Schiwietz, G.; Beye, M.; Kühn, D.; Xiao, G.: The retarding Bessel-Box - an electron-spectrometer designed for pump/probe experiments. Journal of Electron Spectroscopy and Related Phenomena 203 (2015), p. 51-59
10.1016/j.elspec.2015.06.011
Open Access Version
Abstract:
A new type of electrostatic electron spectrometer is developed, capable of particular sensitive measurements of energy spectra and time-of-flight distributions. This instrument is specifically designed and optimized for laser-pump/X-ray-probe measurements, where photo electrons or Auger electrons from surfaces, clusters, molecular or atomic targets are being measured with high time-resolution at an extremely low detection-noise level. The compact and robust cylinder-symmetrical system is a strongly improved Bessel–Box design, featuring electron retardation, a large detection solid-angle, about 100%electron transmission (gridless design) and excellent time-resolution. In this paper we describe the principle of operation of this type of spectrometer and various tests. We present quantitative results for electron measurements with different solid-state targets and two different electron-detection systems in comparison to electron-trajectory simulations inside the electrostatic spectrometer fields. Picosecond-pump/probe operation has been tested with high laser power and even the ability to work under femtosecond-pump-probe conditions with electron detection at the BESSY II slicing facility has been proven.