Utilization of external PIGE and INAA methods for the radio-purity analysis of rock samples relevant for nuclear astrophysics

Three different rock samples were analysed for low Z elements (F, Na, Al, Si, Mg) using 3.75MeV proton beam from tandem accelerator by External Proton Induced Gamma ray Emission (PIGE) method. For the determination of elements at major to trace level, samples were irradiated with high neutron flux (~10¹³ n/cm²/s) for 1 min using PCF (for short lived activation products) and 5hrs using self serve facility ( for medium to long lived activation products) of Dhruva reactor. Radioactive assay was carried out using High Purity Germanium (HPGe) detector having 40% relative efficiency. The elements namely Na, Al, Mg, As, Ba, Br, Ce, Co, Cr, Cs, Eu, Hf, K, La, Lu, Mn, Rb, Sb, Sc, Sm, Th, U, V, Yb, and Zr were determined in all the analyzed samples. The methods were validated by analyzing geological certified reference materials namely AGV-1, RGM-1 and PCC-1. The obtained results were found to be in good agreement with the certified values and the % deviation was found to be within ±5%. The uncertainties on the results were expressed as propagated uncertainties (at ±1s) and found to vary from ±0.8% to ±7%