this post was submitted on 02 Nov 2023
177 points (98.9% liked)
Asklemmy
43945 readers
634 users here now
A loosely moderated place to ask open-ended questions
If your post meets the following criteria, it's welcome here!
- Open-ended question
- 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.
- Not regarding using or support for Lemmy: context, see the list of support communities and tools for finding communities below
- Not ad nauseam inducing: please make sure it is a question that would be new to most members
- An actual topic of discussion
Looking for support?
Looking for a community?
- Lemmyverse: community search
- sub.rehab: maps old subreddits to fediverse options, marks official as such
- !lemmy411@lemmy.ca: a community for finding communities
~Icon~ ~by~ ~@Double_A@discuss.tchncs.de~
founded 5 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
Nice -- you wouldn't happen to have any ideas on how to differentiate positron annihilation, from the continuous distribution of β− 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.
Reverse the polarity of the bussard collectors and push the antimatter from the warp core into space. Collect this with a big test tube.
the trickery is to detect two gammas emitted simultaneously in exactly opposite directions
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.
that's how real commercial PET scanners work, so it's not too hard to make it work
'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.