@jmorris @stdlogicvector Never seen one before, and no, it does not need ³He, just regular LHe
Notices by gigabecquerel (gigabecquerel@chaos.social), page 4
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gigabecquerel (gigabecquerel@chaos.social)'s status on Wednesday, 22-Nov-2023 19:12:23 JST gigabecquerel
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gigabecquerel (gigabecquerel@chaos.social)'s status on Wednesday, 22-Nov-2023 05:34:45 JST gigabecquerel
Science is cool!
And this thing here even more so.
I got to take apart an Adiabatic Demagnetisation Refrigerator Cryostat with the wonderful @stdlogicvector , a small cryostat that was used to cool a transition edge sensor to ~40 mK.
It works by applying a magnetic field to some funny materials, and when removing that field the material cools down below its original temperature, which is 4.2 kelvin in this case.
The main cooling is done by a huge amount of LN2 and LHe. -
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gigabecquerel (gigabecquerel@chaos.social)'s status on Wednesday, 22-Nov-2023 05:34:42 JST gigabecquerel
There was some kind of experiment left over in there, I'm guessing it's a remnant of the CRESST experiment, a crystal, a collimator and a photodiode, so maybe scintillation yield measurements?
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gigabecquerel (gigabecquerel@chaos.social)'s status on Wednesday, 22-Nov-2023 05:34:40 JST gigabecquerel
The entire cryostat consists of an LN2 tank which provides heat shielding and a LHe tank as a "warm" stage. The bottom of the LHe tank forms the base plate and thermal anchor where everything is bolted onto. Inside the tank is the ADR Magnet which we'll get to in a minute. Inside the magnet bore, held by kevlar strings, is the ADR itself. Everything is wrapped in foil for thermal insulation.
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gigabecquerel (gigabecquerel@chaos.social)'s status on Wednesday, 22-Nov-2023 05:34:37 JST gigabecquerel
This is the thermal switch. It links the ADR thermally to the 4k stage when everything is being cooled down and while the magnet is being ramped up. Then the switch opens, separating the ADR themally and letting it cool down below 4k when the magnet is ramped down again.
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gigabecquerel (gigabecquerel@chaos.social)'s status on Wednesday, 22-Nov-2023 05:34:34 JST gigabecquerel
The cryostat coinsists of many layers, it's built like an onion.
This serves to reduce thermal load vial radiation, with the 77k stage sinking the biggest load, after all, LN2 is a lot cheaper than LHe. -
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gigabecquerel (gigabecquerel@chaos.social)'s status on Wednesday, 22-Nov-2023 05:34:31 JST gigabecquerel
This is the magnet itself. As stated earlier it's entirely submerged in LHe to cool it down, afaik it's NbTi used at up to 7 T. It has to be in LHe because its critical temperature is around 10 k.
Interestingly enough it consists of two separate windings with entirely different construction! Maybe one was added later for higher fields, but I don't know -
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gigabecquerel (gigabecquerel@chaos.social)'s status on Wednesday, 22-Nov-2023 03:49:08 JST gigabecquerel
@TechConnectify It's pouring outside, and this is what you made me get!
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gigabecquerel (gigabecquerel@chaos.social)'s status on Monday, 20-Nov-2023 20:40:20 JST gigabecquerel
Stadtbegrünung any% speedrun
Wird sicher richtig angenehm im sommer, jetzt, wo nichtmehr überall schwarzer Asphalt ist.
Wie wärs noch ein paar plastikbaumimmitate da hin zu stellen?
Sicher kann man da noch irgendwas einbauen um mehr geld zu verdienen.Schön immer wieder zu sehen was für ein drecksloch diese stadt doch ist.
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gigabecquerel (gigabecquerel@chaos.social)'s status on Monday, 13-Nov-2023 09:31:26 JST gigabecquerel
Who called it "novel corona virus" instead of "newmonia"
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gigabecquerel (gigabecquerel@chaos.social)'s status on Saturday, 04-Nov-2023 14:33:40 JST gigabecquerel
The driver is coming along as well!
I decided to go with a microcontroller to control it all, just for the learning effect.
And ever since I had a control theory lecture I wanted to implement a controller in software!
Now onto the PCB design... -
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gigabecquerel (gigabecquerel@chaos.social)'s status on Saturday, 04-Nov-2023 14:33:38 JST gigabecquerel
Also, I did end up adding grading rings, printed from conductive PLA.
No need to risk anything withou them, and hot damn it just looks great like that! -
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gigabecquerel (gigabecquerel@chaos.social)'s status on Saturday, 04-Nov-2023 14:33:02 JST gigabecquerel
Perfect!
Well, in diameter, not in the distance to the heatsink.
But that's easy enough to fix. As soon as I get my PETG I can print it! -
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gigabecquerel (gigabecquerel@chaos.social)'s status on Saturday, 04-Nov-2023 14:33:00 JST gigabecquerel
Now comes the worst part:
Waiting. -
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gigabecquerel (gigabecquerel@chaos.social)'s status on Saturday, 04-Nov-2023 14:32:59 JST gigabecquerel
And moooore waiting
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gigabecquerel (gigabecquerel@chaos.social)'s status on Thursday, 02-Nov-2023 04:09:21 JST gigabecquerel
Why is my youtube feed full of videos like this?
Random bs, <50 views, most probably not even made for public consumption. -
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gigabecquerel (gigabecquerel@chaos.social)'s status on Monday, 30-Oct-2023 06:15:17 JST gigabecquerel
Damn, I love this printer!
It just works, just what I was looking for in a tool. -
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gigabecquerel (gigabecquerel@chaos.social)'s status on Saturday, 28-Oct-2023 19:37:33 JST gigabecquerel
@kaia Always!
But the scrapyard has moitors, too -
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gigabecquerel (gigabecquerel@chaos.social)'s status on Saturday, 28-Oct-2023 19:00:49 JST gigabecquerel
@Laberpferd Garkein Typenschild gefunden, also keine ahnung.
Aber am ölauslass waren tropfen, denke die sind schon leer -
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gigabecquerel (gigabecquerel@chaos.social)'s status on Saturday, 28-Oct-2023 19:00:22 JST gigabecquerel
Woooot