Zhi-Ming Jiang

Space‐ and time‐resolved investigation of short wavelength x‐ray laser in Li‐like Ca ions

We have demonstrated the soft x‐ray amplification for lithium‐like Ca17+ 4f‐3d transition at 57.7 A with 900 ps, 1.05 μm drive laser pulse. The spatial distribution of the gain coefficient and temporal history of the lasing line emissions were also obtained.

Filamentation and jets in line-focused laser-produced plasmas

Abstract In line-focused laser-produced plasma experiments on planar and cylindrical targets, we have observed the line-focused laser beam breakup into filaments as well as small-scale plasma jet-like structures. These phenomena might become obstacles in achieving optimum X-ray lasing in the type of experiments using line-focused laser-produced plasmas as a gain medium.

Large-scale jet structures in laser-produced plasmas

Abstract In line-focused laser-produced plasma experiments, we have observed large-scale plasma jets. These plasma jets are in appearance similar to “tips of ox horns”, and always appear at the boundaries between the hot plasmas and the cold target materials, or between two plasmas with different Z-numbers.

Optical diagnostics of line-focused laser-produced plasmas

To find out homogeneous line-shaped plasma as a gain mediuni of soft Xray lasers produced by linefocused lasers the hydrodynamic characteristics and forms of harmonic and X-ray emission profiles of the plasma colunu-is have been studied with optical diagnostic equipments such as the five-frame laser probing diagnostic system the micrographic diagnostic systems and the spectral resolved Xray pinhole camera. Some experimental results are given and the emphasis is put on those of the halfcylindricalgroove shell targets. The results show that the halfcylindrical groove shell target may be favorable for soft X-ray laser research. 1 .

Investigation of soft X-ray spectra from laser plasma by using a transmission grating spectrometer

With the help of the transmission grating spectrometer (PTGS), we have obtained the real emission spectra of several elements. The band structures of the soft x-ray spectra from laser produced plasmas are extensively studied as the function of atomic number and laser intensity. Finally, the PTGS space-resolved spectra from the laser heated half-cylindrically grooved target show that this kind of semi-closed geometry is a promising candidate for x-ray laser targets.

Plasma physics in a half-cylindrical target and its applications in X-ray lasers

Laser plasma interactions, plasmas hydrodynamics, and x-ray emissions in half-cylindrical target have been studied. It is found that this kind of target geometry can converge plasma expanding along the radial direction and form uniform flat distributions of electron density. Based on the unique characteristics of this kind of target, we suggest it be used for x-ray laser research. We also suggest a new configuration of two laser heating for x-ray lasers.