This paper reports the measurement of the energy loss of protons at the energy of 100 keV penetrating a partially ionized hydrogen plasma. The plasma of ne ≈ 1015–16 cm−3; Te ≈ 1–2 eV and lifetime of about 8 µs is created by the hydrogen gas discharge. The experimental results show an increase of a factor of 2.8 in the energy loss, which are in good agreement with the Bethe, Standard Stopping Model, Li–Petrasso and Vlasov models’ predictions within the error limit. The Bethe–Bloch Coulomb logarithm term is found to increase by a factor of 4.0 for free electrons as compared with the situation where bound electrons prevail. The potential application of protons energy loss for diagnosing the electron density in plasma is proposed too.

A spectroscopic protocol is proposed to implement confocal microfluorescence imaging to the analysis of microinhomogeneity in the nanocrystallization of the core of fibers belonging to a new kind of broadband fiber amplifier based on glass with embedded nanocrystals. Nanocrystallization, crucial for achieving an adequate light emission efficiency of transition metal ions in these materials, has to be as homogeneous as possible in the fiber to assure optical amplification. This requirement calls for a sensitive method for monitoring nanostructuring in oxide glasses. Here we show that mapping microfluorescence excited at 633 nm by a He-Ne laser may give a useful tool in this regard, thanks to quasi-resonant excitation of coordination defects typical of germanosilicate materials, such as nonbridging oxygens and charged Ge-O-Ge sites, whose fluorescence are shown to undergo spectral modifications when nanocrystals form into the glass. The method has been positively checked on prototypes of optical fibers—preventively characterized by means of scanning electron microscopy and energy dispersive spectroscopy—fabricated from preforms of Ni-doped Li2O-Na2O-Sb2O3-Ga2O3-GeO2-SiO2 glass in silica cladding and subjected to heat treatment to activate gallium oxide nanocrystal growth. The method indeed enables not only the mapping of the crystallization degree but also the identification of drawing-induced defects in the fiber cladding.

In April-May 1980, two independent outbreaks of influenza-like illness occurred in Leningrad among children's-home children aged from 3 months to 2 years (of 68 children under observation, 50 became ill) and among boarding-school pupils aged 15–17 years (of 50 pupils under observation, 13 became ill).

A total of five influenza A virus strains were derived from one clinically healthy and three affected children of the children's home. Similar viruses were obtained from one affected boarding-school pupil and from an infected woman aged 24 years (a sporadic case within a household). On the basis of laboratory findings, all these seven strains were identified as influenza A H2N2 subtype strains.

Six of the affected children showed significant seroconversion only to H2 haemagglutinin from February to May 1980. Type A influenza H2N2 virus was isolated from three persons, including the sporadic case, who also showed significant seroconversion to H2 haemagglutinin. H2N2 influenza A virus was isolated on two occasions, at a 7-day interval, from the girl N. Ju.

Laboratory findings obtained from the study of the viruses isolated using up-to-date immunological and molecular-biochemical techniques enable us to conclude the following. The A/Leningrad/80 isolates belong to H2N2 sero-subtype. The viruses isolated are similar but not identical to the A/Singapore/I/57 reference strain in details of polypeptide and gene composition.

A comparative study of the low temperature conductivity of an ensemble of multiwall carbon nanotubes and semiconductor nanowires is presented. The quasi one-dimensional samples are made in nanoporous templates by electrodeposition and CVD growth. Three different structures are studied in parallel: multiwall carbon nanotubes,tellurium nanowires, and silicon nanowires. It is shown that the Coulomb blockade regime dominates the electronic transport below 50 K, together with weak and strong localization effects. In the Coulomb blockade regime, a scaling law of the conductance measured as a function of the temperature and the voltage is systematically observed. This allows a single scaling parameter α to be defined. This parameter accounts for the specific realization of the “disorder”, and plays the role of a fingerprint for each sample. Correlations between α and the conductance measured as a function of temperature and voltage, as a function of the perpendicular magnetic field, and as a function of the temperature and voltage in the localized regime below 1 K have been performed. Three universal laws are reported. They relate the coefficient α (1) to the normalized Coulomb blockade conductance $G_{T}(\alpha)$ , (2) to the phase coherence length $l_{\phi}(\alpha)$ , and (3) to the activation energy $E_{a}(\alpha)$ . These observations suggest a description of the wires and tubes in terms of a chain of quantum dots; the wires and tubes break into a series of islands. The quantum dots are defined by conducting islands with a typical length on the order of the phase coherence length separated by poorly conducting regions (low density of carriers or potential barriers due to defects). A corresponding model is developed in order to put the three universal laws in a common frame.


Below is the complete Reference citation for Hoffmann et al. (2005).

