Notices by gigabecquerel (gigabecquerel@chaos.social)

Is it possible to open the aliexpress front page without getting 1337 new project ideas?

On an entirely unrelated note:
Has anyone here tried this condctive filament?
There's tons of it on there, and they promise really low resistance. Some call it PLA-Replacement, some call it Nylon, I can't find anything about what it actually is, but if it holds its 1.4 Ohm*cm claim... damn.

https://de.aliexpress.com/item/1005011856720742.html

Honey, I shrunk the filament!

Oh boy, the manufacturer recommended 50 mm/s max print speed really makes you appreciate modern day printers and materials.

Phew, 5 hours something later and I'm quite happy with the results!

Far from perfect, because I had to abort it early. But plating copper onto this filament works very well, and I ran the entire 1.5 A of plating current through the plastic!

Last week a Biergarten here in munich made the news because someone found a "hotspot" with their geiger counter:
https://www.br.de/nachrichten/bayern/angebliche-radioaktive-strahlung-einsatz-im-englischen-garten-in-muenchen,VI75G4A

OF course I had to go there and check it out myself!
The entire area was slightly elevated, barely noticeable and well withing reason for a change in ground composition. That hotspot must have been a tiny rock.

In the end I got a nice ~30 km bike tour and a good breakfast out of it.

First big radiator built!
If that one doesn't rust I'll build two more.

@f4grx At 20 € for the big cylinder it would be a bit much to just have sitting around, but I'll be honest, the cube is just for that.

Have a look around in that shop, it's all a lot cheaper than expected:
https://www.glass-sphere.com/en/index.html

5 radiators are done, and three of the PMT caps are printed. They still need a graphite coat and a top plate with the connectors, but they nicely show the size of the entire detector.

Unexpected issue: Apparently the bottom seams of the cans is rusting, showing a dark brown line. Here's hoping it's just a surface thing and the cans won't rust through any time soon.

Speaking of soon, the PMTs for this should arive next week!

Motivation for this project is at an all time "meh".
The cans are rusting enough to give the water a brown tint, and DHL has managed to lose my PMTs for it.
I'm re-doing the cans with ones that have a protective coat on the inside, and while I'm at it I'm also switching to 2.5l.
I ordered the PMTs from austria via eBay, and apparently I got someone elses package. which somehow ended up with my address sticker.
DHL says it's post.at's problem, and post.at tells me to go to DHL.

Fuck off.

Yum, soup.

I ordered bigger cans thst have a coat inside. I'll also add another coat of spray paint and then test one for a week, to see if it will hold water without rusting through.

The seller was kind enough to send another set of PMTs, so we might actually be on am upwards swing here!

Speaking of inside coat, I have decided to coat the inside in fluorescent laquor as a WLS.
Here's hoping it has a fast decay, but I have not measured it.

Wheeeee

Sidequest:
Glass cherenkov counter!
I may have overdone it a bit with this order, and two glowy friends also found their way into the package.

Wrapped in plastic

Sidequest: Complete ✅

It counts!
Fun experiment: Integrating what I assume to be single electron pulses gives me 33 pVs (into 50 ohm) or 650 fC. That's 4*10^6 unit charges, and for a spec gain of 3*10^6 on this PMT I'll call that close enough 😁

Using that value as a reference I can trigger on 30-ish Photoelectrons, giving me just under one trigger per second, just what you'd expect for muon flux through a detector this size!

And, of course, I'm getting some beautiful coincidences with the muon detector :)

@f4grx Those are regular paint cans, you can get them in every hardware store

I have been nerdsniped into building cherenkov counters for cosmics. The first three raidators are done, with two more to follow. They're just distilled water with a bit of fluorescent dye, because the PMMA window blocks strongly below 400-ish nm, so I'm trying to shift that part of the spectrum into VIS.

The two flashlights are 365 and 405 mn, demonstrating that only one results in a lot of VIS output, while the other is mostly blocked.