CEOS corrector

Owned by gys37319
Last updated: Apr 12, 2023 by eha56862
Do not attempt to do anything you have not been trained to do by ePSIC staff.

This procedure is for tuning the probe corrector immediately after changing accelerating voltage, e.g. from 200 kV to 80 keV. Normally, if the microscope is at 200 kV the manual alignment / correction of ronchigram is sufficient. In order to run the CEOS corrector a standard STEM tuning sample (evaporated gold on C) needs to be inserted.

Step-by-step guide

Apply lens relaxation before starting the procedure below. 

Step 1- Manually correct coma and 2-fold stig using beam tilt and CORR CRS STIG, respectively. 

Step 2- Insert 20 um CL2 aperture and select 12 cm CL and select JEOL-ADF1 to form an image

Step 3- Form an STEM image at 400 kX MAG, making sure that OL is at standard focus condition.

Step 4- Stop scanning in GMS and switch to CEOS UI. Check that there is communication between CEOS and the microscope, e.g. check MAG. Press Get DP12 button to get the corrected beam tilt value in CEOS. Run C1/A1 checking and press A1-coarse and C1 reach a condition that both are less than 5 nm.

Step 5- Run Zemlin tableau (with the options of standard, fast and enhanced, with enhanced providing the best accuracy).

Step 6- After tableau is finished, press OK button to accept the result and then press the necessary correction button based on the outcome of the measurement. Check A1/C1 as above, and run tableau again and iterate these steps until satisfied with the aberration conditions.

Step 7- Perform fine tuning of ronchigram on sample with manual adjustment of coma / 2-fold stig.