H+2，H+3团簇离子在沟道条件下的背散射 质子产额测量

采用卢瑟福背散射方法，测得了每质子能量为650 keV的H⁺₂，H+₃团簇离子在Si晶体<100>和<110>沟道条件下的质子背散射能谱.结果发现，由于H⁺₂，H⁺₃团簇在晶体中的库仑爆炸和团簇效应，H⁺₂的背散射质子产额大于H ⁺的背散射产额，而H^{+< 关键词： 团簇 沟道效应 库仑爆炸 背散射}     

H+5团簇离子及其中性团簇产物H3和H4

报道了H⁺₅的实验结果.分析讨论了H⁺₅的 形成和分解途径.根据理论分析，以稳定的H⁺₃为核心与一个或多个氢分子结合可能形成稳定的H^{+_n氢团簇离子.另一方面，在高频离子源中, 有发生H+₃与H₂反应的条件.实 验中，从高频离子源引出的离子束被静电加速器加速，然后用9 关键词： +}₅团簇离子')" href="#">H⁺₅团簇离子 3中性团簇')" href="#">H₃中性团簇 4中性团簇')" href="#">H_{4中性团簇}     

4HeH+核间距的实验测定

用MeV量级⁴HeH⁺在超薄无衬碳膜中的库仑爆炸,获得高频离子源产生⁴HeH⁺核间距的实测值为0.094±0.003nm.发现⁴HeH⁺与H⁺₂,H⁺₃不一样,其核间距大小和离子源种类及离子源参数有密切关系,并从⁴HeH⁺的形成机理与形成条件,解 关键词：     

乙醚团簇的激光电离质谱及从头计算

应用激光多光子电离质谱与超声脉冲分子束技术研究了乙醚团簇，实验中观测到乙醚的碎片离子以及强度较小的(E)H⁺，(E)^＋₂和(E)₂H⁺(E代表CH₃CH₂OCH₂CH₃)，没有发现更大尺寸的团簇离子.结合从头计算理论，在B3LYP/6-311++G(d,p 关键词： 乙醚团簇 偶极-偶极相互作用 从头计算     

HD+2，H+3和D+3与固体相互作用和三体尾流效应

从分子离子H⁺₃及其氘化同位素分子离子D⁺₃和HD⁺₂与超薄固体膜相互作用发生库仑爆炸为基础,分析讨论了H⁺₃,D⁺₃和HD⁺₂三种分子离子的形成机理,根据产物能谱分布,利用库仑爆炸技术确定了同位素分子离子HD⁺₂的结构形式,给出具体核间距数值.并确定在实验中不存在线状结构的HD⁺₂.提出一种三原子分子离子和固体相互作用中尾流效应的处理方式,通过和实验结果做比较发现这是一种非常理想的处理三体尾流效应的模式,并用之进一步确认了HD⁺₂的结构形状.文章对H⁺₃,D⁺₃和HD⁺₂三种分子离子的实验结果做了对比和讨论. 关键词： +₂')" href="#">微团簇HD⁺₂ +₃和D⁺₃')" href="#">H⁺₃和D⁺₃ 库仑爆炸 三体尾流势 团簇结构     

低能氘团簇离子(d+3)诱发固体靶内D-D核聚变过程中的团簇效应研究

通过对由三个氘原子组成的氘团簇离子(d⁺₃)与三个分立的氘核(3d⁺)在轰击吸氘固体靶时所发生的D-D聚变反应率的差别的研究，进而揭示氘团簇离子在与固体靶中的氘核发生聚变反应时所体现出的团簇效应.实验结果显示，在10—40keV/d能区，每个氘团簇中的氘核(d⁺₃/3)所产生的聚变反应率高于具有相同速度的独立氘核(d⁺)所产生的聚变反应率.反之，在50—100keV/d能区，独立氘核比之于氘团簇中的单个氘核所产生的聚变反应率要高.两者之间的比值具有非常明显的能量相关性.这种团簇特性与团簇离子本身特性及固体靶环境等多方面因素有关.对其作用过程和实验中观测到的现象的实质做了具体讨论. 关键词：     

GanN－m阴离子团簇的结构及稳定性的研究

利用密度泛函理论(DFT)对Ga_nN^-(n=2—8)和Ga_nN^-₂ (n=1—7)阴离子团簇的结构及稳定性进行了研究.在B3LYP/6-31G^*水平上进行了结构优化和频率分析，得到了Ga_nN^-(n=2—8)和Ga_nN^-₂(n=1—7)阴离子团簇的基态结构.在这些团簇中，原子总数小于等于6的团簇的几何结构为平面结构，原子总数大于6的团簇的几何结构为立体结构；在所研究的团簇中，Ga₄N^-，Ga₆N^-,Ga₄N^-₂和Ga₅N^-₂的基态结构较稳定. 关键词： nN^-_m团簇')" href="#">Ga_nN^-_m团簇 密度泛函理论(DFT) 几何结构     

