| Radiation metrology is an important and effective means of quality control to develop national economy and national defense construction. Radiation dose control involves many emerging disciplines and research in the manufacturing industry, involving medical, pharmaceutical and medical equipment sterilization, polymer modified and many other fields. In view of the importance of radiation dosimetry, International Atomic Energy Agency (IAEA) made the development planning on the standards related to radiation dosimetry in 1977, The plan includes wide dose range from 10Gy to 100kGy of the y-ray and electron radiation, and a total funding of 34 high-dose dosimeter research projects which have achieved remarkable results.Radiation dosimetry in China is an emerging area of expertise; almost all principles and methods of measurement are established in abroad for the first time then introduced to the domestic by the international industry when matured. In recent years, the secrecy of the emergence of some new technologies and materials making me has had to be controlled by others as high-priced purchasing. Original works are also rare in several research units in Beijing, Shanghai, Mianyang. Specific units involved in radiation applications lack not only the professionals staff who specialized in radiation processing dosimetry working, but also the appropriate technical means to China's actual situation. Simple, rapid and more accurate radiation dose measurements system is the basic needs of radiation practitioners in the working conditions.According to the basic principles of chrominance, the issue tried to use today's new technology approach to radiation dose studies. Ionizing radiation can cause color variations in a lot of substances and their aqueous solution, in which have dose-effect relationship. There are no simple analytical methods to get their dose information contained in the complex. Guided by Lambert-Beer law, combined with radiation dosimetry work practice, the study suggests to obtain radiation dose information based on RGB chrominance change and supper-mini whole-spectrum spectrometer. Main research contents include three parts as the color detection devices, material with color-changed induced by radiation and data processing. Try to achieve new type research methods of liquid chemical radiation dosimetry with will have intellectual property rights of China's own, which maybe some application prospects in the industrial and agricultural production, scientific research and national defense fields.1 Study steps, materials and methods1.1 Study of color-changed materialselect two kinds of chemical dyes named Alphaurine A and Tracid Brilliant Red B which could fade when radiation, two kinds of ferrous salt compounds and its coloring-assistant system which could radiation coloration; Experimental materials, reagents and solvents are preparing by conventional chemical laboratory operations methods and procedures. According to the design, the liquid probes for radiation dose are prepared and receiving external irradiation of 60Co y ray with different doses.1.2detection for irradiated samplesDetected the above irradiated samples using the primary colors detection devices which was composed with light transmitter, test tubes fixed installations or color sensor module with a light receiver, D conversion function of the microprocessor, input/output interface and displayer, accessed to the corresponding values in red, green and blue (RGB). The Super-mini whole-Spectrum spectrometer is used to obtain absorbance changes of the whole Spectrum.1.3data processingBased on three color value and changing of the whole Spectrum of experimental samples, multi-factor analysis of the computer software data are processing.2 Experimental results2.1 Results of the dye solution samples by three-color method2.1.1 Solution concentration and radiation dose was the main factors to determine the availability of an ideal three-color data. The whole dose-response relationship has changed markedly in 500mg/L Alphaurine A and 100mg/L Tracid Brilliant Red B radiated by 1.5-13.5kGy dose range. During the range, chrominance of Red (R) in Alphaurine A solution gradually increased with the dose increased, and increased linearly with the radiation dose trend. The changing of chrominance of green (G) is not obvious in irradiation doses; the chrominance of Blue (B) intensity increased with the dose gradually declining, with the red showed the opposite trend change; Chrominance of green (G) in Tracid Brilliant Red B solution gradually increased, and increased linearly with the radiation dose trend; Red (R) intensity declined with the dose gradually increasing, and the Green(G) showed the opposite trend of change; Chrominance of Blue (B) did not change significantly.2.1.2 The chrominance of red (R) and blue (B) in the experimental group of Alphaurine A with concentrations below 500mg/L are increasing and decreasing trend change respectively at the lower dose range. The lower the concentration is, the greater the changes of chrominnance with the radiation dose is, which finally flattening