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The microstructures of a commercial aluminum foil and an aluminum foil alloyed by 0.001 wt % scandium are studied before and after electrochemical etching. The strength properties, the capacitance, and the weldability of the foils subjected to electrochemical etching are investigated. We are the first to show that the alloying of aluminum by such a low amount of scandium affects the microstructure of a foil and is sufficient for increasing the strength properties, the capacitance, and the weldability of the aluminum foil used for capacitors.

Analyzing new experiments with ultracold neutrons (UCNs) we show that physical adsorption of nanoparticles/nano-droplets, levitating in high-excited states in a deep and broad potential well formed by van der Waals/Casimir-Polder (vdW/CP) forces results in new effects on a cross-road of fundamental interactions, neutron, surface and nanoparticle physics. Accounting for the interaction of UCNs with nanoparticles explains a recently discovered intriguing small heating of UCNs in traps. It might be relevant to the striking conflict of the neutron lifetime experiments with smallest reported uncertainties by adding false effects there., 5 pages, 4 figures

In order to access feasibility of increasing albedo of very cold neutrons from powder of diamond nanoparticles, we studied hydrogen bound to surface of diamond nanoparticles, which causes unwanted losses of neutrons. We showed that one could decrease a fraction of hydrogen atoms from a ratio C7.4 ± 0.15H to a ratio C12.4 ± 0.2H by means of thermal treatment and outgasing of powder. Measurements of atomic excitation spectra of these samples, using a method of inelastic incoherent neutron scattering, indicate that residual hydrogen is chemically bound to carbon, while a removed fraction was composed of adsorbed water. The total cross section of scattering of neutrons with a wavelength of 4.4 A on residual hydrogen atoms equals 108 ± 2 b; it weakly changes with temperature. Thus preliminary cleaning of powder from hydrogen and its moderate cooling do not improve considerably neutron albedo from powder of nano-diamonds. An alternative approach is isotopic replacement of hydrogen by deuterium.

Results of the experiments on measurement of ultracold neutron (UCN) storage time in moving vessels are reported. A theory for change of the UCN spectrum in the vessel swinging on a long thread like a pendulum is presented. It is found that the average kinetic energy of the UCN increases proportionally to the first derivative of the acceleration but only during those quarters of a period in which the absolute magnitude of acceleration increases. The results of measurement and theoretical consideration of UCN storage time in a vessel struck by a hammer are also given.

The cause of the small heating of ultracold neutrons (UCNs) by ∼10−7 eV with a probability of 10−8–10−5 per collision with a surface was investigated. Neutrons heated in this way will be called vaporized UCNs (VUCNs). It was established that a preliminary heating of a sample in vacuum up to a temperature of 500–600 K can increase small-heating probability P VUCN by a factor of at least ∼100 and 10 on a stainless steel and a copper surface, respectively. For the first time, an extremely vigorous small heating of UCNs was observed on a powder of diamond nanoparticles. In this case, both the VUCN spectrum and the temperature dependence of probability P VUCN were similar to those previously obtained for stainless steel, beryllium, and copper samples. On the surface of single crystal sapphire, neither the small heating of UCNs nor nanoparticles were found. All these facts indicate that VUCNs are likely produced by inelastic scattering of UCNs on weakly bound surface nanoparticles being in permanent thermal motion.

The formation and evolution of femtosecond laser plasma produced in microvolumes of gases at different pressures upon their multiply ionization by high intensity pulses of fundamental and second harmonics of a Ti:sapphire laser is studied. The interferometric technique for precise ultrafast optical diagnostics of such plasma was applied. The numerical technique of interferogram processing and reconstruction of instant spatial distribution of refractive index and free electron density in laser-induced plasma applied for this proposes is described. The spatiotemporal distribution of the refractive index and free electron density were studied with a spatial resolution of ∼1 μ m and a temporal resolution of ∼70 fs.

The temperature dependence of the loss factor for ultracold neutrons owing to heating at thermal energies on the surface of a beryllium sample is studied. The probability of heating ultracold neutrons is anomalously high throughout the entire measured temperature interval, but especially at low temperatures.

The subbarrier passage of ultracold neutrons through beryllium foils and coatings with a probability much higher than that of tunneling is observed. This effect may be responsible for the so-called anomalous loss of ultracold neutrons.

The temperature dependence of inelastic ultracold-neutron scattering on beryllium and copper surfaces at low energy transfers (about 10−7 eV) is investigated, and the results of this investigation are presented. The recorded flux of neutrons inelastically scattered by these surfaces at liquid-nitrogen temperature is less than that at room temperature by a factor of about two.

1112 Gasificators of lowgrade energy raw materials are a separate group of technological apparatus in which the properties of supercritical water are used. Here, organic raw materials are a fuel, and water is an oxi� dizer. The traditional scheme for constructing such gasificators, which are flowreactor units, includes a heater and a highpressure pump as necessary ele� ments; they provide the required supercritical aqueous oxidation parameters. The requirement of compara� tively high temperatures and pressures in a flow reactor is a factor that decreases the economic effectiveness of