氦氢离子协同注入对锆膜形貌及物相结构的影响

 采用磁控溅射法制备了Zr-Mo膜，随后在低能静电加速器上分别采用剂量为2.80×10¹⁷~1.12 ×10¹⁸ions·cm^-2的He⁺、H⁺离子辐照Zr-Mo膜，利用光学透镜、扫描电镜、原子力显微镜和X射线衍射研究He⁺、H⁺离子协同注入效应对Zr-Mo膜微观结构的影响。实验结果表明：原始Zr-Mo膜表层晶粒清晰可见，尺寸约为200nm；辐照效应可导致Zr-Mo膜表层产生微观损伤区域，在注He⁺基础上注H⁺导致Zr-Mo膜出现更为严重的损伤现象；离子注入的表面溅射效应可使膜面晶粒边界逐渐刻蚀退让，导致膜面更加光滑、细致；He⁺、H⁺ 离子协同注入可使Zr-Mo膜晶格发生畸变，注入期间未使Zr-Mo膜发生吸H相变生成氢化物。     

指数变分方法应用于电荷交换反应

本文考虑如下的电荷交换反应:H⁺+H(1s)→H(1s)+H⁺。用指数变分方法得到类H⁺₂的波函数,并将这样的波函数用于上述的电荷交换反应。对入射H⁺的能量为60和125keV的两种情况,计算了电荷交换反应的角分布。结果表明,指数变分波函数带来明显的改进,理论结果与实验数据符合得比较好。 关键词：     

近玻尔速度Ne2+离子穿过碳膜引起的电子发射

本文测量了入射能为2–25 keV/u的Ne²⁺离子穿过不同厚度碳膜诱导的前向、后向 (分别对应出射表面和入射表面) 电子发射产额. 实验中通过改变炮弹离子的能量, 系统的研究了势能沉积、电子能损以及反冲原子对前向、后向电子发射产额的贡献. 结果表明, 离子的势能沉积只对后向电子发射有贡献, 前向、后向电子发射产额分别与Ne²⁺离子在薄膜出射、入射表面的电子能损近似成正比关系, 其中电子能损很低 (对应于离子能量很低) 的时候, 反冲原子对电子发射的贡献不能忽略. 关键词： 近玻尔速度 电子发射 电子能损 反冲原子     

Transmission of fast H3+ molecules through thin carbon foils

Observed for the first time is the transmission of H₃⁺ molecules (2.4 MeV) through carbon foils (2–7 μg/cm²). The thickness dependence of the yield follows a single decreasing exponential function with a unity coefficient which is expected for H₃⁺ transmitted with their original electrons.     

Radiative capture of deuterons in154Sm and238U

Angular — and velocity — distributions of electrons emitted near zero degree from projectile ions (H⁺, H ₂ ⁺ , H ₃ ⁺ , He⁺, He⁺⁺ at 1.7 MeV/u) traversing solid carbon foils (2 to 20) μg/cm²) have been measured. The data give clear evidence of production mechanisms which go beyond those reported elsewhere.     

Study on the dynamic energy spectra of mev heavy ions penetrating biological sample

In order to study the probability for heavy ions to have a long projectile range in botanic sample, transmission energy spectra of 1.5 MeV F⁺, 3 MeV F²⁺ and 1.5 MeV H⁺ penetrating 100 µm seed cotyledon samples were measured as a function of ion dose. Results show that very fewer ions can penetrate through the samples, though their theoretical ranges are much shorter than sample thickness. Besides, the measured energy spectra of 1.5 MeV and 3.0 MeV F ions change dynamically while increasing the ion dose, they extend to the high energy direction and the count rates of the transmission ions increases quickly. These phenomena can be understood with the special composition and structure of the biological material.     

Balmer Hβ vs. Dβ line intensity in the collisions of H+, H2 +, H3 +, D+, D2 +, and D3 + ions with “realistic” metal surface at energies below 1 keV

The intensities of hydrogen H_β and deuterium D_β spectral lines of the Balmer series were measured as a function of collision energy when H⁺, H₂ ⁺, H₃ ⁺, D⁺, D₂ ⁺, and D₃ ⁺ ions impinged on Al, Ti, Cu, Mo, W, and Pb targets. The collision energies were kept in the 100–1000 eV range. The target surface was contaminated with hydrocarbons from the vacuum pumping system and possibly also by oxygen molecules due to limited vacuum conditions. At projectile velocities above 200 km/s the luminescence of backscattered deuterium atoms is about 30–50% weaker than that of hydrogen atoms.     

