Let's Hover

Hello,

Well, the beamtime may be over, but it just means the train must progress.

A sad non-levitating train, even if steam is coming from its chimney.

Wednesday morning, first thing, I glued up the engine, stinking out the lab with the glue. Had to leave it in the fume cupboard to dry. However, it was ready for an afternoon of testing which... didn't go so well. Turns out the glue wasn't as much as a problem as the bottom warping upon meeting the cold. It was throwing superconductors everywhere.

I did tape it up (seeing as sellotape seems to be the only reliable thing) and managed to get an engine which didn't leak. And didn't levitate. I now blame its weight. I re-glued it to be left over the weekend.

Thursday and Friday I was on holiday because, well, I was fairly tired by this point. 10 day week and all.

Monday morning, though, I was  back and ready to try again. After a quick meeting with a insertion device scientist (he deals in many magnets), we decided to try stronger magnets and different arrangements. The samarium cobalt magnets were replaced first by neodymium iron boron magnets and then by one of the largest permanent magnets I'd seen. It was about the size of  half a brick.

However, this turned out to be too powerful and couldn't even hover a single superconductor disk (a feat I've managed before. This is due to superconductors having a critical magnetic field. Like the critical temperature, once above this, the superconductor can no longer superconductor; it becomes an expensive black disk. The neodymium magnets did provide lift on the disk... but the magnetic field peaked so dramatically, it was hard to balance the disk at a height of about 10 cm.

So we were back with the samarium cobalt magnets... and a non-levitating train.

So, with a public viewing looming, Tuesday morning I was off to the shops. Yes, that's right, I got to spend 2 hours going around toy shops for trains, cars and skateboards (because hoverboards would be awesome too). And look what I manged Tuesday afternoon:

OH YES!!!

Type soon!

PS. All magnets used are those leftover from the building of the beamline. They help direct the beam and maintain its energy.

PPS. I will hopefully be adding to the picture collection here and on Twitter (@AdamasRos) 

Culham, Trains and Nightime Beamtime.

Hello,

I do not apologise for the length of this post as it matches this weekend. Working at Diamond is never monotonous.

A model of the inside of JET, the torus tokamak. The plasma is held within the kidney
shaped areas by magnets... and superconductors play their role!

On Thursday morning, I came back to stuffing quartz wool and YBCO salts into open capillaries. By the end, I had manged to fill and mount one, which I felt was quite an achievement. The afternoon, however, I was off to Culham Centre for Fusion Energy. There, they have the world's largest tokamak. With it, they are able to create a plasma out of heavier isotopes of hydrogen (a hydrogen atom with extra neutrons). With it, they are hoping to help find a clean and abundant power source for the future, along with the developing remote handling systems like MASCOT (who looks so like Wall-e). If you want to know more, visit http://www.ccfe.ac.uk/

Friday, however, was back to the trains. Some more empty engine shells had arrived, so I spent my morning patching up wholes and trying them with the superconductors. No joy... yet... The afternoon, I finished creating a spare gas cell capillary because...

Saturday was BEAMTIME! That morning, we attached and aligned the gas cell and hooked it up to the oxygen flow for the gas to flow through. The experiment involved heating the capillary up using a hot air blower and watching for changes.

Leaving it there for several hours, however, didn't actually seem to do much, so we began loading normal capillary (hard as my salts had clumped a little) and set up a low pressure gas experiment, pumping in oxygen. We watched it heat and began writing scripts for overnight dwelling... until the capillary disappeared. As it was getting late at this point, we left it to get some sleep so we were prepared for...

The beamroom at night... not actually that different from day, except
for the peacefulness.

More beamtime Sunday. This turned into a long day. Since the YBCO had to be loaded into really thin capillaries (it absorbs the radiation well), we put this on the back burner so to speak and moved onto another compound. This one, we were able fill into larger capillaries and pump He through in the hope that it could capture some of it. Slowly increasing the pressure, we hoped to see a change in the diffraction pattern.

My little engine, awaiting the judgement by nitrogen.

Whilst analysing these results, we repeated the experiment, but using Oxygen, to try to show whether the He had changed the crystal more than the beam did. To further our evidence, we followed this up with a different compound which shouldn't react with the He at all. With so many experiments and so much capillary heating, we eventually left the beamline at 1.30AM! Diamond at night is so quiet!

Monday morning, (and I do mean 9am-no liein) we came down to our results... only to find the computer script had failed to take the scans! Sad times, but I was able to manually perform the experiment and follow it up with a repetition of the He experiments in the hope of clearer results. I'm now able to mount the samples, lockup the beam room and set scans going.

