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New Features in GeoPIXE 4.4
- The scattered beam subtraction options, previously in the Fit Results droplist, have now been moved to the
Fluid Inclusion (3 layer) mode of the Result Properties window. Now these corrections are made once, which modifies
the data, and stored as a property.
- A second detector efficiency curve can now be overlaid in red on the detector efficiency being edited in the
Edit Detector window. The ratio of the new detector efficiency to the overlay is also displayed in violet, scaled down
to 10.
- Spectra in Spectrum Display can be optionally displayed with points and errors bars for data, using a new
check-box called “Error bars” next to the Log/Lin button.
- The various colour/intensity scales in the main image window (linear, SQRT, Log), introduced in version 4.0, have been extended
to the 3 Element RGB Image window. Any scale settings for each element in the main image window are now reflected
in the RGB colour scales in the RGB Image window.
- A new Import pop-up window is available to import spectra files into Spectrum Display. This replaces the
lengthy menus and enables the selection of PIXE versus SXRF laboratories and the selection of various file formats
from each.
- An extra tab on the Results Properties window for thick targets enables the calculation of target thickness
from STIM transmission ion energy loss data. This updates the thickness of the target in the yield model, and upon
“Apply” calculates the new yields based on this thickness and applies these to the selected results in Fit Results.
New Features in GeoPIXE 4.0
- In the main GeoPIXE Image window, all concentrations between the bottom and top sliders are
mapped onto the current colour map, using a linear scale by default. Use the new small droplist between the
bottom and top sliders to select between Linear (L), Log (G) and Sqrt (S) scales for the Z axis. The Sqrt and
Log scales have the effect of compressing dynamic range, which can be useful for images with strong hot-spots
and low-level traces.
- The X-ray Spectrum Fit window has been re-vamped to place more subtle parameters and controls
on an “Advanced” tab panel. In addition, a number of controls have been added to this panel to control background,
tailing and parameters specific to PIXE and SXRF.
- “Conc” units can now be specified in “ppm (wt)”, “mmol/l” and “ng/cm2”, the latter being appropriate
for a layered sample such as a fluid inclusion.
- Full detector array support has been added for yield calculation, image projection and spectrum
fitting. Now the take-off angle variation across large arrays can be catered for, as well as arrays with non-planar
geometries (e.g. hemi-spherical), round and square pads, and arbitrary tilt relative to the detector-target axis.
- Support for the Maia series of detector system has been extended to support full-spectral SXRF (or PIXE)
imaging using up to 384 detector elements.
New Features in GeoPIXE 3.9
- Ghost features in images, corresponding to second displaced beam at a fixed offset can be corrected
using the “Process->Correct->Ghost” menu. The menu offers relative intensities of the ghost feature in 10%
and 1% increments. Use these in combination to correct ghost features; the operation is applied to all image
s.
- GeoPIXE can process the HDF format NSLS scan files now as a new device in Sort EVT
and the Spectrum Display Import menu.
- Fixed a bug related to Fit Results files (PFR) that contained fits that used
multi-layer filters. The file format had an error in it. The fix now permits all old PFR files, which may
contain the error, to be read and rectified. All new PFR files have the correct format.
- If a region is selected and highlighted based on element Associations, then the
exclude operation can now be used to remove pixels from the Association highlighted area.
- To remove pixels from the current Associations highlighted area, use the exclude
“-“ mode of region select shape. Select exclude, drag out a shape and use the “sigma” button to remove pixels
within this region from the current Associations selection. Note for this to work, no
include region should be set. To make sure, use the menu “Display->Clear ALL Shapes” and then select the
exclude region.
New Features in GeoPIXE 3.8
- New features have been added to accommodate the MAIA-32 event-file format produced by the CSIRO
Blog server. This device being added to the device list in Sort EVT and to the Import list
in Spectrum Display.
- For Maia-32 EVT files, Sort EVT includes a file specification entry for a pileup limits file,
which specifies the range of valid time-over-threshold for each detector pulse-height. The Import menu
of Spectrum Display also has options for sorting spectra with or without pileup removed by this approach.
The EVT button on the Image Regions window sorts out spectra with pileup removed, if appropriate for the
image data-set.
- A new window (Time Amplitude) is available (in the Spectrum Display “Windows” menu) to plot the
Time-over-threshold time versus pulse-height amplitude for Maia 32 events. Use the “File” menu to select
EVT files to sort. If an image is loaded into Image Display, and a region is selected and the “sigma” button
is pressed, then the Time Amplitude window will sort and display the Time-Amplitude points for all events
that fall within the selected region.
