Published November 2018 | Version v1
Miscellaneous Open

On the influence of the cyclotron components and concrete vault room on the neutron radiation field around the accelerator

  • 1. Comissao Nacional de Energia Nuclear, Centro de Desenvolvimento da Tecnologia Nuclear, Campus da UFMG, Pampulha, 31270-901 Belo Horizonte, Minas Gerais (Brazil)
  • 2. Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico)

Description

In a cyclotron facility, the knowledge of the radiation field around the accelerator is an important issue for shielding planning and optimization of the radiation protection of the workers and individuals of the public. Neutrons emitted by the cyclotron contribute not only to radiation dose fields around the accelerator due to activation of cyclotron components and the concrete in the bunker walls, as well as, the dispersal of radioactive gases produced by activation of the air inside the cyclotron vault. In this work, the Monte Carlo code MCNPX was used to assess the influence of the components of the unshielded Ge-PET trace-8 cyclotron and the concrete vault room in the neutron radiation field during 18F production. A new radiation source term from the bombardment of 18O-enriched water target with protons of 16.5 MeV was used. MCNPX simulations were performed for six different cases, i.e., combining the radiation source term, the accelerator, the components of the accelerator and the cyclotron bunker. The neutron radiation field mapping in terms of the thermal, epithermal and fast neutron fluence rate was performed at seven specific points located inside and outside of the cyclotron vault room defined in a previous work. Results show how the components of the accelerator and the concrete vault room alter significantly the spectral distribution of the neutron fluence and equivalent dose rates around the cyclotron. (Author)

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Additional details

Publishing Information

Publisher
Sociedad Mexicana de Irradiacion y Dosimetria
Imprint Place
Ciudad de Mexico (Mexico)
Imprint Pagination
31 p.
Report number
INIS-MX--3254

Conference

Title
18. international symposium on solid state dosimetry
Acronym
ISSSD 2018
Dates
24-28 Sep 2018
Place
Oaxaca, Oax. (Mexico)