Development of personnel monitoring instruments present scenario in India

BARC has a vast experience of developing instruments for their use in personnel monitoring of radiation workers. In this connection BARC has developed semiautomatic and fully automatic thermoluminescence dosimeter (TLD) badge reader systems, OSL phosphor and associated reader systems, and digital pocket dosimeters. A large number of (more than 50) auto-TLD Badge Readers developed by us (useful in the dose range of 50 μGy to 10 Gy) along with the PC software package has been made available for use in routine personnel monitoring in all the TLD personnel monitoring units of DAE. The know-how for the manufacture of the TLD reader systems (manual and semi-automatic) have also been given on technology transfer to a number of private companies for their commercial production, supply and maintenance. A fully automatic TLD badge reader system based on new TLD card with built-in identification codes have been developed and tested for introduction into routine personnel monitoring applications. In the last five years, the conventional film based personnel dosimetry has nearly phased out and on the other-hand there have been tremendous developments in the field of OSL dosimetry and electronic personnel dosimetry. As a result of these developments, as far as passive personnel dosimetry is concerned, worldwide there is a discernable paradigm shift in personnel dosimetry from TL based systems to OSL based systems. This is primarily driven by the introduction and availability of high sensitive OSL phosphor like α-Al2O3:C and the attractive features of OSL mode of readout like ease in dose estimation and multiple readouts. The factors which have motivated these changes and related personnel monitoring instruments and material development issues (with a specific focus on α-Al2O3:C) have been discussed. The work carried out towards the development of TLD/OSLD personnel monitoring systems and digital pocket dosimeters in BARC in the recent years is discussed. (author)