Thursday 22 May 2014

Graduates on tour


What goes on tour stays on tour. Or not because I’m going to tell you all about ours...

Us graduates are pretty curious folk and like to know what’s going on around CCFE. It’s a pretty big site with lots of departments, different experiments and new technology. There are also lots of tenant companies doing cool science and engineering. So we like to stick our noses in. We took some photos just for you. 

Here is a picture of some of us in front of the JET tokamak, which is currently the largest nuclear fusion reactor in the world.
 

You can’t see JET very well because of the large amount of measuring and testing devices surrounding it (called diagnostics). This tour was also during shutdown so there is a lot of work going on (hence the scaffolding). Dragoslav Ciric (head of the Tokamak and Neutral Beam operations department) took us for a tour around the torus hall, and explained which diagnostics were which. He also took us into the basement below JET which was nice to see (pretty noisy as well). The orange bits in the picture at the top are the limbs of the iron transformer core. The white box to the left of us is the neutron yield monitor. 

Our very own Stevie Wray organised for us to see the JET flywheels- 800 tonnes of Iron, 9m in diameter, spinning 225 times per minute. Fun Fact: if one was set on a horizontal axis (like a wheel) it would get from JET to Newbury on its own momentum (that’s 25 miles!). They are set going before a JET pulse, then they are slowed down to release 400MW of power each destined for the magnetic coils of JET.  Clearly they were non-operational when we went, so we actually got to go inside one of them and have a look, it was really huge, and oily. Here is a picture of Anthony Shaw and James Simpson standing right next to one of the flywheels which is to the left of them. The red things above them are the stator windings which generate the AC current. 


The Active Gas Handling Facility was our next stop- Anthony Hollingsworth showed us round their lab. It’s a hugely important part of CCFE which supplies, handles and recycles tritium and deuterium for JET.  These gases are used as the fuel for fusion reactions. Tritium is radioactive so needs to be handled carefully. They are able to separate tritium and deuterium with their isotope separation systems and the exhaust de-tritiation facility is vital to ensure all tritium from JET is stored safely. In this picture Anthony is pointing out the analytical lab to a few interested grads!

Watch this space for information on our tours of the CCFE Materials Research Facility, the JET roof lab and one of our most exciting tenants, Reaction Engines. Many of us graduates are supernumerary – meaning we spend 6 months each on our placements, then move on to the next. The tours can help us understand more about what goes on at CCFE and give us a good idea of what placements we would like to do next. If you think we’d enjoy a tour of your facility drop us a line! Tokamak.tales@gmail.com

Author: Ailsa Sparkes

Thursday 15 May 2014

The Adventures of Safety Secretary Shepherd



Culham Centre for Fusion Energy is the home of two of the world’s leading tokamaks; the Joint European Torus and the Mega Amp Spherical Tokamak. To ensure that both machines can provide world class physics research, and continue to do so for many years, CCFE has to take its responsibilities towards the safety of the machines, its employees and the surrounding environment very seriously. Overseeing most of the safety processes on site is the Site Safety Working Party, known as the SSWP. 

As one of the secretaries for the SSWP I get a unique insight into the workings of the committee and the dedication to safety shown at Culham. The SSWP is made up of representatives from many different departments; from health physics to central engineering, as well as off-site safety experts. This gives the committee a wide range of experience and professional knowledge to draw upon when reviewing the safety practices of the various departments and facilities. Every month the SSWP meets to review safety forward action plans for the various facilities, renew a holders Authority to Operate (ATO) for a facility and comment on the safety aspects of the many modifications made to the equipment and experiments on site. To ensure the meetings are not all work and no play CCFE provides cake.

