Handheld detector for all types of ionizing radiation improves radiation safety
13 comments
·April 20, 2025frozencooler
KMnO4
TSA employees can use them, they are just not permitted to (for some reason).
toomuchtodo
Federal liability around future health concerns.
Edit: https://www.cdc.gov/niosh/hhe/reports/pdfs/2003-0206-3067.pd...
PaulHoule
Those big backscatter X-ray machines [1] have a powerful X-Ray tube. Not that I'd be worried if I flew once a month, but if I was a member of the aircrew and going through more than once a day I'd be concerned. Think about when you get a medical or dental X-Ray and the operator puts on a lead apron and goes around a corner -- they don't get anywhere near the dose that you get, but they are around the machine all the time time. TSA staff did none of that.
Those machines were killed off because it was easy to demonstrate walking right through them and not getting detected if you wear a gun in a holster the way you would normally wear a gun if you weren't trying to hide it. The trouble is it depends on the gun being between you and the scanner because the gun appears black against the white radiation bouncing back from all the hydrogen atoms in you. With no background the gun is black-on-black and invisible. When people realized you could put a cop in front of the scanner and demo that the scanner couldn't see his gun it got around quickly that the scanner was worthless. [2]
[1] https://en.wikipedia.org/wiki/Backscatter_X-ray
[2] Ok, instead of getting scanned twice on your front and back they could scan you four times but this is getting ridiculous.
krisoft
I'm not sure what is the context of your link. Is it supposed to show that TSA employees are not permitted to wear dosimeters? Because if so, I can't find that in there.
simonebrunozzi
Why aren't they?
goda90
It claims it detects all ionizing radiation but doesn't list high energy UV among the things detected.
momoschili
UV-C radiation is so rare in our lives and even in specific work environments that unless you have a very special need for it, you don't need to detect it. As far as I know, it's mostly just germicidal lamps and arc lamps that generate enough UV-C to be of any real concern, and in that case the operator knows about it.
blueflow
Like UV light, alpha radiation is easily shielded by most kinds of material. Even after skimming the linked publication, it does not seem clear to me how the alpha radiation (and UV) would reach the devices sensor.
Probably something behind "... and measure alpha and beta radiation from contaminated surfaces".
thyristan
"Shielding" is a relatively crude term. Alpha radiation is "shielded" by a sheet of paper in the sense that the attenuation is so high, and the attenuation length is so short when compared to the thickness of that paper, that less than 1/1000th of the original particles arrive on the other side of the paper.
However, this means that there are still very few but not zero alpha particles arriving on the other side. Plus, the energy of those alpha particles doesn't just go away, it will be either transformed into highly energetic photons (in the hard UV to gamma range) or it will ionize the attenuating medium, leading to photons from line emissions (infrared to visible to UV) or other ionization-related effects (e.g. an ionisation current in semiconductor diodes). All those things can be detected, and you can calibrate your detector for the relative sizes of those effects you are seeing when compared to the incident alpha rays.
theglocksaint
Shielding is not a crude term, it is indeed used as technical language in the world of radiation safety. You are also using the term attenuation incorrectly, as sibling comment points out.
mppm
This is somewhat inaccurate from a physical perspective. What you say would be applicable to the attenuation of gamma rays, which is governed by low-probability interactions and is therefore exponential. But alpha particles, being charged an heavy, lose energy continuously through electron interactions and have a relatively fixed range in matter, beyond which the incidence is practically zero.
jjtheblunt
maybe it infers alpha radiation from detection of decay chain particles / photons at energies indicative of alpha presence.
>The device can be used by industrial and medical radiation users, regulatory authorities, the nuclear energy industry, first responders and military users
It cannot be used by TSA employees. They are not allowed to even wear dosimeters.