Muon Testing

Ionic Diffusion test

Preparation

  • Instrument EMU
  • Files 51341.nxs, 51342.nxs and 51343.nxs
  • Make sure the location of these files is included in your search directories. Full instructions are available online.

Time required 5 - 10 minutes


  1. Make sure that the .nxs files are in one of the directories on Mantid’s search path.
  • Open Muon Analysis
  • Choose Machine: EMU
  • In Load Run enter 51341
  • Under Settings tab, ensure the Enable Multiple Fitting is checked
  • In Data Analysis Tab
    • Beside Runs enter 51341-3 and check Simultaneous below
    • Right click the Fit Function table area; select Add Function
    • Add Background > Flat Background
    • Add Muon > DynamicKuboToyabe
    • Check the Global box for: A0, Asym, Delta, Nu
    • Click on the value 0.0000 for Field - a ... box should appear, click it
      • On the Set dropdown, select Fix All
      • Enter values of 0, 5, 10 for the three runs
    • Set A0 = 0.05, Asym = 0.15, Delta = 0.2, Nu = 0.1
    • Click Fit > Fit
  • In the Results Table tab
    • Under Fitting Results check the Simultaneous button
    • Click Create Table
    • A table should appear in the main Mantid work area
  • In the Results Table workspace
    • Expected values (similar to within 50%) ..
    • f0.A0: -0.083439833711330152
    • f1.Asym: 0.19125607982528858
    • f1:Delta: 0.3301445010124604
    • f1:Nu: 0.8574644977974730220884
  • In the workspaces section of the main Mantid window:
    • Click of the MuonSimulFit_5141-3 group
    • Within this there should be three workspaces
    • Right-click each workspace
    • Choose Plot spectrum
    • Choose 1D plot and click Plot All

Possible problems

  • Loading local data for 51341-3; these may not be in recognised directories - make sure that this is the case.

Superconducting Copper Test

Preparation

  • Files EMU00020882.nxsEMU00020900.nxs
  • Make sure the location of these files is included in your search directories

Time required 5 - 10 minutes


  1. Make sure that the .nxs files are in one of the directories on Mantid’s search path.
  • Open Muon Analysis
  • Choose Machine: EMU
  • In Load Run enter 20882
  • Click the > tab next to Load Run a few times, this should produce new plots each time
  • Under Settings tab, ensure the Enable Multiple Fitting is un-checked
  • After loading 20884 switch to the Data Analysis tab
  • Right click under Property and select Add Function
  • Choose Muon > ExpDecayMuon
  • Click Fit > Fit
  • Click Fit > Sequential Fit
  • Beside Runs enter 20889-20900
  • Click start
  • Close the Sequential Fits window
  • Switch to the Results Table tab
  • In the Fitting Results table check the Sequential radio button
  • In the Values table check Run Number and Field_Danfysik
  • Ensure that all runs are checked in the Fitting Results table
  • Click Create Table
  • In the main Mantid GUI select the ResultsTable in the Workspaces tab, this is the one you just created
  • Right click and select Convert to MatrixWorkspace
  • In the resulting dialog select Column X as Field_Danfysik and Column Y as lambda
  • Click Run
  • Right click the new workspace created in the Workspaces tab
  • Select Plot Spectrum
  • You should get something like the following plot:
../../_images/Cu-fitting.png

HIFI Transverse Field Simultaneous Fitting

Preparation

  • Files HIFI00134028HIFI00134039.nxs
  • Make sure the location of these files is included in your search directories
  • Make sure that the instrument in the Muon Interface is set to HIFI

Time required 5 - 10 minutes


  1. Open the Muon interface, load the first file HIFI00134028
  • Using the > to the right of the Load Data box, step through to 134034
  • Go to the Grouping Options tab
  • Click Guess Alpha - in the Pair Table box a value of Alpha close to 1.3 should appear
  • Return to Home tab
  • Click > until all data sets up to 134039 have been loaded
  • In the Settings tab ensure that Enable Multiple Fitting is checked
  • Go to the Data Analysis tab
  • Right-click in the Fit Functions box
  • Select Add function
  • Choose Background>Flat Background
  • Right-click again and Add function
  • Choose Muon>ExpDecayOsc
  • In the Fit Function window select all parameters except Frequency to be Global
  • In the Runs box enter 134028-39
  • Check the Simultaneous radio button
  • Select Fit>Fit
  • After some time the fir should fail to converge, with a large Chi value (>100) reported in the Fit Function box.
  • So we want to re-start to see if the fit works a different way
  • In the main Mantid Workspaces dialog select all the workspaces and delete them
  • Back in the Muon interface load up HIFI00134034
  • Go to Grouping Options and select Guess Alpha
  • Go to the Data Analysis tab
  • In the Runs box enter 134028-39
  • Check the Simultaneous radio button
  • Add the same functions as above (Flat Background and ExpDecayOsc)
  • In the Fit Function window select all parameters except Frequency to be Global
  • Click on the value of the Frequency parameter; a ... box should appear, click it
  • Enter values for each of the rows in the table that opens, values from 0.0 - 1.1 in steps of 0.1
  • Click OK
  • Select Fit>Fit
  • You should now get a significantly lower Chi-sq value (<10)
  • In the main Mantid window
  • Click on the MuonSimulFit_134028-39
  • Scroll to the workspaces
  • Right-click on one, choose Plot spectrum
  • Choose 1D Plot and select Plot All
  • You should get some plots like this:
HIFI-TF-Result.png

Transverse Field Asymmetry Test

Preparation

  • Files MUSR00062260.nxs
  • Make sure the location of these files is included in your search directories
  • Make sure that the instrument in the Muon Interface is set to MUSR

Time required 5 - 10 minutes


  1. Open the Muon Data Analysis interface
  • Go to the home tab and select instrument MUSR
  • Load run 62260
    • Add a “Flat Background” and “GausOsc” functions
  • In the Data Analysis tab “TF Asymmetry Mode” should be ticked
  • Set the “Groups/Pairs to fit” to “Custom”
  • A pop-up should appear and make sure that only “fwd” is ticked
  • Close the pop-up
  • Run a fit