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Ken, The second set of Non-Red “calcite “ pieces you sent me are turned out to be quartz not calcite although they do look pretty much the same. Attached are the XRF, optical, reflectance and assay runs on the parking lot Non Red “calcite” pieces. The optical spectra shows no red at 610 nm (orange-red) like the last pieces sent, however under 365 and 405nm laser they show a weak whitish green fluorescence extending from 450 to 650 nm. The Reflectance spectra have a 40% reflectance monotonically decreasing to 37% in the red to NIR. Again pretty much a white rock with no absorption centers. The Assay was run with an Olympus DP4050 XRF in the Soil REE mode as we were looking for activators in the ppm range. That mode will over report % level elements. None of the chips of “Calcite” show any rare earths at the higher energies. Three samples were run, a small chip , a large piece and the large piece on the dark section in it. The dark section showed strong Fe, Mn, Ca, Cu, Zn, Pb and Rb over the other shots The valid elements detected in the quartz sections are Si, Ca, Mn, Fe, Sr, and weak Pb, Cu and Zn. The others are interferences from peak overlap and should be ignored. The strong presence of Si (which I don’t have an calibrate for), no effervescence under hydrochloric acid and a hardness (7) much greater than calcite indicates quartz. Under a microscope the rock is composed of individual welded angular pieces indicating a metamorphic origin. This is a Quartzite not calcite. Quartzite is a very tough rock and is commonly used for parking lots and decorative fill. The original crystalline calcite probably occurred as veins intruding into the unit at some point in time. Dud KK7IF

Geo, Attached are the XRF runs on Persson’s #15 powdered bag sample labeled Yt+HREE Fluorite from the White Cloud Pegmatite South Platte CO. The powder is remarkably high in the LREE and HREE with even Sm showing up on the 50kV beam. Percent level assay is valid in the …All.png file which was run in the Mining Plus mode which is for materials in the percent range, while the Low E PNG and Hi E.png files were run in the Soils Mode which is accurate for ppm level elements. Ce comes in at 5.7% and Y at 3.8 % Be nice to find a big deposit like this. Dud

The sample- The setup- Amptek SDD-1-2-3 MCA, GEOelectronics SDDCAP exciter AmX8 The results (.mca file attached). More to follow using tube exciter. Geo

Ken, Attached are the XRF, optical, reflectance and assay runs on the parking lot calcite pieces you sent me.. The optical spectra shows a center wavelength at 610 nm (orange-red) with a pronounced tail into the near IR. It has a good red Phosphorescence of about a sec decay under a 405 nm laser. The red is seen in the 405, 365 and in the 256 nm short wave but longer wavelengths are stronger. I couldn’t measure the fluorescent lifetime as that optical bench is pulled apart right now, but it does have a nice red decay. The Reflectance spectra show a 50% reflectance monotonically decreasing to 45% in the red to NIR. Pretty much a white rock with no absorption centers. The Calcite 50kV spectra show no rare earths at the higher energies. The Calcite 40 kV spectra indicate the expected Calcium (Ca) of the CaCO3 but also included Fe, Mn, Sr, Pb and Y. The Assay was run with an Olympus DP4050 XRF in the Soil REE mode as we were looking for activators in the ppm range. That mode will over report % level elements (Ca). The valid elements detected are Ca, Mn, Sr, Y, Fe, and weak Pb, Cu and Zn. The others are interferences from peak overlap and should be ignored. In General, the activators for calcite are most commonly Mn+2, Fe+3 UO2+2 and the rare earths. The red emission and phosphorescence is most likely caused by the Mn+2 and Pb+2. This occurs in calcites that are hydrothermal in origin. A green fluorescent calcite is usually due to the uranyl complex. The only surprise is the Yttrium (Y) which is about 10 times what I would expect to see. Find some big pieces or better yet find out where it came from – that would be a good collecting/field trip. Dud KK7IF

