A5111690037- Laser-Matter Interactions and Applications
- Advanced Fiber Laser Technologies
- Laser-induced spectroscopy and plasma
- Radiation Detection and Scintillator Technologies
- Particle Detector Development and Performance
- Nuclear Physics and Applications
- Spectroscopy and Quantum Chemical Studies
- Mass Spectrometry Techniques and Applications
- Atomic and Subatomic Physics Research
- Nuclear physics research studies
- Laser-Plasma Interactions and Diagnostics
- Atomic and Molecular Physics
- Ion-surface interactions and analysis
- Analytical chemistry methods development
- Advanced Chemical Physics Studies
- Spectroscopy and Laser Applications
- X-ray Spectroscopy and Fluorescence Analysis
- Dark Matter and Cosmic Phenomena
- Quantum optics and atomic interactions
- Astronomical and nuclear sciences
- Laser Material Processing Techniques
- Laser Design and Applications
- Quantum, superfluid, helium dynamics
- Photonic Crystal and Fiber Optics
- Particle physics theoretical and experimental studies
Lanzhou University
2014-2024
Lanzhou University of Technology
2011-2024
East China Normal University
2024
Sorbonne Université
2012
Institut des NanoSciences de Paris
2012
Centre National de la Recherche Scientifique
2012
We investigate the gauge invariance of semiconductor Bloch equations (SBEs) in solid high-order harmonic generation (HHG). It is found that dependence SBEs can be attributed to absence Berry connection terms previous studies. When are considered, naturally preserved under an arbitrary global phase transformation. To satisfy demand continuity transition dipole matrix elements one-dimensional calculations, we propose a easy implement numerically. Finally, saddle point analysis shows...
We theoretically investigate high-order harmonic generation (HHG) from solids in two-color fields. It is found that under the premise of maintaining same amplitude, intensity second plateau can be enhanced by two to three orders a proper field compared with result monochromatic frequency as driving pulse field. This attributed fact most excited electrons driven top first conduction band due larger vector potential fields, which leads higher electron population upper bands. Moreover, we also...
As a successor to the DArk Matter Particle Explorer (DAMPE), Very Large Area γ-rays Space Telescope (VLAST) is being designed strengthen γ-ray observations and extend cosmic ray nuclei measurements up Zr (Z = 40) even heavier ions. Consequently, large dynamic range required by charge detector of VLAST cover particles from proton ultra-heavy To achieve requirements, readout design based on three dynodes signal extracted photomultiplier tube has been proposed. In addition, prototype developed...
An efficient method to generate an isolated short attosecond pulse is investigated theoretically. A broadband extreme ultraviolet supercontinuum harmonics can be generated when a model He${}^{+}$ ion exposed the combination of intense few-cycle laser and low-frequency field. By properly adding $27$th resonantly excite ion, intensity high-order harmonic generation (HHG) plateau enhanced by $3\ensuremath{-}4$ orders magnitude. As result, $24$-as with bandwidth $138$ eV obtained directly from...
We present a method to control the harmonic process by mid-infrared modulated generalized polarization gating for generation of broadband supercontinuum. Using mid-IR weaker linearly polarized chirped field, ionization, acceleration and recombination steps in HHG are simultaneously controlled, leading efficient an ultra-broadband supercontinuum covered spectral range from ultraviolet water window x-ray. this we expect that isolated sub-100 attosecond pulses with tunable wavelength could be...
We present a theoretical study of isolated attosecond pulse generation with multicycle chirped and chirped-free two-color field. show that the bandwidth extreme ultraviolet supercontinuum can be extended by combining pulse. Also, broadband still generated when macroscopic effects are included. Furthermore, ameliorate temporal characteristic single atom, eliminate modulations supercontinuum. Thus very smooth pure 102-as directly obtained. Moreover, structure steadily maintained for relative...
The present work is the first systematic and large scale study on radioactive materials heavy metals in surface soil around Bayanwula prospective uranium mining area China. In this work, both natural anthropogenic radionuclides 48 samples were analyzed using High Purity Germanium (HPGe) γ spectrometry inductively coupled plasma-mass (ICP-MS). obtained mean activity concentrations of 238U, 226Ra, 232Th, 40K, 137Cs 25.81 ± 9.58, 24.85 2.77, 29.40 3.14, 923.0 47.2, 5.64 4.56 Bq/kg,...
When a Λ hyperon is embedded in nucleus it can form hypernucleus. The lifetime and its mass dependence of stable hypernuclei provide information about the ΛN interaction nuclear medium. This work will introduce Jefferson Lab experiment (E02-017), which aims to study heavy using specially developed fission fragment detection technique: multi-wire proportional chamber operating under low gas pressure (LPMWPC). trajectory detected reconstructed used find point on target foil, position...
