Search results for "CHS"
showing 10 items of 313 documents
A Tracking and Timing (t-and-t) Front-end Electronics For Rpc Detectors
1992
Abstract The availability of a detector such as an RPC (resistive plate counter) opens new possibility on the future experiments for accelerator and non-accelerator physics. The main advantage consists on the possibility to obtain accurate tracking and timing with a low-cost detector and electronics. We report results on time resolution, signal transmission on long strips, efficiency and maintenance. A possible front-end electronics able to give tracking and timing information on each input channel operating in free-running mode will be illustrated toghether to the preliminary tests performed.
Dynamics of Non Classically Reproducible Entanglement
2008
We investigate when the quantum correlations of a bipartite system, under the influence of environments with memory, are not reproducible with certainty by a classical local hidden variable model. To this purpose, we compare the dynamics of a Bell inequality with that of entanglement, as measured by concurrence. We find time regions when Bell inequality is not violated even in correspondence to high values of concurrence (up to $\approx 0.8$). We also suggest that these results may be observed by adopting a modification of a recent experimental optical setup. These findings indicate that even highly entangled systems cannot be exploited with certainty in contexts where the non classical rep…
CP symmetry and thermal effects on Dirac bi-spinor spin–parity local correlations
2018
Intrinsic quantum correlations supported by the $SU(2)\otimes SU(2)$ structure of the Dirac equation used to describe particle/antiparticle states, optical ion traps and bilayer graphene are investigated and connected to the description of local properties of Dirac bi-spinors. For quantum states driven by Dirac-like Hamiltonians, quantum entanglement and geometric discord between spin and parity degrees of freedom - sometimes mapped into equivalent low energy internal degrees of freedom - are obtained. Such \textit{spin-parity} quantum correlations and the corresponding nonlocal intrinsic structures of bi-spinor fermionic states can be classified in order to relate quantum observables to th…
Characteristic structure of the resistive relativistic magnetohydrodynamic equations
2012
We present the analysis of the characteristic structure of the resistive (non-ideal) relativistic magnetohydrodynamics system of equations. This is a necessary step to develop high-resolution shock-capturing schemes that use the full characteristic information (Godunov-type methods), and it is convenient to establish proper boundary conditions.
Experiments on tunnelling in small normal-metal junctions influenced by dissipative environment: Critical comparison to the theories of quantum fluct…
1998
We report on experiments of charging in small normal metal tunnel junctions attached to well-defined resistive impedances. Our experiments are in very good agreement with the phase-correlation (PC) theory but not with the simplified voltage fluctuation (VF) model. The strong tunnelling corrections to the PC theory make the agreement with our results even better in the case of junctions with low resistance.
Semi-global simulations of the magneto-rotational instability in core collapse supernovae
2009
Possible effects of magnetic fields in core collapse supernovae rely on an efficient amplification of the weak pre-collapse fields. It has been suggested that the magneto-rotational instability (MRI) leads to rapid field growth. Although MRI studies exist for accretion discs, the application of their results to core collapse supernovae is inhibited as the physics of supernova cores is substantially different from that of accretion discs. We address the problem of growth and saturation of the MRI by means of semi-global simulations, which combine elements of global and local simulations by taking the presence of global background gradients into account and using a local computational grid. W…
Background radioactivity in the scaler mode technique of the Argo-YBJ detector
2011
""ARGO-YBJ is an extensive air shower detector located at the Yangbajing Cosmic Ray Laboratory (4300 ma.s.l., 606 g cm^−2 atmospheric depth, Tibet, China).. It is made by a single layer of Resistive Plate Chambers. (RPCs, total surface ~ 6700 m^2) grouped into 153 units. called “clusters”. The low energy threshold of the experiment is obtained using the ”scaler operation mode”, counting all the particles hitting the detector without reconstruction of the shower size and arrival direction. For each cluster the signals generated by these particles are put in coincidence in a narrow time window (150 ns) and read by four independent. scaler channels, giving the counting rates of channel. >= 1, …
Negative magnetoresistance of ultra-narrow superconducting nanowires in the resistive state
2008
We present a phenomenological model qualitatively explaining negative magnetoresistance in quasi-one-dimensional superconducting channels in the resistive state. The model is based on the assumption that fluctuations of the order parameter (phase slips) are responsible for the finite effective resistance of a narrow superconducting wire sufficiently close to the critical temperature. Each fluctuation is accompanied by an instant formation of a quasi-normal region of the order of the non-equilibrium quasiparticle relaxation length 'pinned' to the core of the phase slip. The effective time-averaged voltage measured in experiment is a sum of two terms. First one is the conventional contributio…