Liquid/amorphous structure measurement

A python program ‘multiangle.py’ is available for automatic data acquisition of EDXD pattern with varying 2θ angle.

  • Open the python program by running ‘multiangle.bat’ from the desktop shortcut.

multiangle_setup

You have the following 3 options:

  1. Create a new setup automatically by clicking Setup in main window. In the pop-up window enter desired q-range and usable E range, and % overlap for the measurements. The built in algorithm will calculate optimal 2theta angles and populate the main window.

multiangle_automatic
  1. Load previously saved setup, click Load in main window

  2. Add 2-theta angles manually by clicking Add in the main window for each angle.

Adjust the slit sizes and exposure times for each 2-theta

Input paramters description

Setting

Description

2theta angle

Exp. (s)

Data collection time in Live time (i.e. Actual data acquisition time is Live time + Dead time)

1stV

1st slit Vertical size

1stH

1st slit Horizontal size

2ndV

2nd slit Vertical size

2ndH

2nd slit Horizontal size

Det.V

Detector slit Vertical size

Det.H

Detector slit Horizontal size

If you want to repeat measurement, you can set ‘Iterations’ = 2 or higher.

Important

Confirm the following:

  • ‘Camera Vpos’ = 110, ‘Beamstop’ = OUT, ‘Tip X’ = 0

  • ‘Scan1 MCA Trigger Toggle’ = OFF (nothing in line 2) Both ‘Preset Real Time’ and ‘Preset Live Time’ = 0

  • Slit and Filter setup is ‘EDXD’ condition (‘Filter’ = 0, slit size is small) ‘position of sample is correct’.

Then, in hpMCA:

  1. Make sure file number is set to auto-increment

  2. Open File ‣ Preferences

  3. In preferences, please check ‘yes’ for ‘autosave when acquisition stopped’. (hpMCA will save file for each angle data with the name suffix of ‘_001’, ‘_002’…).

Then, to start multiangle measurement,

  • On Multiangle control window, click Run

Important

After finishing the Multiangle collection, please do not forget to check ‘no’ for ‘autosave when acquisition stopped’.

If you want to stop the Multiangle measurement, click Stop.