Theoretical basis for solid-state microdosimetry using photochromic alterations

Conference · Wed Dec 31 04:00:00 EST 1997

OSTI ID:292950

Emfietzoglou, D; Moscovitch, M ^[1]

---

1. Georgetown Univ. Medical Center, Washington, DC (United States)

Of special importance for assessing RBE is the study of single HCP (heavy charged particle) tracks in biomatter, because for this type of radiation fields and at low dose levels critical macroscopic sites of the body (e.g., cell nucleus, DNA) will experience single particle traversals. However, currently, no experimental technique can provide such information in a TE condensed-state medium, important for simulating the cellular environment. Therefore, a theoretical study was carried out investigating the feasibility of using the radiation-induced color decay of photochromic molecules doped in a polymer matrix as a probe for solid-state microdosimetry of HCPs. The proposed method is based on photo-exciting the SP molecules prior to irradiation turning them into chromophores, the color-decay rate of which is increased within the HCP track. In principle, by measuring at the appropriate time after the formation of the track the reduction of the optical radiation emitted from the matrix, information relevant to the microscopic distribution of energy deposition in the HCP track may be obtained. The objective of the present study was to calculate the color-decay (or bit-flip) probability of the SP molecules as a function of the radial distance from the HCP track axis. The theoretical model has been developed for single tracks of protons, {alpha}-particles, carbon and oxygen nuclei of 1--10 MeV/amu.

• Sponsoring Organization: National Aeronautics and Space Administration, Washington, DC (United States); USDOE, Washington, DC (United States)
• DOE Contract Number: AC05-76OR00033
• OSTI ID: 292950
• Report Number(s): CONF-960929--; ISBN 0-85404-737-9
• Country of Publication: United Kingdom
• Language: English

Related Subjects

56 BIOLOGY AND MEDICINE
APPLIED STUDIES
ALPHA PARTICLES
CELL NUCLEI
MATHEMATICAL MODELS
MICRODOSIMETRY
RADIATION DOSES
RBE