- If a region is selected on an image while Time Amplitude is open, then only the subset of Maia-32
events that fall within the region will be displayed in Time Amplitude. It will sort through as many
files as needed to display the requested number of events.
New Features in GeoPIXE 3.7
- Entry of energy and A, B data into the Cal window text widgets is now a little smarter, and do not require a to be properly registered.
- Images can be corrected for missing scan lines, or portions of scan lines, in both the horizontal and vertical. Look under Image Operations in the Help for tips. Surround the missing line segment with a Box shape, and go to the “Process->Correct->Missing Rows” menu to replace the missing data with the average on either side. Similarly, “missing columns” works for vertical missing data. Use “Double-counted rows” to attenuate double-counted rows by two, and similarly for columns. These operations are applied to all elemental images, and cannot be undone; save the image file first.
New Features in GeoPIXE 3.6
- The “Convert->APS MDA to LST” operation, on the Spectrum Display File menu,
can now use multiple file select to process a sequence of APS MDA files. These are assumed
to use the same assignment for ion chamber PV, sensitivity and live-time correction.
- Initial support for Hasylab FOI full-spectral pixel data files has been added.
New Features in GeoPIXE 3.5
- Several functions that use regions now will use Association highlighted areas
on images, if no valid Region is selected (i.e. Shape tool on Image window is set to
“Distance” or no shape has been drawn). These include Correct Current and Kill and
Suppress Region.
- In the Association window, a spline region can be cleared using a right mouse
button click.
- A new menu in Spectrum Display (“Display->Get ALL Energy Cals”) can be used to
load all energy calibrations for multiple spectra corresponding to elements of an array
from a selected spectrum file.
- Support has been added for GSE-CARS full-spectral pixel data files at the APS.
New Features in GeoPIXE 3.4
- GeoPIXE now includes an improved elastic and inelastic scattering model for SXRF. The intensities
of these, and the length of the inelastic and multiple-scattering tail, can be varies in the fit.
However, at present there is not control or variation on the electron momentum distribution for
inelastic scattering. These will appear later.
New Features in GeoPIXE 3.3
- The Image Regions window has a new feature for sorting all detectors of an array
into merged spectra for regions. The spectra are mapped onto the energy calibration of the
first spectrum before being accumulated into single spectra. The ADC droplist now starts
with “array” which means sort all array detector enabled for the image in Sort EVT when the
list-mode file was sorted (assumes “Detector Array” type was selected in Sort EVT).
- The Detector Setup window has been updated (access from “Edit Detector” menu). Now the
solid-angle properly reflects detector tilt angle as well as detector dimensions and distance.
- The Filter Setup window now has a new “Special” filter option for Bragg filters.
These are log-spiral X-ray lenses tuned to Bragg diffract a certain energy. The centre, width,
height (enhancement) and background (scattering) of this transfer function can be specified.
- When fitting a series of spectra, using the “Fit All” button on the X-ray Spectrum Fit
window, if only the first spectra has a Q value (e.g. entered into the Q box in the fit window)
then all spectra will assume the same charge/flux.
- Sometimes Spectrum Select was not being updated as spectrum properties were changing.
This has been rectified.
- Support for Tohoku Labo, NSLS MCA image pixel spectra and Sandia Primecore U48 list-mode
formats has been added to GeoPIXE.
- Association highlights on images can now be exported as Transparent PNG images
using a new File->Export menu.
- Results of yield calculations can be exported for examination using the new
“Export” button on the PIXE/SXRF Yield Calculation window.
New Features in GeoPIXE 3.2
- A simple scheme has been added to enable determination of the conversion from Ion Chamber
counts to flux or “charge” for APS generated data using a standard foil.
Quantification is then straightforward for unknown samples.
- The Image Export options have been enhanced to control the format of Exported
output to the printer and various metafile formats. Also, a selected region of an image
can be selected for export by dragging a shape on the image and checking the “Crop Image” option.
- Export of images to CSV file now has the option to export only a selected region of
the image. Use a shape and the new menu item for export of a region.
New Features in GeoPIXE 3.1
- The scene has been set for XRF imaging and analysis for synchrotron X-ray
microprobe applications with the addition of XRF fundamental parameter databases.
To select photons, select “Photons” in the beam particle
droplist in the yield calculation window. Beam energies are then in keV.
