The effects of dose and radiation quality on the shape and power saturation of the EPR signal in alanine

Journal Article · Sat Oct 01 04:00:00 UTC 1994 · Radiation Research

DOI:https://doi.org/10.2307/3578575· OSTI ID:79338

Ciesielski, B; Wielopolski, L ^[1]

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1. Brookhaven National Lab., Upton, NY (United States)

Variations in the shape and the power saturation of EPR spectra of L-alanine irradiated with photons, electrons, neutrons and protons are reported. It is shown that the ratio of the intensities of the satellite lines attributable to {open_quotes}spin flips{close_quotes} and the central line depend on the EPR microwave power, and it is proposed as a quantitative measure of the signal saturation effect. Dependence of this ratio on the microwave power is affected by the radiation quality and for doses in excess of 10 kGy by the absorbed dose. At high doses of low-LET radiation these changes are attributed to a high local density of free radicals, while for low doses of high-LET radiation these are due to changes induced in the crystal lattice. Consequently, the conventional peak-to-peak amplitude measurement of the EPR signal intensity is inaccurate when used for high doses and for comparison between radiations with different beam quality. The possibility to determine radiation quality from an EPR measurement is discussed. 29 refs., 7 figs., 2 tabs.

• Sponsoring Organization: USDOE
• OSTI ID: 79338
• Journal Information: Radiation Research, Journal Name: Radiation Research Journal Issue: 1 Vol. 140; ISSN 0033-7587; ISSN RAREAE
• Country of Publication: United States
• Language: English

Related Subjects

56 BIOLOGY AND MEDICINE
APPLIED STUDIES
ALANINE-L
DOSE RATES
ELECTRON SPIN RESONANCE
IONIZING RADIATIONS
LET
RADIATION QUALITY
RADICALS
VARIATIONS