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 (airborne/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 measurements and implementation of DAE’s Emergency Response Centres (ERC) Programme are also carried out by the Physics Laboratories.
Physics laboratories are located at all the seven Regional Centres 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 Standards 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 concentration and thickness of the mineralisation and equivalent uranium oxide is determined in the range from ppm to percent level using either a GM detector or a 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 equivalent uranium oxide 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 eU3O8 content using an eU3O8 assembly (NaI(Tl) scintillation detector) which helps to delineate the samples for further analysis.
4.2: U3O8 analysis by beta-gamma method: For the estimation of uranium in geological samples, simultaneous beta and gamma radiations are measured. The PC based five channel counting system developed and fabricated in-house, consists of a 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 gamma rays of these elements using DSP based gamma-ray spectrometry system and HPGe detector system for High Resolution gamma-ray spectrometry.
4.4: U3O8 analysis using high resolution gamma ray spectrometry: The uranium content in the geological samples is also determined by using high resolution gamma ray spectrometry using the 1001 keV gamma peak from Pa234.
4.5. Radiometric assay of Beach Sand Minerals (BSM) export consignments for their monazite equivalent content.