Search results for "gas [meson]"
showing 10 items of 409 documents
Construction of large-area micro-pattern gaseous detectors
2016
Particle physics experiments often comprise tracking detectors with areas of up to a few square meters. If a spatial resolution of the order of 100μm and high-rate capability are required, Micro Pattern Gaseous Detectors (MPGD) are a cost-effective solution. However, the construction of large-area MPGDs is challenging, since tight fabrication tolerances have to be met to guarantee a stable and homogeneous performance. A precision granite table and an automated 3-D positioning system with an attached laser sensor, both inside a laminar-flow cell, have therefore been set up in the PRISMA Detector Lab at Mainz. Currently, this infrastructure is used to produce drift panels for the upgrade of t…
Performance studies of the P¯ANDA planar GEM-tracking detector in physics simulations
2018
Abstract The P ¯ ANDA experiment will be installed at the future facility for antiproton and ion research (FAIR) in Darmstadt, Germany, to study events from the annihilation of protons and antiprotons. The P ¯ ANDA detectors can cover a wide physics program about baryon spectroscopy and nucleon structure as well as the study of hadrons and hypernuclear physics including the study of excited hyperon states. One very specific feature of most hyperon ground states is the long decay length of several centimeters in the forward direction. The central tracking detectors of the P ¯ ANDA setup are not sufficiently optimized for these long decay lengths. Therefore, using a set of the planar GEM-trac…
Aging measurements with the gas electron multiplier (GEM)
2001
Abstract Continuing previous aging measurements with detectors based on the Gas Electron Multiplier (GEM), we investigated a 31×31 cm 2 triple-GEM detector, as used in the small area tracking of the COMPASS experiment at CERN. With a detector identical to those installed in the experiment, long-term high-rate exposures to 8.9 keV X-ray radiation were performed to study its aging properties. In standard operation conditions, with Ar/CO2 (70:30) gas filling and operated at an effective gain of 8.5×103, no change in gain and energy resolution is observed after collecting a total charge of 7 mC / mm 2 , corresponding to seven years of normal operation. This observation confirms previous results…
Construction, test and commissioning of the triple-gem tracking detector for compass
2002
The Small Area Tracking system of the COMPASS experiment at CERN includes a set of 20 large area, fast position-sensitive Gas Electron Multiplier (GEM) detectors, designed to reliably operate in the harsh radiation environment of the experiment. We describe in detail the design, choice of materials, assembly procedures and quality controls used to manufacture the devices. The test procedure in the laboratory, the performance in test beams and in the initial commissioning phase in the experiment are presented and discussed.
A compact Time Projection Chamber for the Crystal Ball
2016
Abstract We report on a development of a compact Time Projection Chamber with triple Gas Electron Multiplier readout to replace the current tracking detector in the Crystal Ball/TAPS Experiment at the A2 Tagged Photon Facility at MAMI in Mainz, Germany. Challenges are the limitations in size and the absence of a longitudinal magnetic flied.
Implementation of theP¯ANDA Planar-GEM tracking detector in Monte Carlo simulations
2018
Abstract The P ¯ ANDA experiment at FAIR will be performed to investigate different aspects of hadron physics using anti-proton beams interacting with a fixed nuclear target. The experimental setup consists of a complex series of detector components covering a large solid angle. A detector with a gaseous active media equipped with gas electron multiplier (GEM) technique will be employed to measure tracks of charged particles at forward direction in order to achieve a high momentum resolution. In this work, a full setup of the GEM tracking detector has been implemented in the P ¯ ANDA Monte Carlo simulation package (PandaRoot) based on the current technical and conceptual design, and the exp…
Triple GEM tracking detectors for COMPASS
2002
The small area tracker of COMPASS, a high-luminosity fixed target experiment at CERN's SPS, includes a set of 20 large-size ($31\times 31\,\cm^2$) Gas Electron Multiplier (GEM) detectors. Based on gas amplification in three cascaded GEM foils, these devices permit to obtain high gain and good spatial resolution even at very high particle fluxes. A two-coordinate projective readout yields, for each track, highly correlated signal amplitudes on both projections, allowing to resolve multiple hits in high occupancy regions close to the central deactivated area of $5\,\cm$ diameter. At the same time the material exposed to the beam is minimized. Splitting the amplification in three cascaded stag…
Confined Pt-1(1+) Water Clusters in a MOF Catalyze the Low-Temperature Water-Gas Shift Reaction with both CO2 Oxygen Atoms Coming from Water
2018
[EN] The synthesis and reactivity of single metal atoms in a low-valence state bound to just water, rather than to organic ligands or surfaces, is a major experimental challenge. Herein, we show a gram-scale wet synthesis of Pt-1(1+) stabilized in a confined space by a crystallographically well-defined first water sphere, and with a second coordination sphere linked to a metal-organic framework (MOF) through electrostatic and H-bonding interactions. The role of the water cluster is not only isolating and stabilizing the Pt atoms, but also regulating the charge of the metal and the adsorption of reactants. This is shown for the low-temperature water-gas shift reaction (WGSR: CO + H2O CO2 + H…
Bericht über die Vorarbeiten für die systematische Entwässerung und Reinigung der Stadt Riga [...Vorarbeiten für die systematische Entwässerung und R…
1886
Inhalt: I. Rigas Witterungsverhältnisse nebst einem Anhang: Wasserstand und Eisbedeckung der Düna bei Riga ; II. Chemisch-analytische und mikroskopische Untersuchung des Bodens, des Grundwassers und einiger Brunnen und offenen Gewässer der Stadt Riga ; III. Erläuterungsbericht zu den Messungen zur Bestimmung der Terraingestaltung, der Höhenlage und der Schwankungen des Grundwasserstandes, sowie der Wasserquantitäten und Durchfussgeschwindigkeiten der offenen Gewässer der Stadt Riga ; IV. Angaben über das gegenwärtig in Riga in Gebrauch befindliche Verfahren zur Reinigung und entwässerung der Stadt, nebst einer Beschreibung der im Stadtgebiet vorhandenen Ableitungsanlagen ; V. Beschreibung d…
Beilage zum Bericht über die Vorarbeiten für die systematische Entwässerung und Reinigung der Stadt Riga
1886
Inhalt: Taf. 1. Zeichenerklärung ; Taf. 2-5. Höhenlage und Terrainschichtung der Grundwasserbohrlöcher ; Taf. 6. Curven der täglichen Grundwasserschwankungen ; Taf. 7-13. Graphische Tabellen der Wochenmittel der beobachteten Grundwasserstände vom Juli 1882 bis Juli 1883 ; Taf. 14-16. Darstellung der maximalen und mittleren Grundwasserstände im Verhältniss zur Terrainhöhe ; Taf. 17. Darstellung der Wassermengen, Durchflussprofile und mittleren Geschwindigkeiten von fünf Wasserläufen im Stadtgebiet vom 11. Februar 1884 bis zum 20. Januar 1885 ; Taf. 18-19. Dünaprofile ; Taf. 20. Niederschlags- und Temperaturlinie im Jahr 1882-83 ; Taf. 21. Monatsmittel und Temperaturen ; Taf. 22. Characterisi…