Equipment used-
Amptek CdTe low energy X-Ray sensor with Amptek PX4 power supply/ MCA unit.
The sensor/preamplifier head
plus sampleare inside a Pb-Cd-Cu graded shield with a total of 1" thickness.
First a10 minute precision calibration scan was made by using Am-241 to? excite XRF characteristic X-Rays from a pure Nb metal sample. (Scan No.1)
Immediately following calibration as Gamma Scan was taken of a radioactive rock we have been calling "Columbite" in these early tests. (Scan No.2)
Next we overlaid
both together at once in Amptek's ADMCA program, with the green outline of the calibration peak going slightly taller. Filled-in red peaks are the gamma scan. Peaks around 16.5 are abundant from the higher daughters of Uranium decay, ranging from Ac @15.71 keV to Pa @ 16.70 keV
An NaI(Tl) probe would have difficulty separating them. Switching to Kb XRF @ 18.62 might be a little better but not with NaI(Tl).
It took a full 4096 channels to view this sufficiently closely with enough exactness to make a determination, however going to 8k channels made calibration harder to do and was abandoned.Likewise extensive tests with 1k and then 2k channels quickly showed peaks to be insufficiently spaced out to make a determination.
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