8 research outputs found
Results and Consequences of Magnet Test and Cosmic Challenge of the CMS Barrel Muon Alignment System
In the last year - as part of the first test of the CMS experiment at CERN [1] called Magnet Test and Cosmic Challenge (MTCC) - about 25% of the barrel muon position monitoring system was built and operated. The configuration enabled us to test all the elements of the system and its function in real conditions. The correct operation of the system has been demonstrated. About 500 full measurement cycles have been recorded. In the paper the setup –including the read-out and control - is described and the first preliminary results are presented
Theory of traveling filaments in bistable semiconductor structures
We present a generic nonlinear model for current filamentation in
semiconductor structures with S-shaped current-voltage characteristics. The
model accounts for Joule self-heating of a current density filament. It is
shown that the self-heating leads to a bifurcation from static to traveling
filament. Filaments start to travel when increase of the lattice temperature
has negative impact on the cathode-anode transport. Since the impact ionization
rate decreases with temperature, this occurs for a wide class of semiconductor
systems whose bistability is due to the avalanche impact ionization. We develop
an analytical theory of traveling filaments which reveals the mechanism of
filament motion, find the condition for bifurcation to traveling filament, and
determine the filament velocity.Comment: 13 pages, 5 figure