6 Apr
2012
6 Apr
'12
4:04 p.m.
On Fri, 6 Apr 2012, Tony Duell wrote:
I think X-rays prodeuced with an accellerating
votlkage of 12kV to 15kV
are pretty much harmless...
Over here, the line ouptu valve (horizontal output tube), booster diode
(damper) and EHT rectifier (HV rectifer?) were often in a shield, but it
was a fairly light aluminium thing. Not going to be much protection
against X-rays. I think it was more an RF shield. It was rarely a
complete enclosure anyway.
Low energy X-rays absorb very easily. According to this:
http://henke.lbl.gov/optical_constants/atten2.html
you get 1/e attenuation for 14keV X-rays for every 400 microns of
aluminium, so it doesn't take much thickness to block them entirely.
At 25keV, you need about 2.2mm aluminium, but just 100 microns of iron for
1/e attenuation.
Alexey