Novel time-of-flight electron spectrometer optimized for time-resolved soft-x-ray photoelectron spectroscopy

We developed a time-of-flight electron spectrometer optimized for the detection of photoelectrons generated with femtosecond laser-generated extreme ultraviolet pulses. The low number of electrons requires an electrostatic lens design with a very high transmission over a broad energy range. We show that with an asymmetric lens geometry the chromatic aberration can be reduced and the overall transmission be increased. The setup can be further optimized employing a closed-loop optimization with an evolutionary algorithm to increase the throughput by varying the voltages applied to the lens plates. (c) 2006 American Institute of Physics.