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.

Into the Beam Room

Hello,

 
Starting again on Monday and getting into the week with Beamtime. After gaining a diffraction pattern of the last YBCO I made, the morning was spent attaching the capillary furnace, known as the STOIE, in the beamline; you can see pictures of it to the left. This allows the capillary to be heated more accurately and uniformly than the alternative, the hot air blower, meaning we can get nice diffraction patterns of the YBCO salts heating up.

In principle. After a few coding problems, the furnace started glowing at lower temperatures than expected and the whole experiment switched off early as a safety measure. Turned out, the thermocouple inside was rather damaged, so had to be replaced. Meanwhile, I loaded a capillary of platinum (approx. £10 worth before anyone gets too excited) to use as an alignment help later.

Once working, we started aligning a new salt capillary. This one though provided us with a few difficulties and it was while swapping it for another that I accidentally broke a capillary. Whilst becoming a rarer occurrence, I'm pleased to say, this time it did get stuck in the furnace. In the end, we switch stages (the type of stand in front of the beam) and did 'Rapid Access'; these are samples sent in just for a quick scan.

The STOIE surrounded by the giant detectors.

With the upcoming beamtime over the weekend, on Tuesday I started researching a Plan B for the time then. As a scientist, you must always be prepared for not getting what you expected, because half the time, you're trying something which may not work. For this, I was researching reactions and compounds using the Oxides I'm using for the synthesis (Barium Carbonate, Yttrium Oxide and Copper (II) Oxide).

However, there was a break as I went to a skills session of presentations. It is always useful to be able to talk other people through the work you are doing to encourage interest and further research in the subject.

The gas cell capillary enables gases to flow across the sample in situ.

Wednesday got very cold first thing, as I tried to get a train to levitate with the superconductors attached. Trying several ways and butchering it with pliers, I did get slight lift off the rear of the engine briefly, but the liquid nitrogen poured off almost as fast as it was added.

In the afternoon, I practiced preparing a gas cell capillary. This involves wrapping the sample up in quartz wool and sliding it into an open-ended tube held in a stand as shown. Whilst I didn't break many blank capillaries while practicing loading them into the stand, it turns out the putting cotton-wool-like material is harder than it looks (and it looks hard). However, I didn't break anything while doing it, so tomorrow morning, I should be able to go back and try again.

Type soon.

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!