Wire GEM detector

A wire GEM (WGEM) detector with a gas gap between meshes was constructed. The detector provides the amplification 5x10E5 for the gas mixture of Ar +20% CO2 at atmospheric pressure. As compared with well-known GEM detectors produced by perforation the plastic plate metalized on both sides the WGEM does not suffer from breakdowns between its electrodes and the effect of accumulation of charges on holes walls is absent. As a result the WGEM has high reliability and stability.Comment: Presented at the RD51 Collaboration Meeting, CERN, November 2009, submitted to the Prib. Tech. Expe

RETGEM with polyvinylchloride (PVC) electrodes

This paper presents a new design of the RETGEM (Resistive Electrode Thick GEM) based on electrodes made of a polyvinylchloride material (PVC). Our device can operate with gains of 10E5 as a conventional TGEM at low counting rates and as RPC in the case of high counting rates without of the transit to the violent sparks. The distinct feature of present RETGEM is the absent of the metal coating and lithographic technology for manufacturing of the protective dielectric rms. The electrodes from PVC permit to do the holes by a simple drilling machine. Detectors on a RETGEM basis could be useful in many fields of an application requiring a more cheap manufacturing and safe operation, for example, in a large neutrino experiments, in TPC, RICH systems.Comment: Presented at the RD51 Collaboration Meeting, CERN, November 200

Probability representation and quantumness tests for qudits and two-mode light states

Using tomographic-probability representation of spin states, quantum behavior of qudits is examined. For a general j-qudit state we propose an explicit formula of quantumness witnetness whose negative average value is incompatible with classical statistical model. Probability representations of quantum and classical (2j+1)-level systems are compared within the framework of quantumness tests. Trough employing Jordan-Schwinger map the method is extended to check quantumness of two-mode light states.Comment: 5 pages, 2 figures, PDFLaTeX, Contribution to the 11th International Conference on Squeezed States and Uncertainty Relations (ICSSUR'09), June 22-26, 2009, Olomouc, Czech Republi