贮氢金属中氢同位素的离子束分析方法评估

文章介绍用离子束方法分析贮氢金属中氢同位素含量与分布的实验条件与设计，并分析各自的优、缺点。通过实验测量与分析表明，用离子束分析方法可获得氢同位素含量与分布的丰富信息和精确数值。用6.0MeV的O离子束进行ERD分析的优点是截面为卢瑟福截面，所用的Mylar膜薄，能使H、D、T明显分开，测量精确，缺点则是对样品制备要求高，分析深度小；用7.4MeV的⁴He离子束进行ERD分析能得到H、D、T的分布信息，对Ti的分析深度可达到3.0μm，缺点则是三者的谱图相互重叠，模拟解谱的误差较大；用3.0MeV的质子进行PBS分析，只能获得D、T的分布信息，但分析深度更深。      

钛膜中氢同位素的深度分布

为评估氢同位素效应对其在贮氢金属中深度分布的影响,对H/D-Ti、D/T-Ti、D-Ti及T-Ti样品用7.4MeV的4He离子束进行30°方向弹性反冲(ERD)分析.由H/D-Ti样品ERD能谱获得其1.7μm深度的D分布,结合D-Ti样品ERD能谱的～3 μm深度的H、D分布进行了模拟分析.结果表明,H、D含量均随深度增加,其分布曲线基本一致,说明在Ti中H、D的分布互不干涉,样品制备过程中其同位素效应不明显.用同样的方法对DT-Ti样品中的D、T分布进行了模拟分析.结果表明,在1.7 μm深度内D、T的分布基本均匀,但由于D、T的能谱过于靠近,其解谱误差较大.用3.0 MeV的质子对HD-Ti和D-Ti进行的质子背散射(PBS)分析表明,两样品中的D分布趋势一致,证明了Ti中H、D的分布互不干涉,样品制备过程其同位素效应不明显的结论.     

PBS法测量Ti膜中H同位素深度分布

在Mo底衬上制备了约5m的3个TiDxTy样品,用质子背散射（PBS）法分析了D、T在Ti膜中的深度分布,其中,T的分析能得出较为准确的结果,而D的分析结果受质子在Mo底衬中多次散射信号的影响偏差较大。分析结果表明,PBS法测量的T含量和浓度与样品制备过程中测量的结果一致,且T在Ti膜中分布均匀。这证明PBS法可用于对材料中T浓度与分布的分析。     

采用弹性反冲分析法同时测量薄膜中氢和氘的深度分布

给出由重叠反冲能谱计算氢和氘的浓度及深度分布的解谱技术，用４．５ＭｅＶ和４．２ＭｅＶ的α粒子作入射粒子得到两个反冲能谱。在考虑和不考虑能量展宽效应的情况下分析了钛膜中氢和氘的深度分布；发现考虑能量展宽效应的影响得到的氢和氘的深度分布是令人满意的。     

氧离子与氖原子碰撞转移电离过程研究

采用位置灵敏探测和散射离子-反冲离子飞行时间测量技术，测量了氧离子与氖原子碰撞过程中转移电离截面与单电子俘获截面之比。通过比较，发现测量结果与文献结果的趋势一致，并对测量结果进行了解释。     

氘在钛中的扩散行为

对以氘化钛形式吸附在金属钛中的氘的扩散行为进行了研究。样品经电子束加温至３４３℃，用＾４Ｈｅ－Ｄ前向反冲方法测量氘化钛分解后氘在钛表面和内部的浓度分布。由扩散方程求得吸附的氘化钛样品中氘的扩散系数和表面复合系数，并与通过向钛中注入氘的方法得到的结果进行了比较。     

用C离子的弹性反冲法测固体中氢分布

文章介绍了用1.7MV小串列加速器提供的4—7MeV多电荷C离子,采用弹性反冲法(ERD)分析了α-Si:H中氢元素的深度分布。计算表明,近表面处的深度分辨率为15-30nm,可探测深度100—700nm。探讨了入射能量和散射几何条件的优化问题。比较了几种分析方法的测量结果。     

低能D(d,n)~3He反应中~3He粒子的探测及自生靶稳定性的初步研究

一、引言测量D(d,n)~3He反应中的~3He粒子,对于测量D(d,n)~3He反应的中子产额及应用中子-~3He粒子符合技术很有意义。在D(d,n)~3He反应中,~3He的探测存在困难。原因在于~3He粒子能量低和大量散射氘核脉冲堆积的干扰。另外~3He粒子与竞争的D(d,p)T反应中的氘粒子能量相近。为克服这些困难,人们采用了各种方法:1.用电磁分析器分开~3He,氚,氘粒子。2.用低原子     

