nELBE: A new facility to produce high brilliance pulses of fast neutrons for transmutation research by time of flight.

The Radiation Source ELBE at Forschungszentrum Dresden-Rossendorf (FZD), with electron energies up to 40 MeV, will be used to produce intense pulses of fast neutrons. The neutron radiator consists of a liquid lead circuit where bremsstrahlung photons generated from the electron beam at ELBE produce neutrons in (γ,n) reactions. Monte Carlo simulations with MCNP4C3/MCNP5 were performed to characterise neutron and photon intensities as well as time and energy distributions, and to optimise the neutron beam. The short beam pulses provide the basis for an excellent time resolution for neutron time-of-flight experiments, giving an energy resolution of about < 2 % with a flight path of ~ 5 m.