- Detector array handling has been improved, and a new section in the Scenarios
chapter has been added.
- A new button “Export” has been added to the X-ray Spectrum Fit window to export
the Dynamic Analysis matrix to a binary file (extension DMX) for download into a data
acquisition system for real-time generation of elemental images.
- GeoPIXE has been ported to Linux; the same XDR portable SAV file will run on
both Windows and Linux platforms. All binary files are in XDR format and can be used
on either platform.
- GeoPIXE now assumes IDL version 6.0.
New Features in GeoPIXE 3.0
- GeoPIXE now has support for detector arrays. The Sort EVT
window can process all detectors of an array simultaneously and project all
data onto a common set of elemental images using a Dynamic Analysis matrix.
Sort EVT has a droplist to select the array option.
Select a DA matrix as usual, and enable all ADCs that are part of the array.
- Many device drivers have been moved into external Fortran code to improve
the speed of processing list-mode files. Some file formats show significant
speed increases with throughput up to 20 Mb/sec (on a 2GHz P4).
- A new curvilinear traverse shape “Curve 8” has been added to
the GeoPIXE Image Display window. It provides a
spline curve to tailor non-linear traverses in order to project changing concentration
data along non-linear paths across images.
- The “B” button adjacent to the “EVT File:” button
in the Sort EVT window brings up the Batch
Sort window for editing parameters and controlling batch sorting
of entire directory trees of list-mode files. It also enables a tree directory
structure to be generated and populated with list-mode and related files.
New Features in GeoPIXE 2.9
- GeoPIXE now has Preferences selection (“Preferences” on the “File” menu of the main GeoPIXE
Image Display window). These set options for launching various GeoPIXE windows on start-up, and
parameters referring to XY stage ranges and stepper resolution. Preferences stored to the file
“GeoPIXE.prefs” become the defaults for the next launch of GeoPIXE.
New Features in GeoPIXE 2.8
- An accurate pile-up spectrum can now be calculated using image pixel intensity
products. Use the “Display->Pileup->from Images” menu in Spectrum
Display. PIXE Fit can now use these calculated
image pileup spectra to obtain more accurate fits to spectra corresponding
to total spectra from PIXE images with wide variation in major element spatial
distribution.
- Images can now be corrected for pile-up related effects,
based on pixel-by-pixel calculation of pile-up components. A new menu in Image
Display called “Process->Correct->Image Pile-up” performs this
task in concert with the Spectrum Display window.
See the expanded manual sections for details.
- Export of image plots to structured drawing formats, such as CGM, EPS and
WMF has been improved, and now produce plots with concentration legend, labels,
and axes in microns (if image size was supplied). The Image Display
“File->Export->Save Images as CGM” and “File->Export->Save Images as WMF”
menus, as well as the “File->Print” menu, pop-up a requester to tailor the
size and weight of characters, line thickness, the placement of optional items,
such as a distance bar, and the choice of output format (CGM, WMF, EPS, Printer).
- Export of spectra plots to structured drawing formats, such as CGM, EPS
and WMF has also been improved. The Spectrum Display
“File->Export->CGM Plot” and “File->Export->WMF Plot” menus, as well as the
“Print Plot” menu, pop-up a requester to tailor the size and weight of characters,
line thickness, etc. and the choice of output format.
- The way that user written image processing plug-ins are treated has changed
a little. In particular, the format of the returned history record must contain
the name of the routine. Please check the code in “template_image_plugin.pro”
for details. Image processing plug-ins now appear in the Image Operations
list for easy access.
- A new menu “Process->“Fold” can be used to remove the toggle bit effect,
which produces the effect of a double spectrum. This ‘folds’ a spectrum back
on top of itself to half the length in channels adding contributions to channels
as it goes.
- An accurate pile-up spectrum can now be calculated using image pixel intensity
products. Use the “Display->Pileup->from Images” menu in
Spectrum Display. PIXE Fit can now use these calculated image pileup spectra
to obtain more accurate fits to spectra corresponding to total spectra from
PIXE images with wide variation in major element spatial distribution.
- Images can now be corrected for pile-up related effects, based on pixel-by-pixel
calculation of pile-up components. A new menu in Image Display called “Process->Correct->Image
Pile-up” performs this task in concert with the Spectrum Display window.
See the expanded manual sections for details.
- Image processing operations that were applied to element images in one
image file can now be applied selectively to element images in a new image
file. This makes digital filtering and smoothing of images in a batch run
of many analyses much quicker.