nearly horizontal. Turning points of this change are 1,3,6 kGy respectively according to concentration increasing. The chrominance of green (G) and red(R) gave rise to similar trends in change in Tracid Brilliant Red B below 50mg/L following irradiation dose range of 0-2000Gy,but would gradually flatten nearly horizontal as the dose increase. Dose of the turning point of this change was 500Gy around. Changes of Blue (B) intensity values were not evident in dose range of 0-2000Gy.2.13 Change of chrominance of red (R) and blue (B) was significantly and was complementary to counter-balance in Alphaurine A solution observed of different concentration after irradiation. And change of green (G) was no significant. Change of chrominance of red (R) and green (G) was significantly and was complementary to counter-balance in Tracid Brilliant Red B solution observed of different concentration after irradiation. And change of blue (B) was no significant.2.1.4 Put the experimental samples of 250mg/L Alphaurine A solutionand 100mg/L of Tracid Brilliant Red B solution in the summer environment (direct sunlight during the day and night daytime temperature is 25-35℃) for 2 weeks. Re-measured of RGB color values and statistical analysis showed no significant difference which indicating storage of two weeks in summer temperatures had no effect on the test results. It showed a better chemical stability of radiation of this type of dye.2.2 Results of ferrous salt solution by three-color method2.2.1 In the complex solution of errous sulfate green vitriol with xylenol orange, the dose-effect relationship showed as red (R) chroma values gradually decreased, while blue (B) intensity increased with the dose gradually increased, showing the opposite change in trend with the red; but green (G) intensity values did not change significantly in the irradiation dose range of 0-80Gy2.2.2In the complex solution of ferrous chloride tetrahydrate with xylenol orange, the dose-effect relationship showed as blue (B) chroma values gradually decreased, while green (G) intensity increased with the dose gradually increased, showing the opposite change in trend with the blue; but red(R) intensity values did not change significantly in the irradiation dose range of 0-80Gy2.3 Results by super-mini whole-Spectrum spectrometer method2.3.1Change of absorbance with wavelength was very obvious in Tracid Brilliant Red B solution with 4 various kinds of concentrations as 200mg/L,100 mg/L,50mg/L, 25mg/L. In various experimental dose range of 0-80Gy irradiation, the greater the radiation dose was, the greater the magnitude of changes of the absorbance was compared with the control group,2.3.2In the two kinds of composite solutions system with ferrous of the experiment, the relationship between absorbance (T) and wavelength was "S" shape generally. The absorbance of wavelength range of 600-700nm increased rapidly, while the absorbance of the longer and shorter wavelengths increased gently.2.3.3The influence in absorbance manifested mainly in changes of absorbance below wavelength of 600nm and above wavelength of 700nm of ferrous sulfate complex solution in 0-80Gy radiation dose. Reaction of absorbance becomes more apparent in complex solution of 0.0085mmol/l xylenol orange with 0.01mmol/l sulfate green vitriol in the range of wavelength above.2.3.4Compared with the results of complex solution of xylenol orange andsulfate green vitriol, the change of absorbance was more obvious in the wavelength greater than 700nm in complex solution of 0.0165mmo/l xylenol orange and 0.025mmol/l ferrous chloride tetrahydrate, while hardly evident in the wavelength less than the wavelength of 600nm.3 DiscussionThe basic method of chemical dosimeter is spectrophotometry, and the theoretical basis is Lambert-Beer law. Lambert-Beer law describes that light absorption of colored solution on certain intensity and liquid layer thickness as well as the product of the concentration of colored substances is proportional. Radiochemical yield G value refers to the number of specific products of each arising from loss of 100eV when the charged particles and their secondary particles in the water are blocked. Some products will decrease over time, while some will increase over time. Using spectrophotometry to determine the volume of solution in the product of some radiation is the basic working principle of chemistry dosimeter of radiation. For example, Fricke dosimeter (ferrous sulfate dosimeter) was among the first used as a dose of radiation measuring instruments. When it is irradiated, Fe2+is oxidized to Fe3+to produce Blu-ray, which can be measured by spectrophotometer. This method is to use a specific wavelength of light to analyze the linearity change of absorbance in a particular solution of single substances so as to estimate the changes in the projected dose of radiation. However, it is so few species of solution that can meet the conditions of analysis.Many substances occur the changes of a non-single color after irradiation, such changes also relates to the radiation dose. For example, in the field of environmental