Radiation Metrology and Applications

Abstract

The Bhabha Atomic Research Centre (BARC) is the designated institute in ionizing radiation metrology for the country. The BARC designs, develops, establishes, maintains, and disseminates various national standards for physical quantities of ionizing radiation in India. The IAEA/WHO has recognized the BARC as a Secondary Standard Dosimetry Laboratory (SSDL) for disseminating radiological standards to users in the country. SSDL-BARC provides traceable calibration to the users in the field of teletherapy, brachytherapy, radiation protection, and diagnostic radiology. The pace of the advances in radiation therapy with the expected improvement in patient treatment has brought out the need for greater accuracy in the treatment process. SSDL-BARC participates in international intercomparison programs to establish its equivalence with international standards, thereby validating the calibration procedure followed in the laboratory. Radioisotope targeted therapy has been employed in the treatment of wide variety of cancers. The activity of these radiopharmaceuticals at the nuclear medicine centers is measured using the radionuclide calibrators. BARC as the national metrological laboratory for radioactivity has been conducting the audit program for activity measurements with RC for more than four decades. Neutron sources/fields not only are critical for operating and regulating nuclear reactors but also are important for various other research, industrial, and radiation protection applications. Therefore, precise value of neutron source strength and resultant field is highly essential which is provided by the BARC using several neutron standards developed for the purpose.

Radiation processing technologies are very widely used in different industrial applications like sterilization of healthcare products, processing of food and agriculture products, material modification and emerging fields like environmental remediation, synthesis of advanced materials and products, medical applications such as irradiation of blood, etc. Proper dosimetry is the backbone of success of these applications. Conventional radiation measuring techniques like ionization chambers, calorimeters, etc. are unable to measure absorbed doses for most of these applications. Chemical dosimetry techniques provide a cost-effective alternative for radiation processing dosimetry.

Radiation monitoring instruments are backbone to all the radiological and nuclear installations for the safety of occupational radiation workers. Performance of these monitors depends on calibration and measurement traceability to the national standards. Protection-level radiation monitors cover a wide range of radiation field (gamma ray, X-ray, and beta ray) intensity and energy; therefore, measurement standards of various types and sizes are established. The BARC has also established various radiological facilities for gamma rays, X-rays, and beta rays which are used for calibration and testing of all kinds of protection-level radiation monitors.