- A ten-step colour table has been added to the Image Display “Display->Colours”
menu, and the Export->CGM options will now adjust the Z legend tick marks
to these colour transitions.
- A new output option allows the image shapes to be export as transparent
PNG files. See the “File->Export->Current Shape as PNG”
menu in Image Display.
- Support has been added for reading Fastcom MPAWIN and MPA3 list-mode files
and Sandia EVT data-cube files.
New Features in GeoPIXE 2.7
- The Edit Filters and Edit Detectors windows now show plots of transmission and intrinsic efficiency,
respectively.
- Both the HTML save format in Image Display (menu “File->Save All as HTML (PNG)”) and the Chimage
format save operation (menu “File->Save as Chimage”) now use a pop-up to select elements. This pop-up
also allows selection lists to be saved and restored to enable the use of standard element lists.
- The X-ray Identification window (“Display->Identify X-rays” menu, or the “?” button,
from Spectrum Display window) now has droplists to select X-ray filters and the detector
in “Mark Element” mode. All
X-ray line relative intensities are now calculated assuming detector efficiency and absorption through
these filters. These lines are shown on the Spectrum Display window as orange markers.
- The Sort EVT function now accumulates the total integrated charge for OM DAQ list-mode file during
sorting. The charge field is updated AFTER the sort completes, and the charge is written into the image
header. A new requester will pop-up to allow editing, or scaling the charge up or down by multiples of 10.
- The “File->Save ALL as HTML (PNG)” output menu operation of the Image Display window now pops up a
requester for the entry of the desired elements to output. These element selection lists can also be
saved and restored from this pop-up panel.
- The “Export” buttons on the PIXE Fit and Image Regions windows now bring up pop-up panels to select
options for export, including quantities to export and element selection.
- Menus under the Image Display “Window” menu can be used to bring up “unlinked” versions of the
Image Display or Spectrum Display windows. Normally, all windows are linked together and reflect one
dataset under study. By opening unlinked windows, you can load quite independent images or spectra
without affecting the current images and spectra, or the current path.
- The Layer II Setup window now has a “Plot” button to bring up a plot window to display various
calculation results, such as PIXE yields, as a function of depth or energy.
- Sort EVT, as well as functions to read IMG spectra files or extract spectra from EVT files in
Spectrum Display, all now look for an MP file of the same name. If one is found, relevant details,
such as images sizes, energy calibration and integrated charge are retrieved from the MP file.
New Features in GeoPIXE 2.6
- GeoPIXE can now process list-mode files generated using the Oxford Microbeams OM DAQ data
acquisition systems and software. Select "OM DAQ Data Acquisition for PC" on the input device
droplist in the Sort EVT window.
- Loading of all spectra, and import of spectra from files or extracted from list-mode files,
can now use multiple file selection. Simply use multiple selection in the file requester (using
control or shift keys) to select multiple files within a selected directory.
- Spectra (single or multiple) can now be appended to the spectra already in memory using the
"File->Import->Append-> …" menus. Use the "File->Import->New-> …" menus to clear memory first.
- The PIXE Fit window now has a button to fit ALL spectra currently loaded into GeoPIXE.
Coupled with the ability to load multiple files, this enables simple batch processing of series
of spectra from multi-spectra SPEC files, or loaded from a series of single spectrum files.
- The Cal window for energy calibration now has a button to set the calibration for all
spectra loaded ("All") or just the currently displayed spectrum ("One"), and a button to
set the units to "keV".
- The Spectrum Display window now has a user plug-in facility. Now you can write spectrum
processing and other user spectrum operations in IDL, such as custom fitting. These are
loaded when GeoPIXE runs and appear on the "Process->User Plug-ins" menu.
New Features in GeoPIXE 2.5
- A new Image RGB window displays three element images as the Red, Green and Blue
components of a 24-bit colour image. The intensity of each element is set in the Image
Display windows. The results can be exported as 24-bit PNG or JPEG files.
- The Image Display window now has a user plug-in facility. Now you can write image
processing and other user image operations in IDL. These are loaded when GeoPIXE runs
and appear on the “Process->User Plug-ins” menu. As with other image operations, these
add an information line to the image history record. The “Undo” menu (or button on the
Image Operations window) can be used to undo this user plug-in operation.
