" Tip for calibration
It can be difficult to find 2 peaks at extreme end within a specimen or combination.
Sometimes with? this method it is difficult to identify peaks
Easier way is use 2 different samples
After entering data into the calibration box,delete data and reset?
Enter next sample and repeat"
Good idea, and the calibration points can be radioactive source, or XRF made by exciter.
This last way you can place the cal peak anywhere you wat, up to the limit of your exciter, simply by using pure elements. One very low and one at 59.5 is really all that is needed due to Si-PIN linearity.
Try this:?After an important long run, save the .mca and a BAK.mca of it, change DPPMCA time to longer and add 59.5 source for how long it takes to get a good solid peak at 95.5 and 13.95 or 17.750keV, all the while leaving the original scan on the screen. Save and label this as?"xxxxx"-Post-Run-Am-Cal.mca and use it to tweak the calibration of earlier saved .mca, or as proof of linearity later.?
That's why to include 0-62? keV even though you might have no peaks above ~32 etc. Just set RANGE boxes to highlight the area where the peaks are, maybe 2 to 35 keV.
Also must add, any "drift" in calibration is usually not drift at all, but the maturing of the peak from start to finish to a point where the actual peak is at more clear. In most cases after days of running it may only be a +/- 1 channel change.
Is there an issue/question? with cooling/heatsink?? What you feel on case should be warm like a puppy. This is the 1 Watt or so of heat being removed from the sensor chip inside the tip behind the Be window, which operates in a vacuum at? ~230K = minus 43C.
My SDD sensor has a more sophisticated cooler, it uses a liquid? filled "heat-pipe" to bring heat inside the main box from the tip, a heatsink and fan inside the box to cool it down and blow it away from the sensor end. In a way heat pipe is same idea as a cold finger on HPGe sensors. Heat pipe also = Drinking Bird toy tech.
Geo
From: "taray singh via groups.io" <sukhjez@...>
To: [email protected]Sent: Sunday, October 25, 2020 2:53:13 AM
Subject: Re: [XRF] Supplements exposed
Here is pic of selenium sulphide(dried centrifugal sample of selenium sulphide suspension / Selsun) using 2048 with threshold correction.
The selenium peaks are seen clearly? and not hidden like the one with the supplements.
Tip for calibration
It can be difficult to find 2 peaks at extreme end within a specimen or combination.
Sometimes with? this method it is difficult to identify peaks
Easier way is use 2 different samples
After entering data into the calibration box,delete data and reset?
Enter next sample and repeat
Can delete previous ROI? after entering data into calibration box
Eample Fe and Am241 59.5?
?
Also a pic from Engineer's handbook about heat sink
Maybe a little small to see on a pc
Taray
