| 摘要 |
The invention relates to a method and an apparatus for qualifying the operation of a radiation (e.g. neutron) detector containing an ionizable gas (e.g. He3) and disposed in a logging sonde designed to be lowered in a well, wherein a radioactive source capable of ionizing said gas is disposed inside the detector. From the counts of the ionization pulses, one qualifies the operation of the detector. The method provides either a verification (usually performed outside the well) or, when carried out whilst the detector is operating in the well, a stabilization of the measured spectrum. Preferably, the internal source is an alpha source comprising uranium or americium and which is disposed inside the detector in the form of a thin foil. <IMAGE> |
