Am-241 Calibration UPDATE.
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I think the lowest peak could be Au or Zr or both (see attachment).? I have never been able to reliably get peaks to calibrate at 2keV so this scan is of some interest to me. Geo, have you done something specific to get such a distinct peak at 2keV? Charles On Tue, Oct 27, 2020 at 8:09 AM <GEOelectronics@...> wrote:
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" Geo, have you done something specific to get such a distinct peak at 2keV? Charles" No, Usually it proves to be ionized air, due to the exciter. Notably Argon. Sometimes it's seems to be a chlorine peak, when certain plastic bags are used to hold a radioactive specimen but not most bags. I'm re running same scan and source now, but with a simple paper filter over it to get rid of the unneeded alpha particles, which of course massively ionize gas atoms. The low end already looks much different with distinct peaks at 1.63 keV already. I'm pleased with the new Peaking Time, and wanted to go all the way to 25 but ran into difficulties, so maybe will do that again some day. For now just learning what the SI-PIN will and won't do is keeping me busy enough. Below 3 is going to be difficult without a vacuum or a light purge gas (Helium is ideal but expensive, how about nitrogen?) A small interim update, the low end is really starting to show up different peaks. I'm going to filter the exciter anyway, might as well start with paper. PS I'll look into your Minedat pages too. Can your version of display program calculate total counts under a whole peak? Using only the central peak height #, I'm trying to analyze the 26.34 keV Am y-ray (2 2.4% yield) height vs the 59.5 Am y-Ray @35.9% yield to back-calculate the Si-PIN efficiency curve (slope) between those 2 points. If I did my math right (questionable at best) there is 12.3X difference using peak counts of 10666 for 26.34 and 866 for 59.5. Probably full counts in the peaks would be more accurate. Geo From: "Charles David Young" <charlesdavidyoung@...> To: "XRF" <[email protected]> Sent: Tuesday, October 27, 2020 10:47:51 AM Subject: Re: [XRF] Am-241 Calibration UPDATE. I think the lowest peak could be Au or Zr or both (see attachment).? I have never been able to reliably get peaks to calibrate at 2keV so this scan is of some interest to me. Geo, have you done something specific to get such a distinct peak at 2keV? Charles On Tue, Oct 27, 2020 at 8:09 AM <GEOelectronics@...> wrote:
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See attached.? What are you trying to prove with the alpha block? Yes, between lighting and a new camera I can now get decent photos of my specimens. Charles On Tue, Oct 27, 2020 at 9:45 AM <GEOelectronics@...> wrote: Here's the half way through scan. Check it out (very low end) if you have a minute Charles- .mcaq attached |
¿ªÔÆÌåÓýCharles, If you use the Amptek DPPmca program to look at the data you¡¯ll see that the peak falls right on the Au Ma1 2.12 line. The problem here is using Theremino and its ridiculous calibration mechanizations and not looking at and using raw data. Get rid of it as it¡¯s only going to cause trouble, Its fine for NaI but not for XRF - use the proper tools. Dud ? From: [email protected]
[mailto:[email protected]] On Behalf Of Charles David Young
Sent: Tuesday, October 27, 2020 8:48 AM To: XRF Subject: Re: [XRF] Am-241 Calibration UPDATE. ? I think the lowest peak could be Au or Zr or both (see attachment).? I have never been able to reliably get peaks to calibrate at 2keV so this scan is of some interest to me. ? Geo, have you done something specific to get such a distinct peak at 2keV? ? Charles ? On Tue, Oct 27, 2020 at 8:09 AM <GEOelectronics@...> wrote:
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On Tue, Oct 27, 2020 at 12:03 PM, Charles David Young wrote:
See pic of normal interfering 2 keV peak (black outline) vs Red Filled=Alpha Blocked. Is that a 2 or 3 light setup? I see 2 sidelights but can tell if there is a toplight. Geo |
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Ok, so you are blocking the alphas coming from Am241 so they can't excite the target, right?? But doesn't that also block the lower energy xrays we would like to detect coming from the target? It is a dual gooseneck halogen source. On Tue, Oct 27, 2020 at 10:47 AM <GEOelectronics@...> wrote:
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Fine on the lighting setup. Lots of new lighting tech out there now. I have a dual fiberoptic illuminator for the microscope- need to press that into service for camera pictures too. The President mentioned he was going to reinstate tungsten bulb making in US- good for him. This test was proof of concept, one more step in designing a cleaner exciter. The paper is only on the exciter, blocking alpha particles will reduce the surface count by around 10%. This will all factor out as we flesh out this idea. Eventually we'll get access to the rather new X-Ray lensing tech, called multi-capillary lens, which can transport the rays from a distance and focus them into a tiny spot, Right now they are unobtanium. Geo From: "Charles David Young" <charlesdavidyoung@...> To: "XRF" <[email protected]> Sent: Tuesday, October 27, 2020 12:56:43 PM Subject: Re: [XRF] Am-241 Calibration UPDATE. Ok, so you are blocking the alphas coming from Am241 so they can't excite the target, right?? But doesn't that also block the lower energy xrays we would like to detect coming from the target? It is a dual gooseneck halogen source. On Tue, Oct 27, 2020 at 10:47 AM <GEOelectronics@...> wrote:
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On the loss of? low end excitation, we may find the 13.95 17.75 etc. are really HELPING dig out the low energies, So any metal filter will be experimental and removable until we know for sure. Geo From: "geoelectronics at rallstech.net" <geoelectronics@...> To: [email protected] Sent: Tuesday, October 27, 2020 1:11:02 PM Subject: Re: [XRF] Am-241 Calibration UPDATE. Fine on the lighting setup. Lots of new lighting tech out there now. I have a dual fiberoptic illuminator for the microscope- need to press that into service for camera pictures too. The President mentioned he was going to reinstate tungsten bulb making in US- good for him. This test was proof of concept, one more step in designing a cleaner exciter. The paper is only on the exciter, blocking alpha particles will reduce the surface count by around 10%. This will all factor out as we flesh out this idea. Eventually we'll get access to the rather new X-Ray lensing tech, called multi-capillary lens, which can transport the rays from a distance and focus them into a tiny spot, Right now they are unobtanium. Geo From: "Charles David Young" <charlesdavidyoung@...> To: "XRF" <[email protected]> Sent: Tuesday, October 27, 2020 12:56:43 PM Subject: Re: [XRF] Am-241 Calibration UPDATE. Ok, so you are blocking the alphas coming from Am241 so they can't excite the target, right?? But doesn't that also block the lower energy xrays we would like to detect coming from the target? It is a dual gooseneck halogen source. On Tue, Oct 27, 2020 at 10:47 AM <GEOelectronics@...> wrote:
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