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The aim of this study is to get the photon energy suitable for different thickness detector, different photon energy acts on pixel CdZnTe detector of different thickness. We can obtain the energy spectrum estimation, energy resolution and peak efficiency by the experiment and simulation with the radiation source of 241Am and 137Cs acting on pixel CdZnTe detector. From experiment results, it can be found that at the high energy of 662 keV the thicker the CdZnTe detector is, the higher the energy resolution and peak efficiency is while at the low energy of 59.5 keV tailing increases and charge is loss. It also can be found the characteristic of detector is better at the low energy when the detector thickness is thinner.

Based on self-focusing and uniform dispersion principle, a novel mica uniform dispersion crystal spectrograph (UDCS) was developed, whose linear dispersion was designed to be constant. An aluminum wire-array imploding experiment was performed at “Yang” accelerator and K-shell emission spectra were measured to investigate Z-pinch aluminum plasma characteristics by using the UDCS. The linear dispersion deduced from obtained spectra with linear fitting was in good agreement with the theoretical value. By using the collisional–radiative equilibrium (CRE) model, the intensity ratios of Ly-α/He-α line and Ly-β/He-e were given as a function of electron temperature. The measured intensity ratios were compared to the computed ones and the electron temperatures were estimated to be 512 eV and 489 eV. The slope of the free-bound X-ray continuum provides a model-independent diagnostic of the core electron temperature which was around 1215 eV for this implosion. Analysis of Z-pinch radial temperature gradient shows that the temperature decreases sharply near the core and slowly to the shell regions. Benefiting from the UDCS providing high spectral resolution ( λ /Δ λ ∼2500), the existence of first-order Langmuir dips were observed and reliably identified in Al Ly-α and Ly-γ resonance line profiles. The relationship between the position from the line center of red Langmuir dips and electron density was studied. The electron densities deduced from these fine spectral features were 5.52×10 21 cm −3 and 4.57×10 21 cm −3 respectively, which compared well with those derived from measurements of the line shift. The ion temperature was determined from the Doppler broadening of Al He-α resonance, He-like intercombination and Li-like s, t ( n =2) satellite lines.

On the basis of the conformal characteristics of a logarithmic spiral crystal in a large field of view(FOV),a new type of transmission crystal analyzer used for X-ray monochromatic imaging was investigated.Compared with a reflection type of crystal analyzer,the logarithmic spiral crystal analyzer has a wider FOV for catching the monochromatic X-ray image and a simple space arrangement for achieving the same magnification.According to the diffraction theory of the crystal and the surface equation of log spiral,the imaging principles and characteristics of the transmission type logarithmic spiral crystal analyzer were researched,including the magnifications in horizontal and vertical directions as well as the FOV sizes.A logarithmic spiral analyzer with a quartz crystal was developed.Then with the proposed analyzer,the monochromatic backlighting experiment for the mesh grid with a diameter of 100 μm was carried out by taking an X-ray source of Cu target as the backlighter.The experimental results show that the FOVs of the transmission type logarithmic spiral crystal analyzer are 15.938 7 mm and 5.900 6 mm in horizontal and vertical directions,respectively.Furthermore,the spatial resolution of the analyzer is at least 30 μm under a source diameter of 110 μm.

In order to accurately diagnose the electron density of laser-produced plasma,the method of relative intensity ratio of helium-like resonance to combination lines was proposed based on the polarization spectrum.It took into account polarization characteristics of the X-ray in laser-produced plasma,modified the real intensity ratios of the resonance to intercombination lines of He-like ions,then derivated the density of plasma.The experiment was carried out at the 2×10 J laser facility at Laser Fusion Research Center of,China Academy of Engineering Physics(CAEP).X-ray spectra emitted from the aluminum plasmas were recorded by polarized PET(002) crystal spectrometer.By correcting two Al helium-like spectra,it was calculated that the electron density was about 1.5×1 020 cm-3.The experimental results showed that the arithmetic was adapted to diagnose laser-produced high temperature high-density plasmas.

A flexible induced charge model of CdZnTe pixellated detector is presented. This model takes into account the charge trapping effect in the detection process. The distribution of the trapped carriers in CdZnTe crystal is derived based on the continuity equations. In consequence, an evaluation model based on the presampling modulation transfer function (presampling MTF) is obtained. As shown through the numerical simulation, the detector imaging quality decreases obviously with the increase in incident photon energy. When the electron- and hole-mobility lifetime products are 0.510-3 to 5.010-3 cm2/V and 2.010-5 to 7.510-5 cm2/V, respectively, the model signal is almost due to the electron

