Airport Security Scanners - Millimeter-Wave Vs Low Energy X-Rays - Big Difference!
Please be aware that there is a big-difference between the two types of personnel scanners (as opposed to baggage scanners) aka nudeoscopes used at airports. One uses "millimeter wave scattering" technique while the other uses "x-ray back-scattering"! The x-ray transceiver is from American Science & Engineering and the active millimeter transceiver is from from a L3 Communications, model name ProVision
How big is the difference? Well, typically x-rays pass thru flesh & cartilage (killing cells & tissues on the way to the photographic plate). Millimeter waves have enough energy to penetrate layers of clothing & scatter enough photons back from the surface of skin. Even least powerful x-ray beam is about 10 million times smaller than a millimeter wave* & can pass thru the body.
TSA makes a distinction on their site, but interestingly talks about safety of just the millimeter wave scattering machine & does not say a thing about the safety of x-ray back-scattering machine! American Science & Engineering claims that the radiation dosage is 36,000 times less than wat we receive annually from natural cosmic rays.
No one is disclosing official data for me to roughly calculate anything! This letter mentions that the machine uses 28keV. But if it were true, per my calc the wavelength is 4.4 nanometers which is definitely not a low-energy beam! The response does not give us any real numbers on the machines either.
The face is naked anyway, so why do they want to scan even the face?
So bottom line, if you are okay** with the almost naked b/w images seen by TSA folks, don’t worry about the ProVision millimeter-wave technology machines! But definitely opt for a pat-down instead of those x-ray back-scattering machines, until we have the numbers for someone to okay the use of “low energy beam” x-rays for personnel scanning.
*10nano meters = 10 x 10-9 meters = 10 x 10-6 x 10-3meters = 10 micro millimeters
**super confident about your body & your religion permits pervasive photography ;o)
How big is the difference? Well, typically x-rays pass thru flesh & cartilage (killing cells & tissues on the way to the photographic plate). Millimeter waves have enough energy to penetrate layers of clothing & scatter enough photons back from the surface of skin. Even least powerful x-ray beam is about 10 million times smaller than a millimeter wave* & can pass thru the body.
TSA makes a distinction on their site, but interestingly talks about safety of just the millimeter wave scattering machine & does not say a thing about the safety of x-ray back-scattering machine! American Science & Engineering claims that the radiation dosage is 36,000 times less than wat we receive annually from natural cosmic rays.
No one is disclosing official data for me to roughly calculate anything! This letter mentions that the machine uses 28keV. But if it were true, per my calc the wavelength is 4.4 nanometers which is definitely not a low-energy beam! The response does not give us any real numbers on the machines either.
The face is naked anyway, so why do they want to scan even the face?
So bottom line, if you are okay** with the almost naked b/w images seen by TSA folks, don’t worry about the ProVision millimeter-wave technology machines! But definitely opt for a pat-down instead of those x-ray back-scattering machines, until we have the numbers for someone to okay the use of “low energy beam” x-rays for personnel scanning.
*10nano meters = 10 x 10-9 meters = 10 x 10-6 x 10-3meters = 10 micro millimeters
**super confident about your body & your religion permits pervasive photography ;o)