Four or five years ago, when I was quite new to the fusion community, someone told me that each of the big tokamaks was able to do something that none of the others could do. I was surprised to find that there was no centralized database summarising the specifications and achievements of the machines that have been built. There were many lists of a few tens of machines, and thousands of technical articles giving details of their discoveries, but no complete overview. Hence my collection started. I decided to catalogue tokamaks, but not stellarators and pinches unless they have run in tokamak configuration at some time. Working from the biggest tokamaks, the list grew quite quickly.
About two years ago I was encouraged by some of my friends at Culham to set up a web site to share the collection with the rest of the fusion community. Initially I was reluctant because of the difficulty of obtaining permission to publish the information, even though it is all in the public domain already. However, after some discussions, the web site was agreed by the Culham management, on the condition that it was made clear that it was not part of my formal duties, but simply a hobby. Hence
All-the-World's Tokamaks was created and run rather anonymously. People then started to volunteer more information, send news and photographs and claim discoveries and achievements. A few of the larger fusion labs around the world were kind enough to link to the web site and now it can be found very easily via Google. It has had over 10,000 visits, and the daily hit rate is an interesting barometer of public interest in the subject.
Last year it was suggested that it would be fun to create a poster, and I am pleased to say that the idea has received universal support from all the large machines featured, and in particular, the PR team at JET who provided a graphic designer. Thank you to everyone who has provided a photograph, corrected my text and helped to produce the poster of "Conventional Tokamaks from around the World". Perhaps it is controversial to have excluded spherical tokamaks, but it would be interesting to consider a second poster dedicated to them. Someone has recently suggested creating a new game, "Tokamak Top Trumps" like the popular children's card game. I think he was joking, but... at least I would have a chance of winning this version of the game!
And finally, I have to admit that I still don't know how many tokamaks there have been. I know that at least 210 have been built in the last 50 years, the smallest being the size of a compact disk! I would be pleased to hear from anyone who can contribute more information.