title: Response of ionization chamber based pocket dosimeter to beta radiation.
abstract: Quantitative estimate of the response of ionization chamber based pocket dosimeters (DRDs) to various beta sources was performed. It has been established that the ionization chamber based pocket dosimeters do not respond to beta particles having energy (Emax)<1 MeV and same was verified using (147)Pm, (85)Kr and (204)Tl beta sources. However, for beta particles having energy >1 MeV, the DRDs exhibit measureable response and the values are ~8%, ~14% and ~27% per mSv for natural uranium, (90)Sr/(90)Y and (106)Ru/(106)Rh beta sources respectively. As the energy of the beta particles increases, the response also increases. The response of DRDs to beta particles having energy>1 MeV arises due to the fact that the thickness of the chamber walls is less than the maximum range of beta particles. This may also be one of the reasons for disparity between doses measured with passive/legal dosimeters (TLDs) and DRDs in those situations in which radiation workers are exposed to mixed field of gamma photons and beta particles especially at uranium processing plants, nuclear (power and research) reactors, waste management facilities and fuel reprocessing plants etc. The paper provides the reason (technical) for disparity between the doses recorded by TLDs and DRDs in mixed field of photons and beta particles.
authors: Radiological Physics and Advisory Division, Bhabha Atomic Research Centre (BARC), Mumbai 400085, India. Electronic address: munish_pms@rediffmail.com.
authors: Munish
authors: M
authors: Kumar
authors: Anil
authors: A
authors: Gupta
authors: S M
authors: SM
authors: Pradhan
authors: A K
authors: AK
authors: Bakshi
authors: M P
authors: MP
authors: Chougaonkar
authors: D A R
authors: DA
authors: Babu
mesh_terms: D001610:Beta Particles / Q000009:adverse effects*; D005720:Gamma Rays / Q000009:adverse effects; D006801:Humans; D016273:Occupational Exposure; D017785:Photons / Q000009:adverse effects; D011829:Radiation Dosage; D011834:Radiation Monitoring / Q000295:instrumentation*; D011868:Radioisotopes / Q000009:adverse effects; D011874:Radiometry / Q000295:instrumentation*; D013819:Thermoluminescent Dosimetry; D014501:Uranium / Q000009:adverse effects
chemical_list: D011868:Radioisotopes; D014501:Uranium
keywords: Beta particles; Direct reading/pocket dosimeter; Ionization chamber; Thermo-luminescent dosimeter and beta response TLD–DRD dose disparity