Analysis of the3 He(K−,K +)n reaction by the potential quark model

We analyze the production of H dihyperson (J ^π=0⁺,S=?2) via the (K ^?, K⁺) reaction by means of the non-relativistic quark model. First, the H mass and mass spectrum of single baryons are calculated. When the single baryon spectrum is well reproduced, the H dihyperson has the binding energies about 20 MeV or 60 MeV corresponding to the choice of the strength of the confinement potential. Using this model and parameters, cross sections for H production are estimated. A new effect, contributions from color-octetQ ³?Q ³ components of H dihyperson, is taken into account. The cross sections for H production are enhanced about ten times by these contributions. TheK ⁺-neutron coincidence cross section for H production is found to be 99–115 nb/sr² at theK ⁺ forward direction forM _H=2212 MeV and theK ^? beam momentum 1.8 GeV/c.     

1,4-二氧六环的真空紫外同步辐射光解离电离研究

The photoionization and photodissociation of 1,4-dioxane have been investigated with a reflectron time-of-flight photoionization mass spectrometry and a tunable vacuum ultraviolet synchrotron radiation in the energy region of 8.0-15.5 eV. Parent ion and fragment ions at m/z 88, 87, 58, 57, 45, 44, 43, 41, 31, 30, 29, 28 and 15 are detected under supersonic conditions. The ionization energy of DX as well as the appearance energies of its fragment ions C₄H₇O₂⁺, C₃H₆O⁺, C₃H₅O⁺, C₂H₅O⁺, C₂H₄O⁺, C₂H₃O⁺, C₃H₅⁺, CH₃O⁺, C₂H₆⁺, C₂H₅⁺/CHO⁺, C₂H₄⁺ and CH₃⁺ was determined from their photoionization efficiency curves. The optimized structures for the neutrals, cations, transition states and intermediates related to photodissociation of DX are characterized at the B3LYP/6-31+G(d,p) level and their energies are obtained by G3B3 method. Possible dissociative channels of the DX are proposed based on comparison of experimental AE values and theoretical predicted ones. Intramolecular hydrogen migrations are found to be the dominant processes in most of the fragmentation pathways of 1,4-dioxane.     

Phase shift analysis of elastic proton scattering by12C

Angular distributions of the polarization and cross section in¹²C (p,p)¹²C were measured at 24 energies between 9.95 and 10.90 MeV. A phase shift analysis of the data was carried out. The results show four resonances in¹³N atE _x =11.40, 11.64, 11.67 and 11.82 MeV with spins 5/2⁺, 5/2^?, 3/2^? and 3/2⁺.     

New highly excited 4He levels found by the 2H(d,p)3H reaction

The differential cross section, the vector- and the tensor-analyzing powers of the reaction ²H($\text{d}$, p)³H have been measured. The polarization data were obtained at 11 energies between 1.0 and 13 MeV at lab angles between 5° and 160°. The data were fitted with Legendre polynomials and the resulting coefficients analyzed for resonances in ⁴He. Overwhelming evidence for a 1^? level at 24.1 MeV and a strong indication of a 4⁺ level at 24.6 MeV excitation energy have been found.     

7Li(p,n)7Be reaction with polarized protons from the threshold to 3.0 MeV

A polarized beam was used to measure angular distributions of the proton analyzing power of the ⁷Li(p,n)⁷Be reaction at 11 energies from 2.05 to 3.00 MeV. The analyzing power is generally large and positive. The analyzing power can be fitted with associated Legendre polynomials. The coefficient of P₁¹ rises rapidly from threshold to a maximum near the 3⁺ state at 2.25 MeV from which it drops to a minimum at 2.42 MeV, whence it gently rises to 3.00 MeV; the coefficient of P₂¹ has small values that increase with energy. The data were measured typically to an accuracy of 0.02 with a target 20 keV thick at 2 MeV bombarding energy. Polarization contour maps are given. Comparison of these analyzing power measurements with previous data for the neutron polarization induced with unpolarized protons shows equality at some energies and slightly higher values at others.     

Molecular effects in ion-induced secondary electron spectra

The energy spectra of slow secondary electrons from a copper surface under bombardment with H⁺, H⁺₂, and H⁺₃ ions have been measured at an energy of 200 keV/atom. Distinct molecular effects are revealed in the ratios of the respective distribution curves for molecular ion and proton impact.