Electron-TOF-analyser for complete momentum analysis in photoemission fromsurfaces

We present a new method for momentum-selective imaging by means of a time-o f-flight (TOF) technique. The instrument employs a time- and space-resolvin g delayline detector in combination with a parabolic electrostatic field an d a drift space. We use this kind of spectrometer, to raise the efficiency of experiments, which are total momentum resolved. The main difference to c onventional photoemission experiments using a rotatable spectrometer is the simultaneous detection of all emitted photoelectrons. In addition to this feature. the angular distribution should be directly visible, to observe so lid state symmetries. In order to facilitate these requirements, we use a d elayline detector as a position and time sensitive device with a versatile user interface. First results obtained at BESSY I are presented. (C) 2001 E lsevier Science B.V. All rights reserved.