Assessment of quantities for radiation protection in the ICRU standard tissue sphere for intermediate energy neutrons

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1985

OSTI ID:5924125

Lee, J K

The effect of the fluctuating cross section structure in the energy range of 0.4 to 10.0 MeV on the responses of neutrons in the ICRU standard tissue sphere is analyzed. The point-energy, coupled neutron-secondary particles Monte Carlo method was used in the direct estimation of the absorbed dose and the dose equivalent. A new approach was adopted where energy band-averaged responses were calculated instead of the previous method, which generated them as point values. By analyzing the depth-dose distributions with an improved searching method, assessments were made for the important quantities in radiation protection; the index quantities, the newly defined operational quantities, and other relevant quantities defined in the standard receptor. The energy dependencies of the resulting response functions were consistent with the cross section structure and were dominated by the oxygen content in tissue due to both the oxygen resonance cross section and the characteristic behavior of the recoil proton quality factor. The relative differences between the present index quantities and the previous values vary from -17.0 to +3.4% with respect to the present results for the deep dose equivalent, and from -19.2 to +8.6% for the shallow dose equivalent values on the principal axis, these relative differences deviate from +4.0 to 33.8%.

• Research Organization: Illinois Univ., Urbana (USA)
• OSTI ID: 5924125
• Country of Publication: United States
• Language: English

Related Subjects

61 RADIATION PROTECTION AND DOSIMETRY
655001* -- Medical Physics-- Radiation Protection Standards
BARYONS
DOSE EQUIVALENTS
DOSES
ELEMENTARY PARTICLES
ENERGY DEPENDENCE
ENERGY RANGE
FERMIONS
HADRONS
ICRU
INTERMEDIATE NEUTRONS
INTERNATIONAL ORGANIZATIONS
KEV RANGE
KEV RANGE 100-1000
MEV RANGE
MEV RANGE 01-10
NEUTRONS
NUCLEONS
RADIATION DOSES
RADIATION PROTECTION
STANDARDS