Fast microwave detection system for coherent synchrotron radiation study at KEK: Accelerator test facility

A fast room temperature microwave detection system based on the Schottky Barrier-diode detector was created at the KEK ATF (Accelerator Test Facility). It was tested using Coherent Synchrotron Radiation (CSR) generated by the 1.28 GeV electron beam in the damping ring. The speed performance of the detection system was checked by observing the CSR from a multi-bunch (2.8 ns bunch separation time) beam. The theoretical estimations of CSR power yield from an edge of bending magnet as well as new injection tuning method are presented. A very high sensitivity of CSR power yield to the longitudinal electron distribution in a bunch is discussed.     

Propagation of strain waves and compaction of a viscoelastic material by a cylinder rolling over it

This paper considers problems on the rolling of rigid driven and driving cylinders slipping on a compactible viscoelastic base. As a result of the investigation of the process of propagation of viscoelastic decaying strain waves in a deformable medium caused by a cylinder rolling over it and the action of the sliding friction forces, formulas and calculation algorithms have been obtained for determining the indices of the stressed-strained state and compactness of the base, the rolling resistance of the driven and diving cylinders, and the driving force of the driving cylinder. Calculations of these indices have been performed for the cases of cylinders rolling over a soil whose viscoelastic properties have been investigated experimentally. __________ Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 80, No. 5, pp. 122–132, September–October, 2007.     

A threshold temperature effect for a carbon particle heated in plasma

Numerical simulations of the heating of a carbon dust particle (pellet) in hydrogen plasma showed that the character of heating depends in a threshold manner on the initial temperature of the pellet. The heating proceeds at a high rate if the initial temperature is above a certain threshold (“hot” regime), and at a much lower rate for an initial temperature below this threshold (“cold” regime). An important factor in this process is thermionic emission, which leads to positive charging of a pellet in hydrogen plasma due to electron emission from the surface in the hot regime. In the cold regime, the pellet acquires a negative charge that retards the electron flux from plasma to the particle. A method for the experimental observation of this effect is proposed.     

The structure and thermo EMF of a nanotubular carbon deposit formed in electric discharge plasma

We have studied the structure and thermo emf of a nanotubular carbon deposit formed in electric arc discharge plasma. The deposit contains flocky granules with dimensions of 15–20 μm within a 20–60 μm-thick layer on the substrate surface. This deposit is characterized by a sufficiently high thermo emf (60 μV/K) and electric conductivity (600 Ω⁻¹ m⁻¹).     

The Influence of Ir and Pt Addition on the Synthesis of Fullerenes at Atmospheric Pressure

The addition of metallic Ir and Pt to a fullerene-forming, atmospheric-pressure plasma reactor was found to influence the generation of carbonaceous products. It was observed that the added metals were efficiently dispersed into the plasma and that their presence increased the yield of fullerenes. The addition of Ir led to a noticeable shift in the fullerene distribution towards C₆₀, whereas the addition of Pt increased the proportion of C₆₀ oxides and decreased the proportion of higher fullerenes. Addition of Ir also caused a reduction of the soot particle size and the formation of a considerable quantity of carbon nanotubes.     

A VLSI architecture for a half-edge-based corner detector

Corner detection is a low-level feature detection operator that is of great use in image processing applications, for example, optical flow and structure from motion by image correspondence. The detection of corners is a computationally intensive operation. Past implementations of corner detection techniques have been restricted to software. In this paper we propose an efficient very large-scale integration (VLSI) architecture for detection of corners in images. The corner detection technique is based on the half-edge concept and the first directional derivative of Gaussian. Apart from the location of the corner points, the algorithm also computes the corner orientation and the corner angle and outputs the edge map of the image. The symmetrical properties of the masks are utilized to reduce the number of convolutions effectively, from eight to two. Therefore, the number of multiplications required per pixel is reduced from 1800 to 392. Thus, the proposed architecture yields a speed-up factor of 4.6 over conventional convolution architectures. The architecture uses the principles of pipelining and parallelism and can be implemented in VLSI.     

An asymptotic extraction technique for evaluating Sommerfeld-type integrals

An asymptotic extraction process is developed which leads to an efficient method for the evaluation of the electric field from a Hertzian dipole in a layered geometry. This technique allows for a rapidly converging expression for the electric field which remains well behaved as the source and observation heightsz', zcoincide. A useful application of this method is in the calculation of mutual impedance between printed dipoles.     

Vitamin allowance of cosmonauts during preflight training and after completing short space flights

Supply of the main and doubling crews of cosmonauts with vitamins C, A, D, E, B1, B2, B6, PP, and B12, folic acid and carotinoids was studied during training and after the completion of short-term space flights (from 4 to 13 days). As the result of the investigation conducted during the intensive training, 1 month before the space flight some cases of certain vitamins deficiency were revealed. Administration of additional vitamins during 2 weeks before the flight led to a rise in the cosmonauts' supply with vitamins. The findings obtained after the short-term space flights evidence an intensive metabolization of vitamins and increased vitamin requirements during this period.