XRF Wiki
Welcome to the XRF Wiki. This Wiki is a repository of information contributed by members of [email protected]. Members can view and edit the pages. The pages are currently not viewable by the public. The pages below represent a rough overview of the technology and techniques associated with X-Ray Florescence Spectroscopy as well as serving as a place for members to organize the spectra that they have contributed to the forum.?
As a starting point, the pages will be populated by information taken from member posts from the past few years - with references/attribution. Perhaps in time, these pages can be edited by members to make them more complete and less choppy. Members can also edit this page, making the structure of the content more organized.?
Pages can contain information about a particular topic, links to relevant resources (such as manuals, research papers, etc.), links to relevant forum discussions on the topic, book titles, or anything that might be useful.
What follows is very much a work in progress.
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Adding to the Wiki
For those unfamiliar with the Wiki phenomenon, it is basically a user editable encyclopedia. The idea is that there are pages with different articles, which the user can read and also choose to edit if desired. If a piece of information is incorrect, a link outdated, or the presentation choppy or unclear, the user can just click "Edit Page" at the bottom and then fix the mistake. There is also a "Page History," so if you a user were to make a mistake or maliciously destroy a page (which wouldn't happen here) an editor can come along and restore the page to a previous version.?
If you have used MediaWiki (the engine that runs behind the scene of Wikipedia.org) you will be familiar with a certain style of creating an article. There are tags that one uses to change the formatting of the parts of the article. The Wiki on Groups.io uses a different background engine and so the standard MediaWiki syntax does not apply here. Rather, the page is edited using the same tools as one would use to compose a message on the forums. If you are a programmer or someone who likes using the tagged syntax directly, you can access the underlying page source code, be activating the advanced editing toolbar (the icon with three lines on the far right of the basic toolbar) and then clicking on the source code icon <> on the far right of the Advance Editing Toolbar. You will immediately notice that the underlying source code is HTML. Most things can be done just by using the various icons, but advanced features like table can only be implemented by manually writing the source code. (Although there are website available that will generate the source code for you through a graphical interface.)
Here are some useful resources from Groups.io:?
Wiki Guide for Users and Editors
Message Composition Tips and Tricks
Overview of XRF
X-Ray Florescence vs. X-Ray Diffraction
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Hardware
This section describes the hardware used for XRF. We will describe the basic theory of operation of each stage in the processing tool chain and then present different commercial systems that are available as these systems are often integrated together.
[Editor note: General theory needs to be in an independent page separate from specific manufacturer information.
[Editor note - question: Should this be arranged by category, e.g detectors, preamps, etc or by manufacturer with the manufacturers product line on one page. Perhaps it's best to put a list of products with theory but the details of the products on a manufacture page...]
Detectors?- what's available, theory of operation, tradeoffs
Detector Cooling?- keeping detectors cool to avoid thermal noise and keeping the TEC from overheating
Preamps?- theory of operation, brief summary of what out there (and what not to do - such as trying to use a PMT preamp for a SiPIN diode...)
Pulse Processing Theory - high level overview of the stages of going from detector pulse to channel peaks on the computer
Commercial Systems - many commercial systems are integrated so it seems to make sense to present, for example all Amptek products together. [question: are their other affordable integrated systems besides Amptek?]
Amptek XRF System
Activation Sources - what do you use to make the sample fluoresce (that's within the amateur budget and doesn't require special licensing)
Software
- Device Control Software - what do you use to collect the data from the detector system
- XRF Analysis Software - what do you use to analyze the data, especially for quantitative measurements (composition percentages, thin film measurement)
- Free Software Tools
Note: there may be software packages that possess some or all of these characteristics.
