Test and simulation of a MICROMEGAS detector

Abstract

We report on the recent test results of a MICROMEGAS detector in terms of position resolution, time resolution and efficiency. With a Ar+CO2 (10%) gas mixture and a strip pitch of 200 µm an accuracy of 80 µm in sigma on the position has been measured. The time resolution is better than 20 ns and a cosmic ray detection efficiency of 94% was obtained. A Monte Carlo simulation indicates that transverse diffusion, gain fluctuation and electronic noise limit the position resolution.

Asymptotic solution of a weak nonlinear model for the mid-latitude stationary wind field of a two-layer barotropic ocean

“…Consider the following weakly nonlinear model in the absence of base flow, mass change between two levels, as well as Rayleigh friction induced by vertical stationary atmospheric wind stress: [10][11][12] (…”

“…Therefore, wind stress in the meridional shows nonuniform distribution. In order to overcome the limitations of a one-dimensional horizontal model, Lu et al [10] and Zhang et al [11,12] built a two-dimensional barotropic quasi-equilibrium ocean linear model under wind forcing, which involves the Rayleigh friction. The analytic solution is given under the influence of a mid-latitude large-scale wind field.…”

Prototype studies on the forward MWDC tracking array of the external target experiment at HIRFL-CSR

“…[12], heavy ion collisions in this energy regime are favored for discriminating the effect of symmetry energy because the degree of isospin fractionation is large. While many detector researches and developments are ongoing for the physics programs at CSR [13][14][15][16][17][18][19][20][21], a CSR external target experiment (CEE) has also been proposed for the experimental studies on the asymmetric nuclear equation of state [22,23].…”

A class of asymptotic solution for the time delay wind field model of an ocean

“…Considering a time delay weakly nonlinear model in the absence of a base flow and mass change between two levels, as well as Rayleigh friction induced by vertical stationary atmospheric wind stress: [6][7][8][9] (…”

“…So wind stress in the meridional zone shows no uniform distribution. In order to overcome the limit of a horizontal one-dimensional model some scholars [6][7][8][9][10][11][12][13] built a two-dimensional barotropic quasi-equilibrium ocean linear model under wind forcing, considering Rayleigh friction. Recently, many scholars [14][15][16][17] have studied nonlinear problems and built many approximate methods.…”