UB Sample Alignment Panel

UB Sample Alignment Panel

Introduction

This panel helps the user align a sample in UB Matrix Mode.

Description

Components of the UB Sample Alignment Panel

The Alignment Mode drop down menu must be set to "UB Matrix enabled" to use the Sample Alignment Panel in UB mode.

  1. Setting Up the Orientation Lattice

    • a, b, c

      The user specifies vectors a, b, c that approximate spacings of the crystal lattice of the sample.

    • alpha, beta, gamma

      The user specifies angles between vectors of the orientation lattice. By default these angles are set to 90 degrees.

    • Apply/Reset Buttons

      The user must press the Apply button in order for changes to take effect. Pressing the reset button will reset the parameters to its default values.

  2. Align Sample at Lattice Reflections

    • h, k, l

      The user is required to specify the lattice reflection. In order to define the scattering plane, at least two reflections have to be found.

    • Drive A4

      The user may choose to drive motor A4 (sample 2theta) to specified lattice reflection.

    • Drive Q (A3/A4)

      Alternatively, the user can change values of motors A3 and A4 together by driving vector Q.

    • Calculated Angular Alignment Position

      Current sample position as given by values A4 (sample 2theta) abd A3 (sample theta) are displayed.

    • UB Reflection Set for Calculated Matrix

      Current positions of h, k, l, A3, A4, lower tilt, and upper tilt for Reflection Set.

    • Calculate UB Matrix Button

      The user must press the "Calculate UB Matrix" button to update the UB Reflection Set for the Matrix.

  3. Reflections for UB Calculation

    • Add Reflection Button

      The user can add a reflection by pressing the "Add Reflection" button. A new reflection will appear.

    • h, k, l, A3, A4, LTilt, UTilt

      The user may specify the lattice reflection, positions for A3 and A4, and positions for lower tilt and upper tilt.When a lattice reflection value is changed, the field's value is changed.

    • Apply Button

      The user must press the Apply button in order for changes to take effect.

    • Included Check Box

      To include a reflection, the Included check box must be checked. This enables the "Make Primary" button.

    • Make Primary Button

      To make a reflection primary, click the "Make Primary button". This changes the button label to "Primary".