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高能Ar离子辐照PET膜引起的表面改性研究 总被引:2,自引:0,他引:2
采用傅立叶转换的红外光吸收技术在反射方式下分析研究了35MeV/u Ar离子辐照半晶质PET膜引起的表面改性及其对吸收剂量的依赖性。结果表明,辐照导致PET膜中与晶态区域相关的吸收带强度随吸收剂量增加普遍减弱,而与非晶区域相关的吸收带强度随吸收剂量增加逐渐增加,表明辐照使PET膜发生了非晶化转变。化学键断裂主要发生在苯环的对位和酯的C-O键上,而苯环的基本结构在整个辐照过程中变化较小。非晶化效应和化学键断裂同时依赖于离子的照射剂量和样品表面的电子能量沉积。此外,在约5.0MGy以上的吸收剂量,辐照还引起了炔端基团的形成,炔端基团浓度随吸收剂量的增加显著增加。对实验结果进行了定性解释。 相似文献
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A. Domaracka E. Seperuelo Duarte P. Boduch J.M. Ramillon S. Pilling E.F. da Silveira 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2010,268(19):2960-2963
Water, carbon oxide, carbon dioxide, and ammonia ices are known to be pervasive constituents of the solar system and the interstellar medium. These ices and ice-covered surfaces are exposed to bombardment by energetic projectiles like photons, electrons, and ions. Laboratory experiments have been carried out to study the effects of such irradiation. However, there is a clear lack of information about the interaction of heavy ion components of solar/stellar wind and galactic cosmic rays (e.g. Fe) with ices in the keV to GeV energy range. The objective of this work is to study the effects produced in astrophysical ices by highly charged nickel ions at relatively high energy (∼50-500 MeV) in the electronic energy loss regime, and to compare them with those produced by protons, photons, and electrons. Our results for CO2 and CO indicate that sputtering induced by heavy ions can be an important mechanism to desorb molecules in astrophysical environments. 相似文献
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《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2007,256(1):199-206
In this work a study of damage production in gallium nitride via elastic collision process (nuclear energy deposition) and inelastic collision process (electronic energy deposition) using various heavy ions is presented. Ordinary low-energy heavy ions (Fe+ and Mo+ ions of 110 keV), swift heavy ions (208Pb27+ ions of 1.1 MeV/u) and slow highly-charged heavy ions (Xen+ ions of 180 keV) were employed in the irradiation. Damage accumulation in the GaN crystal films as a function of ion fluence and temperature was studied with RBS-channeling technique, Raman scattering technique, scanning electron microscopy (SEM) and transmission electron microscopy (TEM).For ordinary low-energy heavy ion irradiation, the temperature dependence of damage production is moderate up to about 413 K resulting in amorphization of the damaged layer. Enhanced dynamic annealing of defects dominates at higher temperatures. Correlation of amorphization with material decomposition and nitrogen bubble formation was found. In the irradiation of swift heavy ions, rapid damage accumulation and efficient erosion of the irradiated layer occur at a rather low value of electronic energy deposition (about 1.3 keV/nm3), which also varies with irradiation temperature. In the irradiation of slow highly-charged heavy ions (SHCI), enhanced amorphization and surface erosion due to potential energy deposition of SHCI was found. It is indicated that damage production in GaN is remarkably more sensitive to electronic energy loss via excitation and ionization than to nuclear energy loss via elastic collisions. 相似文献
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A. Audren D. Gosset X. Portier F. Garrido M. Levalois C. Reynaud 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2009,267(6):976-979
In this study, we performed irradiation experiments on nanostructured 3C-SiC samples, with 95 MeV Xe ions at room temperature. This energy permits the observation of the combined electronic and nuclear interactions with matter. The grazing incidence X-ray diffraction results do not reveal a complete amorphization, despite value of displacement per atom overcoming the total amorphization threshold. This may be attributed to competing effects between nuclear and electronic energy loss in this material since a total amorphization induced by nuclear interactions was found after low energy ion irradiation (4 MeV Au). Moreover, electronic interactions created by high energy ion irradiations induce no disorder in single crystalline 6H-SiC. But in samples previously disordered by low energy ion implantation (700 keV I), the electronic interactions generate a strong defects recovery. 相似文献
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P.F. Zhai J. Liu J.L. DuanH.L. Chang J. Zeng M.D. HouY.M. Sun 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2011,269(18):2035-2039
