Once the spectrum image (SI) acquisition parameters and any artifact corrections are set up, select the Capture button on the SI palette to start an acquisition. If you wish to update the survey image before proceeding with acquisition, right-click on it and select Restart scan from the context menu.
Once started, the SI acquisition routine will control the microscope beam, and the acquisition will then begin. During acquisition, the Capture button pulses in blue to indicate that an acquisition is active and that a subsequent click of the Capture button halts the acquisition. A new workspace is created and filled with a copy of the survey image and data containers for all acquired signals.
Note: During active SI acquisition, the spectrometers are unavailable for single-spectrum acquisition.
If spatial drift correction is enabled, some preliminary measurements are performed. Depending on the preferences specified, visual feedback on the measurements may be provided.
You can monitor how the acquisition is proceeding using the visual feedback provided. Each SI is displayed in a new image window, which fills as the acquisition proceeds. Live spectra may also be shown or hidden as desired. If you wish to halt the acquisition, click the pulsing Capture button. When the acquisition is halted or completed, the beam control returns to the Beam Safe Point (if one has been set up), or alternatively, it is returned to the microscope.
During an SI acquisition, performing a microscope adjustment that temporarily degrades the data collected by the spectrometer may become necessary. At such times, you should pause the acquisition, adjust, and resume after conditions have stabilized. To pause the acquisition at any time, click on the pulsing Capture button in the STEM-SI palette while keeping the Alt key pressed at the same time—the label of the Capture button changes to Resume.
When you pause the acquisition, the beam either moves to the Beam Safe Point (if you defined one) or returns otherwise beam control to the microscope. If the acquisition is paused and restarted, the software immediately carries out spatial drift corrections if you enable Apply on Resume from Pause before acquiring data from where it was before the pause.
To resume acquisition from the paused state, click the Resume button. To stop acquisition from the paused state, click on the Resume button while pressing the Alt key at the same time.
Note: Pausing is not available for hardware-synchronized acquisitions. On systems that, by default, use hardware synchronized acquisition, you can force software synchronization via the Setup dialog.
All experimental data is saved immediately using the current SI group saving options if the autosave functionality is enabled. If the close column values after acquisition option is enabled, the microscope column valves are closed (on systems that support column valve access). You can use the (still) active survey image on the View workspace to immediately restart an identical or similar acquisition after adjusting survey ROIs and parameters.