We investigate the limitations of single-electron time-dependent Schr\"odinger equation (TDSE) in studies solid high-order harmonic generation (HHG). Two main differences are found by comparing spectra calculated TDSE and semiconductor Bloch equations (SBEs) same conditions. One is that spectrum obtained from SBEs only contains clear odd harmonics, but derived consists even harmonics. The other two approaches derive different linear dependence cutoff energy on electric strength wavelengths...
High-sensitivity and high-resolution depth-encoding positron emission tomography (PET) detectors are required to simultaneously improve the sensitivity spatial resolution of a PET scanner so that quantitative accuracy studies can be improved. The semi-monolithic scintillator detector has advantage measuring depth interaction with single-ended readout as compared traditional pixelated detector, significantly reducing edge effect deteriorates at edges monolithic if long rectangular is used. In...
In this paper, the effect of laser pulse energy on orthogonal double femtosecond induced breakdown spectroscopy (LIBS) in air is studied. experiment, probe changeable, while pump held constant. At same time, a systematic study signal dependence inter-pulse delay between two pulses performed. It noted that configuration yields 2-32 times enhancement for ionic and atomic lines as compared to single LIBS spectra when an optimum temporal separation used, there no significant molecular studied...
We theoretically investigate high-order harmonic generation in a two-color multi-cycle inhomogeneous field combined with 27th pulse. By considering bowtie-shaped gold nanostructure, the spatiotemporal profiles of enhanced plasmonic fields are obtained by solving Maxwell equation using finite-domain time-difference method. Based on quantum-mechanical and classical models, effect pulse, temporal profile inhomogeneity supercontinuum analyzed discussed. As result, broadband can be generated from...
A novel ceramic Gas Electron Multiplier (GEM) has been developed to meet the demand of high counting rate for neutron detection which is an alternative 3He-based detector at China Spallation Neutron Source (CSNS). An experiment was performed measure transmittance ceramic-GEM and FR4-GEM small angle scattering (SANS) instrument. The result showed higher less self-scattering especially cold neutrons. One single GEM could give a gain 102-104 in mixture gas Ar CO2 (90%:10%) its energy resolution...
We theoretically investigate the generation of elliptically polarized isolated attosecond pulses from an oriented CO gas medium using a linearly driving pulse. Our results reveal that largely modulated supercontinuum at microscopic level can be generated properly molecule. Moreover, it is found nonsymmetric structure highest occupied molecular orbital molecule responsible for elliptical harmonics. In addition, propagation effects are also employed to macroscopically select short quantum...
In this paper, an experimental study of collinear geometry double-pulse femtosecond LIBS was performed on a Ni sample in ambient air effort to clarify the contributing processes responsible for signal enhancement observed comparison with single-pulse case. Double-pulse spectra show very clear when optimum inter-pulse delay used. The influences between two pulses intensity, electron temperature and density were investigated. It is most remarkable that evolutions versus showed same behavior...
It has been recently predicted theoretically that due to nuclear motion light and heavy hydrogen molecules exposed strong electric field should exhibit substantially different tunneling ionization rates [O. I. Tolstikhin, H. J. Worner, T. Morishita, Phys. Rev. A 87, 041401(R) (2013)]. We studied isotope effect experimentally by measuring relative yields for each species in a mixed ${\mathrm{H}}_{2}/{\mathrm{D}}_{2}$ gas jet interacting with intense femtosecond laser pulses. In reaction...
We theoretically investigate the dynamic processes of solid harmonics generation using one-dimensional time-dependent density functional theory and three-band recollision model. Compared with gas harmonics, more quantum paths contribute to harmonics. Moreover, number further increases as laser vector potential increases. Analysis indicates that multiple velocity reversals electrons play an important role in which induces collisions holes forms paths. Besides, we find dephasing effect cannot...
We theoretically investigate the isolated attosecond pulse generation from pre-excited medium with a chirped and chirped-free two-color field. It is found that large initial population of excited state can lead to high density free electrons in distortion driving laser field after propagation, though it benefits enhancement harmonic intensity single atom response. These effects weaken phase-match macroscopic supercontinuum. On contrary, small 4% generate well intense also an by using filter...
A beam of 33 fs laser pulse with peak power 15-40 GW was employed to explore a convenient method determine the nonlinear refractive index coefficient an optical glass. It is rare investigate nonlinearities glass such extreme ultrashort and powerful pulse. According our method, only single few experimental apparatuses are necessary measure coefficient. The results from in reasonable agreement others, which demonstrates that this new works well, independent measuring technology. Meanwhile,...
α decay half-lives are calculated using the Qα values obtained by Semi-empirical Shell Model in framework of Unified Fission (UFM) with Coulomb repulsion, nuclear attraction due to proximity potential, and rotational energy angular momentum transfer particle. In addition, experimental 425 nuclei compared check validity model applied on decay. The good agreement data. Finally, some useful predications provided for future experiments.