Physics laboratories provide analytical support to the exploration activities and carry out radiometric analyses of rock, soil and core samples, gamma-ray logging of boreholes, shielded probe logging of the trenches/outcrops, calibration of gamma-ray spectrometers (air borne-portable/ground-jeep/car borne) for radiometric survey at fixed calibration pads at civil airport, Nagpur and portable calibration pads at heliborne survey base station. In addition, preparation of standards for radiometric analyses, Instrumental Neutron Activation Analysis (INAA), radon measurement and implementation of DAE’s Emergency Response Centers (ERC) Programme are also carried out by the Physics laboratories.
Physics laboratories are located at seven Regional Centre i.e. Northern Region, New Delhi; Southern Region, Bengaluru; Eastern Region, Jamshedpur; North Eastern Region, Shillong; Western Region, Jaipur; Central Region, Nagpur and South Central Region, Hyderabad and one Radiation Standard and Analytical (RSA) Laboratory at HQ, Hyderabad
Regional Physics Laboratories
The laboratories are equipped with following facilities:
1. Gamma-ray logging of boreholes: Gamma-ray logging is the technique which is used to know the subsurface thickness of the mineralisation and the concentration of eU3O8 is determined in the range from ppm to percent level using either GM detector or scintillation detector.
2. Shielded probe gamma-ray logging:This technique is used to know the surface extent of the mineralisation in outcrops / trenches and the concentration of eU3O8 is determined using GM detector.
3. Radiometric analysis of borehole core: This method is used to know the eU3O8 concentration of borehole core samples using GM detector based system.
4. Radiometric analysis of rock and soil samples:
4.1: eU3O8 analysis: Total gamma activity of the samples is measured for their content using eU3O8 assembly (NaI(Tl) scintillation detector) which helps to delineate the sample for further analysis.
4.2: U3O8 analysis by beta gamma method: For the estimation of uranium in geological sample, simultaneous beta and gamma radiations are measured. The PC based five channel counting system developed and fabricated in-house, consists of NaI (Tl) crystal (solid or well type) for gamma measurement with four single channel analysers and pancake type beta tubes for total beta counting. In case the samples are in disequilibrium state, PC based five channel counting system is used for determination of uranium along with radium, thorium and potassium for disequilibrium studies.
4.3: Gamma-ray spectrometry ( using HPGe & NaI(Tl) detector): The radium, thorium and potassium contents of rock samples are determined by measuring the characteristic gammas of these elements using DSP based gamma-ray spectrometry system and HPGe detector system for High Resolution gamma-ray spectromety.
4.4: U3O8 analysis using high resolution gamma ray spectrometry:The uranium content in the geological sample is also determined by using high resolution gamma ray spectrometry.