Indirect Inelastic Testing

Prerequisites

Data reduction

Preparation

  • Instrument IRIS

  • You need access to the ISIS data archive

Time required 2-5 minutes

  1. Open Interfaces > Indirect > Data reduction

  2. Make sure Instrument is set to IRIS

  3. Go to the ISIS calibration

  4. Enter Input Runs 26173

  5. Click Run

  6. This should generate a workspace with _calib at the end, delete this workspace

  7. Change the Scale by factor value to 0.5

  8. Click Run

  9. This should generate a workspace with _calib at the end

  10. Check the Create RES box

  11. Click Run

  12. This should generate a workspace with _res at the end

  13. In the Output options, select the _res workspace and click Plot Spectra. This should produce a spectrum plot.

  14. Then select the _calib workspace and use the down arrow to click Plot Bins. This should produce a bin plot.

  15. Enter Input Runs 55878-55879 and check Sum Files

  16. Click Run, this should produce a _calib workspace

  17. Make sure that you keep the _calib workspace, it is needed for the next test

  18. Enter Input Runs 59057-59059 and check Sum Files

  19. Set Reflection to 004

  20. This should produce a new _calib workspace, with 004 in the name.

  21. Before moving on, set Reflection to 002

Time required 5-10 minutes

  1. Open Interfaces > Indirect > Data reduction

  2. Make sure Instrument is set to IRIS

  3. Make sure the tab is set to ISIS Energy Transfer

  4. Check the Sum Files box

  5. In the Input Runs box enter 26184-26185

  6. Click Run

  7. Check the Use Calib File box

  8. Change File to Workspace and choose the _calib workspace previously created (55878 from the previous test)

  9. Click Run

  10. In the main GUI right-click on the iris26184_multi_graphite002_red workspace

  11. Choose Plot spectrum, note the number of spectra, should be 51

  12. Click Cancel

  13. In the Data reduction GUI, change the Detector Grouping to Groups

  14. Set Groups to 5

  15. Click Run

  16. In the main GUI right-click on the iris26184_multi_graphite002_red workspace

  17. Choose Plot spectrum, note the number of spectra, should be 6

  18. Choose Plot All, this should result in a plot of all 6 spectra

  19. Open Interfaces > Inelastic > Data Manipulation and go to the S(Q, W) tab

  20. Change File to Workspace and load the _red workspace just created

  21. Q-Low and Q-High should be automatically updated to the y axis range of the contour plot.

  22. E-Low and E-High should be automatically updated to the x axis range of the contour plot.

  23. Click Run. An _sqw workspace should be created.

  24. Check Rebin in energy

  25. Click Run

  26. Within the Output section, click the down arrow on the Plot Spectra button and then select Open Slice Viewer, this should open a slice viewer window.

  27. Click Manage User Directories and set the default save location

  28. Click Save Result

  29. Check that the .nxs file was created in the correct location

Data analysis Elwin

Preparation

  • ISIS Sample data set, available here

  • Make sure that the data set is on your list of search directories

Time required 3 - 5 minutes

  1. Go to Interfaces > Inelastic > Data Manipulation

  2. Go to the Elwin tab

  3. Enter irs26176_graphite002_red.nxs in Input file

  4. Click Run - this should produce 3 new workspaces _elf, _eq and _eq2

  5. Now in Input file choose browse, navigate to the ISIS-Sample data and select the two files above simultaneously, by using shift key

  6. Change the integration range from -0.2 to 0.2

  7. Click Run

  8. This should result in three new workspaces again, this time with file ranges as their name

  9. In the main GUI right-click on irs26174-26176_graphite002_red_elwin_eq2 and choose Plot Spectrum, choose Plot All

  10. This should plot two lines of \(ln((meV))^{-1}\) vs \(Q2\)

  11. Right-click on the irs26176_graphite002_elwin_eq workspace and Save Nexus; save to a location of your choice; you will use this file in the next test

