开云体育

Geo,

What beam current where you using? Based on the dead time (DT) of 25% the current could probably be backed off a bit. Note that most of this DT is dealing with the higher energy counts that you’re not interested in due to the 50 kV tube voltage. The optimal approach would be to set the tube HV to just above the energy range of interest. In this case Cu, which has a binding energy of 8.8 keV. So a 10 or 15 kV HV would eliminate all the high energy counting and just optimize the energy range of interest. You would then set a current to keep the dead time in the 10 – 15% range and you could play with the peaking time to optimize the resolution. For low count rates use a long peaking time which will get better resolution and use a shorter time for higher count rates but with lower resolution.

When I run an unknown it’ll be 50kV, then a run at 40, then a run at 20 which gets the HV near a general binding energy range which gives a much better resolution and count time and lowers the limit of detection.

Dud

?

?

This is a sample cut from a piece of sheet metal, the assay printed on it was Cu-70% Ni-30%.


,mca and pics of the scan attached. Later will post pics of setup. Like the pictures indicate - SDD sensor, XRF via W tube, 50kVp @ 10 uA.