Rubidium ore from New Mexico EDIT: Correct .mca file is posted to message 1715. Geo XRF done with an experimental AmX8 exciter with the elements angled towards the central hole by 22.5 degrees. Made from an aluminum frame and backed by thin Pb layer and a large entrance hole. First a display in Squareroot mode. It is a modified LOG mode supported by DPPMCA program, The advantage is it not as extreme as LOG but still shows more details in the smaller peaks. This mode is superior to LIN when there are two sets of peaks, but they are very different heights. SQRT mode is good for identifying smaller peaks, but LINEAR mode , below, shows a much more accurate relationship in the relative concentrations. Have fun Geo

Hi guys I scanned a free gift tall decorated glass. I have been drinking from it for years . This particular one is partially broken and ended in my lab as a holder These tall and narrow glasses are rather unstable and many have accidentally broken thankfully. So decided to scan this broken one hoping to pickup elements like Ba etc Surprisingly found lead instead On further reading , drinking glasses can contain harmful levels of lead in the decorative enamel. I scanned from bottom(no designs) and from the sides as a comparison. Only the painted enamel side show lead Beware of decorative glasses Scan everything under your nose Taray

Recent Si-PIN Gamma Spectrometry studies of different types of uranium has shown up some puzzling peaks up around 58-59 keV. Nothing in the databases shows anything to be at the those exact energies, and we all know that uranium has strong peaks above 60 keV- the normal top range of my previous Gamma and XRF scans. That led to expanding the upper range on the Si-PIN detector which is accomplished by lowering the GAIN, then recalibrating. Using the 59.5 from Am, you can move the peak down to wherever it needs to be from it's normal position near the right edge (high energy) spot. Icon buttons 27 thru 30 do that. 27 and 28 set the increment of the steps of change make, while 29 and 30 increment up or down by the selected increment. This test with a Spectrum Techniques Ba-133 calibration disk shows the result. It's being show in both LINEAR and LOGARITHMIC graphical mode to show how each has it's merits. Another function of this test is to demonstrate what using the 81keV Gamma Ray of Ba-133 as an exciter will give you to deal with down at the low end when XRF'ing. For those using DPPMCA, you can print out the first picture to use as a reference when we discuss the Icon Panel controls. When looking at either the LINEAR or LOG display, always keep in mind that the height of the peak is governed by 2 distinct factors. #1 is of course the actual intensity of the radiation making that particular peak and #2- and more important- the point on the energy-efficiency curve that the peak occupies. Two peaks that look early the same in LOG display may be nowhere near the same in LINEAR mode. Si-PIN for example falls off rapidly over 25 keV, as you can plainly see there is life up above 60keV! I put together a .lib file just for Ba-133, which is also attached along with the .mca file for this test. EDIT: Groups.io bounced thisl library file so it's now a txt file, change the suffix to dot-lib when you download it to your AMPTEK LIBRARY foder. Have fun Geo

I went ahead and notched the pick and pluck foam to fit. Not bad for $20.

Pictures of the 3rd CdTe for the XRF lab. This one is assembled from parts, all by Amptek. Everything was tested before assembly and the sensor is one I picked up on eBay a few years ago and has been in storage until today. Right now it is a backup for the other two but can be put on line with a PX power supply and Amptek MCA8000D if needed. Geo

Uranium Ore , Depleted Uranium, Natural Uranium (Unat) Compared For this topic we will examine the various forms of Uranium and its decay chain. Using XRF and also Gamma Spectrum Analysis, and any other scientifically sound methods. We will compare the characteristics of : Uranium Ores, including species of minerals that include any naturally selected Uranium decay progeny. Unat or natural uranium, which includes chemically separated materials, but always with the natural abundance of U-234/U-235/U-238. DU or Depleted Uranium, which is of course natural uranium from which lighter U isotopes have been removed for use elsewhere. Geo

