organisers for getting this event running again after the pandemic. It was a fantastic opportunity to learn from experts, communicate with others working in fusion, and to enjoy a week in Germany.

The famous Schlossgarten of Karlsruhe ~ Credit: James Hodson

Finally, if anybody reading this would like the attend, the next Summer School will take place at KIT in Karlsruhe, Germany from September 11 to 15, 2023. I invite you to keep an eye on this page for details: https://summerschool.fusion.kit.edu/index.php.

You can also check out our own Plasma Physics Summer School here at UKAEA in Oxfordshire, UK at: https://culhamsummerschool.org.uk/.

Article by: Luke Humphrey

KIT Summer School Factfile

From our experience at the KIT Summer School (see the full blog post here) we compiled a list of interesting facts about FUSION that we learnt, and also facts about GERMANY.

 Fusion Factfile 

1. The TF coils in ITER will store over 40GJ of magnetic energy! That’s 15 times the kinetic energy we store in our massive flywheels at JET. 

2. I was surprised to learn that the Lorentz force generated by the maximum current planned for one of ITER’s TF coils would cause them to collapse if they were self-supported. 

3. The assembly tolerances for the ITER vessel and magnets are phenomenally tight. This will be an incredible feat of engineering when they achieve it.

4. Stellarators look freakin’ awesome 

5. The ITER toroidal field coils will contain 150,000km of superconducting strands – enough to stretch over 3 times around the circumference of the earth.   

6. Super conductivity is really clever! But making superconducting magnets seems painfully difficult. High temperature super conducting materials are going to be really important for future fusion devices. 

7. KIT have the largest tritium lab in Europe and are the only lab capable of conducting tritium research for ITER. ITER will weigh 27,000 tonnes (3 times Eifel Tower).
 

    8. Cryopumps don’t actually “pump” anything! They work by condensing all the gas molecules onto a very cold surface, which periodically has to be regenerated by heating it up  - just like your freezer! This makes long-term continuous operation a big challenge for DEMO.

9. ITER will be testing out 6 different breeder blanket concepts to see which one works best.

10. The Tore Supra tokamak has an 8-metre long ‘Articulated Inspection Arm’ which is fully integrated in the tokamak vacuum. An inspection can be done after every pulse without interrupting the vacuum! 

 

Germany/KIT Factfile

 

    1. Karlsruhe’s beautiful palace gardens are open to the public every day; for free! 

    2. If you are not used to Steins, be careful not to drink them like a pint…  

    3. There’s a free shuttle bus between KIT south and north campus, which is very convenient! 

    4. German cycle commuting is awesome! Much better infrastructure for cycling, and European style commuter cycles (rather than sport oriented cycles) are actually a lot better than I had expected – really easy for commuting with.

  

5. Mike from Mike’s Bikes: what a dude. He will rent you a bicycle for around 10 €/day. Do it. Cycling through the forest, along beautifully smooth cycle paths to and from the KIT campus is sweet. Beats the bus.  

6. Karlsruhe was dreamt up by Charles III William in 1700s during a nap – he designed the city to look like the sun radiating from the palace in the east. 

7. It’s easy to buy really good non-alcoholic wheat beer and non-alcoholic cocktails at almost all restaurants and bars. 

8. Don’t forget to ask for a receipt at the KIT canteen 

9. When you’re packing to go to the KIT summer school leave room for about 2kg of lecture notes and 2 or 3 bottles of souvenir wine. 

10. Three-course meals every night take their toll. Germany is very good at providing individual receipts. 

11. The free KIT wi-fi is also available at the Studentzentrum on the south campus (i.e. where the shuttle bus stops), and in the grounds in front of the palace in the city centre (Karlsruhe Schloss) 

12. “Europabad” is well worth a visit. 

13. Sometimes German transport isn’t on time!

KIT summer school 2014

This year 74 people new to Fusion Research went to the Karlsruhe Institute of Technology (KIT) in Germany for the yearly 2-week holiday…ahem... I mean Summer School on Fusion Technology. There were people there from all over Europe, but also people from as far away as India. There were 17 of us going from Culham, 10 graduates, 1 PhD student, and 6 experienced engineers/physicists (semi-) new to the field of Fusion. 

Image courtesy of KIT

It was a chance to learn some basics about plasma physics, the politics and future of fusion, technology used in the industry and other tokamaks across the world. It was also a chance for eating good food, drinking good beer and general partying (ahem…I mean networking). We had some very good lectures and tours at KIT, but I’m not going to bore you with details of everything, so I’ll just give you some highlights. 

