Internal Bremsstrahlung emission during 32P decay. (July 2022)

• Record Type: Journal Article
• Authors: Auditore, Lucrezia; Juget, Frederic; Pistone, Daniele; Nedjadi, Youcef; Amato, Ernesto; Italiano, Antonio
• Is Part Of: Radiation measurements. Volume 155(2021)
• Publication Date: 2022-07
• Subjects: Internal bremsstrahlung -- Phosphorus-32 -- Monte Carlo -- Ionization chamber -- External exposure; Nuclear emulsions -- Periodicals; Particle tracks (Nuclear physics) -- Periodicals; Thermoluminescence -- Periodicals; Cosmic rays -- Periodicals; Radiation -- Measurement -- Periodicals; Radiometry -- Periodicals; Radiation Monitoring -- Periodicals; Émulsions nucléaires -- Périodiques; Particules (Physique nucléaire) -- Traces -- Périodiques; Thermoluminescence -- Périodiques; Rayonnement cosmique -- Périodiques; Radiométrie -- Périodiques; 539.77
• DOI: 10.1016/j.radmeas.2022.106799
• Languages: English
• ISSNs: 1350-4487

Abstract

Abstract: The aim of this work is to experimentally investigate the role of Internal Bremsstrahlung (IB) in the decay of 32 P, a pure β-emitter with end-point energy of 1.71 MeV and half-life of 14.28 days. IB is a continuous electromagnetic radiation occurring in β-decay, that had been widely studied in the past years. Its contribution, even if appreciable, is neglected in Monte Carlo (MC) simulation as well as in dosimetric and radiation protection calculations. Ionization current measurements were carried out using a well ionization chamber and compared with MC simulations, performed in the GAMOS (GEANT4-based Architecture for Medicine-Oriented Simulations) framework. Two experimental data sets of 32 P IB spectra, taken from the literature, were used to model the IB photon spectral distribution and to include IB emission as an additional source term in MC calculation. Without IB, MC simulations underestimate up to about −18% the measured exposure, whereas the inclusion of IB according to either of the two spectra lead to differences of +2% or +8%. Consequently, the IB process is relevant for high-energy pure β-emitters such as 32 P, and its contribution should be considered in all the dosimetric and radioprotection calculations. Highlights: Relevance of Internal Bremsstrahlung (IB) was experimentally studied for 32 P. Radiometric measurements were compared with Monte Carlo (MC) simulations. 15–17% relative differences were found between measurements and MC estimates. Including IB photons in MC simulations leads to a fair agreement with measurements. IB inclusion among electromagnetic processes in MC simulations is advisable.