As gaseous detectors are operated at high rates of primary ionisation, ions created in the detector have a considerable impact on the performance of the detector. The upgraded ALICE Time Projection ...Chamber (TPC) will operate during LHC Run\(\,3\) with a substantial space charge density of positive ions in the drift volume. In order to properly simulate such space charges, knowledge of the ion mobility \(K\) is necessary. To this end, a small gaseous detector was constructed and the ion mobility of various gas mixtures was measured. To validate the corresponding signal analysis, simulations were performed. Results are shown for several argon and neon based mixtures with different \(\textrm{CO}_2\) fractions. A decrease of \(K\) was measured for increasing water content.
A detector has been constructed for measuring ion mobilities of gas mixtures at atmospheric pressure and room temperature. The detector consists of a standard triple GEM amplification region and a ...drift region where ions drift. A method has been developed to measure the ions' arrival time at a cathode wire-grid by differentiating the recorded signals on this electrode. Simulations prove that this method is accurate and robust. The ion mobility in different gas mixtures is measured while applying different drift field values ranging from 200 V cm\(^{-1}\) to 1100 V cm\(^{-1}\). From an extrapolation of a Blanc's law fit to measurements in Ar-CO\(_2\) mixtures we find the reduced mobility of the drifting (cluster) ion species in pure argon to be \(1.94\pm0.01\) cm\(^{2}\) V\(^{-1}\) s\(^{-1}\) and in pure carbon-dioxide to be \(1.10\pm0.01\) cm\(^{2}\) V\(^{-1}\) s\(^{-1}\). Applying the same procedure to our measurements in Ne-CO\(_2\) yields \(4.06\pm0.07\) cm\(^{2}\) V\(^{-1}\) s\(^{-1}\) and \(1.09\pm0.01\) cm\(^{2}\) V\(^{- 1}\) s\(^{-1}\) for the reduced mobilities in pure neon and carbon-dioxide, respectively. Admixtures of N\(_2\) to Ne-CO\(_2\) reduce somewhat the mobility. For the baseline gas mixture of the future ALICE Time Projection Chamber, Ne- CO\(_2\)-N\(_{2}\) (90-10-5), the measured reduced mobility of the drifting ions is \(2.92\pm0.04\) cm\(^{2}\) V\(^{-1}\) s\(^{-1}\). Ion mobilities are examined for different water content ranging from 70 ppm to about 2000 ppm in the gas using Ar-CO\(_2\) (90-10) and Ne-CO\(_2\) (90-10). A slight decrease of ion mobility is observed for the addition of several hundred ppm of water.
In this paper, we examine the dynamic nature of equity market integration for the South Asian countries. The daily data for local equity indices is used from 6 January 2004 to 31st March 2015. Copula ...GARCH models have been employed to study the inter-temporal process of equity market integration. Empirical results show that the sample countries of the region exhibit very little or no levels of integration between them. Equity portfolio flows within the South Asian region reconfirm the findings based on price data that regional integration is strengthening over time. Further, trend analysis of the fundamental determinants of financial integration for the SAARC member states indicated that these countries have to work on their governance parameters, improve on their trade linkages and trade tariffs and develop their equity market infrastructure to achieve higher levels of financial integration as is observed by its neighbouring ASEAN+6 group members. The paper contributes to the International Finance literature, especially dealing with regional economic blocs by suggesting that South Asian member countries require collaboration in efforts of policy realignment and above all political commitment to make their alliance viable enough to enhance equity market integration
Dans ce papier, nous analysons la relation empirique entre le developpement financier mesure par les credits et la croissance economique au Maroc, ainsi que les canaux de transmission entre les deux ...variables. En utilisant un modele VAR pour des donnees annuelles (1975-2010,) nous avons trouve qu'un choc positif du developpement financier favorise la croissance economique. Cet effet passe plutot par les transferts de fonds des migrants et les echanges commerciaux. This paper attempts to explore the empirical relationship between credit as proxy to financial development and economic growth in Morocco, and transmission channel between these two variables. We used annually data from 1975 to 2010 and VAR model to examine the impact of financial development on economic growth. We found that financial development induce economic growth via remittance and trade.
Cet article analyse la relation empirique entre les transferts de fonds et la croissance economique dans les pays en transition se situant au sein de l'ancien bloc sovietique. Il cherche egalement a ...mesurer si l'effet des transferts de fonds est plus efficace dans les pays ou la stabilite politique est plus presente, en utilisant la methode des moindres carres generalises pour des donnees de panel, afin de controler l'heteroscedasticite et la correlation serielle. Les resultats montrent principalement que les transferts de fonds ont un impact negatif sur la croissance et que ce dernier depend de la stabilite politique des pays concernes. This paper examines the empirical relationship between remittances and economic growth in post-Soviet states, and the role that political stability plays in this context. Using Feasible Generalized Least Squares to tackle group heteroskedasticity and serial correlation in panels, we find that remittances have a significant negative correlation with the receiving countries' economic progress. Besides, this relationship is contingent upon the political stability the country enjoys.
Measurements of proton-nucleus scattering and high resolution neutrino-nucleus interaction imaging are key to reduce neutrino oscillation systematic uncertainties in future experiments. A High ...Pressure Time Projection Chamber (HPTPC) prototype has been constructed and operated at Royal Holloway University of London and CERN as a first step in the development of a HPTPC capable of performing these measurements as part of a future long-baseline neutrino oscillation experiment such as the Deep Underground Neutrino Experiment. In this paper we describe the design and operation of the prototype HPTPC with an argon based gas mixture. We report on the successful hybrid charge and optical readout, using four CCD cameras, of signals from Am-241 sources.
