[HN Gopher] Citizen scientists observe gamma ray glow associated...
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Citizen scientists observe gamma ray glow associated with lightning
flash
Author : PaulHoule
Score : 77 points
Date : 2023-07-16 15:54 UTC (7 hours ago)
(HTM) web link (agupubs.onlinelibrary.wiley.com)
(TXT) w3m dump (agupubs.onlinelibrary.wiley.com)
| tomrod wrote:
| This is a fantastic article.
|
| > The Cogamo detector is a small (23 cm x 28 cm x 10 cm) and
| lightweight (3 kg) radiation monitor, using a CsI (Tl)
| scintillator (5 cm x 5 cm x 15 cm) coupled with a Silicon
| Photomultipliers (SiPMs) MPPC (Multi-Pixel Photon Counter) as a
| photo sensor (Figure 1b). The energy range for gamma-ray
| spectroscopy is the ~0.2-10 MeV band. The detector acquires the
| energy deposit and arrival time of each radiation event and
| records them into a microSD card. The time tagging is performed
| using GPS signals. In addition, 20-s bin count rates in six
| energy bands for 0.2-0.5, 0.5-1, 1-2, 2-3, 3-8, and >8 MeV, GPS
| status, ambient temperature, humidity, and optical luminosity are
| recorded on the microSD card and are also sent to the web server
| for a quick-look purpose. An observation is started simply by
| connecting a GPS cable and a power cable and then turning on the
| power switch. Energy calibration of the Cogamo detector was
| performed for each file of one-hour data when analyzing, using
| environmental background radiation lines of 40K (1.46 MeV) and
| 208Tl (2.61 MeV).
|
| Is the state of IOT such that these kinds of sensors and
| measurements are widespread and reasonably priced? Where can I
| learn more?
| joshvm wrote:
| More or less. What do you consider reasonably priced? The
| sensors aren't particularly special. PMTs are used widely in
| science for photon counting, but maybe the ones they chose have
| some specific characteristics.
|
| Most of this system is very fast readout circuitry - fast ADC.
| You need an FPGA to get the data off at 12-bit 50MSPs.
|
| The crystal is a few hundred bucks: http://www.epic-
| scintillator.com/CsI-crystal-scintillator/Cs... (not quite the
| right dimensions) but for other experiments you could go
| smaller.
|
| The expensive stuff is probably the PMTs from Hamamatsu and the
| power supply from Matsusada. They will certainly give you a
| quote, but their sensors can be pretty pricey. Probably
| hundreds each for the PMTs and that again for the power supply.
| Hamamatsu are the experts and they have a good monopoly. Edmund
| sell some pre-packaged tubes for example:
| https://www.edmundoptics.com/f/hamamatsu-photomultiplier-tub...
| (but Edmund are always $$$)
|
| Everything else is glue really, with a custom PCB for the data
| capture. Though some of the components like the FPGA and the
| ADC are $50 each (and there are two ADCs). I don't know if they
| would release this open source, but I suspect not (which is a
| shame).
|
| As is typical with science, the authors emphasise how they
| designed this to be a low cost system, but never actually say
| how much it cost. I would hazard a guess that you could do this
| for under $5k BOM cost (ignoring design and labour) if you
| planned it well. Let's say $500-1k for a crystal with some
| provenance, $2-3k for optics and $1k for the circuitry and
| housing. Might be well off on the crystal if you have to buy it
| from somewhere reputable though. You could probably MacGuyver
| something for a lot less if you could get away with bits from
| eBay.
|
| See: https://academist-cf.com/projects/16?lang=en
| CamperBob2 wrote:
| Assuming the CsI:Tl crystal doesn't need to be quite that
| big, then it is possible to do gamma spectroscopy with much
| cheaper hardware:
|
| https://www.ebay.com/itm/125966951416
|
| http://www.ke5fx.com/r7400u.htm
|
| http://www.sciencemadness.org/talk/viewthread.php?tid=159366
|
| With a bit of creative scrounging you could put something
| together for less than US $100, I imagine. The budget would
| probably be driven by the question of whether the surplus
| pager scintillators are sensitive enough to observe the
| effect.
| jacquesm wrote:
| As soon as you're into surplus for sourcing parts you've
| essentially done an end-run around your target pricing: it
| will work, for a very limited run and then you find the
| 'true cost'.
|
| What would probably be better is to see what design
| limitation crop up if you try doing it for say $1000
| without any surplus parts.
| CamperBob2 wrote:
| Yep, a lot depends on the size of the 'production run.'
| The seller had over 3000 of those scintillators
| originally, not clear how many they have left.
|
| Digitization is another question -- they used a fast
| FPGA-based digitizer but it's not clear why it was
| necessary given the duration of the events being
| recorded. If it really is needed, then driving the cost
| down on the digitizer will be as big a challenge as the
| scintillator itself.
