Cl/HN3/I2全气相化学激光体系的化学动力学模拟计算

对Cl/HN3/I2产生NCl(a)/I激光的过程进行了化学动力学计算,主要考察了Cl,HN3和I2的初始粒子数密度及其配比对小信号增益系数的影响。结果发现,当温度为400K, 初始Cl粒子数密度为1×1015,1×1016和1×1017cm-3时,小信号增益系数分别达到1.6×10-4,1.1×10-3和1.1×10-2cm-1,获得最佳小信号增益系数的HN3和I2的初始粒子数密度分别为初始Cl粒子数密度的1～2倍和2%～4%。同时,对Cl,HN3和I2配比对小信号增益系数和增益持续时间的影响进行了讨论。     

Cl/HN3/I2全气相化学激光体系的化学动力学模拟计算

 对Cl/HN₃/I₂产生NCl(a)/I激光的过程进行了化学动力学计算，主要考察了Cl,HN₃和I₂的初始粒子数密度及其配比对小信号增益系数的影响。结果发现,当温度为400K, 初始Cl粒子数密度为1×10¹⁵，1×10¹⁶和1×10¹⁷cm^-3时,小信号增益系数分别达到1.6×10^-4,1.1×10^-3和1.1×10^-2cm^-1，获得最佳小信号增益系数的HN₃和I₂的初始粒子数密度分别为初始Cl粒子数密度的1～2倍和2%～4%。同时，对Cl，HN₃和I₂配比对小信号增益系数和增益持续时间的影响进行了讨论。     

NCl(a1Δ)/I（2P3/2）传能体系的实验研究

 利用微波放电Cl₂/He等离子体作为Cl源，对反应NCl(a¹Δ) + I(²P_3/2)→NCl(X³Σ) + I(²P_1/2)进行了实验研究，得到了较大的I(²P_1/2)自发辐射荧光信号，检测到NCl(a¹Δ，b¹Σ)自发辐射荧光光谱在存在少量I(²P_1/2)下发生的显著变化，其中NCl(a¹Δ)自发辐射荧光信号降低，同时由于I(²P_1/2)的作用，NCl(b¹Σ)自发辐射荧光信号大幅度增加。在考察各反应气体流量对I(²P_1/2)自发辐射荧光信号的影响时发现，在本次实验条件下，各种气体的最佳流量：He为1～4mmol/s, I₂为0.01～0.03mmol/s, Cl₂为1.0mmol/s左右,而HN₃流量略大于Cl₂流量时信号升高幅度开始变缓，约为Cl₂流量的两倍时信号不再有显著的变化。     

The He/Cl2 laser at 258 nm

Lasing from e-beam pumped He/Cl₂ mixtures at 258 nm was investigated in a longitudinal pumping geometry. Time dependence, output powers and energies as well as the spectral composition of the laser pulses were determined for different experimental conditions. Optical gain was observed for eight transitions around 258 nm. The fine structure results from isotopic splitting and contributions from different vibrational states. No bottle-necking occurs. However, saturation and absorption by excited states limited the total output power to 6MW and the output energies to 200 mJ. A simple kinetic model is proposed that reproduces the larger number of experimental data quite sufficiently.     

Optical characteristics of the plasma of a transverse volume discharge in Cl2 and He/Cl2 mixtures

Results are presented from a study of UV and VUV emission from the plasma of a transverse volume discharge in chlorine and a He/Cl₂ mixture. In the wavelength range Δλ=140–300 nm, the Cl₂(D′-A′) band with an edge at 258 nm and the Cl ₂ ^* band with edge at λ=195 nm are found to be dominant. It is shown that, in the pressure range [Cl₂]=0.1–2.0 kPa, the intensity of emission with λ≤195 nm is higher than the intensity of the Cl₂(D′-A′) band. At [Cl₂]≥2 kPa, emission in the 258-nm band is dominant.     

Potentiostatic investigation of the vitreous carbon / RbCu4Cl3I2 interface

The electrochemical processes occurring at vitreous carbon electrodes in contact with the solid electrolyte RbCu₄Cl₃I₂ has been investigated. The reaction $$Cu^ + - e \leftrightarrow Cu^{2 + } $$ in the range of potentials ?0.05...+ 0.57 V on the electrode takes place. The exchange current density of this reaction is about 25·10^?2 A·m^?2. The rate of the electrode processes is controlled by the slown diffusion of Cu²⁺ ions near the electrode. The diffusion coefficient of Cu²⁺ ions in the electrolyte is about 1.5·10^?12 m²·s^?1. At potentials higher than 0.57 V on the electrode surface, a divalent copper phase is deposited. The rate of this process is controlled by the instantaneous nucleation and the two-dimensional growth of the phase. At potentials lower than ?0.05 V, the reaction $$Cu^ + - e \to Cu^0 $$ begins at the electrode and metallic copper is deposited. The rate of this reaction is controlled by the instantaneous nucleation and the three-dimensional growth of the deposit. Perpendicular to the electrode surfaces, the growth rate of the deposition has the order of magnitude of 10^?9 m·s^?1 and the quantity of nuclei is not less than 10¹² m^?2.     

