Beamtime!

Hello

I start by saying I hope to get my camera into a lab soon. But the past few days, I've been rather busy as I went...

From hot to cold these past few days. It started Friday, when I has not one but two furnaces heating away as I worked on another batch of capillaries. Having made:

The tablets go from a clay colour to black when heated

•  pelleted and pelleted-halfway-through-heating (phth as I will now call it... 'cos I'm lazy) superconductor in air
•  a unpelleted and phth superconductor with a low flow of oxygen (and the furnace did switch off and I did jump for joy)

  the final combination was pelleted in oxygen and unpelleted in air. Since the latter didn't required oxygen, I used the box furnaces instead.

This wouldn't have been so bad if I hadn't been making more capillaries from samples of the last four pellets in the room next door. Phew! And for the mathematician who likes to have a scoreboard:

Capillary 5  Ros 10

I also made a capillary of the salts mixed but not heated because...

Monday I had beamtime!

What's more, I froze! A student on a brief bit of work experience has a small project and for it there were three of us grinding up samples to compared usin7g the beam. And my sample needed to be kept cool, so I did it in the fridge. 

I say three of us, since there was also another intern getting a taste of lab life; he's designing software to help with the data collected on our beamline and came to have a look at what we do. Goes to show, there are a lot of people working outside the beamline rooms to get it running smoothly.

The afternoon, we actually placed  14 samples (including my superconductor samples and mixed salts) into the beam in order to get results. The beam hit the sample and we took a diffraction pattern using the detectors that surround the capillaries. The equipment at Diamond is really highly sensitive and so it gave rather wiggly lines, but by the end, I could make out distinct peaks showing a change from the mixed salt to the cooked superconductors.

Overnight, we left the detectors taking periodic scans of the mixed salts being heated and cooled in situ so we look at the phase change. That's right: I'm doing an experiment using a synchrotron.

The beamline has a traffic light warning system. Red means 'No Entry'. And yes, I hope to get a proper photo.

Coming in Tuesday morning, I'd found my capillary had... well... exploded overnight. On the bright side though, most of the measurements had been made by that point and were waiting to be analysed. 

However, the day was rather busy. There were new users setting up, a meeting with a H&S man, who told us about the 5S process of organisation, a beamline safety meeting (extremely important), tidying up in the lab ready for the monthly Health and Safety checks (like I said, extremely important) and capillaries to load of the superconductors made on Friday. 

The data rather feel by the side for the day, but we did establish that the salts would need to be mixed in a quartz capillary to survive the heating. 

Last job of the day was to put on a new superconductor to cook. I feel I'm becoming quite  chef.

And the final capillary count (inc. the colder attempts):

Capillary 9  Ros 13

 Still winning.

Type soon!

Picture from Clipart.

Out of Mortar, Into the Furnace

Hello,


The past few days have been fairly warm across my area of the UK. And, as a typical British person, I must complain about its timing. Just when I have to share a lab with a furnace.

On Tuesday, it was decided that it would be a good opportunity for me to get to know the tube furnace I'll be baking the superconductor in. As previous readers know, this experienced a minor set-back last week when my previous attempt at YBCO sort of... well... micro-exploded in there. Thus, when I came to having a go at practical trials after reading the instruction booklet, I found that the inside was covered in black, partially burnt nitrate mix. Eww...

Luckily, my beamline manager gave me a hand at clearing it out, using towels and solvents. Being nitrates, we also got to use dust masks... and I realised I've never had to use one before. Yes, I tried to put it on sideways first attempt.

The solvents needed time to dry though, so I came back to it in the afternoon and set it on a quick heating cycle. Just up to 250 degrees Celsius at 5 degrees a minutes and then hold for half an hour. This seems trivial, especially when you think some ovens can do that, but simple practice allowed me to monitor the cooldown rate too.

While this was heating, I was also able to prepare miniature glass vials of Yttrium Oxide, ready for synthesis. We're still waiting on the copper oxide.

The outside of Diamond. The large canister is filled with Liquid Nitrogen... though I don't think I'll be using all of that!

This had arrived by Wednesday, so that morning I was able to start grinding up all the salts together to create my first batch of superconductor using the Oxides. And it didn't turn to paste. Instead, it was a dusty, clay-coloured substance, which I was able to press into a mini pellets of superconductor and stick in the oven.

I was also able to make a second boat of mixture, but this one without pressing. Why? Because we're still experimenting with the process of making the superconductor; we're trying several techniques to see which works best. Science can sometimes be trial and error.

While it was cooking, I prepared two boats of salts to cook tomorrow. I also tried to make a capillary of the nitrate mix... and I tried again... well, maybe another day. *sigh* Before the end of the day, I took out the second boat of unpressed salts, reground, pelleted and replaced it. Just to see what happens.

To the left, you can see the bridge that allows access to Diamond. It is slightly like entering a spaceship, I won't lie.

I came in on Thursday to find the furnace hadn't cut out after ten hours like I thought I'd set it. I blame it on fiddling about with the settings after it had started. Never mind, I let the superconductor cool and was able to load the new boats in and set them off, this time under a flow of oxygen. And yes, I got to make pretty warning signs. I then mixed up two new boats for Friday's firing. 

Once cool, I ground up a little of the second superconductor to place in a capillary... Second attempt lucky. In between this, I was able to sneak into the beamline to watch a new experiment being set up. And I hope to learn more.

My final task was to withdraw one of the boats to regrind and pelleted before replacing. Every angle covered. Now I must hope the furnace switches off over night. Not least, because it makes the lab pretty warm. Well, I am setting it to 930 degrees C.

Type soon.