Proton-boron fusion in a compact scheme of plasma oscillatory confinement.

We present the results of experiments on the aneutronic fusion of proton-boron (pB) in a single miniature device with electrodynamic (oscillatory) plasma confinement. The device is based on a low energy (∼1-2 J) nanosecond vacuum discharge with a virtual cathode, the field of which accelerates protons and boron ions to the energies required for pB synthesis (∼100-300 keV) under oscillating ions' head-on collisions. The yields of α particles registered for different conditions of the experiment are presented and discussed in detail. The experiment was preceded by particle-in-cell modeling of main processes accompanying pB reaction within the framework of the full electromagnetic code karat. The summary yield of α particles of about 5×10^{4}/4π was obtained during the pulse-periodic operation of the generator within total 4µs of the high voltage applied, which is ∼10α particles/ns.

Generation of Rogue Waves in Gyrotrons Operating in the Regime of Developed Turbulence.

Within the framework of the average approach and direct 3D PIC (particle-in-cell) simulations, we demonstrate that the gyrotrons operating in the regime of developed turbulence can sporadically emit "giant" spikes with intensities a factor of 100-150 greater than the average radiation power and a factor of 6-9 exceeding the power of the driving electron beams. Together with the statistical features such as a long-tail probability distribution, this allows the interpretation of generated spikes as microwave rogue waves. The mechanism of spikes formation is related to the simultaneous cyclotron interaction of a gyrating electron beam with forward and backward waves near the waveguide cutoff frequency as well as with the longitudinal deceleration of electrons.

Generation of powerful subnanosecond microwave pulses by intense electron bunches moving in a periodic backward wave structure in the superradiative regime.

Experimental results of the observation of coherent stimulated radiation from subnanosecond electron bunches moving through a periodic waveguide and interacting with a backward propagating wave are presented. The subnanosecond microwave pulses in Ka and W bands were generated with repetition frequencies of up to 25 Hz. The mechanism of microwave pulse generation was associated with self-bunching, and the mutual influence of different parts of the electron pulse due to slippage of the wave with respect to the electrons; this can be interpreted as superradiance. The illumination of a panel of neon bulbs resulted in a finely structured pattern corresponding to the excitation of the TM01 mode. Observation of rf breakdown of ambient air, as well as direct measurements by hot-carrier germanium detectors, leads to an estimate of the absolute peak power as high as 60 MW for the 300-ps pulses at 38 GHz. These results are compared with numerical simulations. The initial observation of 75-GHz, 10-15-MW radiation pulses with a duration of less than 150 ps is also reported.

[Treatment of urethral strictures in children]. / Lechenie striktur uretry u detei.

The article is concerned with difficulties of the treatment of urethra strictures, complicated in particular, and analyzes results of the surgical treatment resulting from localization of the stricture, its extension and the treatment method. The best results were obtained following resection of the urethra by Rusakov's method. From 65 operated children 59 patients showed complete recovery. The results were less consolatory when scrotum skin was used for the reconstruction of posterior urethra strictures of great extent.