- Image processing operations have been added to the Image Display window ("Process" menu)
for edge enhancement (Roberts and Sobel filters), erosion and dilation, and rotation and
mirroring of images. Many of these are also in the Image Operations window list for quick access.
New Features in GeoPIXE 2.4
- A new window Correlation is used to plot correlations of two elements in images. In
other words, each pixel in a set of elemental images represents a data point in multi-element
space. Correlation displays two-element projections from this space. This can show up
discrete phases in a sample, for example, which appear as discreet blobs that may be
separated in some two-element views.
- A spline tool is available in the Correlation window to select arbitrary areas in
two-element space. These selections can be used to highlight all pixels in the element
images that represent this area in two-element composition space. These pixel selections,
plus the average concentrations within these highlighted areas, are saved in the Image Region
s window table. As with normal image region selections, the spectra from any ADCs within
these selected areas can be extracted.
- If a normal image region is used, to select a spatial area within an image, then the
element correlations shown in the Correlation window only show data from within this spatial
area of the image. For example, this can be used to learn about specific phases in an image,
exclude a dominant phase, or to separate subtle intergrowth compositions.
- An Image History window is now available from the “Windows->Image History” menu of the
Image Display window. It shows all image processing operations that have been performed on
each elemental image. This will show all history for all existing image files as well.
- The Image Table window now has a button to update just the currently selected region.
To make an adjustment to a region, select it by clicking on the row in Image Table, and then
click on the “Update: One” button. This will update the concentrations and store the new
region shape and position in the selected table row.
- The Image Operations window has been updated. It now includes an “Undo Last” button to
undo the last image processing operation performed. This also updates the Image History
window accordingly.
- Line profiles generated using the “Traverse” region now include an overlaid plot of the
detection limit (99% confidence) in each distance step, as a dashed curve.
New Features in GeoPIXE 2.3
- Fit Results now has an “Export All” button to export all results and parameter categories
to the output ASCII .CSV table.
- The “Traverse” image region now has shear control. The side handles, moved using the left
mouse button, usually control the width of the traverse region, perpendicular to the projection
axis. Now you can shear this projection, so that it’s not perpendicular. Use the right mouse
button to select these side handles and slide parallel to the main axis to change the shear.
New Features in GeoPIXE 2.2
- Spectrum Display now has two ASCII spectrum file import options. One reads spectra, one
from each column, into consecutive spectra. The other reads ASCII spectra files that contain
channel energy as the first column (e.g. as produced by the “File->Export->CSV Table” menu)
and one or more spectra channel counts as the subsequent columns. These files can be white
space, comma or tab delimited, or a combination of these.
- More import options have been added for old format GeoPIXE VAX binary spectra files and
for ASCII files. The ASCII import option can read files with multiple spectra as columns. There
are two menus. One reads files where the first column is channel energy. The second reads
all columns as spectra. Both assume that the first row contains column labels, and if energy
mode is chosen, it uses the label for the first column as energy units. These functions can
handle column separation using white-space (spaces, tabs) or commas, or a combinations of these.
- Spectrum Display now has Windows Metafile export options. Go to menu “File->Export->WMF
Plot on Black” for output for a dark background, or “File->Export->WMF Plot on White” for
output for a light background. These files, like the CGM ones, can be imported into PowerPoint
as pictures.
- The detector efficiency function has generally followed the function of Cohen (Nucl. Instr.
Meth 178 (1980) 481), as corrected by Ryan et al. (C.G. Ryan, D.R. Cousens, S.H. Sie and W.L.
Griffin, "Quantitative Analysis of PIXE Spectra in Geoscience Applications", Nucl. Instr. Meth.
B49 (1990), 271-276), which uses a multiplicative factor of 0.717. GeoPIXE has used this to be
consistent with packages such as PIXAN. A new option in the Detector Setup window makes this
factor optional. Use this to be consistent with other packages that do not follow Cohen.
- The menus for display of calculated pileup and Si and Ge escape spectra are now active in
Spectrum Display, under the Display menu.
New Features in GeoPIXE 2.1
- There is a new feature in the Correct Yields window
for the correction of artifacts in images caused by the spatial variation
of X-ray absorption across the image. Details of the process can be found
in (C.G. Ryan, E. van Achterbergh, G. Mark, C.J. Yeats, S.L. Drieberg, B.M.
McInnes, T.T. Win, G. Cripps and G.F. Suter, "Quantitative, High Sensitivity,
High Resolution, Nuclear Microprobe Imaging of Fluids, Melts and Minerals",
Nucl. Instr. Meth. B188 (2002) 18-27.).
