dtcollect on-line help
On-line help in dtcollect is provided by HyperText Markup Language
files that are viewable via a HTML viewer such as NCSA mosaic.
Help is available by choosing Help in the dtcollect menubar.
With dtcollect you can:
- Open and close the X-ray shutter,
- Move the crystal goniometer to any allowed position,
- Move the detector goniometer (if motorized) to any allowed position,
- Move the source to any allowed wavelength (if motorized),
- Collect single or multiple exposures with and without opening the shutter and with or without
moving the crystal goniometer: shutter-closed stills (dark images), shutter-open stills,
shutter-open scans, or shutter-closed scans. For scans, the crystal can be rotated
around either of two crystal goniometer axes that are usually called omega and phi;
- Edit, save, and load scans and/or tables of scans,
- Collect one scan or a series of up to 100 scans.
- Monitor the progress of the experiment through nearly instantaneous feedback on the
current status of the hardware devices: shutter, goniometers, counters, and detectors.
- Communicate with dtdisplay to automatically display images.
What is a SCAN?
As used through the d*TREK documentation a scan is a contiguous set (in time and often in
rotation angle) of collected images. For example, the first image in a scan might be
acquired by exposing a crystal for 10 seconds while rotating the phi axis from 0 to 1
degree, the second image by rotating the phi axis from 1 to 2 degrees, and the last image
by rotating phi from 179 to 180 degrees. Or a scan might consist of 100 dark or shutter-closed
images without moving any motors as a way to characterize the dark current in a
CCD (charge-coupled device) detector.
For more help, choose one of the following topics:
Hyperlinks are usually underlined and displayed in blue letters.
To close a Help window, choose File->Close or
File->Exit from the menubar in this window.