Hoffmann, D.H.H., Blazevic, A., Ni, P., Rosmej, O., Roth, M., Tahir, N., Tauschwitz, A., Udrea, S., Varentsov, D., Weyrich, K. & Maron, Y. (2005). Present and future perspectives for high energy density physics with intense heavy ion and laser beams. Laser Part. Beams23, 47–53.

The study of heavy ion stopping dynamics using associated K-shell projectile and target radiation was the focus of the reported experiments. Ar, Ca, Ti, and Ni projectile ions with the initial energies of 5.9 and 11.4 MeV/u were slowed down in quartz and arogels. Characteristic radiation of projectiles and target atoms induced in close collisions was registered. The variation of the projectile ion line Doppler shift due to the ion deceleration measured along the ion beam trajectory was used to determine the ion velocity dynamics. The dependence of the ion velocity on the trajectory coordinate was measured over 70–90% of the ion beam path with a spatial resolution of 50–70 μm. The choice of SiO2 aerogel with low mean densities of 0.04–0.15 g/cm3 as a target material, made it possible to stretch the ion stopping range by more than 20–50 times in comparison with solid quartz. It allowed for resolving the dynamics of the ion stopping process. Experimentally, it has been proven that the fine porous nano-structure of aerogels does not affect the ion energy loss and charge state distribution. The strong increase of the ion stopping range in aerogels made it possible to resolve fast ion radiation dynamics. The analysis of the projectile Kα-satellites structure allows supposing that ions propagate in solid in highly exicted states. This can provide an experimental explanation for so called gas-solid effect.

A comparative assessment of physiological and cygotenetical parameters in Lymnaea stagnalis populations from Perstok lake and the inlet of Pripyat river with the highest in Belarus and moderate levels of radioactive contamination have been carried out. In 2004 f γ-activity of snails from river and lake amounted to 39.2 and 567.8 Bq kg-1, respectively, and β-activity - to 123.4 and 7055 Bq kg-1 respectively. Snails from the lake were characterized by the increase of the cells with cytogenetic damages (micronuclei) and by the decrease of cells with interphase death and proportion of young cells in hemolymph. It indicates the unfavourable environmental conditions in the lake due to increased level of radioactive contamination. Nevertheless, the embryonic mortality in the progeny of the snails from lake was lower and the average population radioresistance of snails much higher than that in the river indicating intensification of the radioadaptation processes in populations from the lake.

The galvanomagnetic effects in new diluted magnetic semiconductors Pb$_{1-x}$SnxTe:Yb were studied to build the energy level diagram under variation of the alloy composition and establish the connection between the parameters of electronic structure and magnetic properties. It was found that the Hall coefficient increases almost by order of magnitude with increasing the temperature. As tin content decreases, while the ytterbium concentration grows, the hole concentration decreases by several times. The results are explained by assuming a formation of an ytterbium-induced deep defect level in the energy spectrum of the alloys, which moves up to the top of the valence band with increasing the ytterbium concentration and pins the Fermi level within the valence band at sufficiently high impurity content. The hole concentration vs. ytterbium content dependence was used to calculate the energy position of the Fermi level in the frame of two-band dispersion law and to determine the position of Yb level in the alloys. The diagram of the charge carrier energy spectrum under varying the alloy composition was built.

The experimental results of the activation spectra, dose rate measurements, and the residual nuclide production cross sections obtained after the irradiation of the NatCu and 59Co targets by 12C ion beams at ITEP and GSI are presented in this paper. These results are compared with simulations by the CASCADE and LAQGSM codes.

The hydrodynamic response of metal targets to volume heating by energy deposition of intense heavy-ion beams was investigated experimentally. Recent improvements in beam parameters led to a marked increase in specific deposition power: 2·101040Ar18+ ions of 300 MeV/u focused to a spot size of 300 μm (σ) × 540 μm (σ) yield a specific deposition energy in solid lead of approximately 1 kJ/g in the Bragg peak, delivered within 250 ns [full width at half maximum (FWHM)]. This value allowed us for the first time to observe heavy-ion-beam-induced hydrodynamic expansion of metal volume targets. Measurements comprise expansion velocities of free surfaces of up to 290 ± 20 m/s, surface temperatures of ejected target matter of 1600–1750 K, and pressure waves in solid metal bulk targets of 0.16 GPa maximum absolute value and 0.8 μs FWHM. The experimental results agree well with the results of a 2D hydrodynamic code. Inside the interaction zone, which can only be accessed by simulation, maximum temperatures are 2800 K and maximum pressures are 3.8 GPa.

It was recently proposed to use synthetic opals as a host matrix for obtaining 3D arrays of electronic nanodevices [1]. In the present work the opal matrices were infiltrated with GaN. We study electronic properties of opal-GaN, by means of transient photoconductivity (TPC) measurements using 5 ns laser pulses at wavelengths above (266 nm) and below (532 nm) the GaN bandgap (3.4 eV). A broad plateau is observed in the photocurrent decay covering several orders of magnitude. We compare the results with measurements in conventional GaN.