Changes between Version 20 and Version 21 of TartuSchoolSasView

Timestamp:

Sep 14, 2017 2:43:21 PM (7 years ago)

Author:

ajj

Comment:

—

TartuSchoolSasView

@@ -61 +61 @@
 
 == [=#section2 2.]  Exploring geometrical models ==
-
-
+In this part of the exercised, you will plot the scattering patterns calculated using different geometrical models and explore the effect that the model parameters have on the scattering.
+
+{{{
+#!div style="background: lightblue"
+**TASK:** Restart !SasView
+
+Before starting this part of the exercise, you should have a clean !SasView instance. Quit !SasView and restart it.
+}}}
+
+
+=== Spheres ===
+
+{{{
+#!div style="background: lightblue"
+**TASK:** Plot the scattering from a collection of spherical particles
+
+In the Fit Panel, there should be a single tab labelled "Fitpage1". In that tab, choose the model category "Sphere" and the model "sphere".
+}}}
+
+The fit panel and a plot panel that appears should look like the following:
+
+[[(Image(tartu_fitpage1_1.png)]][[Image(tartu_sphere.png)]]
+
+{{{
+#!div style="background: lightblue"
+**TASK:** Change the parameters and note the changes in the scattering pattern.
+
+In the "Fitpage1" tab, scroll down to the bottom and:
+ * Increase "Npts" to 200
+ * Check the "Log" box
+
+Next, click "Compute"
+
+This will improve the fidelity of the modelled curve.
+
+Now scroll back up and try adjusting the various model parameters one at a time. Pressing enter after changing a value should recalculate the scattering. If not, use the Compute button.
+
+What effect do the each of the parameters have on the scattering curve?
+* scale
+* background
+* sld and sld_solvent
+* radius
+}}}
+
+
+=== Cylinders ===
+
+{{{
+#!div style="background: lightblue"
+**TASK:** Plot the scattering from a collection of cylindrical particles
+
+From the "Fitting" menu, select "New Fit Page".
+
+In the Fit panel, a new tab labelled "Fitpage2" should appear. In that tab, choose the model category "Cylinder" and the model "cylinder".
+}}}
+
+The fit panel and a plot panel that appears should look like the following:
+
+[[(Image(tartu_fitpage2_1.png)]][[Image(tartu_cylinder.png)]]
+
+{{{
+#!div style="background: lightblue"
+**TASK:** Change the parameters and note the changes in the scattering pattern.
+
+In the "Fitpage2" tab, scroll down to the bottom and:
+ * Increase "Npts" to 200
+ * Check the "Log" box
+
+Next, click "Compute"
+
+This will improve the fidelity of the modelled curve.
+
+Now scroll back up and try adjusting the various model parameters one at a time. Pressing enter after changing a value should recalculate the scattering. If not, use the Compute button.
+
+What effect do the each of the parameters have on the scattering curve?
+* scale
+* background
+* sld and sld_solvent
+* radius
+* length
+}}}
+
+
+=== Polydispersity ===
+
+{{{
+#!div style="background: lightblue"
+**TASK:** Apply polydispersity to model parameters
+
+Select the "Fitpage1" tab that contains the sphere model.
+
+Find the section labelled "Polydispersity and Orientational Distribution"
+
+Click the "On" radio button and a new section should appear labelled "Distribution of radius".
+
+Enter a value for "PD[ratio]" between 0.0 and 1.0 - this is the polydispersity defined as sigma_r/r.
+
+What effect does varying the polydispersity have on the scattering curve?
+
+Repeat the exercise for the cylinder model in "Fitpage2"
+
+}}}