- The projection onto end-member phases now also produces an image corresponding
to the remainder, i.e. the proportion not assigned to the end-member phases.
- Support for 4 list-mode formats is provided: Mpsys on Linux and Unix, Sparrow
Kmax on Macintosh, and XSYS on VAX/VMS.
- Interactive set-up windows for filter and detector definitions are now
provided. Go to the Windows menus on the Image Display
or Spectrum Display windows.
New Features in GeoPIXE 2.0
- There is a new Cuts Setup window for the interactive set-up of energy cuts on spectra.
The window also displays background-subtracted peak-areas deduced using cuts. Cuts can be
named for use in sorting list-mode data, for example from non-PIXE ADC channels.
New Features in GeoPIXE 1.9
- There is a new feature for the correction of concentration due to the spatial
variation of PIXE yields caused by changing sample composition across an image.
The new Correct Yields window allows for this correction,
using a new approximation for combining PIXE yields calculated for end-member
components (see C.G. Ryan, "Quantitative Trace Element Imaging using PIXE
and the Nuclear Microprobe", International Journal of Imaging Systems and
Technology [Special issue on Quantitative Imaging] 11 (2000) 219-230 and C.G.
Ryan, E. van Achterbergh, C.J. Yeats, Tin Tin Win and G. Cripps, “Quantitative
PIXE trace element imaging of minerals using the new CSIRO-GEMOC Nuclear Microprobe”,
Nucl. Instr. Meth. B 189 (2002) 400-407).
- The Correct Yields window also provides projection
of element images onto images of end-member components.
- GeoPIXE can sort list-mode data with up to 16 ADCs.
Features of GeoPIXE II ™
- PIXE/SXRF spectrum fitting (unlimited elements and X-ray lines). See C.G. Ryan, D.R.
Cousens, S.H. Sie and W.L. Griffin, "Quantitative Analysis of PIXE Spectra
in Geoscience Applications", Nucl. Instr. Meth. B49 (1990), 271-276 for details
of the fitting algorithm. This has been developed over the past decade, and
tried and proven in interlaboratory and blind industry checks over the past
10 years (e.g. Federowich et al., Can. Min. 33(1995) 469-480, show GeoPIXE
accuracy of better than 3% in a published blind test).
- PIXE/SXRF yield calculation, including secondary fluorescence and able to treat
virtually unlimited multilayered targets. A special feature is that the yields
of ALL X-ray lines are integrated through the layered structure so that the
X-ray relative intensities accurately reflect the full target structure. This
gives much better spectrum fits for complex samples.
- SNIP background treatment (C.G. Ryan, E. Clayton, W.L. Griffin, S.H. Sie
and D.R. Cousens, "SNIP, a Statistics Sensitive Background Treatment for the
Quantitative Analysis of PIXE Spectra in Geoscience Applications", Nucl. Instr.
Meth. B34 (1988), 396-402). Background shape can accommodate the effects of
detector efficiency and filter absorption.
- The PIXE/SXRF spectrum fit generates a Dynamic Analysis
(DA) transform matrix. This enables the projection of EVT data (list-mode,
or event-by-event data) directly onto quantitative elemental images. This
process resolves element overlaps, strongly rejecting artifacts from overlapping
elements and detector response effects (escape peaks, tails) and subtracts
background. Pileups are well treated in many cases which involve a single
dominant element or majors in fixed ratios. (A more general approach is under
development.) The results are quantitative images in ppm.charge/flux units.
Concentration variance images are also accumulated (at half resolution to
minimize memory usage), so that error estimates and detection limits can be
provided for all extracted concentration values and line profile projections,
etc. The DA method is treated elsewhere (C.G. Ryan, D.N. Jamieson, C.L. Churms
and J.V. Pilcher, "A New Method for On-Line True Elemental Imaging using PIXE
and the Proton Microprobe", Nucl. Instr. Meth. B104 (1995), 157-165; C.G.
Ryan, "Quantitative Trace Element Imaging using PIXE and the Nuclear Microprobe",
International Journal of Imaging Systems and Technology (Special issue on
Quantitative Imaging) 11, (2000) 219-230; C.G. Ryan, "Developments in Dynamic
Analysis for Quantitative PIXE True Elemental Imaging", Nucl. Instr. Meth.
B181 (2001) 170-179; C.G. Ryan and D.N. Jamieson, Nucl. Instr. Meth. B77 (1993)
203-214).