One of the most interesting duties of the SSWP, at least from the secretaries’ point of view, is touring the ATO areas as part of the ATO renewal process. These tours are an excellent opportunity to see parts of the CCFE site outside my normal working routine, and to directly see the importance of a good safety culture. One example that stands out is the tour of the Active Drain & Trade Effluent facility. This facility is on the edge of site, so far out in fact I didn’t even know it existed until the tour. Here all of the trade waste and mildly tritiated water is stored before being safely removed. While on the tour it was explained to us the care that is taken to dilute down the tritium to levels far below acceptable levels set by the government. It was great to see how importantly CCFE took its responsibility to protect the environment. And the environment seemed to agree heartily, as one of the trade effluent tanks was playing host to a family of ducks.
 
When one is asked to explain the advantages of fusion over other energy sources one of the most quoted is the small amount of radioactive waste produced as opposed to fission reactors. No radioactive by-products like caesium-137 are produced in the fusion reactions on JET and MAST, just helium and high energy neutrons. The only radioactive products are materials activated by these neutrons, for example the carbon composite tiles removed during a recent JET upgrade. As with all other safety concerns on site CCFE takes the risk these active components pose very seriously. The components are stored in containers and only once the activity has fallen below very strict safety limits can the materials be disposed of. 

Acting as SSWP secretary has given me the opportunity to experience aspects of CCFE outside my day-to-day job. These are the sorts of opportunities that are abundant at CCFE; from the graduate scheme to fusion outreach. And, did I mention there is cake?

by Alastair Shepherd

Wednesday 7 May 2014

Plasma on the Table (with video!)

CCFE’s graduates Matti Coleman, Alex Cackett, James Buchanan, Steph Hall, Andy Busse and Harry Robinson have been making a table-top plasma device with the aim to show it at Science Fairs and in schools. Here is their account of the first time they turned it on… don't forget to have a look at the video at the bottom of this post! 

On an otherwise uneventful Tuesday afternoon, a new experiment is being run at Culham Centre for Fusion Energy (CCFE). In a dark, dusty laboratory buried deep in the bowels of the K1 building, the lights are dimmed, breaths are held and the air is thick with tense anticipation.
A dial on a power supply is cautiously turned up by lead electrical engineer and bearded Renaissance man Andy Busse; 500V then 1kV, steadily onwards and upwards. At first, there is nothing, just silence and the dim flicker of dust particles moving through the solitary beam of light entering through the small obscured window near the ceiling. A single bead of sweat drops from the brow of project manager and chief mechanical engineer, Matti Coleman, and explodes upon the dirty floor. The grim spectre of failure looms heavily above the room. But then, sparks appear, small and faint at first, then brighter, and gradually a dense ball of light forms in the centre of a bell jar which, in the middle of the room, is the focus of all attention. Success! A plasma!  

Breaths are released and the tension falls away as hands are shook and pats on the back are heartily given and received in the knowledge that several months of hard work (well reasonably hard, there was tons of paperwork) were not in vain.

This experiment marks a new endeavour for CCFE. While all of the other main plasma devices on the site are based on magnetic confinement, the trapping of charged particles using complicated toroidal helical magnetic fields, and are geared towards the development of fusion energy, this new device, which will not produce any fusion at all, is geared solely towards looking really awesome. 

‘Inertial Electrostatic Confinement’ (IEC) devices, known colloquially as ‘Fusors’ and frequently fabricated by internet enthusiasts in their garages, simply use two metal grids with a large potential difference across them to create and trap a plasma. The large electric field between the two grids accelerates ions towards the centre where they collide and can, in principle, initiate fusion reactions if the potential difference is large enough and if deuterium gas is used.  

Fusors have been shown not to be capable of generating net power and so the device being built by the crack team of CCFE graduates is for the sole purpose of engaging the public in science, and helping to give them a visually stunning demonstration of how electric and magnetic fields can be used to trap charged particles.

Having successfully completed a trial run in the laboratory the team now intends to design and construct a portable demonstration stand for the Fusor so that it can be taken to fairs and schools. It will only be run with air or inert gases such as Neon or Argon, which also make colourful plasmas, and not deuterium due to the belief that irradiating children with fusion neutrons might be bad and may not lead to the development of awesome superpowers. Work continues... 