protection, treatment technology of dye wastewater using ionizing radiation degradation is a viable option. Taking 60Co y-rays as a radiation source, the azo dyes methyl orange and Reactive Brilliant Blue KNR aqueous solution of the radiation degradation of studies have shown that decolorization achieved very good results in the dye solution before and after irradiation by UV-visible spectra and radiation dose associated with clear change. Solid membranes and liquid-gel chemistry as a radiation dosimeter in the dose of radiation detection range has reached a very low level, and they can be used to measure the dose of a variety of sources, including the high-energy protons, high-energy electrons,γrays and X-rays and so on. But because of its complexity of mechanism and color change, it is difficult to use conventional spectrophotometric techniques to determine an accurate dose of radiation.Colorimetric method suggests the superior features to score spectrophotometry to non-single-color changes. In recent years, due to the rapid development of optical components and electronic chip industry, the development of photoelectric colorimeter becomes a set of optical, mechanical, and electronic in one system. As the modern industrial production to high-speed, automated direction, the use of color measuring instruments as the product of the principal means of objective assessment. For example, a use of the RGB color sensor of world's advanced precision, it gathers in an area of 3×3mm integrating dozens of R (red), G (green), B (blue) sensors. Colored solution through the light projected onto the RGB color sensor has been on three different currents through the three kinds of conversion was proportional to the different RGB data. Established a three-dimensional numerical matrix algorithm model and the standard sample database of principles established by the value of precision transmission, effectively overcome the deviation caused by errors. The resulting rapid rise to the water quality testing techniques attaches great importance to the State Environmental Protection Department; the core testing tube method has been incorporated into the country's environmental protection industry standards. In earthquake-stricken Wenchuan and the water security and health security of our military exercises, joint logistics have been satisfied with the practical application of results.Another more advanced spectral filter array technology is the research results of key basic research development program. The technical design, omni-directional photonic crystal heterostructure spectroscopic devices are to make up for ordinary photonic crystal heterostructure light spectral efficiency of the device insufficient to achieve UV-visible near-infrared spectra of ultra-miniaturized devices [7,8], will equip the successfully developed 128-channel to integrate filter assembly directly to the detector array, jointly constitute a volume of less than a cubic centimeter of the super-1 micro-spectrometer, which is an international leader in new technologies, planning to use our resources satellite assembly. Without environmental vibration in use can be a long time without calibration wavelength and energy, and it is the best product spectrum analysis in a harsh environment. At present this technology only has related concepts in foreign countries.With the technological advances of optical technology, computer technology, microelectronics and materials science, technologies improving study of liquid chemical dosimeter have developed sophisticated. In the near-ultraviolet-visible-infrared spectra within the framework of full-color,the subjects studied dosimeter associated with the radiation dose using the new technology conditions based on two kinds of chrominance study above(three primary colors sensor technology and ultra-micro-array spectral filter technology), then received a large number of the experimental data of chrominance changes of irradiated materials according to radiation dose. A number of written research papers have been published in the journal in the domestic core. Preliminary findings suggest that the new color analysis techniques can be used studying relatively radiation dose, especially low dose of radiation, also can be used analyzing ionizing radiation-induced non-uniform color change compared to chemical of the traditional methods of radiation dosimetry.Study of liquid chemical dosimeter based on new technique chrominance principles has theoretical and practical significance, such study vision is different from the current conventional research of liquid chemical dosimeter domestic and foreign in terms of measuring container, the type and ratio of dosimeter solution components as well as data measurement principle and devices After refining it could have the features with full intellectual property rights and may be fast, easy, economic and technical characteristics of miniaturization, and there will be a strong application value. The search have not yet found in the same study at home and abroad, for which patent protection has been declared (No. ZL 2009 2 0066735.9). |
