581 research outputs found
The CLAS12 large area RICH detector
Abstract A large area RICH detector is being designed for the CLAS12 spectrometer as part of the 12 GeV upgrade program of the Jefferson Lab Experimental Hall-B. This detector is intended to provide excellent hadron identification from 3 GeV/ c up to momenta exceeding 8 GeV/ c and to be able to work at the very high design luminosity-up to 10 35 cm 2 s −1 . Detailed feasibility studies are presented for two types of radiators, aerogel and liquid C 6 F 14 freon, in conjunction with a highly segmented light detector in the visible wavelength range. The basic parameters of the RICH are outlined and the resulting performances, as defined by preliminary simulation studies, are reported
The CLAS12 Software Framework and Event Reconstruction
We describe offline event reconstruction for the CEBAF Large Acceptance Spectrometer at 12 GeV (CLAS12), including an overview of the offline reconstruction framework and software tools, a description of the algorithms developed for the individual detector subsystems, and the overall approach for charged and neutral particle identification. We also present the scheme for data processing and the code management procedures
A Method to Polarize Stored Antiprotons to a High Degree
Polarized antiprotons can be produced in a storage ring by spin--dependent
interaction in a purely electron--polarized hydrogen gas target. The polarizing
process is based on spin transfer from the polarized electrons of the target
atoms to the orbiting antiprotons. After spin filtering for about two beam
lifetimes at energies MeV using a dedicated large acceptance
ring, the antiproton beam polarization would reach . Polarized
antiprotons would open new and unique research opportunities for spin--physics
experiments in interactions
A bulk superconducting MgB2 cylinder for holding transversely polarized targets
An innovative solution is being pursued for the challenging magnetic problem of producing an internal transverse field around a polarized target, while shielding out an external longitudinal field from a detector. A hollow bulk superconductor can trap a transverse field that is present when cooled through its transition temperature, and also shield its interior from any subsequent field changes. A feasibility study with a prototype bulk MgB2 superconducting cylinder is described. Promising measurements taken of the interior field retention and exterior field exclusion, together with the corresponding long-term stability performance, are reported. In the context of an electron scattering experiment, such a solution minimizes beam deflection and the energy loss of reaction products, while also eliminating the heat load to the target cryostat from current leads that would be used with conventional electromagnets
Test of the CLAS12 RICH large scale prototype in the direct proximity focusing configuration
A large area ring-imaging Cherenkov detector has been designed to provide
clean hadron identification capability in the momentum range from 3 GeV/c up to
8 GeV/c for the CLAS12 experiments at the upgraded 12 GeV continuous electron
beam accelerator facility of Jefferson Laboratory. The adopted solution
foresees a novel hybrid optics design based on aerogel radiator, composite
mirrors and high-packed and high-segmented photon detectors. Cherenkov light
will either be imaged directly (forward tracks) or after two mirror reflections
(large angle tracks). We report here the results of the tests of a large scale
prototype of the RICH detector performed with the hadron beam of the CERN T9
experimental hall for the direct detection configuration. The tests
demonstrated that the proposed design provides the required pion-to-kaon
rejection factor of 1:500 in the whole momentum range.Comment: 15 pages, 23 figures, to appear on EPJ
Toward polarized antiprotons: Machine development for spin-filtering experiments
The paper describes the commissioning of the experimental equipment and the
machine studies required for the first spin-filtering experiment with protons
at a beam kinetic energy of MeV in COSY. The implementation of a
low- insertion made it possible to achieve beam lifetimes of
s in the presence of a dense polarized hydrogen
storage-cell target of areal density . The developed techniques can be directly
applied to antiproton machines and allow for the determination of the
spin-dependent cross sections via spin filtering
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