this post was submitted on 02 Nov 2023
177 points (98.9% liked)

Asklemmy

43946 readers
570 users here now

A loosely moderated place to ask open-ended questions

Search asklemmy πŸ”

If your post meets the following criteria, it's welcome here!

  1. Open-ended question
  2. Not offensive: at this point, we do not have the bandwidth to moderate overtly political discussions. Assume best intent and be excellent to each other.
  3. Not regarding using or support for Lemmy: context, see the list of support communities and tools for finding communities below
  4. Not ad nauseam inducing: please make sure it is a question that would be new to most members
  5. An actual topic of discussion

Looking for support?

Looking for a community?

~Icon~ ~by~ ~@Double_[email protected]~

founded 5 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
[–] [email protected] 41 points 1 year ago (2 children)
[–] silas 19 points 1 year ago
[–] [email protected] 8 points 1 year ago (2 children)

Nice -- you wouldn't happen to have any ideas on how to differentiate positron annihilation, from the continuous distribution of Ξ²βˆ’ energies caused by the more common decay mode, using only a PIN photodiode? I'm a bit stumped on this point and suspect it's not possible. I probably need to do gamma spectroscopy but would really rather not.

[–] [email protected] 4 points 1 year ago

Reverse the polarity of the bussard collectors and push the antimatter from the warp core into space. Collect this with a big test tube.

[–] [email protected] 3 points 1 year ago (1 children)

the trickery is to detect two gammas emitted simultaneously in exactly opposite directions

[–] [email protected] 3 points 1 year ago (1 children)

Yeah, that's going to be too hard. I only have two SiPMs (besides the current detector) and they are expensive. I figured I could maybe rely on the gamma from the annihilation energy being a quite different energy than the gammas from the more common electron-capture.

However you raise a good point that that would not be a very good demonstration of positron annihilation at all -- just evidence that it's not the other 2 decay modes (and it would take ages to collect that evidence besides). Ah well. Got plenty of other science I can do instead.

Probably I'll tackle something easier like checking for radon decay products in petrol.

[–] [email protected] 2 points 1 year ago (1 children)

that's how real commercial PET scanners work, so it's not too hard to make it work

[–] [email protected] 4 points 1 year ago

'Not too hard' is a bit of a spectrum I guess ;)

I mean yeah, in principle I could cram textbooks for a few months (I know EE and SE pretty well, but particle physics only very basic stuff), order parts made at the factories I know, and would probably succeed eventually. More realistically I'd have to hire a university prof as a consultant to save time.

What I am really unable to construct is a powerpoint presentation that justifies that expense and labor to management :P

Especially in a cost-driven market (my company is in Vietnam). Often the parts for these things are export-controlled too, that can be a real pain. I've gotten irate phone calls from the US DoD before over fairly innocent parts orders -- it's not super fun. I recall it was some generic diode, I must have stumbled on something with a military application I wasn't aware of. The compliance paperwork ended up costing me hundreds of dollars for 20$ in parts, too.

Anyway, if it was something I could just tack on to ongoing research projects, I could maybe get away with it as a marketing expense. It's for a STEM program. It's hard enough to convince management to take the risk on a nuclear & quantum module as-is! I can mostly get away with it because the locally-manufactured beta-detectors cost like 20$ per classroom.