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A Aharony

Publications and source records attributed to A Aharony.

At least 19 recordsLinked to original sources

Diffusion-limited aggregation as a markovian process: bond-sticking conditions

Cylindrical lattice diffusion limited aggregation (DLA), with a narrow width N, is solved using a Markovian matrix method. This matrix contains the probabilities that the front moves from one configuration to another at each growth step, calculated exactly by solving the Laplace equation and using the proper normalization. The method is applied for a series of approximations, which include only a finite number of rows near the front. The matrix is then used to find the weights of the steady-state growing configurations and the rate of approaching this steady-state stage. The former are then used to find the average upward growth probability, the average steady-state density and the fractal dimensionality of the aggregate, which is extrapolated to a value near 1.64.

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Cyclotron resonance maser experiments in a bifilar helical waveguide

Oscillator and amplifier cyclotron-resonance-maser (CRM) experiments in a spiral bifilar waveguide are presented in this paper. The slow-wave CRM device employs a low-energy low-current electron beam (2-12 keV, approximately 0.5 A). The pitch angle of the helical waveguide is relatively small; hence, the phase velocity in this waveguide, V(ph) congruent with0.8c (where c is the speed of light), is much faster than the axial velocity of the electrons, V(ez)</=0. 2c. Thus traveling-wave-tube-type interactions are eliminated in this device. According to the CRM theory, the dominant effect in this operating regime, V(ez) 2%). The wide tunable range of this CRM device due to the nondispersive bifilar helix is discussed.

Journal Article↗