The edges cleaned up well, and I made a small jig for glueing the spacers to the first bakelite electrode. Once that's cured I'll move on to the second electrode, after which more cursed steps are in order, like filling the thing with linseed oil!
Professional bulk resistivity measurement! The material is not ideal at 8.1*10^11 Ohm*cm, and order of magnitude less would be great, but hey, I'm not after high rates.
And it's all glued up! Now I have to wait for the tubing to connect it all up and and figure out how to do the graphite coating, ~500 kOhm per square. I can't get my stuff above 10 kOhm before there are breaks in conductivity :/
The RPC is coming along nicely! Still missing its linseed oil coating and the pickup strips, I decided to go with a 1-Dimensional readout for now to make things easier. These detectors are so simple, I can just make another one and use that in 90° to this one!
Well, all the gas connectors and stuff are ordered and a second RPC is glued up, now all I can do is wait. Once everything gets here I can oil both at once and polymerize them at the same time
Oiling went terrible (thanks leaking connectors from ebay) but now they're oiled and will be pumped with air for the next days or weeks or however long it will take. Hope the vastly inconsistent oil speed won't cause any issues, but we'll see
And here, finally, is the ADR itself. At this point I was pretty tired and forgot to take pics of the good stuff :< You can see the two stages hanging on kevlar threads, the entire assembly would be sitting inside the magnet bore in its original position. The stainless tube is the second ADR stage, consisting of ferric ammonium sulfate. This salt is slightly hygroscopic, and through years of storage it accumulated water which caused it to swell.
I think that's all for now, but I'm sure I forgot something. If you have any questions feel free to ask! I'm sure there will be more images of everything, especially the magnet, as we want to take it apart to get to the NbTi wire.
the magnet is doing its best not to come apart in one piece. They used the *good* resin, as well as way too much glass fiber reinforcement. At least too much to be any fun when taking it apart again.
I took some SEM shots of the wire, and you can kinda see how it's NbTi embedded in a copper matrix, but to be honest, I was hoping for way more contrast with the SE detector. BSE is broken, and EDX is in the works... Maybe @breakingtaps has any tipps?
Better sample preparation should do the trick. Casting two pucks of epoxy with the SC wire in all directions, one to be etched, one to be left as is after polishing. Now comes the hardest part, waaaaaaiting