A magnetic bottle time-of-flight electron spectrometer suitable for continuous ionization sources.

We present a newly developed magnetic-bottle time-of-flight electron spectrometer suitable for continuous or quasicontinuous photoionization sources such as synchrotrons. A strong magnetic field collects almost all photoelectrons from a well-defined ionization volume and quantitatively suppresses background electrons which originate outside of this interaction region. Although it is a pulsed instrument, a relatively high duty cycle is achieved by storing the photoelectrons generated between two cycles in an electromagnetic trap. This makes the new instrument suitable for experiments with very low sample densities. Another advantage is the high energy resolution, 50 meV in the first version of the spectrometer described here, which simply depends on the length of the time-of-flight instrument.