The paper describes the results of measurements carried out at VNIIEF on a laser facility ISKRA-5 with spherical targets of different type. Spectra of X-rays are measured with the aid of cylindrical Ni/C multilayer mirror (MM). To absolutely normalize the results of spectral measurements, there is additionally registered X-rays by semiconductor detectors with different filters. Detectors’ serviceability at operation in the mode of deep current saturation is demonstrated. Experimental and calculation data of spectrum of target X-rays are presented and compared.

This work is a description of a wide-range X-ray spectrograph design for fast physical processes in the hot non-equilibrium plasma investigation. Two ways of registration range broadening in the offered scheme are simultaneously used: curving of a mirror and creation of a multilayer structure period gradient. Computation performances of spectrograph and multilayer mirror for prospective geometry of measurements are explicitly described: structure, energy registration range, energy resolution, luminosity and line form on the detector.The mirror is supposed to be produced at BINP (Novosibirsk, Russia), where the production process of cylindrically curved multilayer mirrors is organized and there is an experience of manufacturing mirrors with variable period.The given spectrograph is supposed to be used for spectral X-ray measurements of hot non-equilibrium plasma at VNIIEF impulse facilities: ISKRA-5, plasma focuses and devices with plasma magnetic compression. (c) 2005 Elsevier B.V. All rights reserved.

The results of a study of radiation characteristics of a high-current pinch discharge of the plasma-focus type in the region of soft and ultrasoft X-rays are presented. Experiments were performed at a moderate energy of discharges in a mixture of H2 and Ne. It was shown that a comparatively narrow spectrum region of the generated radiation, which corresponds to the line emission of lithium-like ions Ne7+ with an average effective quantum energy Eeff≈ 0.16 keV, can be selected. The Ne7+ emission fluence was (0.2–1.0) × 1012 quant/cm2 per pulse with a duration τ0.5 = 40–100 ns. The results obtained demonstrate the feasibility of using such discharges in laboratories as pulse sources of quasi-monochromatic ultrasoft X-rays.

The paper presents the results of absolute spectral responsivity measurements for SPPD11 and SPPD11-04 pulse-type silicon detectors, carried out in the X-ray energy range from 0.3 to 1.5keV with a relative uncertainty of about 8% (1σ). The measurements were performed using the detector exposure to a well-calculable synchrotron radiation through the selective filters with well-known transmittance. Synchrotron radiation from the VEPP-2M storage ring was utilized for these measurements. The spectral responsivity of the detectors was restored by solving the proper system of integral equations on the base of measurement data. For increasing the calibration accuracy, the X-ray transmittance near the L-absorption edges of the filters used and the angular spread in the positron beam of the storage ring were experimentally determined.

The results are presented of absolute spectral responsivity measurements for SPPD11 and SPPD11-04 pulse-type silicon semiconductor detectors (developed by the Research Institute of Pulse Technique, Moscow), carried out over the X-ray energy range from 1.5 keV to 20 keV with a relative uncertainty (k = 1) of typically 5 × 10−2. In our measurements, the detector is positioned in a calculable synchrotron radiation flux behind filters of well-known transmittance. The spectral responsivity of the detector is restored on the basis of measurement data using a set of integral equations. Two procedures have been developed to improve the calibration accuracy: one for the experimental determination of the X-ray transmittance near the K absorption edge of the filters used, with a relative uncertainty not exceeding 2 × 10−2; and another for the estimation of the angular spread of the electrons.

Measurements of spectral and energy X-ray characteristics of almost transparent Fe plasma produced by laser radiation inside the inverted-corona targets have been made at ISKRA-5 facility. The targets were spherical plastics cavities with 2-mm diameter and 4.6-μm thickness covered from inside with Fe layer 0.25-μm thickness. X-ray spectrum, X-ray total energy, and the energy of a HeαFe resonance line have been measured. Experimental data and calculation results are collated.

Experimental results of the soft X-ray spectra investigation from a hot plasma produced by impulse discharge of a dense plasma focus in pure neon are presented. The spectral-energy characteristics of X-ray emission were measured in the photon energy range of 0.5-5.0 keV with the help of thin absorber filters set and silicon semiconductor p-i-n detectors SPPD11-04. A study was made at the filling gas pressure P/sub Ne/=2.0-6.0 Torr and at the stored capacitor bank energy W=15-21 kJ. A high degree of monochromatization for the soft X-ray emission (/spl sim/90 %) was obtained. According to the experimental data characteristic plasma electron temperature in the time duration of X-ray pulse /spl tau//sub 1/2/=10-100 ns has been estimated as T/sub e//spl sim/0.2-0.3 keV. The plasma parameters obtained are compared with the results of computer simulation of the emission process.

Results of measurements of the absolute spectral sensitivity of silicon semiconductor detectors in the X-ray quanta energy range of 1.5-15 keV are presented. The detectors, being calibrated, were placed into the direct ''white'' synchrotron radiation (SR) beam from the VEPP-3 storage ring. The spectrum of X-radiation at the entrance window of the detectors was changed by using sets of calibrated filters, as well as by varying the energy of the electrons in the storage ring. The possibility of accurate calculation of the SR spectrum on the calibrated detector under its irradiation in different conditions allowed us to determine the detector spectral sensitivity from a set of integral equations connecting the spectral sensitivity to the registered detector currents. The analysis of possible experimental errors indicates that the absolute spectral sensitivity of the detectors was restored with an accuracy of not worse than 10% in the total photon energy range under the study.

Synchrotron radiation (SR) with a well deterministic time structure from the VEPP-3 storage ring was used to measure the time parameters of silicon semiconductor X-ray detectors. The time pulse response and the pulse sensitivity of the detectors were investigated. A stroboscopic oscilloscope with further data digitizing and processing was employed to register the detector pulse signal generated by repetitive SR X-radiation bursts. It is shown that taking the time dependence of the SR bursts and the distortions of the signal registration path into account allows one to obtain the pulse time characteristic function of X-ray detectors with a time resolution of not worse than 0.5 ns. The pulse and the static sensitivities of the studied X-ray detectors were compared, and a discrepancy of about 10% was revealed. The results of independent measurements with a powerful pulse X-ray tube are in a good agreement with the ones obtained with SR.

The experimental station for detector calibration with synchrotron radiation (SR) in the photon energy range of 0.1–1 keV has been designed and constructed at the storage ring VEPP-2M. SR from a positron beam is extracted from a bending magnet of the storage ring and monochromatized by a multilayer mirror. The first calibration procedures are to use the good calculability of the SR photon flux and the measured parameters of the multilayer monochromator when the calibration is performed in a monochromatic beam, or the reconstruction of a detector spectral sensitivity from detector signals measured in “white” SR beam through a set of calibrated absorbing filters and at different positron energies. A description of the station, the estimations of the calibration uncertainties and preliminary results of the monochromator testing are presented.

Results of measurements of the absolute spectral sensitivity of silicon semiconductor detectors for 7–20 keV x rays are presented. Synchrotron radiation from a 2-T wiggler, installed at the VEPP-3 storage ring, was used for this study. Two quite different approaches were applied to measure the detector spectral sensitivity. According to the first approach, the measurements were performed in monochromatic radiation. The absolute photon flux was determined by a scintillation counter with known detection efficiency and monitored by a transmission ionization chamber. The second approach corresponds to the measurements in a ‘‘white’’ synchrotron radiation beam through sets of known absorption filters and via the following unfolding of the spectral sensitivity from a set of integral equations. The experimental results obtained by both procedures are in good agreement. The accuracy of the experimental calibration procedures is assumed to be not worse than 10%.