Construction Materials for Neutron Capture-Gamma-Ray Measurement Assembly Using Californium-252

If a small (multimicrogram) ²⁵²Cf neutron source is used for neutron capture-gamma-ray analysis, a Ge(Li) detector must be placed relatively close to the source to obtain a reasonable counting rate. Thus, the encapsulation, moderating, shielding, and perhaps detector materials all become potential gamma-ray sources which cause spectral interference. An interference parameter for a number of elements generally used in source and detector construction is presented. Using this parameter, construction materials can be chosen to minimize the spectral interference. For minimum interference as well as fabrication and durability, zirconium, niobium, or tantalum alloys are among the better materials for source encapsulation or detector hardware.