Absolute dielectronic recombination rate coefficients of highly charged ions at the storage ring CSRm and CSRe

Dielectronic recombination(DR)is one of the dominant electron-ion recombination mechanisms for most highly charged ions(HCIs)in cosmic plasmas,and thus,it determines the charge state distribution and ionization balance therein.To reliably interpret spectra from cosmic sources and model the astrophysical plasmas,precise DR rate coefficients are required to build up an accurate understanding of the ionization balance of the sources.The main cooler storage ring(CSRm)and the experimental cooler storage ring(CSRe)at the Heavy-Ion Research Facility in Lanzhou(HIRFL)are both equipped with electron cooling devices,which provide an excellent experimental platform for electron-ion collision studies for HCIs.Here,the status of the DR experiments at the HIRFL-CSR is outlined,and the DR measurements with Na-like Kr25^(+)ions at the CSRm and CSRe are taken as examples.In addition,the plasma recombination rate coefficients for Ar12^(+),14^(+),Ca14^(+),16^(+),17^(+),Ni19^(+),and Kr25^(+)ions obtained at the HIRFL-CSR are provided.All the data presented in this paper are openly available at https://doi.org/10.57760/sciencedb.j00113.00092.

KLn Dielectronic Recombination Process of B- Through He-like Cu Ions

通过象他一样 Cu 离子的套住的高度控告的象 B 一样的 KLn dielectronic 再结合进程理论上被学习，并且理论结果被用来在海德堡电子横梁离子陷井(EBIT ) 分析我们的以前的试验性的数据。理论反响的位置同意试验性的反响的位置到 0.4% 的精确，与在理论和实验之间的那些最高的山峰的反响的位置比较。试验性的系列然后与理论反响的精力和力量用一个公式被适合，结果在一个宽电子精力范围上显示出在理论和实验之间的好全面同意。高度控告的状态的分发从恰当的参数被获得。

Pair Production in an Intense Laser Pulse: The Effect of Pulse Length

Production of positron-electron (e^(+) e^(-) ) pairs in an intense laser pulse is investigated by solving the Dirac equation with analytical and numerical methods.We observe that the probability of the pair production will firstly decrease slowly as the pulse length T becomes shortened.Then it will increase until T is reduced to the Compton time Tc =(h)/(mec) ≈ 1.29 × 10^(-21)s and finally decrease exponentially to zero.Hence,for a prominent pair production,we not only require that the electric field strength should be higher than the Schwinger critical value Ecr =m^(2)c^(3)/(e(h)) ≈ 1.32 × 10^(16) V/cm,but also that the pulse duration T should be larger than Tc.The latter is shown to be related to momentum requirement for the transition.For fields with different pulse lengths,the phase and chirp influences upon the pair production are also explored.

P-Type Nitrogen-Doped ZnO Films Prepared by In-Situ Thermal Oxidation of Zn_3N_2 Films

P-type nitrogen-doped ZnO films are prepared successfully by in-situ thermal oxidation of Zn3N2 films. The prepared films are characterized by x-ray diffraction, non-Rutherford back.scattering （non-RBS） spectroscopy, x- ray photoelectron spectroscopy, and photoluminescence spectrum. The results show that the Zn3N1 films start to transform to ZnO at 400℃ and the total nitrogen content decreases with the increasing annealing temperature. The p-type fihns are achieved at 500℃ with a low resistivity of 6.33Ω.cm and a high hole concentration of ＋8.82 × 10^17 cm-3, as well as a low level of carbon contamination, indicating that the substitutional nitrogen （No） is an effective acceptor in the ZnO：N film. The photoluminescence spectra show clear UV emissions and also indicate the presence of oxygen vacancy （Vo） defects in the ZnO：N films. The p-type doping mechanism is briefly discussed.

Calculation of photon angular distribution and polarization for radiative recombination for high-charged hydrogen-like ions

In this paper a systematic study is carried out on the angular distribution and polarization of photons emitted following radiative recombination of H-like ions by a non-relativistic dipole approximation. In order to incorporate the screening effect due to inner-shell electrons, a distorted wave approazh is used. The dependences of the calculated angular distribution and polarization on the reduced energy and nuclear charge are fitted by the corresponding empirical formulas respectively.

