Geo,

Attached is a manually selected ROI showing the Cr, Fe, Mo, and the missing Ni. ?Using auto generated ROI computer picks usually are not very helpful and in the end its probably best to set your own using a quasi-heuristic approach (by eye-ball) for the ROI’s.

Note that these peaks are noisy and under sampled with the largest peak, Fe, having only 212 counts in it for a 20 sec count.? The count rate is 2306 cps which is slow for this detector which can handle a much higher count rate. ?For your 4.8 usec peaking time you should be able get up to 50,000 cps.? To do that try a couple of things, ?get the detector closer to the target, increase the beam current and optimize the collimator’s beam diameter. ?I suspect? the large standoff distance of the detector may be the most sensitive to the problem.?

The Cal Check.bmp ?attachment is a 30 sec 50 kV shot of a 316 SS calibration disk resulting in a count rate of 31,861 cps.? Note the Fe peak is well defined and has a 1909 count peak.

Dud

KK7IF

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