6533b7dafe1ef96bd126ea9f

RESEARCH PRODUCT

Spatially resolved observation of dynamics in electrical and magnetic field distributions by means of a delayline detector and PEEM

subject

description

Abstract Photoemission electron microscopy (PEEM) was exploited to observe the dynamics in local field distributions on microstrip-line devices with a best time resolution of 133 ps. A delayline detector system served as imaging unit capable of a time resolving data acquisition and processing. The setup can be operated at the resolution limit of the PEEM of about 20 nm while a continuously illuminating UV-lamp excites the photoelectrons in threshold photoemission. A pulsed photon source is not needed to obtain time resolved images, the time reference of the data acquisition was taken by a periodic signal (clock, here typ. 100 MHz) in phase with the pulse pattern applied to the microstrip-line device. Ultra-short current pulses passing the microstrip-line are associated with local changes of the magnetic field at the device surface and with a fast propagation of the electrical potential as well. The photoelectron imaging is immediately responding to small local field distortions due to the small kinetic energy of the electrons escaping from the surface. Thus, local field distortions can be detected as temporal changes between the 133 ps wide image-slices which are sorted by time in reference to the clock signal.