The JRC produces and characterises a variety of targets for high-precision measurements of neutron-reaction data at the GELINA and MONNET accelerators.
Targets
The targets are thin stable deposits of 6,7,natLiF, metallicLi, 10B, tristearine or thin actinide deposits of U, Pu, Np or Am isotopes, on a thin metallic or plastic foil. These deposits need to be homogeneous, mechanically stable and well characterised for their isotopic composition, mass and areal density. Other samples like metallic disks, wires, alloys and powder compacts are also prepared.
The stable layers are prepared by physical vapour deposition and characterised for their total mass by difference weighing.
For the production and characterisation of actinide targets, the Target Preparation laboratory has a nuclear-controlled area equipped with vacuum evaporators, molecular plating cells and alpha-particle counters. Each process is performed in separate glove boxes; each dedicated to a certain isotope.
For fission fragment spectroscopy the deposited material is often requested on very thin substrate foils to keep the absorption of fission fragments in the substrate as low as possible. Therefore thin polyimide foils with an areal density about 35 µg·cm-2 are produced by in situ polymerisation. The areal density of the polyimide foils is measured by spectrophotometry.