FAST LEED INTENSITY MEASUREMENTS WITH A VIDEO CAMERA AND A VIDEO TAPE-RECORDER

The measurement of LEED intensities with a TV camera-computer system, which has been published in an earlier paper, is reported to be improved with respect to the speed of data collection by a factor of about 102. Other properties such as sensitivity, reliability and handling facility have also been improved. The new measuring mode, which applies a video tape recorder, allows the simultaneous measurement of all appearing diffraction spots down to a beam current of 10-11 A with a rate of 50 energy points/s. This pushes the total measuring time for LEED spectra to the order of seconds and makes possible to monitor non-stable surfaces. As an example intensity measurements for different adsorption stages of hydrogen on W(100) are presented. © 1979 Springer-Verlag.