Background gamma radiation surveying in the Indian peninsula with a portable USB spectrometer

Isotopic analysis of radioactive Monazite sand from the beaches of Kanyakumari was carried out using a handheld, USB powered 'plug and play' gamma spectrometer which was developed. The dominant decay chain to be ²³²Th has been identifies, and have also correlated other spectral features. The recorded spectrum also has excellent value from a teaching perspective due to the complex, multi-layered nature of the associated spectrum, and is a much safer alternative to enriched sources. A comparison study of the energy efficiency of the 10mm * 10mm * 8mm scintillator was also carried out against a lab grade 3 inches x 3 inches NaI scintillator available at IREL (India) Ltd, Manavalakurichi, India in order to establish its usability for surveying purposes. The results indicated good performances up to 1.5MeV, but reduced efficiency at higher energies due to the smaller scintillator volume