Highly oriented pyrolytic graphite (HOPG) samples were irradiated with swift heavy ions (Ar, Kr, Bi, U) of fluences between 1011 and 1013 ions/cm2 in energy range MeV-GeV. The irradiated samples were analyzed by Raman spectroscopy with laser wavelength of 532.2 nm. It is shown that the ratio between the integrated intensities of the disorder-induced D and the original G Raman bands which denotes the degree of the damage induced by ion irradiation increases as a function of ion fluence as well as the electronic energy loss. This agrees with the previous reports. However, quantitative analysis of the peak intensity at a fixed fluence discloses that ion velocity is also a significant parameter in determination of damage. The conclusion is that the extent of discontinuity of ion track may change with ion velocity besides the electronic energy loss. Considering the radial distribution of the energy deposited on the matter being velocity dependent, the energy density which combines the influence of the electronic energy loss and ion velocity may be more suitable for explaining the effect induced by swift heavy ions. 相似文献
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《Journal of Nuclear Materials》1994,211(1):46-51
Measurements of G-values (number of molecules emitted per 100 eV of absorbed radiation energy) have been made for helium and boron ion irradiations of polystyrene (PS) films of different thicknesses. These ions were chosen because the electronic linear energy transfer (LET) values for B+ with energy near 200 keV is comparable to the corresponding LET for He+ near 400 keV. In contrast, the nuclear of ‘recoil’ LET of B+ is several times larger than that of He+ throughout the B+ depth range. When the G-values for H2 and C2H2 gas production were measured for these ions, three important findings were noted: (1) The G-values for H2 and C2H2 showed only a slight increase and decrease respectively with increasing electronic LET. (2) The G(H2) for B+ irradiation was approximately 50% larger than that for He+ irradiation. (3) The G(C2H2) was about a factor of five larger for the B+ irradiation compared to the He+. In contrast to earlier speculation, no evidence was seen for an electronic LET threshold, above which the G-values rapidly increase. It appears that this anomaly was primarily due to changing the bombarding ion (increasing the atomic number) to reach a larger LET in the measurement. While G-value effects due to different ion-track energy densities are not yet resolved, our findings imply that most of the molecular gases formed from radiochemical reactions in polymers during typical ion irradiations are dependent not simply upon electronic energy, but upon a mechanism involving momentum transfer from the ion to the atomic nuclei of the target. 相似文献
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ZHANG Hong LI Wen-Jian ZHENG Rong-Liang 《核技术(英文版)》2005,16(4):209-213
1 Introduction Ionizing irradiation has been widely reported to damage organism by attacking proteins, nucleic acid and lipids in cells.[1,2] However, irradiation hormesis after low dose irradiation has been becoming the focus of research in radiobiology in recent years.[3,4] Many studies have shown that low dose ionizing irradiation can produce stimulating effects on the immune sys-tems and induce adaptative response to harmful ef-fects of subsequent high-dose radiation exposure.[3,5-7] Furth… 相似文献
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Lakhwant Singh 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2007,263(2):458-462
Makrofol-N polycarbonate thin films were irradiated with copper (50 MeV) and nickel (86 MeV) ions. The modified films were analyzed by UV-VIS, FTIR and XRD techniques. The experimental data was used to evaluate the formation of chromophore groups (conjugated system of bonds), degradation cross-section of the special functional groups, the alkyne formation and the amorphization cross-section. The investigation of UV-VIS spectra shows that the formation of chromophore groups is reduced at larger wavelength, however its value increases with the increase of ion fluence. Degradation cross-section for the different chemical groups present in the polycarbonate chains was evaluated from the FTIR data. It was found that there was an increase of degradation cross-section of chemical groups with the increase of electronic energy loss in polycarbonate. The alkyne and alkene groups were found to be induced due to swift heavy ion irradiation in polycarbonate. The radii of the alkyne production of about 2.74 and 2.90 nm were deduced for nickel (86 MeV) and copper (50 MeV) ions respectively. XRD analysis shows the decrease of the main XRD peak intensity. Progressive amorphization process of Makrofol-N with increasing fluence was traced by XRD measurements. 相似文献