FWHM calibration is one of the essential procedures in gamma-ray spectra analysis.Traditional method is time consumption and poor flexibility because of extra measurement on calibration source.This paper introduces an...FWHM calibration is one of the essential procedures in gamma-ray spectra analysis.Traditional method is time consumption and poor flexibility because of extra measurement on calibration source.This paper introduces an implicit calibration method based on symmetric zero-area conversion.The single peaks can be differentiated from doublets.Meanwhile,the extracted FWHM values can be applied in the fitting process.Various forms of calibration equations are introduced and compared with practical spectrum data under this method.展开更多
The effects of gamma irradiation on absorption properties of Carbol Fuchsin (CF) with crystal violet dyed Poly Vinyl Alcohol (PVA) blended for possible use in dosimetry and measurement of radiation dose in gamma rays ...The effects of gamma irradiation on absorption properties of Carbol Fuchsin (CF) with crystal violet dyed Poly Vinyl Alcohol (PVA) blended for possible use in dosimetry and measurement of radiation dose in gamma rays have been studied using UV-Visible spectrophotometer method. The films were irradiated to accumulated doses from (10 to 70) Gy using Co60 gamma ray source at a constant dose rate. The absorption spectra were measured using UV-Visible spectrophotometer in the wave length range (200 to 900) nm, resulting in a decrease of the absorbance at 560 nm band peak with increasing dose. Regarding to the IR transmittance it’s appearing that for the samples with crystal violet the band at 1716 divided two small bands which become obvious for the irradiated one which indicate also the effect of gamma doses. In this study, the less Full Width at Half Maximum (FWHM), the better is the dosimeter. The FWHM due to sharpness in the band peak and this is useful for determine the fine dosimeter.展开更多
Due to its ubiquitous occurrence in igneous,metamorphic,and sedimentary rocks and its wide application in geochronology and geochemistry,zircon has become the most widely used accessory mineral in the geological commu...Due to its ubiquitous occurrence in igneous,metamorphic,and sedimentary rocks and its wide application in geochronology and geochemistry,zircon has become the most widely used accessory mineral in the geological community.Nevertheless,the decay of U and Th causes radiation damage to the zircon structure,resulting in various degrees of metamictization,which can affect the accuracy of U–Pb dates and Hf and O isotope results.If the degree of zircon radiation damage can be quantified,the influence on geochemical analyses can be evaluated,and the results can be corrected more precisely.In this paper,synthetic and natural zircon crystals with different crystallization ages were selected for Raman spectroscopy analysis,cathodoluminescence imaging,and determination of the U and Th concentrations.The results show that Raman FWHM(full width at half bandmaximum)and Raman shift correlate with alpha dose(Da)ofzirconsfollowingtheseequations,FWHM=44.36(±2.32)×[1-exp(-2.74×Da)]-+1.7(±0.19),Raman Shift=-6.53×Da+1007.69.Analysis of synthetic zircon crystals shows that doped REEs(rare earth elements and P)can also lead to an increase in the FWHM.However,this effect can be ignored for natural zircon samples with REE contents at a normal level of hundreds to a few thousand ppm.The FWHM and Raman shift can be used as proxies to measure the degree of zircon radiation damage.Using the updated equations to calculate the latest age when zircon began to accumulate radiation damage,a more accurate and more meaningful“radiation damage age”can be obtained.展开更多
Laser shock peening is a modernized surface enhancement performed methodically to improve fatigue life, enhance the hardness of the material and make coarse grains flat under the superficial layer. In this current stu...Laser shock peening is a modernized surface enhancement performed methodically to improve fatigue life, enhance the hardness of the material and make coarse grains flat under the superficial layer. In this current study, the effect of varying optimized multiple laser shock peening (LSP) is studied on the surface integrity, microhardness, and mechanical properties. The results show that the LSP-treated specimens have visible signs of valleys, wavy and varying height distribution as well as dimples. However, the presence of non-uniformity and sharp protrusions was detected from the superficiality of the as-received specimen and this was so because of the SiC abrasive material used to polish the superficial layer of the specimen before the test experiment. Prior to LSP, the surface roughness was 2 μm, however, after LSP the roughness increased to 4 μm, 6 μm and 17 μm for 1, 2, and 4 impacts, respectively. High-density dislocation can also be observed close to the grain boundary because the grain boundary prevents the migration of dislocation which could lead to dislocation walls and dislocation tangles. The increase in impacts decrease the average grain size, nevertheless, the micro-strain increased after multiple impacts. Furthermore, coarse grains after LSP were transformed into finer grains. The increase in the number of impacts increases the micro-strain likewise the full-width half maximum (FWHM). Finally, the increase in microhardness increases as the LSP impacts increase.展开更多
基金Supported by National Nature Science Foundation of China(No.11175101)
文摘FWHM calibration is one of the essential procedures in gamma-ray spectra analysis.Traditional method is time consumption and poor flexibility because of extra measurement on calibration source.This paper introduces an implicit calibration method based on symmetric zero-area conversion.The single peaks can be differentiated from doublets.Meanwhile,the extracted FWHM values can be applied in the fitting process.Various forms of calibration equations are introduced and compared with practical spectrum data under this method.
