75 research outputs found
Analysis of possibilities to utilize excess heat of supermarkets as heat source for district heating
Status of the PANDA barrel DIRC
The PANDA experiment at the future Facility for Antiproton and Ion Research in Europe GmbH (FAIR) at GSI, Darmstadt will study fundamental questions of hadron physics and QCD using high-intensity cooled antiproton beams with momenta between 1.5 and 15 GeV/c. Hadronic PID in the barrel region of the PANDA detector will be provided by a DIRC (Detection of Internally Reflected Cherenkov light) counter. The design is based on the successful BABAR DIRC with several key improvements, such as fast photon timing and a compact imaging region. Detailed Monte Carlo simulation studies were performed for DIRC designs based on narrow bars or wide plates with a variety of focusing solutions. The performance of each design was characterized in terms of photon yield and single photon Cherenkov angle resolution and a maximum likelihood approach was used to determine the π/K separation. Selected design options were implemented in prototypes and tested with hadronic particle beams at GSI and CERN. This article describes the status of the design and R&D for the PANDA Barrel DIRC detector, with a focus on the performance of different DIRC designs in simulation and particle beams
Feasibility studies of time-like proton electromagnetic form factors at PANDA at FAIR
Simulation results for future measurements of electromagnetic proton form
factors at \PANDA (FAIR) within the PandaRoot software framework are reported.
The statistical precision with which the proton form factors can be determined
is estimated. The signal channel is studied on the basis
of two different but consistent procedures. The suppression of the main
background channel, , is studied.
Furthermore, the background versus signal efficiency, statistical and
systematical uncertainties on the extracted proton form factors are evaluated
using two different procedures. The results are consistent with those of a
previous simulation study using an older, simplified framework. However, a
slightly better precision is achieved in the PandaRoot study in a large range
of momentum transfer, assuming the nominal beam conditions and detector
performance
Heat Resistance Mediated by a New Plasmid Encoded Clp ATPase, ClpK, as a Possible Novel Mechanism for Nosocomial Persistence of Klebsiella pneumoniae
Klebsiella pneumoniae is an important opportunistic pathogen and a frequent cause of nosocomial infections. We have characterized a K. pneumoniae strain responsible for a series of critical infections in an intensive care unit over a two-year period. The strain was found to be remarkably thermotolerant providing a conceivable explanation of its persistence in the hospital environment. This marked phenotype is mediated by a novel type of Clp ATPase, designated ClpK. The clpK gene is encoded by a conjugative plasmid and we find that the clpK gene alone renders an otherwise sensitive E. coli strain resistant to lethal heat shock. Furthermore, one third of a collection of nosocomial K. pneumoniae isolates carry clpK and exhibit a heat resistant phenotype. The discovery of ClpK as a plasmid encoded factor and its profound impact on thermal stress survival sheds new light on the biological relevance of Clp ATPases in acquired environmental fitness and highlights the challenges of mobile genetic elements in fighting nosocomial infections
Study of doubly strange systems using stored antiprotons
Bound nuclear systems with two units of strangeness are still poorly known despite their importance for many strong interaction phenomena. Stored antiprotons beams in the GeV range represent an unparalleled factory for various hyperon-antihyperon pairs. Their outstanding large production probability in antiproton collisions will open the floodgates for a series of new studies of systems which contain two or even more units of strangeness at the P‾ANDA experiment at FAIR. For the first time, high resolution γ-spectroscopy of doubly strange ΛΛ-hypernuclei will be performed, thus complementing measurements of ground state decays of ΛΛ-hypernuclei at J-PARC or possible decays of particle unstable hypernuclei in heavy ion reactions. High resolution spectroscopy of multistrange Ξ−-atoms will be feasible and even the production of Ω−-atoms will be within reach. The latter might open the door to the |S|=3 world in strangeness nuclear physics, by the study of the hadronic Ω−-nucleus interaction. For the first time it will be possible to study the behavior of Ξ‾+ in nuclear systems under well controlled conditions
New developments of the PANDA Disc DIRC detector
The DIRC principle (Detection of Internally Reflected Cherenkov light) allows a very compact
approach for particle identification detectors. The PANDA detector at the future FAIR facility at
GSI will use a Barrel-DIRC for the central region and a Disc DIRC for the forward angular region
between 5◦
and 22◦
. It will be the first time that a Disc DIRC is used in a high performance 4π
detector. To achieve this aim, different designs and technologies have been evaluated and tested.
This article will focus on the mechanical design and integration of the Disc DIRC with respect to
the PANDA environment
The DIRC detectors at the PANDA experiment
PANDA is an experiment at the new FAIR facility at GSI and will, among other physics goals,
perform charmonium spectroscopy and search for gluonic excitations using high luminosity antiproton beams up to 15 GeV/c. A high performance particle identification system applying DIRC
detectors will allow pion/kaon separation up to 4 GeV/c. A Barrel DIRC with fused silica radiator bars or plates will surround the target at a radial distance of 48 cm and will cover a polar
angle range of 22 to 140 degrees; a novel Endcap Disk DIRC built of a segmented fused silica
disk of 210 cm diameter will be installed in the forward region to cover the polar angles from
5 to 22 degrees. The design of the optics and the readout of both DIRCs will be presented in
this paper. Different prototypes were tested in particle beams. The performance of the latest prototypes, which are close to the final DIRC design, are discussed and compared to the PANDA
requirements
Frontend electronics for high-precision single photo-electron timing
The next generation of high-luminosity experiments requires excellent particle identification detectors, which calls for imaging Cherenkov counters with fast electronics to cope with the expected hit rates. A Barrel DIRC will be used in the central region of the Target Spectrometer
of the planned PANDA experiment at FAIR. A single photo-electron timing resolution of better
than 100 ps RMS is required for the Barrel DIRC to disentangle the complicated patterns created
on the image plane. R&D studies have been performed to provide a design based on the TRB3
readout using FPGA-TDCs with a typical precision of 10 ps RMS and custom frontend electronics with high-bandwidth pre-amplifiers and fast discriminators. The discriminators also provide
time-over-threshold information, thus enabling walk corrections to improve the timing resolution.
Two types of frontend electronics cards optimised for reading out 64-channel PHOTONIS Planacon MCP-PMTs were tested: one based on the NINO ASIC and the other, called PADIWA, based
on FPGA discriminators. Promising results were obtained in a full characterisation using a fast
laser setup and in a test experiment at MAMI, Mainz, with a small scale DIRC prototype
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