The IEC—A plasma-target-based neutron source

In the inertial electrostatic confinement (IEC) device, deuteron ions are accelerated, producing fusion reactions as they react with a deuterium plasma target. Present devices offer 106–107 2.5 MeV D-D n s−1 during steady-state operation. Higher yield pulsed versions are under development. Consequently the IEC neutron source is currently competitive, in terms of neutron strength, with Cf-252 and accelerator solid-target sources and offers a number of advantages, including an on-off capability, longer lifetime without deterioration in strength, and minimum involvement of radioactivity. These features simplify IEC usage and ease licensing restrictions. Conversion to higher energy (14 MeV) neutrons by substituting D-T fill gas for pure deuterium fill gas has confirmed the higher source strength of 108–109 D-T n s−1 for the same IEC unit size. For these reasons, the IEC provides an excellent research laboratory neutron source as well as long life, a low maintenance cost industrial source for neutron activation analysis and non-destructive testing. Two basic geometries have been developed—a spherical unit and a cylindrical unit. Spherical units have vacuum vessel diameters ranging from 15 cm to 60 cm. Present cylindrical units are approximately 12 cm in diameter and 1 m long, but smaller designs are under development. The two geometries are complementary: the spherical unit provides a ‘point’ source of neutrons, while the cylindrical device provides a ‘line’ source.