Submitted by albert.lehmann@... on Fri, 14/09/2018 - 11:41.
The charged particle identification at the PANDA experiment will be mainly performed with DIRC detectors. Because of their advantageous properties the preferred photon sensors are MCP-PMTs. However, until recently these devices showed serious aging problems which resulted in a diminishing quantum efficiency (QE) of the photo cathode. By applying innovative countermeasures against the aging causes, the manufacturers recently succeeded in drastically improving the lifetime of MCP-PMTs. Especially the application of an ALD coating technique to seal the material of the micro-channels proves very powerful and results in a lifetime of ~6 C/cm2 integrated anode charge without a substantial QE degradation for the latest PHOTONIS XP85112. This paper will present a comparative measurement of the lifetime of several older and recent MCP-PMTs demonstrating this progress.
Submitted by albert.lehmann@... on Thu, 13/09/2018 - 15:54.
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
Submitted by albert.lehmann@... on Thu, 13/09/2018 - 11:41.
DIRC Cherenkov detectors will be the main devices for pi/K separation at the PANDA experiment at
FAIR. Due to their advantageous properties in terms of time resolution and especially inside magnetic
fields micro-channel plate photo multipliers (MCP-PMTs) are very attractive sensor candidates. In this
paper we present the investigation of several types of multi-anode MCP-PMTs. The darkcount rate, the
behavior inside a magnetic field of up to 2 T, the time resolution, the gain homogeneity and crosstalk of
multi-pixel MCP-PMTs were found to be well suitable for the PANDA requirements. Even the rate
capability of the latest models from Burle-Photonis and Hamamatsu is satisfactory. Although a big step
forward was accomplished with these recently available MCP-PMTs, the lifetime is still not sufficient for
the photon densities expected for the PANDA DIRCs.
Submitted by m.fritsch on Thu, 13/09/2018 - 03:35.
Proceedings of CHEP2013 - In 2018 data taking for hadronphysics facility PANDA is planned to commence. It will be build at the antiproton accelerator HESR, which itself is a part of the FAIR complex (GSI, Darmstadt, Germany). The luminosity at PANDA will be measured by a dedicated subdetector, which will register scattered antiproton tracks from ̄pp elastic scattering. From a software point of view, the Luminosity Detector is a tracking system. Therefore the most of its offline software parts are typical for a track reconstruction. The basic concept and Monte Carlo based performance studies of each reconstruction step is presented in this paper.
Submitted by j.schwiening on Wed, 12/09/2018 - 13:18.
The PANDA experiment at the new Facility for Antiproton and Ion Research in Europe (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.
Efficient Particle Identification (PID) for a wide momentum range and the full solid angle
is required for reconstructing the various physics channels of the PANDA program.
Hadronic PID in the barrel region of the detector will be provided by a DIRC (Detection of
Internally Reflected Cherenkov light) counter.
The design is based on the successful BABAR DIRC with important improvements, such as
focusing optics and fast photon timing.
Several of these improvements, including different radiator geometries and optics, were tested
in particle beams at GSI and at CERN.
We will discuss the design and performance of the prototypes in the 2011 and 2012 test beam