Mechanism of excited state formation in the radiolysis of hydrocarbon liquids. [Beta particles]

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1980

OSTI ID:6157974

Walter, L

A variety of saturated hydrocarbon liquids were chosen as model systems to investigate the primary processes that occur upon excitation with /sup 85/Kr beta particles. Radiolytic yields (G values) were measured for the production of the lowest excited singlet states of cyclohexane, methylcyclohexane, 2,3-demethylbutane, dodecane, hexadecane, cis-decalin, and bicyclohexyl. The measurement is based on a direct fluorescence technique utilizing the emission properties of these liquids and directly compared to neat benzene. The results obtained in this manner with those obtained by a solute sensitization technique indicate that the solute technique may strongly underestimate the true G value. The failure of the solute sensitization technique was further investigated via the measured energy transfer efficiencies of a large number of donor plus acceptor systems. From the concentration dependence of perfluorocarbon electron scavengers on the fluorescence intensity of a typical saturated hydrocarbon liquid (i.e. bicyclohexyl) when excited with beta particles and 184.9 nm light, two relevant questions pertaining to the geminate ion recombination process were answered. That is, (1) What contribution does the geminate ion recombination process make to the total yield of the lowest excited singlet and triplet states, and (2) What is the probability (averaged over the spur size distribution) that a geminate ion pair will generate an excited singlet state on recombination. This latter value is compared to theoretical values and it is concluded that in bicyclohexyl the geminate electron does not spin relax prior to recombination. Preliminary results for p-xylene are also presented and compared to bicyclohexyl.

• Research Organization: Minnesota Univ., Minneapolis (USA)
• OSTI ID: 6157974
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400600* -- Radiation Chemistry
ALKANES
BETA DECAY RADIOISOTOPES
BETA PARTICLES
BETA-MINUS DECAY RADIOISOTOPES
CHARGED PARTICLES
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTIONS
CHEMISTRY
DECOMPOSITION
ELECTRONS
ELEMENTARY PARTICLES
ENERGY LEVELS
EVEN-ODD NUCLEI
EXCITED STATES
FERMIONS
FLUIDS
FLUORESCENCE
G VALUE
HOURS LIVING RADIOISOTOPES
HYDROCARBONS
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
KRYPTON 85
KRYPTON ISOTOPES
LEPTONS
LIQUIDS
LUMINESCENCE
NUCLEI
ORGANIC COMPOUNDS
RADIATION CHEMISTRY
RADIATION EFFECTS
RADIOISOTOPES
RADIOLYSIS
SCAVENGING
YEARS LIVING RADIOISOTOPES