TOF-PES
(Time of Flight mass spectrometer coupled to a photoelectron spectrometer)
The machine is shown above, and consists of a cluster-ion source, a Wiley-McLaren style time of flight mass spectrometer, and a magnetic bottle photoelectron spectrometer.We can create exotic clusters between anion and several neutral molecules or atoms, mass select the one we want to study, hit it with UV laser radiation, and collect the ejected photoelectrons. We started building in 2008, and finished in 2009 (well not really, as we are constantly working on it to improve it!).
In essence, Time of Flight Photoelectron spectroscopy determines the energy spectrum of electrons via their time of flight. How is this possible? Because the kinetic energy and Time of Flight are linked,

Schematic of the Cluster Ion source.

Schematic of the magnetic bottle photoelectron spectrometer. The ions (entering from the top in the figure) are intersected with a pulse of laser radiation (at the "x"). The photoelectrons are directed along the flight tube

How do we do it?
Our set up uses magnetic fields to deliver the ejected photoelectrons to a detector at the end of a 1.5m flight tube. A strong, pulsed, electromagnet produces a strongly divergent magnetic field. This the maps onto an homogeneous field that exists within the flight tube. The end result is that close to 100% of the ejected electrons are captured, and are sensed at the end of the flight tube.