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Penetration depth and concentrationdistribution for implanted heavy ions with low energies in plant seeds bySEM and EDS 总被引:1,自引:0,他引:1
WANGXin-Fu LIYong-Liang 《核技术(英文版)》2001,12(1):26-31
The penetration depth and concentration distribution of implanted ions have been studied for low energy heavy ions implanted in the dry seeds of plant,such as peanut,mung bean,sunflower,wheat and radish seeds,etc.by SEM EDS.The results show that the maximum penetration depth is about 12μm for V^ with an energy 200keV implanted in cotyledon of the peanut,18μm,15μm,20μm for V^2 with 90keV implanted in sunflower,wheat,radish seeds,respectively.The penetration depth of implanted Cu^2 with 80keV is about 90μm in the remainder funicle derivative of the mung bean seeds.The experimental result of the maximum penetration depth of implanted V^ in the peanut seeds was compared with the calculated value of the TRIM95. 相似文献
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离子注入植物种子的生物效应研究 总被引:21,自引:0,他引:21
用35-180keV离子束对玉米、水稻、小麦、黑麦等材料种子进行了氮或磷离子注入。结果发现,在被处理的当代种子中,发芽率,生长速度,植物株型等方面均出现了变异;对染色体行为的观察发现有丝分裂基本正常,减数分裂出现异常,对注入离子在种子内的分布进行了RBS测量,并以TRIM程序进行理论估算。对离子束作为诱变源的前景及机理进行了讨论。 相似文献
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中能氮离子束辐照小麦种子产生自由基的研究 总被引:5,自引:2,他引:3
用ESR波谱术研究了室温下中能氮离子辐照小麦种子产生的自由基,发现氮离子贯穿和注入小麦种子产生的自由基浓度随剂量的变化具有不同的特征。对氮离子贯穿小麦种子产生的自由基浓度随剂量率的变化规律也进行了研究。 相似文献
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特征X射线能谱法测定Fe^+注入小麦种子的深度 总被引:5,自引:2,他引:3
用110keV Fe^+离子束垂直注入小麦种胚后,在扫描电子显微镜上沿种子纵沟剖面,在不同深度上测量Fe元素被激发出的特征X射线强度分布,结果表明分布呈指数衰减,与晶体中的热扩散分布相类似,并对此进行了讨论。 相似文献
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部分种子成分的特征X射线在等效生物材料中衰减的测定 总被引:6,自引:5,他引:1
用Si(Li)探测器实现了Na、Mg、S、Cl的特征X射线在有机膜中的相对衰减以及与O、K元素的特征X射线能量相当的X射线或轫致辐射在有机膜中的相对衰减,分别得出了它们减的数学描述,并把实验得到不同能量的X射线在有机膜中的质量吸收系数与Berkeley的OCG软件计算出的结果相比,相关都小于30%。 相似文献
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采用红外光谱(IR),X射线衍射分析和扫描电镜(SEM)对低能离子(N+)注入纤维素粉微观结构的变化进行了研究。结果表明,低能离子辐照使纤维素分子内和分子间氢键均发生了断裂;随着辐照剂量的增加,纤维素相对结晶度逐渐减小,当注量增加到1500×1014cm-2时,相对结晶度较对照减少6.84%;纤维素颗粒直径逐渐变小,纤维变得越来越不完整,纤维表面出现较明显分层脱落现象,大多呈现的是细小碎片。 相似文献
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Per Persson Bengt Erlandsson Kim Freimann Ragnar Hellborg Ragnar Larsson Johan Persson Gran Skog Kristina Stenstrm 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2000,160(4):510-514
Accelerator mass spectrometry (AMS) is an ultra-sensitive method for counting atoms, both radionuclides and stable nuclides. When using small tandem accelerators to measure heavy isotopes, interfering isobars are often troublesome. One way to reduce this interference is to combine AMS with the detection of characteristic X-rays of the projectile. After analysis in the AMS system it is possible to identify ions of different atomic number by their characteristic X-rays, by slowing down the ions in a suitable target. In this paper, the detection limit of 59Ni at the Lund AMS facility is reported. A method for the chemical extraction of nickel from stainless steel, combined with a purification step to reduce the cobalt content in the sample by several orders of magnitude, is also described. 相似文献
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Chen Yu Lin Zhixin Zou Zuyao Zhang Feng Liu Duo Liu Xianghuai Tang Jianzhong Zhu Weimin Huang Bo 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》1998,140(3-4)
Conidia of Streptomyces erythreus, an industrial microbe, were implanted by nitrogen ions with energy of 40–60 keV and fluence from 1 × 1011 to 5 × 1014 ions/cm2. The logarithm value of survival fraction had good linear relationship with the logarithm value of fluence. Some mutants with a high yield of erythromycin were induced by ion implantation. The yield increment was correlated with the implantation fluence. Compared with the mutation results induced by ultraviolet rays, mutation effects of ion implantation were obvious having higher increasing erythromycin potency and wider mutation spectrum. The spores of Bacillus subtilis were implanted by arsenic ions with energy of 100 keV. The distribution of implanted ions was measured by Rutherford Backscattering Spectrometry (RBS) and calculated in theory. The mechanism of mutation induced by ion implantation was discussed. 相似文献
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Determination of L3 subshell X-ray production cross-sections and fluorescence yields of Pb, Th and U
nder
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ek 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2000,170(3-4):293-298