NCl（a^1△）／I（^2P3／2）传能体系的实验研究

利用微波放电C12／He等离子体作为Cl源，对反应NCl(a^1△) I(^2P3/2)→NCl(X^3∑) I(^2P3/2)进行了实验研究，得到了较大的I(^2P3/2)自发辐射荧光信号，检测到NCl(a^1△，b^1∑)自发辐射荧光光谱在存在少量I(^2P3/2)下发生的显著变化，其中NCl(a^1△)自发辐射荧光信号降低，同时由于I(^2P3/2)的作用，NCl(b^1∑)自发辐射荧光信号大幅度增加。在考察各反应气体流量对I(^2P3/2)自发辐射荧光信号的影响时发现，在本次实验条件下，各种气体的最佳流量：He为1—4mmol/s，I2为0．01—0．03mmol/s，Cl2为1．0mmol/s左右，而HN3流量略大于Cl2流量时信号升高幅度开始变缓，约为Cl2流量的两倍时信号不再有显著的变化。     

C2Cl3+NO2反应的实验研究

利用时间分辨傅立叶变换红外发射光谱(TR-FTIR)研究了C2Cl3自由基和NO2分子的反应．并且通过高分辨的TR-FTIR光谱可观察到三种振动激发态产物，它们分别是Cl2CO、NO和CO．从而确定了四个主要的反应通道，分别为：C2Cl3O+NO、ClCNO+Cl2CO、CO+NO+CCl3和CCl3CO+NO．光谱拟合显示产物CO是高振动激发的，其初生态的平均振动能为60.2 kJ/mol．并推测其可能的反应机理是通过中间体C2Cl3NO2和C2Cl3ONO进行的．     

Stability of the α-RbCu4Cl3I2 solid-electrolyte cell

Summary The performance of the solid-state galvanic cells with α-RbCu₄Cl₃I₂ as the solid electrolyte has been investigated. The role of moisture in the decomposition of α-RbCu₄Cl₃I₂ has been studied, too. Paper presented at the ?V International Conference on Ternary and Multinary Compounds?, held in Cagliari, September 14–16, 1982.     

Microscopic study of the low-energy3He(3He, 2p)4He and3H(3H, 2n)4He fusion cross sections

We have calculated the³He(³He, 2p)⁴He and³H(³H, 2n)⁴He reaction cross sections at low energies within the microscopic multichannel resonating group method. For both reactions, we find good agreement with experiment. For the³H(³H, 2n)⁴He reaction, our calculated energy dependence reproduces that of each individual low-energy experimental data set, except for a normalization constant. Using this fact, we derive at a low-energy³H(³H, 2n)⁴He rate by taking the averaged mean of these fits.This work has been supported in part by the National Science Foundation, Grants PHY86-04197 and PHY88-17296.     

用于CEPC探测器超导磁体的小型氦虹吸回路实验研究

在环形正负电子对撞机(CEPC)大型探测器超导磁体拟采用低温虹吸冷却系统的预研背景下,搭建了氦低温虹吸冷却回路实验平台,进行了气-液两相自然循环传热传质特性实验研究。实验测量了不同充装量下,压力、温度随热流量的变化规律,计算了实验段的表面传热系数。研究表明,充装率对热虹吸冷却循环具有重要影响,在40%55%合适的充装率下能够保证该系统的正常运行;另外实验段不同位置的表面传热系数不同,烧干先在上端发生,然后逐渐向下端发展。     

Kinetics of decomposition of the solid electrolyte RbCu4Cl3I2

The processes of electrochemical decomposition of the solid electrolyte RbCu₄Cl₃I₂ at the vitreous carbon electrode and chemical decomposition of RbCu₄Cl₃I₂ by iodine has been investigated. The anodic decomposition of the electrolyte occurs in two steps. At first, the oxidizing electrode reaction of Cu⁺ ions up to Cu²⁺ ions takes place at potentials higher than 0.57 V and onto the electrode surface the layer of decomposition products is formed, including the compound of divalent copper RbCuCl₃. Then the oxidizing reaction of I ions occurs at potentials higher than approximately 0.67 V with deposition of the iodine layer onto the electrode surface. The deposition rate of the layers of decomposition products is controlled by instantaneous nucleation and two-dimensional growth of the deposit. It was shown that slow diffusion of the iodine in the reaction product layer is a limiting step in the chemical interaction of iodine with RbCu₄Cl₃I₂. For the compressed RbCu₄Cl₃I₂ sample investigated, iodine diffusion coefficient was calculated to be 6.2×10⁻⁷ cm² s⁻¹. Iodine loss from the glassy carbon surface is about 1.1×10⁻⁴ g cm⁻² s⁻¹ at the thickness of the RbCu₄Cl₃I₂ sample is equal to 2 mm.     

