Investigations of the biological effects of radiation: a multi-discipline approach. Progress report, September 1, 1976--August 31, 1977
The quasi-free electron attachment rate, k/sub e/, and mobility, ..mu../sub e/, were studied in non-polar solutions using pulsed conductivity techniques. Measurements of k/sub e/ of >50 nitro compounds in liquids have ..mu../sub e/ ranging from <0.1 to 100 cm/sup 2//volt sec at temperatures from -100 to +40/sup 0/C indicated electron-dipole interactions are important in liquids having ..mu../sub e/ < 1 cm/sup 2//volt sec. The Smoluchowski equation was modified to include electron-dipole interactions and calculated k/sub e/'s agreed with observations within +-20%. The cellular enhancement ratio, CER, of nine of the nitro compounds were measured and a correlation between k/sub e/ and CER was found which was used to refine a model of cellular radiosensitization involving quasi-free electrons. Diffusion-controlled k/sub e/'s were observed for several carcinogens and in reversed micellar solutions. Field-dependent k/sub e/'s were measured in liquids having ..mu../sub e/ ranging from 10/sup -4/ to 500 cm/sup 2//volt sec and were found to increase at ..mu../sub e/ < 1 and decrease at ..mu../sub e/ > 70 cm/sup 2//volt sec with increasing field. The ..mu../sub e/ of liquid C/sub 2/H/sub 6/ was measured from -40/sup 0/C through the critical temperature at fields up to 180 kV/cm and a transition from polaron to delocalized electron conduction was observed. A pico-second (ps) pulse conductivity technique was developed and hot electron and/or autoionization processes were observed in tetramethylsilane, TMS, 200 ps after the ionizing pulse. A dose, field, and polarity dependent conductivity spike having a lifetime of 100 ps was observed in TMS and is interpreted as a prebreakdown phenomenon.
- Research Organization:
- Case Western Reserve Univ., Cleveland, Ohio (USA). Dept. of Radiology
- DOE Contract Number:
- EY-76-S-02-2486
- OSTI ID:
- 5301650
- Report Number(s):
- COO-2486-366; TRN: 78-001694
- Country of Publication:
- United States
- Language:
- English
Similar Records
Dynamics of electron attachment to AOT/H{sub 2}O reversed micelles
Minimum metallic conductivity of fluid hydrogen at 140 GPa (1.4 Mbar)
Related Subjects
59 BASIC BIOLOGICAL SCIENCES
ANIMAL CELLS
BIOLOGICAL RADIATION EFFECTS
CARCINOGENS
BIOCHEMICAL REACTION KINETICS
ELECTRONS
IONIZATION
PULSE TECHNIQUES
LIQUIDS
ELECTRON TRANSFER
NITRO COMPOUNDS
RADIOSENSITIVITY
BIOLOGICAL MODELS
SOLUTIONS
BIOLOGICAL EFFECTS
DISPERSIONS
ELEMENTARY PARTICLES
FERMIONS
FLUIDS
KINETICS
LEPTONS
MIXTURES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
RADIATION EFFECTS
REACTION KINETICS
560121* - Radiation Effects on Cells- External Source- (-1987)
550200 - Biochemistry