Graeme,
Clutching at straws a bit here but is there a string theory or some such that guarantees somewhere Mr. MWS actually gets to ‘do the nasty’?
String theory - you might google ‘shibari’. But not at work.
In this case Mr MWS is just watching.
VB
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Thought I’d pop this up, my mate’s just visited here.
Just had an incredible tour of the Diamond Light Source synchrotron at Harwell. Even if you’re not into the physics, the engineering is incredible. The floor of the 600m ring has remained level to within 1mm in the last 15 years by being built on floating concrete, the temperature remains within 0.1C and the vacuum inside the tube is maintained to 10^-8 bars, pretty close to space vacuum. And they’ve used it all to image protein and virus molecules, understand why batteries of electric cars deteriorate over a few years, how Solar panel cell efficiency can be increased, and how plastic recycling bacteria work - it’s all pretty mind blowing.
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This is the place right next to where @Valvebloke lives. I think I asked him what it did on here at one point.
I have had tour of this place five years ago when I was interviewed to be a H&S bod for them. Very impressive indeed. Back in the 1980’s I was a draughtsman working on a compact (still big room sized) synchrotron, many of the people I worked with then transferred to the Diamond Light project.
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Yes. It was built, somewhat controversially, on the same site I worked at. Because it’s a photon source my department (the Central Laser Facility - also providers of photon sources) were already doing stuff which was closest to what it would be doing. So before the Diamond team had any buildings they set up offices in our buildings. The first Director occasionally popped into my office to borrow laser books.
Towards the end of the Phase 1 build we got tours - often in very small groups, so you could ask very particular questions. I remember once the Technical Director being asked what, so far, had been the biggest cock-up. He gave us an answer and then said that the wasted money had only been £2-3M, so of the order of 1% of the budget, and he thought that wasn’t too bad.
Although the concrete is very stable, 1mm is not insignificant in terms of things like the synchronisation of timing signals around the machine. So there’s an active control system that detects and corrects timing jitter and drift. If you look at the working of this system you can see it correcting for the concrete being stretched and squashed twice a day by the gravitational field of the moon - the same thing that causes tides.
VB
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What cables does it use?
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Me and @stu would probably be interested in a tour if there are free pens and tote bags happening?
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Laser pens ftw 
Stu doesn’t need any more of them
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Actually not a trivial question. I don’t recall now, but probably for bog-standard signal-level stuff they’ll be using Andrews Heliax FSJ1-50A. Nice enough cable. If you pay Andrews enough they will ‘phase stabilise’ it for you which involves some proprietary heat treatment process which gives it a zero temperature coefficient of phase at one particular temperature. But it’ll still only be cable.
For anything that matters they’ll send the signals around as laser pulses on optical fibre. These can be retro-reflected from the far end and compared with the original timing reference and any effect of (optical) cable phase noise can then be corrected by sending a (slow) correction signal to the remote location on ‘ordinary’ cable. It’s a very, very sophisticated business.
VB
Laser pens. Not laser penis.
VB
I’m already limbering up for the annual Bristol pillage
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Chord wont know what hit em.
stronzetto on diversion tactics again?
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Now if you could only buy a few drums of that, put clunky reassuringly heavy terminations on 1m interconnect lengths, advertise them as being used in secret defence contracts in systems that correct timing jitter and drift at’ laser levels of accuracy’ you might be able to return a decent mark up!
I wonder if anyone has thought of that before? 
My dad worked for a firm who made aircraft wiring looms. They went bust and sold off all their stock really cheap… unfortunately he told me after the sale… 
It’s good stuff. Very noise immune. Not all that expensive. But I don’t think anyone makes an RCA or XLR connector for it. And when they call it ‘super-flexible’ they are using that in the context of solid-outer cable. It’s ‘so flexible’ that you can bend it using just your hands.
VB
I was taking the piss!
You either get the reference and know the history or you don’t.
But as the dealer in question is still very much in business I will leave it there 
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Nope. I am reminded by the first post though that when people say ‘the thing about electronics engineers is that they don’t understand everything there is to know about cables’ then the right response is to smile. If an hour or two looking round a state-of-the-art particle accelerator doesn’t convince them that there are people who understand a great deal more than cables then they’re really beyond help 
.
VB
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