• Journal of Life Science
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• v.11 no.6
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• pp.612-617
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• 2001

Seedlings of red pepper (Capsicum annum L.) were exposed to various doses of ${\gamma}$-radiation )($^{60}$ Co)and cultivated in the 1/2,000 a pot. Plant hight the number of leaves, flowers and fruits, chlorophyll contents, plant dry weight, ac- tivites of antiozidant enzymes such as superoxide dismutase(SOD) adn peroxidase(POD), were determined. Plant height of seedling treated with 1 Gy of ${\gamma}$-radiation was increased up to 16.6% as compared to untreated control at 80 days after treatment, while those treated with 20 Gy or 50 Gy was decreased 22.0% or 75.0% respectively. The plants treated with 1 Gy or 5 Gy were increased the number of leaves up to 41.2% and 24.9% as well as dry weight of fruit up to 58.4% and 49.4% respectively. However treatment of radiation higher than 20 Gy significantly inhibited the growth, chlorophyll content and yield of pepper fruit. Activities of antioxidant enzymes, SOD and POD were tem-porary increased within one or five days after treatment depending on the doses of treatment , and the activities were gradually decreased to control level of lower thereafter. The SOD and POD activities in the leaves of pepper plant treated with 50 Gy were 5.5 and 6.0folds higher than that of control at five days after treatment, respectively.

• Journal of Radiation Protection and Research
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• v.23 no.4
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• pp.229-236
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• 1998

In order to establish a testing system for personnel dosimetry performance, the radiation fields from photons, beta particles and neutrons are required, in recent, Korea Institute of Nuclear Safety(KINS) established the reference radation fields except neutrons and tested a variety of their properties. As a result of the test, the reference beams were shown to meet satisfactorily not only the standards of the International Organization for Standardization(ISO), but also the standard levels of the developed countries which are intercomparable with the international traceability. This paper describes the reference beam of gamma radiation. The self-designed and established reference radiation fields were investigated and analyzed by ISO and other international standards. The secondary photon contribution and the beam uniformity of the gamma radiation field were measured and evaluated to fulfill those requirements suggested by the ISO-4037. The measured air kerma rate for the $^{137}$Cs and $^{60}$Co gamma fields was 0.1891 $\sim$ 23.4967 $\mu$Gy/s sand 0.5844 $\sim$ 15.9954 $\mu$Gy/s respectively. The uncertainty with 95 % confidence level of the measured air kerma rate was determined to be less than 2.5 % which is comparable to the international reference gamma radiation fields. It was found that the evaluated air kerma calibration factors of Exradin ionization chamber were in good agreement within 0.9 % and 0.03 % with those given by PTB and NIST, respectively. The gamma radiation fields installed at KINS can maintain traceability systems in Korea, Germany and United State.