Fluorescence was recorded directly from protein samples as a function of X-ray energy
using a photo-multiplier tube (Thorn EMI 9826B) couple to a cylinder of plastic
scintillator material (NE technology Pilot U). Both PMT and scintillator are contained in
a light tight aluminium housing and the front window is light insulated by 
aluminium
foil.
The detector is mounted so that it accepts a solid angle of fluorescent radiation centred
at 
to the incident beam in the horizontal plane. In this way the amount of scattered
radiation entering the detector is minimised since the majority of the incident radiation is
horizontally polarised as established by the use of the photo-emission device.