Our first lecture of the school was CCFE’s very own David Ward, a pioneer for the role of fusion in future energy. He reminded us of the massive problems the world faces with respect to energy, and how little is being spent on new energy research.  Personally I was struck by how often people doing research into Fusion claim that too much is being spent on other renewables and not enough on Fusion, and vice versa- people doing research into solar or wind power often have the opinion that too much is being spent on Fusion. The reality seems to be that nowhere near enough money is being spent on any of it, and instead of attacking each other, we should be advertising this fact. Anyway enough of that because David has inspired a new blog post on this subject- coming soon.

All of this learning was pretty exhausting, so we decided to let off some steam by going to the local water park ‘Europabad’. There were some awesome slides, including one where you stand in a pod, press ‘go’, a countdown begins and then the floor disappears and you are *dropped* vertically down a slide. It was great. There is a random YouTube video here https://www.youtube.com/watch?v=0PqooMXBr1Q. 

Back to school: after some introductory plasma physics, we headed straight for the deep end, and got up to speed on the latest on plasma heating and diagnostics, breeder blanket designs, divertors and neutronics. In between lectures we had some great tours of the KIT site. In the first week we went to the Test Blanket Module (TBM) facilities and learned about the research they are doing for ITER. We also saw the HELOKA facility, which is designed for testing various components for nuclear fusion facilities including the ITER test blanket modules and divertor modules, and the High Flux Test Modules for IFMIF (International Fusion Material Irradiation Facility). Here are some of the Culham Engineers next to the big vacuum vessel they use.

We were staying in the Jugendherberge (Youth Hostel ) which was very close to the city centre (and the huge beautiful park). However, this meant that there was a 10km journey to the KIT north campus every day. There was a free bus which was great, but a few of us decided to make use of the amazing bicycle paths through the forest all the way to the campus and hired bikes for the duration of the school. Here is a selfie Jon C took while enjoying a nice pootle through the forest. Great idea until Germany decided to rain (pour) on us. We got soaked and Jon K got a puncture and had to walk 6km in the rain. A large Weissbier was required after that. 

At the weekend the KIT organisers had arranged for us to go on an excursion to a nice town called Speyer. I think they knew exactly what kind of people we were because after eating the biggest pretzels you’ve even seen, and looking at the nice cathedral with pretzel decorations (they like their pretzels), we went to the Technic Museum Speyer. They had a “large collection of aircraft, classic cars, locomotives and fire engines, some of the highlights are an original BURAN spaceshuttle, the largest space flight exhibition in Europe, a Boeing 747 Jumbo Jet, the submarine U9, a former German Navy submarine and a gigantic Ukrainian Antonov AN-22 cargo plane.”  This, plus 70 engineering enthusiasts resulted in the most excited group of geeks you can imagine. When Jon saw the moon-rock we thought he might implode, and we had to drag Greggles out of the submarine so we could go on the slide from the Jumbo jet.  If the day wasn’t good enough already, we then we sent off to taste some wine from the Rhine valley, and had a large buffet dinner. An epic day out was had by all.

The following week we were taught about tritium handling, vacuum pumping, superconducting magnets and remote handling. We learnt about various tokamaks around the world – Tore Supra (France), JT-60SA (Japan), ASDEX (Germany), Wendelstein 7-X (stellerator, Germany) and ITER.  These were interspersed with nice sunny evenings in the park (with a 1.30 Euro beer from the student bar), some slacklining and juggling and Chinese takeaway. Not forgetting Scruffys the Irish bar which specialised in live music and Jägermeister.

Another tour around KIT gave us the opportunity to see TOSKA, where they are doing tests on scaled-down versions of the ITER superconducting magnets, the cryogenic test facility (CryoMaK) and the tritium lab. We also got to have a go on the remote handling arms, and to play with liquid nitrogen using a glove box. 

On our final day we welcomed CCFE’s Nick Balshaw and Liz Surrey who spoke to us about JET and DEMO respectively - two fantastic talks to finish the school with (unbiased of course).  We went away feeling enthused and happy and at least 5 pounds heavier.

I asked attendees to give me two facts that they took away from our experience in Germany, one about fusion and one about Germany. If you’re thinking of attending KIT next year these will be useful! Link here.