文摘The effects of gamma irradiation on absorption properties of Carbol Fuchsin (CF) with crystal violet dyed Poly Vinyl Alcohol (PVA) blended for possible use in dosimetry and measurement of radiation dose in gamma rays have been studied using UV-Visible spectrophotometer method. The films were irradiated to accumulated doses from (10 to 70) Gy using Co60 gamma ray source at a constant dose rate. The absorption spectra were measured using UV-Visible spectrophotometer in the wave length range (200 to 900) nm, resulting in a decrease of the absorbance at 560 nm band peak with increasing dose. Regarding to the IR transmittance it’s appearing that for the samples with crystal violet the band at 1716 divided two small bands which become obvious for the irradiated one which indicate also the effect of gamma doses. In this study, the less Full Width at Half Maximum (FWHM), the better is the dosimeter. The FWHM due to sharpness in the band peak and this is useful for determine the fine dosimeter.
基金supported by funds from the Strategic Priority Research Program(B)of the Chinese Academy of Sciences(XDB 41000000)the National Natural Science Foundation of China(41973002,41772187)+1 种基金the Fundamental Research Funds for the Central UniversitiesNatural Sciences and Engineering Research Council of Canada(NSERC)Discovery Grant to J.M Hanchar(RGPIN/004649-2015)。
文摘Due to its ubiquitous occurrence in igneous,metamorphic,and sedimentary rocks and its wide application in geochronology and geochemistry,zircon has become the most widely used accessory mineral in the geological community.Nevertheless,the decay of U and Th causes radiation damage to the zircon structure,resulting in various degrees of metamictization,which can affect the accuracy of U–Pb dates and Hf and O isotope results.If the degree of zircon radiation damage can be quantified,the influence on geochemical analyses can be evaluated,and the results can be corrected more precisely.In this paper,synthetic and natural zircon crystals with different crystallization ages were selected for Raman spectroscopy analysis,cathodoluminescence imaging,and determination of the U and Th concentrations.The results show that Raman FWHM(full width at half bandmaximum)and Raman shift correlate with alpha dose(Da)ofzirconsfollowingtheseequations,FWHM=44.36(±2.32)×[1-exp(-2.74×Da)]-+1.7(±0.19),Raman Shift=-6.53×Da+1007.69.Analysis of synthetic zircon crystals shows that doped REEs(rare earth elements and P)can also lead to an increase in the FWHM.However,this effect can be ignored for natural zircon samples with REE contents at a normal level of hundreds to a few thousand ppm.The FWHM and Raman shift can be used as proxies to measure the degree of zircon radiation damage.Using the updated equations to calculate the latest age when zircon began to accumulate radiation damage,a more accurate and more meaningful“radiation damage age”can be obtained.
文摘Laser shock peening is a modernized surface enhancement performed methodically to improve fatigue life, enhance the hardness of the material and make coarse grains flat under the superficial layer. In this current study, the effect of varying optimized multiple laser shock peening (LSP) is studied on the surface integrity, microhardness, and mechanical properties. The results show that the LSP-treated specimens have visible signs of valleys, wavy and varying height distribution as well as dimples. However, the presence of non-uniformity and sharp protrusions was detected from the superficiality of the as-received specimen and this was so because of the SiC abrasive material used to polish the superficial layer of the specimen before the test experiment. Prior to LSP, the surface roughness was 2 μm, however, after LSP the roughness increased to 4 μm, 6 μm and 17 μm for 1, 2, and 4 impacts, respectively. High-density dislocation can also be observed close to the grain boundary because the grain boundary prevents the migration of dislocation which could lead to dislocation walls and dislocation tangles. The increase in impacts decrease the average grain size, nevertheless, the micro-strain increased after multiple impacts. Furthermore, coarse grains after LSP were transformed into finer grains. The increase in the number of impacts increases the micro-strain likewise the full-width half maximum (FWHM). Finally, the increase in microhardness increases as the LSP impacts increase.
