Table of Contents
This custom interface integrates several tasks related to engineering diffraction. It provides functionality for calibration, focusing, and pre-processing of event mode data. Further extensions can be expected for next releases as it is under active development. Feedback is very much welcome. The following sections describe the different tabs or functionality areas of the interface.
This tab provides a graphical interface to calculate calibrations and visualize them.
It is possible to load an existing calibration (as a CSV file) and to generate a new calibration file (which becomes the new current calibration).
With the help of Cropped Calibration user can also calibrate according to bank or by setting the SpectrumIDs once the Cropped Calibration group box has been enabled.
These parameters are required to generate new calibrations:
The calibration process depends on several additional parameters and settings which can be modified in the Settings section (tab), see below for details.
Here it is possible to focus run files, by providing a run number or a range of run number to enable multi-run focusing, along with that the user may also select the files with the help of Browse button.
The focusing process uses the algorithm EnggFocus. In the documentation of the algorithm you can find the details on how the input runs are focused.
The interface will also create workspaces that can be inspected in the workspaces window:
Three focusing alternatives are provided:
Depending on the alternative chosen, the focusing operation will include different banks and/or combinations of spectra (detectors). In the firs option, normal focusing, all the selected banks and all the spectra present in the input runs are considered. In the second alternative, cropped focusing, all the banks are considered in principle but only a list of spectra provided manually are processed. In the third option, texture focusing, the banks are defined by a user-defined list of banks and corresponding spectrum IDs provided in a file. For these alternatives, the output focused workspace will take different suffixes: _bank_1, _bank_2, and so on for normal focusing, _cropped for cropped focusing, and _texture_bank_1, _texture_bank_2, and so on for texture focusing (using the bank IDs given in the detector grouping file).
Cropped focusing and Texture focusing have been disabled by default to declutter the interface, but each section can be enabled simply by ticking the check-box next to Focus Cropped and Focus Texture.
For texture focusing, the detector grouping file is a text (csv) file with one line per bank. Each line must contain at least two numeric fields, where the first one specifies the bank ID, and the second and subsequent ones different spectrum numbers or ranges of spectrum numbers. For example:
# Bank ID, spectrum numbers
1, 205-210
2, 100, 102, 107
3, 300, 310, 320-329, 350-370
When a focus run process is being carried out, Focus Stop button will be enabled. Focus Stop button will allow the user to abort once the current focus run process has been completed. Inside the Result Log a warning message will be displayed with last successful run and total number of focus runs that could not be processed.
The run provided to focus can be for example 228061-228063, this will run all the files within the given range as long as the file directories are included in the User Directories. The user may also provide an input of 228061-3 or 228061, 228062, 2280623 which should work the same way.
If a red star sign is displayed next to the Browse Button, it is mostly likely because the file specified has not been found. Error message can be viewed by hovering over the red star sign.
Checking the availability of all the files can take some time, for this reason it is also possible that a file may not have been found but the red star sign has not been displayed. If you manage to click Focus before red sign is displayed, the interface will process the last valid focus run instead.
Under the output section, the user is provided with an option of plotting data in three different formats. One Window - Replacing Plots: will replace the previous graph and plot a new graph on top. One Window - Waterfall: will plot all the generated focused workspace graphs in one window which can be useful while comparing various graphs. The Multiple Windows: will plot graph in separate windows. However, user may also change the Plot Data Representation drop-down box while a run is being carried out. This will update the interface and plot workspace according to the new given input. For example, if a user has selected One Window - Replacing Plots and then decides to change it to One Window - Waterfall during a run, the interface will carry on by plotting Waterfall within the same window.
The user also has an option of generated GSS, XYE and OpenGenie formatted file by clicking the Output Files checkbox. This will generated three different files for each focused output workspace in Mantid. These files can be found with appropriate name at location: C:EnginX_MantidUser236516Focus on Windows, the EnginX_Mantid folder can be found on Desktop/Home on other platforms.
The Multiple Runs Focus Mode combo-box enables two alternative focus mode. Focus Individual Run Files Separately is the default option set, which allows user to run focus with multi-run files. Whereas the Focus Sum Of Files option merges all the multi-run number files together and applies the Focus Process to the merged file.
Warning
This is a new capability that is currently in a very early stage of definition and implementation. Not all options may be supported and/or consistent at the moment.
The focusing options can be applied directly to histogram data. For event mode experiments, the event data (which would be loaded as event workspaces in Mantid) need to be pre-processed.
The simplest pre-processing option is “regular time binning” which will produce a histogram data workspace (as a Workspace2D). The only parameter required is the bin width. The workspace will be named with the following convention:
When the input run file contains multiple workspaces (it would be loaded by Load as multiple EventWorkspace workspaces) the output workspace will be a group with the corresponding number of histogram workspaces, binned separately. This is the case when the input run file comes from a multi-period experiment. Note that the time bin can be a multiple of the pulse time.
A different way of pre-processing event data is by rebinning multi-period data by pulse times. In this case the input required is the time step for the binning (the x axis of the output will be time instead of time-of-flight). It is also possible to specify the number of periods that will be processed (starting from the first one). This type of pre-processing produces workspaces with the following naming convention:
This tab uses the algorithms Rebin and Rebin to bin the data in different ways when converting event data into histogram data.
Controls several settings, including the input folders where the instrument run files can be found. Other advanced options can also be controlled to customize the way the underlying calculations are performed.
The calibration settings are organized in three blocks:
The input directories will be used when looking for run files (Vanadium and Ceria). They effectively become part of the search path of Mantid when using this interface.
The pixel (full) calibration file contains the calibration details of every pixel of all banks, as produced by the algorithm EnggCalibrateFull. A default pixel calibration file is provided with Mantid packages. This calibration has been produced for the Vanadium and calibration sample (Ceria) runs indicated in the name of the calibration file. Note that this calibration is currently subject to changes, as the fitting of peaks is being refined.
The Following advanced settings are available to customize the behavior of this interface:
Most of the functionality provided by this interface is based on the engineering diffraction Mantid algorithms (which are named with the prefix Engg). This includes EnggCalibrate, EnggCalibrateFull, EnggVanadiumCorrections, EnggFocus, and several other algorithms, explained in detail in the Mantid algorithms documentation.
Categories: Interfaces | Diffraction