- Direct interrogation of the images to extract concentration data from within
arbitrary "regions", or projected along traverses or line projections. These
include error estimates and detection limits.
- "Regions" supported at present include, box (sizeable, rotatable, movable
rectangle), circle, ellipse, 10-point spline curve, 32-point spline curve,
line projection rectangle (sizeable, rotatable, movable, and with shear control).
All can be positioned and moved, or changed in shape or orientation using
"handles". If many image windows are opened, or cloned, to display many elements,
then these regions will appear in the same place on all images. Clicking on
a button will then extract average concentrations (and errors, MDLs) from
within these areas (or projected along a centre line, in the case of line
projection mode). These results are tabulated, and can be exported.
- Spectra can be extracted from these regions, by sorting the EVT file, by
simply pressing a button. The resulting spectra from these regions appear
in a spectrum window, overlaid by the "fit" to each. This “fit” is estimated
from the DA deduced concentration data and pure-element spectral signatures.
This enables an immediate assessment of the quality of the images by looking
at the accuracy of the "fit" to the extracted spectra. This can often show
up a rare (concentrated in one spot) element that was missed from the initial
inspection of the overall PIXE/SXRF spectrum, for example. Such omissions can be
corrected, a new DA matrix generated, and the images re-projected. Extraction
of spectra from other ADCs is also supported here.
- GeoPIXE also supports sorting using energy cuts. Cuts are set-up and named
interactively, and can also perform background subtraction during list-mode
file processing.
- A GUI interface (built on IDL) allowing interactive spectrum fitting, EVT
sorting and image projection using Dynamic Analysis (or simple energy windows),
and quantitative analysis of arbitrary regions and line projections of the
images (all elements simultaneously). The windows are linked and communicate
with each other, as outlined below.
Windows include:
- IMAGE: Multielement image display (the main GeoPIXE window). Select the
element with a droplist. Zoom in steps (in and out), pan using scroll bars
(very fast, using fast graphics card features). Image operations (e.g. median
filter, boxcar, Gaussian smooth, edge enhancement, ...). Arbitrary region
selection (see below). Distance measurement. Colour map selection. Conc range
min/max mapped onto colour map. Multiple IMAGE windows can be cloned and positioned
at will over the screen. However, these remain linked, so that region selection
is visible in all (used to display multiple elements). Menus select sort EVT
window, spectrum window, image regions results window, image processing window,
yield correction window, mineral end-member mapping window. Any number of
these windows can be cloned for the display of multiple elements.
- IMAGE OPERATIONS: A range of image operations for smoothing, etc. appear
as a list so that these functions can be performed with a single click.
- IMAGE HISTORY: A window that lists all image processing operations performed
on a selected elemental image.
- YIELD CORRECTION: A new method for pixel-by-pixel correction of images
for the changing PIXE yields with changing sample composition across an image
area can be performed very easily within this popup control panel. (See C.G.
Ryan, "Quantitative Trace Element Imaging using PIXE and the Nuclear Microprobe",
International Journal of Imaging Systems and Technology [Special issue on
Quantitative Imaging] 11 (2000) 219-230).
- END-MEMBER PROJECTION: An alternate function of the yield correction window,
this projects element images onto a set of end-member composition images.
- SORT EVT: Accepts parameters about the imaged area (scan size, pixel ranges,
etc.), EVT file, mode (image, line traverse, stepping modes) and controls
the sorting of the EVT file. You can sort using DA projection or using simple
energy windows (with background subtraction, for PIGE, RBS, etc.). You don't
need to specify the list of elements to sort for, as this comes with the DA
matrix, straight from the PIXE/SXRF Fit fitting process.
- IMAGE REGIONS: Lists the results of integration of images within regions
in a table. These can be exported. Clicking on a row of results displays the
corresponding region on all images for this data-set on the screen (and displays
the corresponding extracted spectrum, if loaded). A droplist selects the display
in the table of concentration, error estimates, MDL (99% confidence limits),
relative error, and raw results. These can be save/restored to/from files.
A button "EVT" on this window starts sorting the EVT file to extract all spectra
from within these regions. These are saved to disk, and also popup in the
open spectrum window. With these loaded, clicking on a row of results will
select the corresponding spectrum in the spectrum window, and overlay it with
the “fit” estimated from the concentrations and the pure-element spectral
signatures.
