GHz sample excitation at the ALBA-PEEM

Ultramicroscopy. 2023 Aug:250:113757. doi: 10.1016/j.ultramic.2023.113757. Epub 2023 May 9.

Abstract

We describe a setup that is used for high-frequency electrical sample excitation in a cathode lens electron microscope with the sample stage at high voltage as used in many synchrotron light sources. Electrical signals are transmitted by dedicated high-frequency components to the printed circuit board supporting the sample. Sub-miniature push-on connectors (SMP) are used to realize the connection in the ultra-high vacuum chamber, bypassing the standard feedthrough. A bandwidth up to 4 GHz with -6 dB attenuation was measured at the sample position, which allows to apply sub-nanosecond pulses. We describe different electronic sample excitation schemes and demonstrate a spatial resolution of 56 nm employing the new setup.

Keywords: Cathode lens microscopy; Electronic modules; High frequency electrical excitations; LEEM-PEEM; Sample environment.