Backscatter X-Rays Coming to Airports

TSMABob writes "Wired News reports that a recent, but expensive, technology of backscatter may grace airport security in the future. Nice Bombs Ya Got There is an article that explains how this technology is far superior to the metal detectors of today, pointing out that 'Richard Reid, convicted of trying to blow up a trans-Atlantic jetliner with explosives in his shoes, walked through metal detectors at Orly Airport in Paris several times before boarding the plane.' Read More about backscatter x-rays and their ability to pick up non-metallic objects."

Comments

Any good technical descriptions?

[sleepingsquirrel]

Since I'd never heard of X-Ray backscatter before I'd thought I'd do a google search, but I couldn't find much in the way of technical details of the how and why xray backscatter works. There didn't seem to be much for academic/research papers available. Is this a relatively new thing? The article mentions that the xrays are bounced off of you, but I wonder what dosage you would be exposed to. Are they using an xray source, or is it background radiation? These were my findings so far...

More pictures.
More detail as to how the machine works.

Re:Any good technical descriptions?

[rusty0101]

From the perspective of a Niel Stephenson reader, think of this as a x-ray frequency varient of milameter radar.

What this does is send extreamly low dose x-ray radiation in the direction of the subject being scanned. Some percentage fo the x-rays (being extreamly high energy, even if it is low dose) will pass through the subject. Some percentage will be absorbed by the subject. Some other percentage will be reflected by the subject.

A percentage of the reflected x-rays will be captured by an x-ray sensitive varient of a CCD and an image will be created by a computer.

The demonstrations so far indicate that x-rays for the most part are passing right through clothing, and being reflected by the skin of the subject. Harder objects (such as plastic and metals) are either going to absorbe a higher percentage than usuall, or reflect a higher percentage than the subject, and will present visable difference in the image collected.

Some training will be required, however most weapons are going to be fairly visable to this equipment.

I have not heard however if glass is something that this equipment will recognize. We could be back to seeing metal and ceramic knives, but not glass.

Much of this is my own opinion, so take what you will from it. Critizism is welcome as well.

-Rusty

Re:Any good technical descriptions?

[SpeedRacer]

X-ray backscattering has been studied on an experimental level pretty extensively for quite a while. Perform a Google search on bremsstrahlung. Bremsstrahlung means "braking radiation." Electron bremsstrahlung is the most common. When an electron is deflected by the electron cloud of an atom, that acceleration produces an X-ray at an angle that is oblique to the original direction of the electron's path.

My Bachelor's degree is in Physics, and my junior/senior research back in 1987-1989 was on bremsstrahlung. You can find more on the subject at:

http://scienceworld.wolfram.com/physics/Bremsstrah lung.html

Re:Another version of the same story.

[msheppard]

heres a picture of the woman in the picture without the xrays.

M@

Sample Pictures

[Alric]

Here's a link to a company, AS-E, who manufactures some of the most respected Backscatter equipment.

For a sample of some slightly frightening pictures check out these images:

http://www.as-e.com/technology/image_1.html
If somebody has time, it might be good to provide a mirror for these images.

Re:Another version of the same story.

[Quixote]

If you click on the image in the Wired story, you can see a better picture of the lady.

Backscatter shouldnt be a health problem.

[Omni Magnus]

Since the Xrays bounce OFF of the skin and do not go through it, it shouldn't be a hazard. Also, you are only bombarded for a second or two. Even for frequent flyers, a couple of seconds a week should not hurt anybody.

Re:Health risks for frequent flyers?

[NickDngr]

The MSNBC version of this story says "The radiation dosage is about the same as sunshine."

Re:Health risks for frequent flyers?

[Country_hacker]

RTFA man. "The radiation dosage is about the same as sunshine, Hallowell said." So you'd have to be a real frequent flyer to have as much chance of getting skin cancer as, say, a sun worshiper/surfer dude.

'Course since most geeks haven't been exposed to the sun in years..... ;-)

3 microREMs

[sleepingsquirrel]

According to the FAQfor one of these machines...

Q: How much radiant energy is a person exposed to?

A: Each full body scan of the SECURE 1000 produces approximately 3 microREMs of emission. This is equivalent to the exposure every person receives each five minutes from naturally occurring background environmental radioactivity.

Q: Is background radiation exposure really a good comparison?
A: Yes, because SECURE 1000 scanning and background radiation both expose a large portion of the body to a very low level of x-rays. The only difference is that background radiation has slightly higher x-ray energy resulting in deeper penetration.

Q: What about exposure levels for individuals who are frequent flyers or for employees in companies or high security facilities who have to be screened each day?
A: Under current international guidelines (such as the ANSI 43.17 Standard) up to 5000 scans per year can be conducted safely.

Q: Will SECURE 1000 detect objects in the body?
A: No, the x-rays penetrate only about 1/10 (0.1) inch of the skin. Any object that would be deeper than that level would not be detected. Under current regulations generally body cavity inspections must be performed by high dose medical x-ray systems in the presence of a medical professional or body cavity searches must be performed manually by trained enforcement personnel.

It's not new, but it's big and expensive

[Animats]

Check out this image gallery. That's a small version of that image; at full scale, you can count the change in the guy's pocket. California prisons have been using these units for several years.

The AS&E BodySearch unit is huge. It's about 12 feet high, and costs about $1 million. The technology needs a redesign for production. Another generation or two, and it might be widely used. The X-ray exposure is surprisingly low, although well above background, of course.

In a few years, we might see them in nightclubs.

Re:Interesting

[Thng]

At the moment, very difficult. One of the problems with the device is that they're already fairly large. Cnn had an article yesterday.

Null said the biggest problem with the backscatter machines may be their size. One version, the BodySearch system made by Billerica, Massachusetts-based American Science & Engineering is about 4-feet by 7-feet by 10-feet -- awfully big for an airport lobby, Null said.

Re:Another version of the same story.

[dissy]

> ...of a seemingly shaven lady...

Just to point it out, these xrays bounce off the skin only.
So, she could possibly be as retro as the 70's downstairs, but you still couldnt tell.

Look at the top of her head, she does have a full head of hair there atleast, so you can see what I mean.

Re:This scares the hell out of me.

[spotteddog]

This technology will never be able to see inside your house (unless you live in a tent). The wood/brick/wallboard would require a much higher energy to penetrate. They would have to be penetrated twice, the incident x-rays and the reflected x-rays. If the x-rays had low enough energy to reflect off your stuff, they would not have sufficent energy to pass back through the wall. Now they could put a detector on the opposite side of your house, blast it with high energy x-rays, and image anything - but I think you would notice that (large truck parked in front of your house with big cables conneced to power grid, large screen set up behind your house, etc).