Precision study of the eta3He system using the dp--> 3Heeta reaction

The differential and total cross sections for the dp--> 3Heeta reaction have been measured in a high precision high statistics COSY-ANKE experiment near threshold using a continuous beam energy ramp up to an excess energy Q of 11.3 MeV with essentially 100% acceptance. The kinematics allowed the mean value of Q to be determined to about 9 keV. Evidence is found for the effects of higher partial waves for Q >or= 4 MeV. The very rapid rise of the total cross section to its maximum value within 0.5 MeV of threshold implies a very large eta3He scattering length and hence the presence of a quasibound state extremely close to threshold.     

Experimental determination of the potential energy curves of the I(3/2u) and I(3/2g) states of Kr+ 2

The I(3/2u) and I(3/2g) states of Kr⁺ ₂ have been investigated by pulsed-field-ionization zero-kinetic-energy (PFI-ZEKE) photoelectron spectroscopy following (2 + 1′) resonance-enhanced multiphoton excitation via the 0⁺ _g Rydberg state located below the Kr?([4p]⁵5p[1/2]₀) + Kr(¹S₀) dissociation limit of Kr₂. From the positions of a large number of vibrational bands in the spectra of the ⁸⁴Kr₂ and ⁸⁴Kr-⁸⁶Kr isotopomers, the adiabatic ionization potentials (IP(I(3/2u)) = 112672.4 ± 0.8cm^?1, IP(I(3/2g)) = 111 395.0 ± 1.4cm^?1), the dissociation energies (D ⁺ ₀(I(3/2u)) = 368.8 ± 2.0cm^?1, D ⁺ ₀(I(3/2g)) = 1646.2 ± 2.3cm^?1) and vibrational constants for both ionic states have been determined. Potential energy curves have been extracted which perfectly reproduce all experimental observations and are accurate over a wide range of energies and internuclear distances. The equilibrium internuclear distances (R ⁺ _e(I(3/2u)) = 4.11 ± 0.04 Å, R ⁺ _e(I(3/2g)) = 3.35 ± 0.10 Å) have been derived by comparing the intensity distribution in the PFI-ZEKE photoelectron spectra to calculated Franck-Condon factors. The dissociation energy of the I(3/2g) state and the equilibrium internuclear distance of the I(3/2u) state differ markedly from previously reported values.     

Numerical density of3He in coexisting phases of the system CO3-3He

The method of slow-neutron transmission is used to investigate the behavior of the numerical density of³He in the binary solution 2.46%³He + 97.54% CO₂₀ on the liquid-vapor boundary curve. Data on the numerical density are analyzed within the framework of the expanded theory of scale transformations.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 63–67, September, 1983     

Stability of 3He2 4He M and 3He3 4He M L = 0,1 Clusters

We have studied the stability of mixed ³He/⁴He clusters in L = 0 and L = 1 states by the diffusion Monte Carlo method, employing the Tang-Toennies-Yiu (TTY) He-He potential. The clusters ³He⁴He_M ( ) and ³He₂⁴He_M (L = 0, S = 0) are stable for M > 1, while to bind two ³He in a triplet state the minimum number of ⁴He is four. Considering clusters with three ³He, ³He₃⁴He₄ is the smallest stable system in the L = 1 state, while ³He₃⁴He₈ is the smallest stable system in the L = 0 state.     

Experimental Study of Photon Induced Reactions on 3He and 4He at Low Energies

Data are reported for the photodisintegration cross section of the reaction ³He(??, p)²H at ten energies between 7.0 and 16.0?MeV. Very preliminary data are presented for the reaction ⁴He(??, p)³H between 22.0 and 29.5?MeV in 0.5?MeV energy steps, and for the reaction ⁴He(??, n)³He at three energies around 28.0?MeV. High-pressure He/Xe gas scintillators served as target and detector. Our data are in better agreement with recent theoretical calculations than the majority of the existing data for all three reactions, but differ significantly from recent data taken with a mono-energetic photon beam and a time-projection chamber.     

利用~3He中子监测仪对中子管产额进行实验监测

以自主研制的ZFD-1型中子发生器为例,研究了在不同加速高压下D-D型中子管中子的轴向分布情况,以及影响3He中子监测仪探测性能的一些主要因素.根据所得实验数据拟合图线,可对中子管产生中子的轴向分布进行标定.