I’m really enjoying all of the discussion about analyzing various materials with XRF. I’m quite impressed with the resolution and detail that some of you are obtaining using your ‘amateur’ in-home laboratories. I use the term “amateur” lightly – you put the efforts of my past experience in a chemistry laboratory at a nuclear power plant to shame. Granted, our objective was to analyze for very specific elements of interest, primarily zinc and cobalt, and maybe iron and chromium as well. We had our XRF set up in a very simplistic manner of push-button, get-banana. We never strayed from any elements outside of an atomic number Z-range of 24 to 30. Anyway, back to my main point of discussion. I’ve always been a rockhound, and can’t resist picking up something of interest. Last year I snagged a couple of pieces of some greenish-gray cobble stone that had some white veins of calcite running through it. On a lark, when it got dark, I shined my Convoy S2+ UV-LED flashlight on the stone. I wasn’t surprised to see some red fluorescence in the calcite, but was surprised by a relatively bright red phosphorescence that lasted for a few tenths of a second. What I found even more perplexing is that this phenomenon only seemed to be evident when the stone was illuminated with the Convoy UV flashlight. I tried getting fluorescence excitation with a combination longwave-shortwave Model UVSL-15 Mineralight (longwave 365 nm, shortwave 254 nm) as well as a dedicated longwave Model UVL-56 Blak-Ray lamp (366 nm). Surprisingly, I didn’t get any appreciable fluorescence, and no phosphorescence, from either of these mercury-vapor based lamps. Only the LED-based flashlight seemed to elicit the phosphorescence. Now for my question: Would any of you fine gentlemen want to exercise the quest for knowledge to analyze some of this mystery calcite for trace element content to ascertain what might be leading to the phosphorescence? Being calcite, one would expect Calcium, Sulphur, and Oxygen, but there must be some trace element (rare earth??) that is contributing to the fluorescence and/or phosphorescence? I went back to the parking lot where the crushed cobble had been placed, and maybe only about a quarter of the cobbles I collected exhibited fluorescence/phosphorescence. I was able to find several chunks of the ‘pure’ calcite (no green-gray matrix), and it too showed about a 25% to 30% of the number of pieces exhibiting fluorescence. All of the stone looked similar and probably came form the same quarry, but only a fraction of it showed any fluorescence/phosphorescence. Any takers? I’d be happy to drop a chunk or two of the “mystery” calcite in the mail to anyone who might want to take a crack at running an XRF to look for anything unusual. Drop me an email if you’re interested. Thanks, and keep up the great work! Ken Sejkora, WB0OCV East Falmouth, MA Email: kjsejkora@...

Hi guys I am interested in drinking water quality testing and most drinking water test kits are not accurate. They give positive readings on concentrated samples like sewage and not for trace elements in drinking water. So I wanted to try out this interesting Chinese gadget. Search you tube for.. Water Electrolyzer (Quality Tester). The Most Dangerous Appliance Ever? Negative comments being dangerous and a scam. I checked it out There are 2 pairs of electrodes A shiny aluminium and a dull iron pair. Repeated usage caused the iron to rust. Aluminium was confirmed by exclusion being shiny,light,cheap and nondescript. My drinking water sample is RO waste water . This discharged RO waste water is about 4 times more concentrated than my tap water depending on machine cycling. Concentrated means more residue better than plain tap water for analysis. My 14 in 1test kit was basically negative for heavy metals. I tested this RO concentrated with this Chinese toy. It produced a brownish residue as expected. Collected it and allowed it dry on cap and a tissue. This cap/tissue was analyzed with Xrf with Am241/Si pin detector. True enough like the you tubers described there is Fe from galvanic reactions. There appears to be Pb peak as well I need to repeat this test with a thicker sample to confirm . Taray .

