Radiation Chemistry of Water with Pulsed High Intensity Electron Beams
The radiation chemistry of water, aqueous ferrous sulfate, hydrogen peroxide, and formic acid was studied using pulsed electron beams from the Argonne linear electron accelerator. With a pulse length of ~1.4 mu sec and an electron energy of ~15 Mev, the dose rate received by the solutions during a pulse is equivalent to ~ 2 x 10/sup 23/ ev ml/sup -1/ sec/sup -1/. Under these conditions, ~10/sup -5/ M hydrogen atoms (and hydroxyl radicals) are generated throughout the irradiated volume. All irradiations are monitored with the Fricke dosimeter, for which G(Fe/sup 3+/) is 11.4 plus or minus 0.5 under these irradiation conditions. Preliminary studies with neutral water and with 0.8 N sulfuric acid solutions show that the initial yields of both hydrogen and hydrogen peroxide are about 80% higher in the acid solution but that, in each case, G(H/sub 2/) = G(H/supb 2/O/sub 2/. Oxygen is not an initial product. Yields of hydrogen were measured in 0.8 N sulfuric acid up to 8 M hydrogen peroxide and up to 0.1 M in neutral solution. Hydrogen peroxide exerts a much stronger scavenging action in neutral than in acid solution. In cach case, but at different concentrations of hydrogen peroxide, the scavenging curves eventually coincide with those determined using Co/sup 60/ gamma radiation at a dose of ~10/sup 17/ ev ml/sup -1/ sec/sup -1/. Although difficulties remain, these data are consistent with the transient existence of two reducing species designated as the solvated electron, e/sub aq -bar/, predominant in neutral solutions, and the H atom, predominant in acid solution. Hydrogen peroxide is 50 times more effective in suppressing hydrogen formation in neutral solutions than in 0.8 N sulfuric acid solutions. Some relative hydrogen atom (or-bar e/sub qaq- bar) and hydroxyl radical rate constants consistent with the G(H/sub 2/) and G(H/ sub 2/O/sub 2/) are reported. In contrast to the lower G(Fe/sup 3+/) obtained with ferrous sulfate, measurements with the formic acid dosimeter (0.01 M HCOOH, 0.001 N H/sub 2/SO/sub 4/, 0.001 M O/sub 2/) give the same yields as with Co/sup 60/ gamma radiation at much lower dose rates. G(H/sub 2/O/sub 2/) for oxygen saturated neutral water is higher than that for gamma rays. This greater yield can be explained on the basis of competing radical --radical reactions.
- Research Organization:
- Argonne National Lab., Ill.
- Sponsoring Organization:
- USDOE
- NSA Number:
- NSA-16-007593
- OSTI ID:
- 4818829
- Journal Information:
- Journal of Physical Chemistry, Vol. 66, Issue 1; Other Information: Orig. Receipt Date: 31-DEC-62; ISSN 0022-3654
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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Related Subjects
ATOMS
COBALT 60
DIAGRAMS
DOSEMETERS
ELECTRON BEAMS
FORMIC ACID
GAMMA RADIATION
HYDROGEN
HYDROGEN PEROXIDES
IRON SULFATES
IRRADIATION
LINEAR ACCELERATORS
MEASURED VALUES
MONITORING
OXYGEN
PULSE GENERATORS
RADIATION CHEMISTRY
RADIATION DOSES
REACTION KINETICS
SOLUTIONS
SULFURIC ACID
THERMODYNAMICS
WATER