Rui Jin

Tsinghua University | TH · Department of Physics

The nonlinear interaction of x-rays with matter is at the heart of understanding and controlling ultrafast molecular dynamics from an atom-specific viewpoint, providing new scientific and analytical opportunities to explore the structure and dynamics of small quantum systems. At increasingly high x-ray intensity, the sensitivity of ultrashort x-ray...

The electronic and nuclear dynamics inside molecules are essential for chemical reactions, where different pathways typically unfold on ultrafast timescales. Extreme ultraviolet (XUV) light pulses generated by free-electron lasers (FELs) allow atomic-site and electronic-state selectivity, triggering specific molecular dynamics while providing femto...

The electron impact excitation (EIE) cross sections of an atom/ion in the whole energy region are needed in many research fields, such as astrophysics studies, inertial confinement fusion researches and so on. In the present work, an effective method to calculate the EIE cross sections of an atom/ion in the whole energy region is presented. We use...

We theoretically investigate the formation of highly charged ions in a germanium (Ge) solid driven by intense, ultrashort x-ray pulses and its effect on the cross sections for nonsequential two-photon absorption from the K shell. Our investigation is related to an experiment conducted at the Linac Coherent Light Source, in which Kα fluorescence was...

High energy density (HED) matter exists extensively in the Universe, and it can be created with extreme conditions in laboratory facilities such as x-ray free-electron lasers (XFEL). In HED matter, the electronic structure of individual atomic ions is influenced by a dense plasma environment, and one of the most significant phenomena is the ionizat...

This corrects the article DOI: 10.1103/PhysRevE.103.023203.

Following structural dynamics in real time is a fundamental goal towards a better understanding of chemical reactions. Recording snapshots of individual molecules with ultrashort exposure times is a key ingredient towards this goal, as atoms move on femtosecond (10−15 s) timescales. For condensed-phase samples, ultrafast, atomically resolved struct...

We investigate the capability of attosecond transient absorption spectroscopy to characterize the dynamics of inner-shell-excited systems. In the transient absorption spectroscopy setup considered, wave packets are prepared by an attosecond XUV pulse and probed by a femtosecond NIR pulse. By using this, we study coherent electron dynamics in core-e...

The advent of x-ray free-electron lasers (XFELs), which provide intense ultrashort x-ray pulses, has brought a new way of creating and analyzing hot and warm dense plasmas in the laboratory. Because of the ultrashort pulse duration, the XFEL-produced plasma will be out of equilibrium at the beginning, and even the electronic subsystem may not reach...

The advent of x-ray free-electron lasers (XFELs), which provide intense ultrashort x-ray pulses, has brought a new way of creating and analyzing hot and warm dense plasmas in the laboratory. Because of the ultrashort pulse duration, the XFEL-produced plasma will be out of equilibrium at the beginning and even the electronic subsystem may not reach...

Highly charged ion systems play an important role in simulation and diagnostics of astrophysical and fusion plasmas. Due to dominant strong Coulomb interactions from the nuclear charge, electron correlations are generally thought to be less prominent than relativistic effects and other effects in HCIs. In this paper, we demonstrate the importance o...

An extended atomic data base with sufficiently high precision is required in astrophysics studies and the energy researches. For example, there are “infinite” energy levels in discrete energy region as well as overlapping resonances in autoionization region. We show in this paper the merits of our relativistic eigenchannel R-matrix method R-R-Eigen...

The scattering matrices of e+O+(2p3S3/24,D3/2,5/22) with Jπ=3- in various energy regions including discrete and adjacent continuum are calculated using our modified eigenchannel R-matrix method. The analytical properties of the scattering matrices for this multichannel scattering process with strong interchannel interactions are unveiled by our met...

The ionization potential (IP) is a basic property of an atom, which has many applications such as in element analysis. With the Dirac-Slater methods (i.e., mean field theory), IPs of all occupied orbitals for elements with atomic number (Z ≤ 119) are calculated conveniently and systematically. Compared with available experimental measurements, the...

In this paper three aspects of photoionized plasmas are discussed in both laboratory and astrophysical contexts. First, the importance of accurate atomic/ionic data for the analysis of photoionized plasmas is shown. Second, an overview of present computer codes for the analysis of photoionized plasmas is given. We introduce our computer model, radi...

The electron and photon scattering data of an atom are crucial for many scientific fields, including plasma physics, astrophysics, and so on. For high enough but nonrelativistic incident energies, the first Born approximation is applicable for calculating these data, in which the key physics quantity is the generalized oscillator strength (GOS). In...

The scattering matrices of Oxygen in various energy regions are calculated using our modified eigenchannel R-matrix method R-R-eigen. We can obtain abundant atomic dynamical data with accuracies determined based on analytical continuation properties of the scattering matrices. Our calculated discrete and autoionization spectrum can be readily exami...

With our relativistic eigenchannel R-matrix method R-R-Eigen, the physics parameters of Ne⁺ in multi channel quantum defect theory (MQDT) are calculated directly, such as eigenchannel quantum defects, transformation matrix etc al. Various physical quantities can then be derived from a straightforward application of the MQDT procedure. Using our pro...

Full-relativistic Dirac-Fock calculations with Breit and QED correction of seven alkali elements (from Z=3 to 119) are performed to check the accuracy of the empirical formula which is used to estimate the binding energy of electrons in the mass measurement of nuclear physics. Some improvements are made to the empirical formula.

Accurate electromagnetic transition rates between the ground electronic configurations are important in diagnostic studies of planetary nebulae. Based on a “quasi complete basis” set, we present large-scale multi-configuration Dirac-Fock calculations of the forbidden transition rates within the ground electronic configuration along the nitrogen-lik...

The $E2$ and $M1$ transition rates among the lowest five states (${{[}^{4}{S}_{3/2}^{o}]}^{$'${}},{{[}^{2}{D}_{5/2}^{o}]}^{$'${}},{{[}^{2}{D}_{3/2}^{o}]}^{$'${}},{{[}^{2}{P}_{3/2}^{o}]}^{$'${}},{{[}^{2}{P}_{1/2}^{o}]}^{$'${}}$), i.e., the ${{[}^{2}{D}_{5/2,3/2}^{o}]}^{$'${}}$\rightarrow${}{{[}^{4}{S}_{3/2}^{o}]}^{$'${}}$ and ${{[}^{2}{P}_{3/2,1/2}^...