Advertisement

Noble gas activity monitor with gamma compensation

  • Akshiv GoelEmail author
  • P. Y. Bansode
  • Sadhana Bhattacharya
Article
  • 10 Downloads

Abstract

Noble gas monitoring system is used to measure the volumetric activity of beta particles due to radioactive noble gases—41Ar, 85Kr and 133Xe. Background compensation in these monitors is necessary as ambient radiation field, mainly due to gamma field, influences the measurement of noble gas activity. Algorithm based on two gamma compensation methods have been developed and implemented on two channel gross counting data acquisition system having embedded controller. Modified floating mean algorithm has been incorporated and implemented in firmware to estimate the count rate with better accuracy (Dharmapurikar et al., in: National symposium on radiation physics (NSRP-17), November 14–16, 2007 organized by Indian Society on Radiation Physics (ISRP), 2007). The algorithm has been developed to reject spurious counts generated due to electronic noise and transients. Experiments have been carried out using 90Sr + 90Yr (Beta source) and 137Cs (Gamma source) to compare the above two gamma compensation methods and beta shielding effectiveness of different shielding materials. The results have been validated in presence of gamma field of 100 mR/h and beta source of 200 µCi. The system was calibrated using 90Sr + 90Yr and 137Cs sources of known strength.

Keywords

Gamma compensation Shielding method Gamma sensitive detector method Modified floating mean algorithm Shield materials Bremsstrahlung effect Dead time 

Notes

Acknowledgements

The authors are thankful to Smt. Anita Behere, Head, Electronics Division, BARC for allowing us to undertake this research work. We are also thankful to Shri Sunil Sawant, Smt. Shalaka Phadke and Electronics Division workshop for their help and support.

References

  1. 1.
    Noble gas monitor detector systems technical specification. Eberline Instrument CorporationGoogle Scholar
  2. 2.
    Ar-41 decay scheme. http://www.nucleide.org/DDEP_WG/Nuclides/Ar-41_tables.pdf. Accessed 11 Mar 2019
  3. 3.
    Kr-85 decay scheme. http://www.nucleide.org/DDEP_WG/Nuclides/Kr-85_tables.pdf. Accessed 17 Mar 2019
  4. 4.
    Xe-133 decay scheme. http://www.nucleide.org/DDEP_WG/Nuclides/Xe-133_tables.pdf. Accessed 26 May 2019
  5. 5.
    Knoll GF (2000) Radiation detection and measurement, 3rd edn. Wiley, New York, pp 119–127Google Scholar
  6. 6.
    Shielding Beta radiation to reduce Bremsstrahlung. Australian National University; March 2, 2011. https://policies.anu.edu.au/ppl/download/ANUP_001188. Accessed 15 July 2019
  7. 7.
    Huffman RK (1999) Microprocessor implementation of a time variant floating mean counting algorithm. Nucl Instrum Methods Phys Res Sect Accel Spectrom Detect Assoc Equip 431(3):556–562CrossRefGoogle Scholar
  8. 8.
    IAR Embedded Workbench. https://www.iar.com/iar-embedded-workbench. Accessed 01 July 2019
  9. 9.
    Basic physics of nuclear medicine/attenuation of gamma-rays. https://en.wikibooks.org/wiki/Basic_Physics_of_Nuclear_Medicine/Attenuation_of_Gamma-Rays. Accessed 23 June 2019
  10. 10.
    IEC 61331-1; Protective devices against diagnostic medical X-radiation—part 1: determination of attenuation properties of materials; Edition 2.0; 2014-05. https://standards.globalspec.com/std/1680449/iec-61331-1. Accessed 26 June 2019
  11. 11.
    Dharmapurikar AV, Bhattacharya S, Jakati RK (2007) A modified floating mean algorithm for nuclear pulse counting. In: National symposium on radiation physics (NSRP-17), November 14–16, 2007 organized by Indian Society on Radiation Physics (ISRP)Google Scholar

Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2019

Authors and Affiliations

  1. 1.Bhabha Atomic Research CentreTrombay, MumbaiIndia

Personalised recommendations