纳米晶粒钛膜中氦注入的剂量保持和释放规律

在室温～400℃范围内,用卢瑟福质子背散射技术测量了100keV、注入剂量2 2×1018cm-2的纳米晶粒钛膜中氦的浓度分布、不同温度下的剂量保持及其浓度释放。室温下经210d后,氦在该纳米晶粒钛膜中的剂量保持达68%,其He Ti原子比为52 6%;100℃下氦的保持剂量为室温下的89 6%,此时的He Ti原子比为44%;400℃下的保持剂量为室温下的32 6%,He Ti原子比为17 1%。同时观察到了氦的释放随温度上升呈现波浪式的变化特点。从能量稳定性观点初步探讨了纳米晶粒钛膜有效保持氦的可能机制。     

反冲质子望远镜效率计算中的相对论修正

反冲质子望远镜和伴随粒子法是绝对测量14 MeV单能快中子通量的两种独立的方法,在高压倍加器上利用T(d,n)~4He反应可以获得14 McV单能快中子。反冲质子望远镜是通过中子入射在聚乙烯辐射体上产生反冲质子,用记录反冲质子数来确定中子通量的,而伴随粒子法则是通过记录α粒子数来测定中子通量。随着14 MeV单能快中子的应用越     

Cross-section for D(p,p)D elastic scattering from 1.8 to 3.2 MeV at the laboratory angles of 155° and 165°

The D(p,p)D cross-sections for elastic scattering of proton on deuterium over incident proton energy range from 1.8 to 3.2 MeV at both laboratory angles of 155° and 165° were measured. A thin solid state target Ni/TiD_x/Ta/Al used for cross-section measurement was fabricated by firstly depositing layers of Ta, Ti and Ni film on the Al foil substrate of about 7 μm in turn using magnetron sputtering and then deuterating under the deuterium atmosphere. The areal density of metal element in each layer of film was measured with RBS analysis by using a 4.0 MeV ⁴He ion beam, while the areal density of the deuterium absorbed in the Ti film was measured with ERD analysis by using a 6.0 MeV ¹⁶O ion beam. The results show that the cross-sections of p-D scattering under this experimental circumstance were much enhanced over the Rutherford cross-section value. It was found that the enhancement increases linearly as the energy of the incident beam increases. The total uncertainty in the measurements was less than 7.5%.     

贮氢金属多层膜制备技术及吸氢性能研究

研究了用电子束蒸发方法在Mo底衬上制备Ti-Ni复合膜和在SiO2底衬上制备Mo-Ti-Ni复合膜的方法,用离子束分析方法测量了各膜层的厚度,并对样品的吸氢性能进行了分析。研究发现,Ti膜表面镀Ni后,其吸氢温度降低,吸氢总量增加,表明其吸氢活性增强;Mo-Ti-Ni复合膜在Ti氢化后与SiO2底衬结合良好,并具有较高的强度,但这种膜对底衬的清洁度要求更高;50nm的Ti膜难以吸氢,原因可能是膜制备过程中温度过高,导致Mo-Ti-Ni之间扩散加深,形成相对过厚的过渡层,这还需进一步研究。     

PIXE measurements of Kr-sputtered TiN coatings

Titanium nitride films of 30–300 nm thickness deposited via dc magnetron sputtering were irradiated with 150–700 keV Kr ions at fluences up to 2.1 × 10¹⁷ cm⁻². These films were then scanned with a well-collimated 400 keV proton beam and the X-ray yield of Ti was measured both in and outside the Kr beam spot. This procedure results in a precision determination of the average film thickness (± 1% in the case of tens of nm films). The PIXE results are found to be consistent with RBS data of the same specimens. Sputtering yields were determined from the variation of X-ray yields assuming unchanged Ti/N stoichiometry in the implanted area. For thick TiN films (d₀ > 100 nm) the sputtering yields are in good agreement with predictions of the collisional cascade model by Sigmund. In contrast, sputtering of thin layers (d₀ = 30 nm) depended sensitively on the ion energy, being a factor of 2 higher at 150 keV than at 500 keV.     