Photon Angular Distribution and Polarization of Radiative Recombination

系统的研究在角分布上被执行，光子的极化射出放射再结合的追随者暴露，有一个单向性的电子的 Ne， Ar， Ni 和瞬间的象他一样离子微笑。以便由于内部壳的电子合并屏蔽效果，一个弄歪的波浪方法被使用。跟随放射的再结合到的光子的极化的可伸缩的规则暴露，象他一样离子为事件精力区域被给乘最后的状态的电离阀值精力的六。

Dielectronic recombination of Co-like tantalum

Ab initio calculation of the total dielectronic recombination （DR） rate coefficient from the ground state of Co-like tantalum is performed using the relativistic distorted-wave approximation with configuration interaction. The contributions to the total DR rate coefficients are explicitly calculated from the complexes of Ni-like tantalum：3s^23p^63d3/2^33d5/2^6n′l′,3s^23p^53d^10n′l′,3s3p^63d^10n′l′,3s^23p^63d^84ln′l′,3s^23p^53d^94ln′l′ and 3s3p^63d^94ln′l′ with n′≤25, and 3s^23p^63d^85ln′l′ with n′≤9.The l′and n′ dependences of partial DR rate coefficients are investigated. The contributions from higher n^complexes are evaluated by a level-by-level extrapolation method. The total DR rate coefficients mainly come from the complex series 3s^23p^63d^84ln′l′,3s^23p^53d^94ln′l′and are fitted to an empirical formula with high accuracy. Comparison of the present results with those of other works shows that the previously published data underestimate significantly the DR rates of Co-like tantalum.

Electron beam density imaging system at Beam study using a portable slit the Shanghai Electron Ion Trap

In this work, a portable slit imaging system is developed to study both the electron beam diameter and the profile of the newly developed Shanghai Electron Beam Ion Trap （Shanghai EBIT）. Images are detected by a charge coupled device （CCD） sensitive to both X rays and longer wavelength photons （up to visible）. Large scale ray tracings were conducted for correcting the image broadening effects caused by the finite slit width and the finite width of the CCD pixels. A numerical de-convolution method was developed to analyse and reconstruct the electron beam density distribution in the EBIT. As an example of the measured beam diameter and current density, the FWHM （full width at half maximum） diameter of the electron beam at 81 keV and 120 mA is found to be 76.2 μm and the density 2.00 × 10^3 A.cm-2, under a magnetic field of 3 T, including all corrections.

Second-Order Contribution of the Incompressibility in Asymmetric Nuclear Matter

With the complementarity of the nucleonic three-body force,we present the saturation points of symmetric nuclear matter with different interactions adopted within the Brueckner-Hartree-Fock scheme,and a more accurate empirical parameterization function for the equation of state of symmetric nuclear matter and pure neutron matter.On the basis of this fit formula,the symmetry energy and its derivatives are investigated,and ultimately the higher-order coefficient of the isobaric incompressibility for isospin asymmetric nuclear matter is predicted.

Dielectronic Recombination of Na-like Kr^(25+) at the CSRm

The absolute rate coefficients for dielectronic recombination(DR)of Na-like Kr^(25+) ions were measured by employing the electron-ion merged-beam technique at the heavy-ion storage ring CSRm.The measured DR spectrum covers the energy range of 0~70 eV.

Dielectronic Recombination of F-like Ni^(25+) at the CSRm

The absolute rate cofficients for dielectronic recombination(DR)of F-like Ni^(19+) ions were measured by employing the electron-ion merged-beam technique at the heavy-ion storage ring CSRm.The measured DR spectrum covers the energy range of 0~70 eV.

Growth of C30 and C31 Clusters： Structures, Energetics and Dynamics

We obtain the isomer spectra of C30 and C31 dusters by time-going-backward quasi-dynamics method and perform molecular dynamics simulations of the duster growth from isolated atoms in He buffer gas at 2500 K. The geometrical structures of the isomers of C30 and C31 can be classified into closed cages, open cages, bowls, sheets and other irregular shapes, where closed cages are found to have the lowest potential energies. However, dynamics simulations show that the sheet structures of C30 and C31 are the dominant outcome at the simulation temperature. Compared with relevant experimental results, we propose a different view in interpreting the experimental data and a research procedure to predict isomers that would be formed most probably under specific experimental conditions.

Single-Electron Detachment for Ti-, Fe-, Co-, Ni-, and Cu-, in Collision with Ar

与我们测量的延期线阳极由使用微隧道的板放敏感察觉者为在有在精力区域的 Ar 的碰撞的一些转变元素的单个电子分开十字节 1030 keV。这些单个电子分开十字节作为速度和电子亲密关系依赖表现。实验用生长率方法被执行。

Periodic thermodynamics of laser-driven molecular motor

Operation of a laser-driven nano-motor inevitably generates a non-trivial amount of heat, which can possibly lead to instability or even hinder the motor＇s continual running. This work quantitatively examines the overheating problem for a recently proposed laser-operated molecular locomotive. We present a single-molecule cooling theory, in which molecular details of the locomotive system are explicitly treated. This theory is able to quantitatively predict cooling efficiency for various candidates of molecular systems for the locomotive, and also suggests concrete strategies for improving the locomotive＇s cooling. It is found that water environment is able to cool the hot locomotive down to room temperature within 100 picoseconds after photon absorption. This cooling time is a few orders of magnitude shorter than the typical time for laser operation, effectively preventing any overheating for the nano-locomotive. However, when the cooling is less effective in non-aqueous environment, residual heat may build up. A continuous running of the motor will then lead to a periodic thermodynamics, which is a common character of many laser-operated nano-devices.