GeoUr using higher energies I am sure ur setup is optimum Are u using a lead compartment?Taray

' You’ll note that the 19.2 peaking time has a much better 13.6 keV FWHM resolution than the 4.8 (0.192 vs .396 FWHM)." Dud,THANKS for that update and analysis> is there a report log to determine FWHM for a particular peak or do you have to set ROI, and if so how do you invoke FWHM? Geo To: [email protected] Sent: Friday, October 30, 2020 11:40:36 AM Subject: Re: FW: [XRF] 59.5keV spectrum cleanup Geo, The 4.8 usec doesn’t have the filter fast thresholds set correctly as a result it has you seeing 3135 valid counts with a noise count of 128,980.While The 19.2 PT has 4534 valid counts with a noise count of 56627 counts and both with comparable count times. (Note that the 19.2 still has a lot of low energy noise that needs a better threshold setting but its way better than the 4.8 PT data set ). So the 19.2 has better count statistics 4534 vs 3135 counts for roughly the same count time counts and is getting better peak shape. You’ll note that the 19.2 peaking time has a much better 13.6 keV FWHM resolution than the 4.8 (0.192 vs .396 FWHM). Dud Sent: Friday, October 30, 2020 6:35 AM To: [email protected] Subject: Re: FW: [XRF] 59.5keV spectrum cleanup Thanks for that report Charles. Of the two, can you say what is the lowest peak that can be resolved and is there a difference between them? My just finished overnight run using the Si-PIN on a weakly radioactive sample for Gamma Spec (not excited XRF) is resolving individual peaks down to less than 1.5 keV. In the Peaking Time topic thread I'll post that test @19.2us PT along with a nearly similar test done last February at 4.8us. The main difference between those seems to be both in the clarity and narrowness of the big peaks, and better performance at the lowest end going to the 19.2. Today I'll try even longer peaking times, up to 32us just for the historical record. I think you've been using 32us and I can't fault your scans, that's for sure. Geo

