Natural Gamma Radiation Spectroscopy
The earth crust contains all natural elements of the periodic system from Hydrogen to Uranium. Although the vast majority of these elements are stable, some of them have radioactive isotopes with long half life times. Uranium, Radium, Thorium, Radon and Potash belong to this group. Especially Uranium and Potash deposits show concentrations where the radiation can be well distinguished from the background. This radiation can be detected using high sensitive gamma detectors.
For instance, it is common practice to detect the gamma intensity in bore holes to quantify Uranium or Potash deposits. There usually only the total amount of radiation is measured since only one element with radioactive isotopes have to be measured. So all detected photons are counted and the concentration of the specific element is derived from the total intensity per time interval.
The NIAGARA (Natural Isotope Analysis/GAmma RAdiation) spectrometer counts not only the number of photons but it also measures the photon energy. Therefore the different elements can be clearly identified and quantified by the number of photons belonging to the element.
NIAGARA can be integrated into the ANCORELOG drill core scanner beside the TEXAS XRF unit and the HyperSpectral Camera. The results obtained with NIAGARA are then integrated into the core data base. So all results acquired with the different measurement systems can be compared directly.
The advantage of the spectroscopic measurement is obvious. If drill cores are scanned then the elements inside of the core can be identified directly without additional chemical analysis. The spectra above and beside show the typical footprints of Potash and Uranium. The measuring time is 150 seconds; this time corresponds to the measuring time which is required in the ANCORELOG scanner to measure 5 meters of bore core using the fast mode.