Abstract: An apparatus is provided for determining the thermal history of an environment for purposes of monitoring thermal aging in equipment or the extent to which a process has proceeded. The apparatus comprises a plurality of solid state track recorders, and the range of activation energy values among the solid state track recorders encompasses the activation energy of the thermal aging process of the equipment to be monitored. Using Arrhenius functions, data obtained from the apparatus can be used to determine an equivalent average temperature which is combined with the equipment life data to determine the extent of thermal aging.

Abstract: A high fluence neutron dosimetry method is described, including the steps of: exposing a dosimeter containing an alpha-emitting target isotope to neutron irradiation to form an alpha-emitting product isotope; determining the alpha decay rates of the target nucleus and the product nucleus; and using known alpha decay constants for the target nucleus and the product nucleus and the determined alpha decay rates of the target nucleus and the product nucleus to determine the neutron capture rate of the product nucleus.