Data analysis MSD

Preparation

  • The _eq.nxs file from the previous test

Time required 3 - 5 minutes

  1. Go to Interfaces > Indirect > Data Analysis

  2. Go to the MSD fit tab

  3. Click Add Workspace

  4. With the combo box set to File click browse and select the file that you saved in the previous test

  5. Check All Spectra

  6. Click Add and close the dialogue.

  7. Set Fit type to Gaussian

  8. Click Run

  9. This should produce a plot of the fitted function in the interface

  10. Change End X to 1.0

  11. Click Run

  12. Repeat the previous steps with Peters and Yi functions

  13. Try run fits using the different Minimizer options (except FABADA), each time change the End X value either + or - 0.1

Data analysis I(Q, T)

Preparation

  • Access to ISIS sample data

Time required 3 - 5 minutes

  1. Go to Interfaces > Inelastic > Data Manipulation

  2. Go to the Iqt tab

  3. Load the irs26176_graphite002_red.nxs file from the sample data

  4. Load the resolution file irs26173_graphite002_res.nxs from the sample data

  5. Click Run

  6. A new workspace with the suffix _iqt should appear in the main GUI, it should be a workspace with 51 histograms and 86 bins. NB keep this workspace for the next test

  7. Click Plot Current preview this should plot the same data as the preview window

  8. Choose some workspace indices (e.g. 0-2) in the Output section and click Plot Spectra this should give a plot with the title irs26176_graphite002_iqt

  9. Click the down arrow on the Plot Spectra button and then select Plot Tiled. This should give a tiled plot of the selected workspace indices.

Data analysis I(Q, T) Fit

Preparation

  • The _iqt workspace from the previous test

Time required 3 - 5 minutes

  1. Go to Interfaces > Indirect > Data Analysis

  2. Go to the I(Q, T) Fit tab

  3. Click Add Workspace

  4. With the combo box set to Workspace select the _iqt workspace from the previous test

  5. Check All Spectra

  6. Click Add and close the dialogue.

  7. Set Exponential to 1

  8. In the data table set EndX for WS Index 0 to 0.14

  9. Using shift select the EndX for all spectra and click unify range, this should set the EndX for all spectra to 0.14

  10. Click Run

  11. This should produce a fit and a difference plot in the window

  12. Click Plot current preview this should open a plot with three datasets plotted

  13. Select the runs 6 - 50 and click Remove

  14. Click Run

  15. Select Lifetime from the Output drop-down

  16. Click Plot this should open a new plot with the lifetimes plotted

Data analysis Conv Fit

Preparation

Time required 3 - 5 minutes

  1. Go to Interfaces > Indirect > Data Analysis

  2. Go to the Conv Fit tab

  3. Click Add Workspace

  4. With the combo box’s set to File

  5. Click browse and load the irs26176_graphite002_red.nxs file from the sample data

  6. Click browse and load the resolution file irs26173_graphite002_res.nxs from the sample data

  7. In Workspace Indices enter 0-5

  8. Click Add and close the dialogue.

  9. Set Lorentzians to 2

  10. Set Max iterations to 400

  11. Click Run

  12. Three new workspaces should be created in the main GUI - Parameters, Result and Workspaces

  13. In the Mini plots widget, change Plot Spectrum to 3

  14. Click Fit Single Spectrum the plot should update and new workspaces are created in the main Mantid GUI

  15. Remove spectra 0-2, then remove spectra 5. do these as separate removals.

  16. Click Run; the plot should update and new workspaces are created in the main Mantid GUI

  17. Try the various Plot options in the interface

    1. Output drop-down set to All and click Plot - should give 5 separate plots

    2. Plot Current Preview - should result in a plot with three datasets

    3. Enable the Plot Guess checkbox - should not change anything, but should not break anything either!

  18. Change the Fit type to different functions and run fits

Data analysis F(Q) Fit

Preparation

Time required 3 - 5 minutes

  1. Go to Interfaces > Indirect > Data Analysis

  2. Go to the F(Q) Fit tab

  3. Click Add Workspace

  4. With the combo box set to Workspace select the 0-5__Result workspace from the previous test

  5. In Parameter Name select f1.f0.FWHM

  6. Click Add and close the dialogue.

  7. Under Fit Type select TeixeiraWater

  8. Click Run

  9. Three new workspaces should be created in the main GUI - Parameters, Result and Workspaces

  10. Change the Fit type to different functions and run fits