Materials Spectra
Metals Spectra
Historic/Archeological Spectra
Reference Materials Spectra
Household Objects Spectra
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Resources
Videos
Articles
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Non-XRF Techniques
Gamma Spectroscopy
Raman Spectroscopy
FTIR - Fourier Transform Infrared Spectroscopy
Atomic Emission Spectroscopy
Inductively Coupled Atomic Emission Spectroscopy
Spark Emission Spectroscopy
Atomic Absorption Spectroscopy
LIBS - Laser Induced Breakdown Spectroscopy
Photoacoustic Spectroscopy
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Re: Chinese water filter analysis
taray singh
Geo
Here is the Am 241 spectrum with the same settings. Sorry for the delay. As for scale error above I misquoted being way from my pc, On starting Dppmca? ,calibrating? and connecting to si pin,the scale box upper? range is about 700 with spectrum about 80. Not the other way round That seems odd. But on actually starting acquisition, everything normalizes. Like I told you before I am unable to save calibration despite following the usual way Always have to? recalibrate? playing with lifedata files on starting Getting used to the routine Not an issue. Anyway let me know what you think about the RO sample Thanks Taray |
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Re: Chinese water filter analysis
taray singh
Geo
toggle quoted message
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It appears to need overlapping data files? I will check it ?when free Regarding calibration data ,you can get by?opening mca file with notepad . If you continue scrolling below <data> ,lots of numbers in single rows Continue downwards full config data Taray On Sunday, November 1, 2020, 10:23 PM, GEOelectronics@... wrote:
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Re: Chinese water filter analysis
taray singh
Hi guys
I repeated this test with additional RO discharge residue soaked in filter paper pressed against a yellow sample cap As a control I also checked a new dry filter paper with the cap Both samples were run for 1000 counts for statistical significance . Ok Charles,this is a long run . Quick XRF of the iron/Al electrodes The RO sample show Fe and Pb peaks Fe is coming from galvanic reaction. Both the control and electrodes show no Pb peaks Without any doubt there is lead in my drinking water My impression is that the iron electrode acts as catalyst? for electrolytic precipitation reactions. Pics are RO water residue,control sample and electrodes |
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Re: 59.5keV spectrum cleanup
¿ªÔÆÌåÓýCharles, ?This is a classic example of what I have been trying to get across with respect to thermion, calibrations and interpretation You¡¯re not exactly sure what you are looking at here because you¡¯re using an incorrect program with a bad calibrate and relying on pre established lines to do your interpretation for you. ?All of this is a result of using Theremino and not using the proper program and calibrations that were designed to do this type of work.? The Sn La1 at 3.44 keV are ID¡¯d using the pre-assigned labels but it¡¯s actually the K La1 at 3.31. The labeled Sn Lb1 at 3.66 is actually the K Lb1 3.59 which is apparent when using the correct calibration and the DppMCA program to look at it. The difference in energy between the Ka1¡¯s and the Kb1¡¯s is 0.13 and .07 keV. That is the accuracy and precision that a calibration needs to address and that is done using a linear or polynomial regression to establish the energy/channel relationship not a dumb slider in a kid¡¯s program. When you do a regression you can look at the fitting error and correct problems of a wrong peak pick. You¡¯re blind in Theremino. The Ba La1 ID doesn¡¯t have enough detail to say what it is, but if its Ba then where is the Ba Ka1 at 32.2? and where is the Sn Ka1 at 25.27? Using pre-established lines is a poor crutch for interpretation and leads to? pre-conceived expectations and bad results. I would suggest leaving the Theremino to NaI applications and start using DppMCA to establish the calibration and do peak interpretations. Get a table listing, in increasing order, the atomic number, it¡¯s element and the Ka1, Ka2, ..La1, La2..etc energies and yields. (see attached) ??In the calibrated DppMCA program start with the prominent peaks and find the max count and centriod, look up that energy in the table and look to see what¡¯s around it paying attention to the Ka1 and La1 and intensities. Find and verify the associated energies of that element, put an ROI around the Ka and La¡¯s. note any weaker lines. One line is not a positive ID it needs corroboration. In the ROI tab click show details and the elements and associated data will be displayed (if it¡¯s in the look up table, if not add it). You can take a screen shot using the Capture Plot (Control C) and add any labels you want to it in Photoshop or whatever. It¡¯s time to move up. Dud From: [email protected]
[mailto:[email protected]] On Behalf Of Charles David Young
Sent: Friday, October 30, 2020 7:28 PM To: XRF Subject: Re: [XRF] 59.5keV spectrum cleanup ? I am not sure exactly what I am looking at here but I like the sharpness of the peaks and the low noise.? Is this a scan with an Am241 exciter?? See attached. ? Charles ? On Fri, Oct 30, 2020 at 5:36 PM <GEOelectronics@...> wrote:
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