Geo, I don’t see how normalizing accounts for flux? There are 2 different count times and 2 different activities? And a filter. The 1.6 mm Al “filter” will drop the flux by a factor of 0.5. The count times are different by a factor of 4.5, and there is an unknown activity difference. If you count for the same times then the peak count differences will be the activity ratio (with all other things equal). Peak counts must be corrected for the source activity to compare the two. Putting an Al filter in there is just an attenuator and only addresses the low energy range below Al binding energy. Most filters are 100s of microns thick and are tailored to a small energy range to kill the tube background and allow lower limits of detection in that smaller energy range. 1.6 mm at 59 keV would act as an overall attenuator The C0-57would be nice but has a bad $/half like ratio what about a Ba133 which would get 80 keV + or a Eu 154 at 123KEv + ? The question I had was your photo showed a Peak Time of “rise value” I wonder how that got in there. K’s are stronger if you can get 'em and they have less interference, but the heavies are tough to get Dud From: [email protected] [mailto:[email protected]] On Behalf Of GEOelectronics@... Sent: Monday, October 26, 2020 12:45 PM To: [email protected] Subject: Re: [XRF] 59.5keV spectrum cleanup ----- Original Message ----- From: Dude <dfemer@...> To: [email protected] Sent: Mon, 26 Oct 2020 13:27:01 -0400 (EDT) Subject: Re: [XRF] 59.5keV spectrum cleanup What thickness Al filter are you using? 1.6mm Why normalize to the Am peak? Just use the same count time to see what the attenuation factor is for the same source. So the next experiments can use the same flux @ 59.5keV as previous experiments, to evaluate the positive or negative aspects that the Np X-Rays and other low end "noise" from the exciter may have . A "monochromic" test at the expense of run time. This in prep for possible investment in Co-57 source for K line from heavy elements. At this time the yield of K vs L lines in literature doesn't make that seem like a worthy investment. What is the Peak Time “rise value”? Is there another name or description of that parameter? RESC=?; Reset Configuration CLCK=80; 20MHz/80MHz TPEA=19.200; Peaking Time GAIF=1.0238; Fine Gain GAIN=18.686; Total Gain (Analog * Fine) RESL=204; Detector Reset Lockout TFLA=0.600; Flat Top TPFA=400; Fast Channel Peaking Time PURE=OFF; PUR Interval On/Off RTDE=OFF; RTD On/Off MCAS=NORM; MCA Source MCAC=2048; MCA/MCS Channels SOFF=OFF; Set Spectrum Offset AINP=NEG; Analog Input Pos/Neg INOF=DEF; Input Offset GAIA=14; Analog Gain Index CUSP=0; Non-Trapezoidal Shaping PURS=??; Secondary PUR PDMD=NORM; Peak Detect Mode (Min/Max) THSL=0.878; Slow Threshold TLLD=OFF; LLD Threshold THFA=53.12; Fast Threshold DACO=SHAPED; DAC Output DACF=50; DAC Offset RTDS=0; RTD Sensitivity RTDT=0.00; RTD Threshold BLRM=1; BLR Mode BLRD=3; BLR Down Correction BLRU=0; BLR Up Correction GATE=OFF; Gate Control AUO1=SCA8; AUX_OUT Selection PRET=2370.0; Preset Time PRER=OFF; Preset Real Time PREC=OFF; Preset Counts PRCL=1; Preset Counts Low Threshold PRCH=8191; Preset Counts High Threshold HVSE=190; HV Set TECS=230; TEC Set PAPS=ON; Preamp 8.5/5 (N/A) SCOE=FA; Scope Trigger Edge SCOT=12; Scope Trigger Position SCOG=1; Digital Scope Gain MCSL=1; MCS Low Threshold MCSH=8191; MCS High Threshold MCST=0.01; MCS Timebase AUO2=ICR; AUX_OUT2 Selection TPMO=OFF; Test Pulser On/Off GPED=RI; G.P. Counter Edge GPIN=AUX1; G.P. Counter Input GPME=ON; G.P. Counter Uses MCA_EN? GPGA=ON; G.P. Counter Uses GATE? GPMC=ON; G.P. Counter Cleared With MCA Counters? MCAE=OFF; MCA/MCS Enable BOOT=ON; Turn Supplies On/Off At Power Up Good luck with the total reflection it’s a complicated set up. Dud From: [email protected] [mailto:[email protected]] On Behalf Of GEOelectronics@... Sent: Monday, October 26, 2020 8:53 AM To: [email protected] Subject: Re: [XRF] 59.5keV spectrum cleanup Obviously the Pyro is much cleaner. Mostly due to the added filters and other manufacturing differences between vintage low volume commercial productions vs. today's mass produced but more safety minded production. These are thin, flat metal strips that could be taped into position. CAVEAT- RISK FACTOR-These have been know to leak/shed. Please don't use without a permanent Kapton or Mylar tape protective layer. To reduce the low end energy even further, some aluminum filters were placed between the pyro source and the sensor. Time for the scan is adjusted so the 59.5 peak is the same for both The pictures I think are striking. This will be the exciter source used for the next series of experiments into what is called "Grazing Angle Total Reflection XRF"" or "Edge XRF". In this method the sample being tested for elemental content is placed edge-wise (90 degrees) to the sensor vs. face to face, and the exciter is at right angles to the sample, thus the "grazing angle" of excitation and the readout is gathered from the edge of the target. There are a number of studies being done on TR-XRF, but the search term most fertile will include the term "grazing angle". Filters remove most of the low energy component, leaving the 59.5 the same (time adjusted) PYRO_RAW-VS-PYRO-FILTERED-NOTES.png Here is the comparison of what we have been using and the difference that can be achieved: Residential_Vs_PYRO-_notes.png The included Gamma Spectrum mode .mca files were all done with the newly adopted 19.2us peaking time. Some things achieved by that study thanks to suggestions of members: Deadtime virtually eliminated. Low end "electronic noise" virtually eliminated. Resolution improved. Speed of which the pattern forms improved. Overall "look" of the scan improved. Geo