IPES is used to study the empty electronic states of solids. The sample is bombarded
with a beam of electrons with well defined energy and light is emitted when electrons
make direct transitions into the unoccupied states. We manufacture an IPES electron
gun and control unit, IPES photon detector with power supply and pre-amplifier /
discriminator and also supply a data system. The photons are detected as a function of
the kinetic energy of the incident electron beam. The data system ramps the beam
energy using a DAC and recovers the CEM pulses to obtain an IPES spectrum.

IPES Electron Gun：
Cathode: BaO dispenser for low thermal spread. Emits at approx 1000 C.
Beam energy 5 to 100eV.
Sample current typically 10 mA.
Electronic control unit: To allow control of cathode heater current, kinetic energy, focus
voltage.
Simultaneous display of beam energy, cathode heater current, sample current.
The gun is supplied with Z100 100mm linear translator.

IPES Detector：
Photon energy filter (Fluoride window / coated Ta cone) and electron multiplier.
Mounts on 70mm OD CF flange.
Power supply for CEM HV, and pre-amplifier/discriminator with TTL output to recover
pulses.
The IPES detector is mounted on a Z100 100mm linear translator.