Radiation chemical studies with heavy ions: oxidation of ferrous ion in the Fricke dosimeter

Journal Article · Thu Oct 22 04:00:00 EDT 1987 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100306a050· OSTI ID:5570835

La Verne, J A; Schuler, R H

The yields for oxidation of ferrous ions in the Fricke dosimeter have been determined for /sup 4/He, /sup 7/Li, /sup 9/Be, /sup 11/B, and /sup 12/C ions with energies up to 35 MeV. These particles have a linear energy transfer (LET = -dE/dx) in water of up to 20 eV/A for /sup 4/He ions and 100 eV/A for /sup 12/C ions. For these high LET particles the radiation chemical yields for ferric production, which range from approx. 3 to approx. 8, are appreciably lower than for fast electrons (15.5). The differential yields determined from the observed energy dependences show that the yields are not uniquely determined by LET but increase with increased atomic number (Z) of the irradiating particle. Related measurements on deaerated solutions provide detailed information on the dependences of the H atom and water decomposition yields on particle type and energy and show that there is, at a given LET, increased diffusion of H atoms out of the track with increase in Z. However, at high energies this effect becomes relatively less important because of increase in the track radius. There is an indication that for heavy ions of very high energies the limit at low LETs may be well below the yield for fast electrons because energy is deposited in more dense spurs. The yield of H atoms which escape the track at the Bragg peak decreases from 0.30 for /sup 4/He ions to 0.09 for /sup 12/C ions. The low-energy limiting yields for particles of very high LET are less than 0.01 for H atom production and approx. 2.8 for water decomposition. This report includes a comprehensive summary of previous studies of the Fricke system with heavy ion radiations.

• Research Organization: Univ. of Notre Dame, IN
• OSTI ID: 5570835
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 91:22; ISSN JPCHA
• Country of Publication: United States
• Language: English

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38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400600* -- Radiation Chemistry
ALKALI METAL ISOTOPES
ALKALINE EARTH ISOTOPES
BEAMS
BERYLLIUM 9
BERYLLIUM 9 BEAMS
BERYLLIUM ISOTOPES
BORON 11
BORON 11 BEAMS
BORON ISOTOPES
CARBON 12
CARBON 12 BEAMS
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CATIONS
CHARGED PARTICLES
CHEMICAL REACTION YIELD
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EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
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HELIUM 4
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INFORMATION
ION BEAMS
IONS
IRON
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LET
LIGHT NUCLEI
LITHIUM 7
LITHIUM 7 BEAMS
LITHIUM ISOTOPES
METALS
MEV RANGE
MEV RANGE 01-10
MEV RANGE 10-100
NUCLEI
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ODD-EVEN NUCLEI
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STABLE ISOTOPES
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YIELDS