A Statistical Model for Predicting Thermal Chemical Reaction Rate:Application to Bimolecule Reactions

A model based on the statistics of individual atoms[Europhys.Lett.94(2011)40002],which has been successfully applied to predict the rate constant of unimolecular reactions,was further extended to bimolecular reactions induced by collisions.Compared with the measured rate constants of the reactions S+SO_(2)→SO+SO and NH_(3)+Cl→NH_(2)+HCl,the model is proved to be significantly better than conventional transition state theory.In order to strictly test the model,we perform molecular dynamics simulation of C_(60)+C_(60)→C_(120),and show that the rate constants are in excellent agreement with our model but far away from the transition state theory.

Single-Particle Properties of Isospin Asymmetric Nuclear Matter

The single-particle potentials in isospin asymmetric nuclear matter is investigated in the framework of the Brueck-ner theory by adopting the realistic Bonn B two-body interaction in combination with a consistent microscopic three-body force.The rearrangement contribution induced by the ground state correlations to single-nucleon potentials is calculated in terms of the hole-line expansion of the mass operator.With the modification of this rearrangement term the symmetry potential is discussed as a function of momentum for several isospin asymme.

金属离子导致的丝素蛋白的构象转变

How the silkworm spins out such an excellent silk fiber has been a hot topic. The issue here is to know how the coil chains in the gland of silkworm transform to β sheet in silk fiber. We used the regenerated silk fibroin to imitate the silk fibroin of the gland to investigate the effect of metal ion(Ca 2+ . Cu 2+ ) on the silk spinning process of Bombyx mori silkworm. The solutions or gel obtained from hte mixture of regenerated silk fibroin and metal ions were dried for mimicking the gradual loss of water in the spinning process. The 13 C NMR spectrum simulation for C β nucleus of alanine quantitatively demonstrated that the conformation of the regenerated silk fibroin is dominantly of silk Ⅰ, whereas the fibroin with metal ions has more silk Ⅱ conformation. Raman spectroscopies show the consistent results with that of NMR. The binding of metal ion with carbonyl and amide in protein backbone allows the protein chain to array regularly, therefore leading to the β sheet formation.

Large area planar plasma sustained by surface microwave

In this paper, we show theoretically and experimentally that the large-area planar plasma with high density and good uniformity can be sustained by a surface microwave when the electron density is over-dense. From the experimental results we find that the nonuniformities in azimuthal plasma density and electron temperature have been greatly improved and in particular the nonuniformity is less than 10% when the gas pressure is 30 Pa. By improving the antenna shape, enhancing the microwave power and choosing the appropriate gas pressure, the large area planar plasma with high density can be produced.

Relating the probability distribution of a de Broglie wave to its phase velocity

We show that the phase velocity in a stationary state of a de Broglie wave can be directly obtained from the probability distribution, i.e. the quantum trajectories, without detailed knowledge of the phase term itself. In other words, the amplitude of a de Broglie wave function describes not only the probability distribution but also the phase velocity distribution. Using this relationship, we comment on two calculations of the Goos-H nchen shift in de Broglie waves.

储存环CSRm上的类硼Ar^(13+)离子的低能双电子复合实验研究

Based on the successful dielectronic recombination(DR)experiments with intermediate charge state ions of Belike Ar^(14+[1]) and Ca^(16+[2]) at the CSRm,we are preparing the precision spectroscopy of DR experiments with highly charged ions and even radioactive ions at the CSRe.A test electron-ion recombination experiment of Boron-like Ar13+ions was performed with a section of the new electron beam energy detuning system,which will be installed at the CSRe.Fig.1 presents the measured and also the calculated DR spectra for B-like Ar^(13+) from 0 to 3 eV.The experimental result indicates that the new detuning system is more stable and has a higher energy resolution than the previous detuning system used at the CSRm.It paves the way for the upcoming DR experiments with highly charged heavy ions at the CSRe.In addition,the flexible atomic code(FAC)was employed to calculate the DR resonance strengths of Boron-like Ar^(13+) to compare with the experimental result.