A polarized spectroscopy was designed and manufactured based on the laser-produced plasma experiments to diagnose the X-ray polarization of a laser-produced plasma in 0.2-20 nm.The experiment was performed at the 20 J laser facility in Research Center of Laser Fusion,China Academy of Engineering Physics(CAEP).In the experiment,Poly Ethylene Terephthalate(PET) crystals were used as dispersive elements in the two orthogonal directions and the imaging plates with the effective area of 30 mm×80 mm were taken as detectors.The optical paths of the X-ray beam were about 980 mm and 310 mm from the source to the detectors via the PET crystals,respectively.The X-ray spectrum emitted from the aluminum plasmas was recorded by the image plates.It shows that the polarization of the two Al Ⅻ spectra are about 0.123 3 and 0.148 1 after correcting helium resonance and combination spectrum.The experimental results demonstrate that there is anisotropic phenomenon in the laser-produced plasma,and the proposed method is effective to diagnosis of the polarized spectrum of high-temperature plasma.

Zone plate coded imaging is an experimental technique for particle and strong X-ray imaging, which is widely applied to astronomy, nuclear medicine, and laser inertial confinement fusion researches. From conventional perspective, spatial resolution of zone plate depends on the encoding zone plate width of outermost ring r with a size greater than 1.22r. In X-ray region, however, the outermost ring width of Fresnel zone plate is limited by processing technology. Such a limitation makes it impossible to fabricate a sufficiently small zone plate, thus restricting the applications of Fresnel zone plate coded imaging. In this paper, we present a new reconstruction method of zone plate coded imaging by using a higher-order order Gabor zone plate. With the proposed method, higher spatial resolution can be achieved than with the regular methods, thus the spatial resolution is improved by 1/m times the width of outermost ring (where m is a positive integer). Consequently such a breakthrough goes beyond the limits of Rayleigh criterion in general.

Based on the Bragg law and imaging principle of bent crystal, the imaging properties of the monochromic backlighting system with a toroidally bent crystal were studied via ray-tracing simulations and experiments. Comparison experiments with both toroidally and spherically bent crystals using a Cr line as the backlighter were performed, showing that using toroidally bent crystal, a 2D image with the same magnifications in meridional and sagittal directions can be obtained with higher spatial resolution. Experiments with laser-produced plasmas using Mica crystal were carried out on the Shenguang II laser facility. Five laser beams were focused onto a Ti planar target producing a line at 4.75 keV as the backlighter and an image of a metal grid with size of 200 μm × 200 μm was recorded with an x-ray image plate. A spatial resolution of 40 μm was demonstrated with a magnification of 3 due to the restriction of the target chamber size. 10 μm spatial resolution might be possible if the detector can be located outside the chamber to enlarge the magnification.

The reflection type toroidally bent crystal analyzer was investigated based on the Bragg diffraction to diagnose the laser plasma X-ray. The dispersive element of crystal analyzer was mica. The bent radiuses of the crystal analyzer in meridian plane and in sagittal plane are 296 mm and 198 mm respectively, and the corresponding Bragg angle is 54°.

Several experiments are performed on the ShenGuang-II laser facility to investigate an x-ray source and test radiography concepts. X-ray lines emitted from laser-produced plasmas are the most practical means of generating these high intensity sources. By using a time-integrated space-resolved keV spectroscope and pinhole camera, potential helium-like titanium K? x-ray backlighting (radiography) line source is studied as a function of laser wavelength, ratio of pre-pulse intensity to main pulse intensity, and laser intensity (from 7.25 to ~11.3 ? 1015 W/cm2). One-dimensional radiography using a grid consisting of 5 ?m Au wires on 16 ?m period and the pinhole-assisted point projection is tested. The measurements show that the size of the helium-like titanium K? source from a simple foil target is larger than 100 ?m, and relative x-ray line emission conversion efficiency ?x from the incident laser light energy to heliumlike titanium K-shell spectrum increases significantly with pre-pulse intensity increasing, increases rapidly with laser wavelength decreasing, and increases moderately with main laser intensity increasing. It is also found that a gold gird foils can reach an imaging resolution better than 5-?m featured with high contrast. It is further demonstrated that the pinhole-assisted point projection at such a level will be a novel two-dimensional imaging diagnostic technique for inertial confinement fusion experiments.

A pixel array CdZnTe imaging system, employing a 40 × 40 × 5 mm3 pixellated CdZnTe detector, is established. The imaging polarization effect in the CdZnTe pixellated detector for a collimated Cs137 Gamma source is investigated in detail. The experimental results for different irradiated fluxes indicate that excessive irradiated flux indeed causes central pixels to be shut off completely. The imaging performance of the polarized detector is severely degraded. Polarized detector counts are simultaneously reduced to one-third of the non-polarized detector counts. A theoretical model of potential distribution is also proposed by solving the Poisson equation and, in turn, the electric potential distortion for high irradiated flux is discussed by comparison with the experimental results.