Influence of thermal conditions on the response of a calorimeter dedicated to nuclear heating measurements

The paper focuses on experimental works performed out-of-pile in order to study the response of a sensitive radiometric calorimeter dedicated to nuclear heating measurements inside a sample, and to optimize its calibration. The influence of external and internal thermal conditions on the calibration curves is studied by means of two kinds of calorimetric cell. The influence of the cooling flow temperature on the sensor response is shown in the case of a classical cell containing a single heat source located into the sample. The decrease of the sensor sensitivity versus the fluid temperature is presented and discussed. Then, a prototype integrating two heat sources (into the sample and the cell body) is detailed. The prototype is used to determine the influence of new internal thermal conditions (generated inside the sensor) on its calibration curve.