Output

herfd task

The output of the herfd task is a data file in the XDI format containing the HERFD spectrum at the specified emission energy and, if requested, gif images with the mask.

At each energy point, the HERFD signal is computed from the Pilatus image using the mask created as described above. The counts on each pixel lying within the illuminated portion of the mask are summed. This sum is the HERFD signal at that incident energy.

A column data file is written containing the energy and several scalars from the original measurement and a column containing the HERFD signal. This file can be imported directly into Athena.

rixs task

The output of the rixs task is the same as for the herfd script at each emission energy.

Todo

Athena .prj output from bla program

xes task

The output of the xes task is a data file in the XDI format containing the XES spectrum from that incident energy with the signal from each emission energy weighted by the number of illuminated pixels in that mask.

plane task

The output of the plane task is a data file in a simple format containing the emission intensity in the RIXS plane. This file can be read by gnuplot to display a map of the RIXS plane.

map task

The output of the map task is a data file in a simple format which can be read by gnuplot to display a map of detector column vs detector row with the color axis showing energy. Gif files for the masks at each emission energy are also written.

mask task

The output of the mask task is a single gif file containing the mask for the specified emission energy.

point task

The output of the point task is the HERFD value extracted from a specified BLA image for a specified emission energy. The value is printed to STDOUT. If files containing the BLA image or the emission mask do not exist or if any other problem is encountered, 0 is printed to STDOUT.

On Windows, tiff files are written rather than gif files.

The herfd, rixs, xes, and map tasks are intended for post-processing of a full data set.

The mask and point tasks are intended for inlining in the data acquisition process. The mask task should be run after measuring the elastic images at the emission energy and before measuring the HERFD data. The mask task takes a couple seconds.

The point task is intended for generating the HERFD value at a specific emission energy during the scan. This value can be used for plotting or storing to the output data file. The point task takes less than 1 second.

Animations

Using ImageMagick on the output masks:

convert -layers OptimizePlus -delay 5x100 *mask.gif -loop 0 mask_animation.gif

Todo

Write animations using PDL

XDI Output

All ASCII column data is written in the XDI format. This is particularly handy for the RIXS function. If XDI metadata is provided, then the BLA.pixel_ratio metadata item will be written to the output file. This number is computed from the number of pixels illuminated in the mask at each emission energy. The pixel ratio for an emission energy is the number of pixels from the emission energy with the largest number of illuminated pixels divided by the number of illuminated pixels at that energy.

The pixel ratio can be used to normalize the μ(E) data from each emission energy. The concept is that the normalized μ(E) data are an approximation of what they would be if each emission energy was equally represented on the face of the detector.

The version of Athena based on Demeter will be able to use these values as importance or plot multiplier values if the Xray::XDI module is available.

XDI metadata about the beamline and sample can be supplied using the -x switch for the bla program, the BLAXDIINI environment variable, or in the [files] block of the configuration file. Here is an example ini file used to provide this metadata.

[column]
1 = energy eV
2 = mu
3 = i0
4 = it
5 = ifl
6 = ir
7 = herfd
8 = integration seconds
9 = ring mA

[xescolumn]
1 = energy eV
2 = xes
3 = npixels
4 = raw

[beamline]
name = APS 10ID (MRCAT)
collimation = none
focusing = HR mirror in the vertical, KB mirror in the horizontal
harmonic_rejection = Pt coated mirror

[facility]
energy = 7.00 GeV
source = APS Undulator A

[mono]
name = Si (111)
d_spacing = 3.13553

[detector]
i0 = 1cm N2
herfd = bent Laue analyzer, Si(660), Pilatus 100K


Xray::BLA and METIS are copyright © 2011-2014, 2016 Bruce Ravel and Jeremy Kropf – This document is copyright © 2016 Bruce Ravel

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