Pulse surface wave generator of millimeter band wavelength

Theoretical and experimental studies of high-power, relativistic surface-wave microwave Cherenkov generators are briefly considered. Some simulation and experiment results included, the experimentation being made in mm-wave region.     

Al-Cu-Fe QUASICRYSTALLINE PHASE FORMATION BY MECHANICAL ALLOYING

Al-Cu-Fe alloys were prepared from elemental powders in a high-energy planetary ball mill. A sequence of solid state reactions resulting in quasicrystal (QC) phase formation takes place during heating of the as-milled powder. These reactions were studied by both differential scanning calorimetry and x-ray diffraction methods. Mechanically alloyed powders were consolidated by cold and hot pressing, as well as by explosive compaction. After annealing at sufficiently high temperatures, the consolidated samples are single-phase QC, except the ones consolidated by explosion. The high reactivity of the as-milled alloys causes the appearance of high porosity of the consolidated samples after the annealing.     

Surface acoustic wave gas sensor of the sorption type sensitive to the thermal properties of gases

The basic principles of a new surface acoustic wave (SAW) gas sensor are described. Being essentially a sensor of the sorption type, the proposed device possesses certain features of the thermometric SAW sensors and is not only sensitive to the vapors of volatile substances, but capable of detecting gases by their thermal properties as well. In contrast to the known thermometric SAW sensors, the proposed sensor is characterized by high temperature stability and fast response. A variant of the sensor based on a LiNbO₃ SAW delay line is described and some results of the test for detecting propane-butane mixtures are presented.     

Dependence of the Parameters of an Electronuclear System on the Composition of Mixed Uranium–Plutonium Fuel

Mathematical simulation is used to study the dependence of the parameters of an electronuclear system with uranium–plutonium mixed fuel on the amount of plutonium and ²⁴⁰Pu admixture in the fuel. As an example, a 10–20 kW(t) experimental system built at Dubna on the basis of a synchrocyclotron with 660 MeV protons is examined. A 2% admixture of ²⁴⁰Pu decreases the neutron multiplication factor from 0.95 to 0.9 and decreases the neutron yield and heat released by almost a factor of 2. This decrease can be compensated by increasing the plutonium content in the mixed fuel from 25 to 27%.     

The Scientific Research Seminar on Computer Algebra in 2000–2001

An annual report on meetings of the scientific research seminar on computer algebra is presented.     

New phenomena in barbotage and sedimentation in magnetic fluids

New multivelocity model was deduced for a dispersive magnetizable medium: magnetic fluid - gas bubbles or solid particles. Resulting equations may be used for discribing the processes of concentration, separation and barbotage. The characteristics of deduced set were examined. The problem was solved concerning floatation and sedimentation of particles or babbles in a magnetic fluid in a solenoidal magnetic field.