Soft X-ray Interferometer Research Articles

Development of compact X-ray laser pumped by pulse-train laser and coherent X-ray optical System for its application

We have been developing a tabletop x-ray laser with cavity based on the recombination plasma scheme where plasmas are pumped by a pulse-train laser. Advanced experiments have been performed with the double-target configuration. The spatial coherence of output x-ray beam were measured by using a dispersing coherent diagnostic system consisted of a Young s double-slit, a transmission grating and an x-ray CCD camera. The fringe pattern has been observed for the Al Xl 3d-4f line (15.47 nm), for which some gain was observed, for .double-slits of 24 μm and 50 μm separations placed 37 cm distance from the source. On the other hand, there has not been observed a clear fringe visibility for the other non-lasing lines. We propose a new soft x-ray interferometer with transmission gratings as a beam splitter and a beam deflector, for applications of coherent x-ray beam.

Dense plasma interferometry with a tabletop soft X-ray laser and an amplitude division interferometer based on diffraction gratings

We have demonstrated a novel Mach-Zehnder soft x-ray interferometer that uses diffraction gratings as beam splitters. The interferometer was used together with a 46.9nm tabletop soft x-ray laser, to map the evolution of the electron density distribution of a large-scale laser created plasma.

Final Diffraction Patterns of the Beam Splitters used in the Soft XRay Interferometer by a He-Ne Laser

The soft x-ray(10㎚-100㎚) interferometer is a modified Mach-Zehnder type interferometer and it consists of two beam-splitters and four totally reflecting mirrors. The beam-splitters used here are 50% transmission and 50% reflection grating type. The diffraction patterns of beam splitters(1st B. S.) were investigated with a He-Ne laser. The diffraction patterns produced by the soft x-ray interferometer(2nd B. S.) were also investigated in intensities and positions. The diffraction patterns of 20 degree grazing incidence on the beam splitters(1st B. S.) show a circular array of spots. Both the reflected and the transmitted beams show the same patterns but symmetric circles on the screen. The maximum intensity appears roughly when n is in the zeroth and odd orders and the suppressed peak(missing order) appears when n is in the even orders. Intensities of 3 center fringes(n = 0, ±1) are stronger than others. These results confirm the reduced grating equation and make agree with the intensity distribution function. It was found that the final patterns produced by the soft x-ray interferometer(2nd B. S.) consisted of fine fringes which were caused by two of three diffraction beams that were arrived at the second beam-splitter.

Design and performance of a soft X-ray interferometer for ultra-high resolution Fourier transform spectroscopy

A Fourier Transform Soft X-ray spectrometer (FT-SX) has been designed and is under construction for the Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory as a branch of beamline 9.3.2. The spectrometer is a novel soft x-ray interferometer designed for ultra-high resolution (theoretical resolving power E/ΔE∼10 6) spectroscopy in the photon energy region of 60–120 eV. This instrument is expected to provide experimental results which sensitively test models of correlated electron processes in atomic and molecular physics. The design criteria and consequent technical challenges posed by the short wavelengths of x-rays and desired resolving power are discussed. The fundamental and practical aspects of soft x-ray interferometry are also explored.

Two-dimensional interferogram of an exploding selenium foil using a soft X-ray laser interferometer

We have developed a soft X-ray interferometer capable of probing large high-density plasmas with micron spatial resolutions. A neon-like yttrium X-ray laser operating at 155 /spl Aring/ was combined with the Mach-Zehnder interferometer to obtain electron density profiles of a laser-produced exploding selenium foil plasma. The plasma was produced with one Nova laser beam using a 120-/spl mu/m line focus, the same conditions used to create a selenium X-ray laser. The interferogram of the selenium plasma was obtained from an end-on perspective.

Electron Density Measurements of High Density Plasmas Using Soft X-Ray Laser Interferometry.

We have developed and used for the first time a soft x-ray interferometer to probe a large laser-produced plasma with micron spatial resolutions. A neonlike yttrium x-ray laser operating at 155 \AA{} was combined with a multilayer coated Mach-Zehnder interferometer to obtain electron density profiles in a plasma produced by laser irradiation of a CH target. The measured electron density profile has been compared to hydrodynamic simulations and shows good agreement near the ablation surface but some discrepancy exists at lower densities.

X-ray optics for X-ray laser research applications

State of the art capabilities in soft X-ray lenses, multilayer mirrors, beamsplitters, and synthetically generated holograms are reviewed. Application of these capabilities in recent X-ray laser cavity experiments, and to the development of a soft X-ray interferometer and a high intensity (≥1013watt/cm2) soft X-ray laser are discussed.