- SPECTRUM DISPLAY: Displays PIXE/SXRF spectra (also X,Y, line profiles, PIGE,
RBS, ...). Can manipulate view, bump up and down, log/linear, and scroll through
spectrum (very fast, using fast graphics card features). Set markers for line
identification, selecting the fitting range, setting "cuts", energy calibration,
etc. A "?" button brings up the X-ray line identification window. Menus select
spectrum selection window, digital filters, sort EVT window, and the PIXE
Fit window. There is also a growing list of import options.
- XRAY IDENTIFICATION: Works in two modes: Line identification mode, uses
a marker positioned on the spectrum to identify peaks. As you move this marker,
the closest match in the line database is provided in the scrolling identification
window, along with a number of lines on each side. The relative intensity
threshold adjusts which lines are viewed. In mark element mode, the window
transforms into a periodic table. Clicking on an element causes all lines
for that element to be marked in the spectrum. You can optionally select K,
L and M lines (all, separately or in combinations).
- SPECTRUM SELECTION: A window to select which spectra are displayed and
overlaid, and whether fit overlays are shown. You can also edit spectrum parameters
in this table.
- CALIBRATION: A popup window for spectrum energy calibration. Marked peaks
can be specified as primary X-ray lines, escape peaks, or pileup, and selected
by element names and droplists. An existing calibration can be extracted from
another spectrum using a “Get” button.
- X-RAY SPECTRUM FIT: Controls the fitting of the PIXE/SXRF spectrum. You select filters,
yield calculation (which provides relative line intensities), detector parameter
set, energy range (or this comes from spectrum display), optional cuts, background
algorithm, and elements to fit. As elements are selected, you immediately
see the zeroth-order initial estimate of these on the spectrum. Once the list
is complete, press a button to fit the spectrum. The results can be displayed
in the FIT RESULTS window. Another button will generate a DA matrix for image
projection.
- FIT RESULTS: An interactive table of results from spectrum fitting. You
can view concentration, error estimates, MDL, as well as fit statistics, PIXE/SXRF
yields and relative intensities, detector and filter parameters.
- RESULT PROPERTIES: Properties of fitting results, such as filter, detector,
or yield selection can be altered, or fluid inclusion geometry modeling performed.
- X-RAY YIELD CALCULATION: A button on the X-ray spectrum Fit panel
brings up the panel for PIXE/SXRF yield calculation. The calculation includes secondary
fluorescence and is based on ECPSSR cross-sections. For SXRF, the calculations use the
the recent compilations of sub-shell absorption cross-sections of Ebel (
H. Ebel et al., X-ray Spectrometry 32 (2003) 442.),
the Coster-Kronig rates, fluorescence yields and branching ratios of Elam (W.T. Elam et al., Radiation Physics and Chemistry 63 (2002) 121)
and an empirical treatment of scatter peaks. The yield calculation
can accommodate any arbitrary layered target structure. The GUI panel enables
20 layers to be specified, with thickness in mg/cm2 or microns. Chemical formula
can be specified, or entered as oxide components, with weightings in atomic
fraction or weight %. There are also parameters to specify target rotation
and tilt and detector angle, in and above the plane.
- CUTS SETUP: A window that displays energy cuts for set-up or editing.
- FILTER SETUP: A window for setting-up or editing filter definition files.
- DETECTOR SETUP: A window for setting-up or editing filter definition files.
- ASSOCIATION: A window to display element-element correlations between image
pixel concentrations, treated as data points in multi-element space. There
are tools to highlight regions of the spatial image corresponding to areas
in element-element space, to extract spectra from these regions, and to limit
the correlation to spatial regions in the image.
- IMAGE RGB: A 24-bit colour window that displays three elements as the red,
green and blue components of 24-bit colour.
- BATCH SORT: Window to perform batch processing of list-mode files. It scans
directory trees for list-mode files, builds directory trees with list-modes
in each leaf, and provides an interface to edit parameters and monitor batch
processing.
- EXPORT SET-UP: A window to select options for export of data from GeoPIXE.
Different versions of this window are used for export of images, spectra,
traverses, fitted results as CGM, WMF, EPS, CSV tables for spreadsheet programs
or to the printer.
Return to the main GeoPIXE II page.
Go to the main CSIRO-GEMOC Nuclear Microprobe web page.
CSIRO © 1999-2002
Please direct comments about this web page to Chris Ryan.
Graphics for these pages have been prepared using Amiga
rendering and image processing software.