Fission-product spectrometer

PN1 (Lohengrin) - an exotic-isotope spectrometer

LOHENGRIN is a recoil mass spectrometer for studying the properties of the exotic isotopes produced during the fission process. It allows us to study the mass, kinetic energy and charge distribution of the products of thermal-neutron-induced nuclear fission at very high resolution.

The beam intensity at the separator also makes it possible to detect γ-rays, conversion electrons, β-rays and delayed neutrons, and coincidences between these particles.


the investigation of spectroscopic properties of exotic neutron-rich nuclei:

  • spins and parities
  • magnetic moment and life-time measurements of excited nuclear states
  • conversion electron spectroscopy

fission process investigation and industrial applications:

  • fission fragments' mass, kinetic energy and nuclear charge distributions for different fissile systems from binary and ternary fission reactions
  • delayed neutrons from fission fragments
  • diffusion coefficients for actinids in different surrounding material.

Instrument layout

The instrument combines horizontal magnetic deflection with subsequent vertical electrostatic deflection. The focusing magnet, the Reverse Energy Dispersion (RED) dipole magnet, increases the particle density at the focal position by up to a factor of seven.