REMI end station

Collaboration with R. Dörner group, Frankfurt University

A Reaction Microscope (REMI) is available for ion and electron momentum imaging experiments in the gas phase. Angle- and energy-resolved detection of ions and electrons in coincidence facilitate Cold Target Recoil Ion Momentum Spectroscopy (COLTRIMS) experiments. The spectrometer incorporates two time- and position-sensitive hexanode delay-line MCP-detectors with a 120 mm active area each. The total spectrometer length should not exceed 950 mm (ion + electron arm).

sample:
  gas, or liquid (from bubbler)
particles:
  electrons and ions
detectors:
  MCP + delayline anode, 120mm
max. rep. rate:
  ~200 kHz (depends on ion mass)
kin. energy range:
  0 - 50 eV (ions)
  0 - 500 eV (electrons)
momentum resol.:
  1%, max. 0.1 atomic unit (ions)
  1% (electrons)
mass resolution:
  1% (ions)
acceptance angle:
  100% of 4π (ions and electrons)

Sample Delivery

The sample delivery for the REMI consists of a three-stage supersonic gas jet, that can be extended to four stages in order to generate very dilute targets. Four piezo-controlled apertures can be used to further modify the gas jet geometry. The jet nozzle can be operated at temperatures from 5 K to 450 K, providing the possibility to generate small clusters or droplets, as well as evaporating liquid substances. Three nozzles of different sizes (e.g. 5 µm to 300 µm diameter) are installed in the expansion chamber and can be switched “on the fly”.