Re: terahertz for measuring mass?

On Jul 9, 11:41 pm, "EnigmaP...@xxxxxxxxx" <EnigmaP...@xxxxxxxxx>
wrote:
Everyone,

I'm interested in t-rays or terahertz radiation - I understand this
technology is being used for security imaging and such.

In principle, it's just a radar. But the penetration properties of
radar
(i.e. of EM radiation) change with frequency. With a frequency in the
THz, the wavelength is below a millimeter. This "millimeter wave"
radiation will penetrate clothing, but not skin. So some bright
person thought of security as an application: look for concealed
objects under clothing.

What I'm
interested in are the spectroscopy properties and wondering if tHz
could be used to measure the mass of an object of known properties or
to even count such known objects (metallic, non metallic, or organic
materials) within a defined area?

As much as any radar could. I know that attenuation in air tends to go
up with frequency, so millimeter waves may not go very far. I've
heard of 96 GHz as a frequency of interest, because there's a
window of transparency at that frequency. Not sure how good the
propagation is at 1 THz.

- Randy

.

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