Radiation-chemical and MR studies of aqueous agarose gels containing ferrous ions

Miscellaneous · Sun Jan 01 00:00:00 EST 1989

OSTI ID:5774235

Leghrous, A A

Aqueous agarose gels containing ferrous ions, in 0.05 N sulfuric acid have been studied after irradiation with 6-18 MeV electrons or {sup 137}Cs {gamma}-rays. Such gels can sustain a radiolytic chain reaction, producing Fe{sup 3+} with G (Fe{sup 3+})-values up to 100 having been observed. The Fe{sup 3+} production is independent of dose rate between 0.434 and 3.74 Gy min{sup {minus}1}. Dissolved oxygen is needed to maintain the chain reaction, and initial ferric yields are increased if the gel is oxygen saturated or if the ferrous concentration is decreased below 1 mM. The oxidation of ferrous to ferric alters the magnetic moment of the ion and its electron spin relaxation time, which in turn affects its ability to promote proton spin relaxation rates. Longitudinal proton magnetic relaxation rates are increased in proportion to ferric production, permitting visualization of dose levels in these gels by magnetic resonance imaging (MRI) techniques. Non-uniform dose distribution images of electron irradiated ferrous/agarose (FA) systems have been obtained using MRI. Images of radiation doses surrounding capillary tubes filled with radioactive material embedded in PA systems have also been obtained. In this work, another new method of using the ferrous/agarose gel system doped with xylenol orange to visualize the radiation dose distribution directly by eye has been developed. The color change developed depends both quantitatively and qualitatively on the concentrations of solutes in the gel.

• Research Organization: Rutgers-the State Univ., New Brunswick, NJ (USA)
• OSTI ID: 5774235
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
AGAR
MAGNETIC RESONANCE
RADIOLYSIS
CESIUM 137
COLOR
DOSE RATES
ELECTRON BEAMS
GAMMA RADIATION
GELS
IRON IONS
IRRADIATION
RADIATION DOSES
SPIN-SPIN RELAXATION
ALKALI METAL ISOTOPES
BEAMS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBOHYDRATES
CESIUM ISOTOPES
CHARGED PARTICLES
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTIONS
CHEMISTRY
COLLOIDS
DECOMPOSITION
DISPERSIONS
DOSES
ELECTROMAGNETIC RADIATION
IONIZING RADIATIONS
IONS
ISOTOPES
LEPTON BEAMS
NUCLEI
ODD-EVEN NUCLEI
OPTICAL PROPERTIES
ORGANIC COMPOUNDS
ORGANOLEPTIC PROPERTIES
PARTICLE BEAMS
PHYSICAL PROPERTIES
POLYSACCHARIDES
RADIATION CHEMISTRY
RADIATION EFFECTS
RADIATIONS
RADIOISOTOPES
RELAXATION
RESONANCE
SACCHARIDES
YEARS LIVING RADIOISOTOPES
400600* - Radiation Chemistry