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Chris Jones[_3_] Chris Jones[_3_] is offline
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Default Marantz Model 19 Scope

On 05/05/2019 01:00, Fox's Mercantile wrote:
On 5/4/19 9:29 AM, Chris Jones wrote:
So, to maximise the benefit and minimise the harm, medical x-ray
machines use relatively high voltages and are also required to include
a filter equivalent to a certain thickness of aluminium in the beam
path between the tube and the patient.


While working at ScanRay (airport baggage equipment) it was a
"you learn something new, everyday" when I learned they used
aluminum for lenses.
Unless you work with this stuff, it just doesn't occur to you.


I'd never heard of any refractive optics for x-rays. I did read
something about mirrors for x-ray telescopes, but they were supposedly
very inefficient and only worked at glancing? grazing? angles. And of
course diffraction gratings can be made from crystals, and sometimes
they bend a crystal to focus a certain wavelength on a spot. Apart from
that I thought it was all basically just casting shadows.