[HN Gopher] CO2 laser enables long-range detection of radioactiv...
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       CO2 laser enables long-range detection of radioactive material
        
       Author : EA-3167
       Score  : 38 points
       Date   : 2025-03-21 21:41 UTC (3 days ago)
        
 (HTM) web link (physicsworld.com)
 (TXT) w3m dump (physicsworld.com)
        
       | PaulHoule wrote:
       | Makes me think of
       | https://en.wikipedia.org/wiki/Ionization_chamber which can work
       | at atmospheric pressure.
        
         | MisterTea wrote:
         | The multiplier effect invokes this:
         | https://en.wikipedia.org/wiki/Scintillation_counter
        
       | ziknard wrote:
       | Easily defeated by a large Tupperware container.
        
         | CamperBob2 wrote:
         | Very interesting effect, but yes, the real imagination comes in
         | when you have to explain how it might be used in practice.
        
           | Animats wrote:
           | Yes. 10 meter range, must have line of sight to the
           | radioactive material. When does that come up in practice?
        
             | Terr_ wrote:
             | Could it be useful in a nuclear-reactor context?
             | 
             | If the sensor is further away, it might be easier to
             | maintain, have a longer lifetime, and could even be re-
             | aimed to cover a wider area or identify where a specific
             | hotspot is.
             | 
             | Depending on how l
        
           | SiempreViernes wrote:
           | I think this is for the, now depressingly remote, situation
           | where you want to verify that something at the end of a
           | adversaries missile is really not a nuclear weapon because a
           | treaty says that would be one too many.
           | 
           | In that context a way to measure radioactivity by non-
           | invasive means is great!
           | 
           | Shame that a nuclear weapons treaty with limits and an
           | inspections regime is more sci-fi than the technology needed
           | to remotely verify the presence of a warhead.
        
             | ricksunny wrote:
             | >Shame that a nuclear weapons treaty with limits and an
             | inspections regime is more sci-fi than the technology
             | needed to remotely verify the presence of a warhead
             | 
             | Well articulated. The early history of atomic weapons
             | regulation hinges on precisely the difficulty of
             | independent verification means (as well as judgements on
             | whether or not an adversary would let you into their
             | country without whack-a-mole style circumvention). I still
             | think that verification technology is the main stumbling
             | block. Neutrino detection is what I (and I bet ongoing
             | orograms in the DoE) focus on for this purpose. We need to
             | be able to figure out how to sense neutrinos order of
             | magnitude more effectively than we can currently. Right now
             | it feels like panning for gold silt with sieves as sparse
             | as chicken-wire.
        
         | gh02t wrote:
         | Kinda, but at least for gamma radiation (which is the main one
         | you care about finding at standoff), the same radiation that
         | induces the ionization these lasers detect will go right
         | through tupperware and ionize the air outside, which will be
         | just as detectable as long as it's strong enough to still
         | produce enough ionization outside the tupperware.
         | 
         | Shielding the source with something that actually absorbs
         | gammas like steel or lead is something that would actually
         | render this laser detection null, but that's also true of
         | conventional direct radiation detection methods too. No real
         | way to find something that's not emitting something.
         | 
         | Regardless, this method is probably more intended for scenarios
         | like nuclear accidents where you don't really have to worry
         | about someone hiding the source from you. Though I still don't
         | see that many applications for it even within that niche (and I
         | did my PhD on finding radiation sources and currently work full
         | time on it, so I'm fairly knowledgeable on the subject...), as
         | there are a lot of limitations to this.
        
       | ggm wrote:
       | TSA will be buying.
        
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