321不锈钢在低酸度硝酸铀酰溶液中的腐蚀特性

用称量法和电化学法研究了321不锈钢在不同浓度和pH值的硝酸铀酰溶液中的高温均匀腐蚀和电化学府蚀行为。均匀腐蚀试验结果表明．在选定的腐蚀条件下，321不锈钢样品在960h内，其表面光洁度无明显变化．腐蚀速率小于0．04mg/m^2.h，在低酸度的硝酸铀酰溶液中耐蚀。用腐蚀电入学法研究了321不锈钢在有溶解氧的硝酸铀酰溶液中的腐蚀电化学特性，测量了电极的腐蚀电位、腐蚀电流密度。经AES分析表明，电化学腐蚀后的样品在腐蚀膜中有一定量的铀．深度剖析含铀腐蚀膜的厚度为10—15nm。     

Influence of additional UV-light illumination on preparation of TiN by ion beam assisted deposition

Titanium nitride films were prepared by a newly developed photon and ion beam assisted deposition system at room temperature. Titanium was deposited on Si(111) in a controlled nitrogen environment and simultaneously bombarded with low-energy N ions or illuminated with UV-light. The influence of UV-light illumination during deposition is compared with the influence of ion bombardment on film properties like structure, topography and composition, measured by XRD, AFM and ERD, respectively. The results demonstrate that photon assisted deposition (PHAD) is also a good method to modify film characteristics like ion beam assisted deposition (IBAD).     

Deuterium depth profiling in polymers using heavy ion elastic recoil detection

We have used ²⁰Ne and ⁴⁰Ar beams with energies between 3 and 8 MeV for elastic recoil detection (ERD) analysis of hydrogen isotopes in polymer samples and have also studied the depth resolution and the radiation damage. For the investigation of polymer mixtures it was possible to improve the depth resolution of ERD down to 8 nm FWHM with-out changing the experimental setup of conventional ERD, due to the higher energy loss factor of heavier ions and a reduced stopper foil thickness. For an improved surface depth resolution heavier ions are suitable, whereas lighter elements have a larger profiling depth. We found a ²⁰Ne beam with an energy between 4 and 6 MeV to have a maximum analysing depth of 380 nm with a near surface depth resolution of 9 nm; however, for high resolution ⁴⁰Ar-ERD measurements this maximum profiling depth is reduced to 90 nm. Due to the larger Rutherford scattering cross-section of heavier ions the measuring time decreases with increasing ion mass. We have investigated the ion beam radiation damage in polymer samples and introduced beam current density limits related to polystyrene samples. These results are supported by model calculations which give approximated values of the radiation damage.     

强脉冲离子束辐照混合的RBS研究

采用卢瑟福背散射(Rutherford backscattering spectroscopy,RBS)方法对强脉冲离子束辐照Ti/Al、Al/Ti和Ni/Ti三组薄膜/衬底体系所形成的混合层进行了研究.在Ni/Ti组合中形成了厚度比离子射程大得多的、混合度较高的梯度混合层.发现熔融态混合的程度不仅取决于两材料在熔融态的表面张力的差别,而且取决于它们熔点的差异.这两个参量较接近的混合程度较好.     

离子束处理精密微型轴承滚珠的俄歇电子能谱和电子衍射分析

用离子束动态混合技术将Ｔｉ和Ｎ两种离子同时注入φ１．５７－１．６０ｍｍ的精密微型轴承滚珠。用俄歇电子能谱和电子衍射分析分别检验了注入离子在基体内的纵向分布和在球表面的均匀性。在辅助沉积Ｎ离子的能量为１００ｋｅＶ、注入剂量为３×１０＾１７ｉｏｎｓ／ｃｍ＾２的条件下，混合区宽度达１４０ｎｍ以上，同一球面的不均匀度〈１３％，球间的不均匀度〈１５％。表明在适当工艺条件下，对这种精密部件采用离子束表面优化改     

RBS study of Ti/ZnO interface

We have studied the interface stability of the Ti(overlayer)/ZnO(substrate) system. Ti thin film was grown on the Zn face of single crystal ZnO(0 0 0 1) substrate by the vacuum deposition technique. The Ti film thickness was typically 16 nm. Then the samples were annealed in air at 300 and 400 °C for 15 min, respectively. The deposition and annealing effects on the interface structure were investigated with Rutherford backscattering and channeling spectroscopy using 2 MeV He⁺ ion beam. After Ti deposition the minimum yield from the ZnO substrate increased from 2% to 7%. This suggests severe damage caused by deposition, i.e. the interface reaction between Ti and ZnO (even at room temperature). A significant amount of Zn (approximately 6.4 × 10¹⁶ atoms/cm²) moved onto the surface after post-annealing at 400 °C. Since Ti has a stronger tendency to react with O than Zn, it is expected that Ti reacts with substrate oxygen leaving behind free Zn atoms, which can easily migrate onto the surface. We discuss how the Ti/ZnO interface reaction in detail, and seek to find another good metallic contact for ZnO devices, which are attracting much attention recently for practical applications as well as scientific aspects.