Skip to main content
placeholder image

MOSFET dosimeters: The Role of Encapsulation on Dosimetric Characteristics in Mixed Gamma-Neutron and Megavoltage X-ray Fields

Conference Paper


Abstract


  • This paper is concerned with the role of the package of MOSFETs used in measurements of gamma dose in mixed gamma-neutron fields, in high energy bremsstrahlung and soft X-ray fields. It is shown that a kovar cap should be avoided for dosimetry applications in the presence of strong thermal neutron fluences. In regions of strong electronic disequilibrium the ‘bare’ or unencapsulated MOSFET is a unique tool for surface dose measurements and Monte Carlo model validation. For depths where electronic equilibrium exists (ie. x > depth of Dmax) the MOSFET package is not critical. For low energy X-ray fields the energy dependence of the dose enhancement factor (DEF) will differ depending upon whether the irradiation is performed in free air geometry or on the surface of a phantom. © 1995 IEEE

Publication Date


  • 1995

Citation


  • Rosenfeld, A. B., Carolan, M. G., Kaplan, G. I., Allen, B. J., & Khivrich, V. I. (1995). MOSFET dosimeters: The Role of Encapsulation on Dosimetric Characteristics in Mixed Gamma-Neutron and Megavoltage X-ray Fields. In IEEE Transactions on Nuclear Science Vol. 42 (pp. 1870-1877). doi:10.1109/23.489229

Scopus Eid


  • 2-s2.0-0029518433

Start Page


  • 1870

End Page


  • 1877

Volume


  • 42

Issue


  • 6

Abstract


  • This paper is concerned with the role of the package of MOSFETs used in measurements of gamma dose in mixed gamma-neutron fields, in high energy bremsstrahlung and soft X-ray fields. It is shown that a kovar cap should be avoided for dosimetry applications in the presence of strong thermal neutron fluences. In regions of strong electronic disequilibrium the ‘bare’ or unencapsulated MOSFET is a unique tool for surface dose measurements and Monte Carlo model validation. For depths where electronic equilibrium exists (ie. x > depth of Dmax) the MOSFET package is not critical. For low energy X-ray fields the energy dependence of the dose enhancement factor (DEF) will differ depending upon whether the irradiation is performed in free air geometry or on the surface of a phantom. © 1995 IEEE

Publication Date


  • 1995

Citation


  • Rosenfeld, A. B., Carolan, M. G., Kaplan, G. I., Allen, B. J., & Khivrich, V. I. (1995). MOSFET dosimeters: The Role of Encapsulation on Dosimetric Characteristics in Mixed Gamma-Neutron and Megavoltage X-ray Fields. In IEEE Transactions on Nuclear Science Vol. 42 (pp. 1870-1877). doi:10.1109/23.489229

Scopus Eid


  • 2-s2.0-0029518433

Start Page


  • 1870

End Page


  • 1877

Volume


  • 42

Issue


  • 6