A study of L3 subshell X-ray production cross-sections and fluorescence yields by using characteristic K X-rays as the exciting radiation is described. Only the L3 subshells of Pb, Th and U were excited by the characteristic K X-rays of the elements used as secondary sources. The cross-sections for the production of Ll, L and Lβ groups of L3 subshell X-rays of Pb, Th and U have been measured using photoionization by Rb, Nb and Mo K X-rays. The measured L3 X-ray production cross-section values for Pb, Th and U are in good agreement with the theoretical ones evaluated using L3 subshell fluorescence yield ω3, fractions of the radiative width F3i and L3 subshell photoionization cross-section σ3. The L3 subshell fluorescence yields (ω3) have also been computed using the presently measured cross-section values and the theoretical L3 subshell photoionization cross-section values. These results are compared with the theoretically predicted values. 相似文献
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The biological effects of wheat seeds irradiated by 48MeV/u and 20MeV/u ^14N^7 beams are studied,respectively.The results show.both penetration and implantation of heavy ions can significantly inhibit growing pwer(height of plant stem)of wheat seeds.The greater dose is ,the weaker growing power is,and the implantation influence on growing power is stronger than the penetration;a great variety of chromosomal aberrations were observed in root tip cells of irradiated seeds and the aberration frequencies were several hundred times higher than that of the corresponding control;it has been proved by 3H-TdR incorporation test that unscheduled DNA synthesis exists in irradiated wheat seed embryos.It is found by ESR spectroscopy that the variation of free radical concentration with total dose has different features for the pentrated and implanted seeds. 相似文献
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不同能区重离子束在小麦育种上的比较研究 总被引:7,自引:0,他引:7
介绍了三个不同能区的重离子用于小麦育种的室内实验方法和大田培育情况,并对半致死剂量,细胞学观察和育种情况分别给出了初步结果,最后探讨了三种不同能区的重离子在作物育种上诱变机理。 相似文献
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《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》1987,27(1):104-118
Bombardment of surfaces by ions gives rise to a variety of inelastic collision events leading to the ejection of excited atoms and ions. Such excited sputtered particles have been studied since more than 80 years through their optical emission, when they decay in front of the target to the electronic ground state, having lifetimes of 10−9 to 10−7 s, typically. Information on the energy distribution of such excited states can be obtained by two different techniques: light vs distance measurements (LvD) and by studying line profile broadening in light emission due to the Doppler effect. Only recently it has become possible to study in addition metastable excited atoms using laser induced fluorescence spectroscopy (LIF). Relative sputtering yields and energy distributions have been measured for such metastable states and two types can be distinguished. States with a very low excitation energy (0–0.3 eV), being sublevels of the electronic ground state, were found to have yields and energy distributions comparable to the electronic ground state, while metastable states at higher excitation energies (above 1 eV) seem to behave similar to short lived excited states, typically observed in secondary photon emission (BLE) with excitation energies in the range of 2–6 eV. This behaviour is also clearly visible with respect to oxygen surface coverage or increased near surface oxygen concentration where, similar to secondary ion emission, drastic changes in the yield by orders of magnitude have been found for excited atoms as well as for ions. In addition, under the same conditions a strong decrease in the sputtering yield of neutral ground state atoms has been observed for a number of metals. LIF results for highly excited metastable states are compared with recent results obtained by studying line profile broadening in light emission for Ca, Al and Cr targets. Different mechanisms that have been proposed to account for the observations will be discussed. 相似文献
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Cheol Ho Lee Dae-Sik Chang Byung-Hoon Oh 《Journal of Nuclear Science and Technology》2016,53(12):2072-2078
An electron cyclotron resonance (ECR) ion source operating at 14.5 GHz was developed for the generation of charged ions at the Korea Atomic Energy Research Institute (KAERI). Experiments were carried out to study the plasma inside the ECR ion source by analyzing the X-ray spectra generated by it. The X-ray energy distribution and electron energy inside the plasma chamber are influenced by the status of the heated plasma. That status depends on various operation parameters such as microwave power, injected gas-pressure, and solenoid and trim coil currents. X-ray spectra were recorded to find the correlation between the plasma and the X-rays for variations in the operation parameters. A standard NaI(Tl) detector was used for that purpose. The X-ray energy distribution was studied in the range of 100–500 W for radiofrequency power. The influence of the injected gas pressure and the mirror ratio in the emission of X-rays were analyzed. 相似文献