| jacquesm wrote:
| That's a neat little stash then! Wonder where they got
| them. I used to frequent government surplus auctions and
| the weirdest stuff would turn up. 10 tons of spare parts
| for a Magirus-Deutz vehicle that hasn't seen active
| service since the 50's, five containers full of used army
| boots (but without the containers), a veritable mountain
| of laptops sans harddrive and with various unknown
| defects and so on. I would occasionally buy something and
| usually got something out of it (profit, some useful
| tool) but on the whole the quantities of the lots were
| such that only people with both lots of space and lots of
| money at the same time would be serious bidders on those
| lots.
| gardenfelder wrote:
| Might be a bit more information here:
|
| https://academic.oup.com/ptep/article/2020/10/103H01/5885093
|
| Edit: see also
|
| https://arxiv.org/abs/2007.13618
| jasonhansel wrote:
| This isn't really relevant, but I dislike the term "citizen
| scientists."
|
| It seems to imply that those working within formal institutions
| are normally the only ones capable of "doing science," and that
| it is somehow abnormal to consider mere civilians as even minor
| participants in the scientific process.
|
| Of course, there is no _precise_ line between science and just
| gaining everyday knowledge through observation or
| experimentation, something all of us do, to a greater or lesser
| extent, all the time. So it makes little sense to see
| "scientists" and "citizens" as two sharply distinct groups.
| mcpackieh wrote:
| I had heard that thunderstorms generate gamma rays before, but I
| assumed those were produced by the lightning. Apparently I
| assumed wrong and it might actually be the other way around. Very
| interesting.
| PaulHoule wrote:
| Antimatter too!
|
| https://science.nasa.gov/science-news/science-at-nasa/2011/1...
|
| I was involved in atmospheric physics about 30 years ago and
| back then there were two competing theories for thunderstorm
| electrification, neither of which made complete sense. My
| understanding is that it is still like that today.
| pyinstallwoes wrote:
| Have you any hypothetical thoughts on why that confusion
| might exist? Also have you pondered on the nature of
| thunderstorms and Schumann resonances?
| EMCymatics wrote:
| This is something that I hope continues to get decent
| funding.
| jacquesm wrote:
| The incredible release of all kinds of radiation (including
| gamma rays) around major earthquakes is very interesting from
| this perspective too.
|
| Which makes me wonder: would this hold true for other planets
| that have thunderstorms over them as well and could we detect
| this here? Or is attenuation due to distance such that the
| signal would be lost in the noise?
| wyldfire wrote:
| > five radiation monitors detected a 2-km-long size gamma-ray
| glow, which suddenly terminated with a lightning flash
|
| Wow, does that mean you could predict where lightning might
| strike? I suppose it would only work with ~seconds notice?
| blincoln wrote:
| From the figures in the paper, it looks like some of the
| detectors started picking up an increase a minute or more
| before the lightning flash. However, 2-3 of the detectors also
| picked up increased gamma counts that then died out before the
| flash. It would be interesting to see the data on a longer time
| scale, to see how often there's an increased count with a flash
| at some later point, or no flash at all.
| 01100011 wrote:
| Gamma ray spectroscopy has all sorts of fun applications. I
| wanted to build one to characterize radiation in food and other
| objects. Geiger counters are typically not sensitive enough to
| detect trace quantities of contaminants as they do not produce
| significant radiation above normal background. You are also
| unable to measure energies and identify radionuclides. It takes a
| fair amount of shielding if you want to make accurate
| measurements though since there is so much background noise in
| the typical environment.
|
| I'm curious if you can also detect matter which has been
| activated from the high energy gamma rays. Photon activation
| begins around 6.2 MeV and really gets going above 10MeV. The
| gamma rays have sufficient energy to activate the nuclei of
| stable isotopes, causing them to become unstable, potentially
| decay and produce secondary radiation.
|
| I was really hoping to put together a setup, but some jerk picked
| the lock on my storage unit and took all of my radioactive
| samples and measurement tools. FYI, the typical 'high security'
| circular locks are easily picked now and with most storage
| facilities allowing anyone with a storage unit unchecked access
| to your lock, it's very easy for the thief to go unnoticed.
| PaulHoule wrote:
| The gamma ray spec is a _spectrometer_ and not just a detector
| that gives the exact energy of a radioactive decay so it can
| tell you what exact isotopes are present.
| gnufx wrote:
| The energy resolution of scintillation counters like those is
| rubbish, and spectroscopic results obtained with them can be
| misleading as a result. We initially used NaI just to
| surround high resolution Ge detectors to reject Compton
| scattering events which deposit only part of the gamma energy
| in the Ge. However, the lumps of hyper-pure Ge you need to do
| high resolution spectroscopy are expensive and need to be
| cooled with liquid nitrogen.
| deepfriedchokes wrote:
| Do you have any lock recommendations? My storage unit was
| broken into a year ago and I replaced the locks with those
| circular ones you're referring to!
| scarytom wrote:
| ABUS with the plus core are pretty good according to the lock
| picking lawyer. https://www.youtube.com/watch?v=cm8p4CmeOfk
| isoos wrote:
| Do you have any further notes on the design and required
| accessories?
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