Authors: James Buchanan and Matti Coleman
Pictures and video: A classical spherical grid is being tested, along with a toroidal one; the latter aims to imitate its bigger brother, the Joint European Torus (JET), also on site.

 

Friday 2 May 2014

Playing on the RIFT

The CCFE (Culham Centre for Fusion Energy) graduate scheme includes doing a project outside of the normal placements. It allows the graduates to gain skills that otherwise wouldn’t necessarily be accessible. For example, physicists might be able to do some engineering, and engineers might be able to do some programming etc.

The RIFT (Remote Interactive Feedback Technology) project will be one of the most fun graduate projects when it is completed, as it will create a public facing interactive demonstration of the feedback technology used on the remote handling manipulator known as Mascot. Remote handling is used on JET (Joint European Torus) for in-vessel maintenance and upgrade operations because the radioactive vessel poses a risk to humans. Mascot (the Slave) is set-up to work with a controller (the Master), the operator manipulates the Master and the Slave mimics the action. When the Slave reacts against an object the force of that is mirrored back through the Master allowing the operator to feel the object as if they were touching it. This is hugely beneficial for JET because it means the torus can be accessed without exposing any workers to radiation. Any replacements, repairs or adjustments that are required should be possible. One of the training steps for Mascot operators is to use this technology to play Jenga remotely, relying on the high level of touch needed for the game.

The goal of the project is to promote the current remote handling capabilities at CCFE as well as the future remote handling centre of excellence known as RACE which is being developed on site. This goal will be achieved by creating an interactive demonstration of this feedback technology.

To demonstrate the Mascot technology we will be using two relatively low cost haptic devices called Novint Falcons normally used as PC gaming controllers. Haptic devices allow a level of force feedback that creates the feeling of actually interacting with something which you see on a screen. To a certain extent touch screen phones use haptic feedback when a button is pressed and the phone vibrates. The Falcons will be set-up in the same configuration as the Mascot and its controller, in a Master-Slave configuration which is standard for haptic feedback loops.

We will then think of some fun games to play with this set up, which the public will be able to try when they visit CCFE. We might get to play Jenga like the real Mascot or at least move some objects around remotely.

There is a dream team of graduates working on this endeavour from different backgrounds. We have Mechanical and Electrical engineers and general day-dreamers just like the original Italian teams that would have created the first Mascot back in the 60s. The team have interests in programming, electronics, haptic feedback, and remote handling.

The project is still in its early stages but with a little luck and a lot of push this project could be up and running soon. Then we can all play remote Jenga, just like the Mascot operators do in training to develop their coordination in a low risk situation.

Watch this space for future updates...

Project team:
·         Project Manager/Mechanical Engineer – Keelan Keogh
·         Control Engineer – Jibin James
·         Mechanical Engineer – Jason Hess
·         Electrical Engineer – Steven Wray
·         Electrical Engineer – Zain Ul-Abidin

Author: Keelan Keogh

Thursday 1 May 2014

Welcome to Tokamak Tales

Welcome to Tokamak Tales - the blog about nuclear fusion. We are a bunch of engineers and physicists on the Graduate Scheme at Culham Centre for Fusion Energy (CCFE) near Abingdon in Oxfordshire. Tokamaks are doughnut-shaped devices that are used for magnetic confinement fusion. There are two tokamaks based here, one being JET (Joint European Torus) - currently the largest working tokamak in the world - shown in the second picture from the left in the blog's banner at the top of this page. The other one, MAST (Mega Amp Spherical Tokamak - see the middle picture in the banner), is a spherical tokamak doing ground-breaking research into plasma-physics.
 
We are going to show you what we get up to day-to-day and what progress we are making with fusion energy; we hope to both amuse and enlighten you. Feel free to let us know what you think in our comments section or ask us questions. If you are a fellow fusion researcher, let us know if you would like to contribute to the blog (please note that any contribution will be assessed for quality and suitability).