The afternoon, though, was back to the train and my conclusion was superglue can't cope with liquid nitrogen... oh well. Needless to say, there were many leaks. And 3 broken magnets. Oops.

So to Tuesday, the order of the day was glues. I created samplers of glues and left them to dry over lunch so later in the afternoon I could try them in the liquid nitrogen. They seemed to work so tomorrow, my train is about to get coated!

Type soon!

  PS. It wasn't all work. I've learnt 2 new board games and eaten many biscuits 
whilst waiting for things to heat and pattern emerge.

Foiling the Attraction

Hello,

The magnet 'being put to bed' in aluminum
foil. This weakens the field, but prevents chips
of magnet being lost.

There are some days in science when you get a lot of highly scientific work done. There are others where you get on the bus at the end of the day and say to your friends:

"I spent all day searching the internet for the plastic body of a railway engine."

That was Wednesday's task. It was a little trying, if just because to be held up by such a trivial-seeming task is a little irksome, but 100% necessary - after all, what's a superconducting train track without a good train. The limitations were that the body had to be LIGHT, NON-MAGNETIC and the RIGHT SIZE. You'd be amazed how many toy shops I rang around.

By Thursday morning, though, this was sorted and I began to fill capillaries with the salts used in the synthesis, in preparation for beamtime on Monday; it's a trial time for next weekend. 

However, I was interrupted as I was given safety training for the beamline rooms. You remember the quote I gave from my supervisor at the beginning? The rooms which receive beam, known as hutches, have to be searched for people (and bodies) before the beam is switched off. Pretty serious stuff, given the consequences if anyone is missed. To avoid cutting corners, there are searching buttons which have to be pressed around the beamline rooms.

The magnets can then be positioned on a piece of track. Care has to be taken
though - they snap together with a surprising amount of force.

Friday began me watching a gas cell experiment being prepared; this is similar to what I was hoping to do next week, so the experience was a good indication of the work that goes into it. I then went back to my capillaries so there would be something to do the work on.

That all done, my afternoon was spent re-wrapping the magnets in foil; previously, they wouldn't lie flat, unbalancing the superconductors. I also checked the magnetic field around the track, since at the centre, the magnets can reach up to 160 mT (5 mT is considered strong). Luckily, the strength is very short range, so I was able to use my phone to take picture without risk of scrambling it.

Type soon!

PS. Halfway through my placement now! And things starting the pull together.

Playing with Fi-- Liquid Nitrogen

Hello,

It would seem the temperature isn't about to settle down at any point in the next few days, as I've melted, frozen and melted again over the past week. And people mock when I say I don't know what to wear.

Wednesday was a day of preparation as there is the possibility of more of my samples undergoing x-ray diffraction over the weekend due to a low demand rapid access day (a day for quick sample testing and catch-up for those users who experiments have been blighted by beam problems). This did mean I was stuck in the lab most the day, preparing these samples, as I'm currently up to 7 samples of superconductor. And below you can see the kit I used to make the 8th.

The pestle and mortar used to mixed the salts. Before heating, they must be well grounded together to become a uniform clay-like colour. The white dishes are disposable weighboats used for the Copper Oxide and to the left you can see a toothbrush left over from capillary loading, since the same equipment is used.

Because of this, Thursday started the same and would have appeared to continue the same. This was particularly uncomfortable as the furnaces had not dipped below 200 degrees for over 36 hours by this point. It would seem I was responsible for the heatwave.

However, in the afternoon, my supervisor and the work experience student decided that it would be fun to play... I mean, seriously experiment with liquid nitrogen. So I left the baking lab to clearing ice off petri-dishes.

At first, we just tried to hover a magnet over a pre-made disk, which worked well of course. In some ways, it was inevitable that such high beginnings could not be carried through to my own experimental samples, since I had tried a variety of ways to make them, most which would never work.

Just as I was beginning to worry, though, there was a glimmer of hope as a small black slab I'd made supported a magnet! It wasn't as high as the professionally made piece, but I still call victory.

A view into the furnace, which glows red hot once above approximately 700 degrees. Any closer than that and I'd burn my fingers.

Friday was a day off as I was persuaded to go to London. ... Thankfully, my friend had a pool.

Monday was spent testing my samples with a new piece of kit... the SQUID (Superconducting QUantum Interference Device). This allows me to measure the magnetic moment whilst cooling and heating the samples from as low as 10K (-263 degrees) and varying the magnetic field. This provides a good idea as to whether I have superconducting material, giving a pretty graph to prove it. And do I? Well, early days, but the one superconductor I didn't try on Thursday (no. 8 was cooling still at that time) did look slightly promising... fingers crossed.

Type soon!