Difference: PublicMuon (r9 vs. r8)

CBM Muon Detector (MUCH)

Mini-MuCh

Mini-much is a sub system of the mini-cbm set up. The sectors of the CBM MUon CHamber system (MUCH) are made of trapezoidal shaped GEM modules. Three of those trapezoidal shaped GEM modules with a spacing of 10 - 20 cm will form the mMUCH subsystem providing additional tracking points for track reconstruction. While the actual CBM MUCH design comprises a spacing of any two consecutive layers of about 10 cm a larger distance between the GEM modules for the mCBM test-setup seems to be reasonable to improve the track reconstruction. A detailed simulation in this regard may guide us towards optimum choice of these gaps. Each GEM module will be mounted on a 10 mm Aluminum plate as depicted in the following figure. A photograph of a real-size M1-type module used during the CERN SPS beam test in 2016 is also shown. The updated version M2 which is marginally larger in size will be used for mCBM. The detector will be positioned on one side of the Al-plate while the readout FEBs will be fixed on the other side providing a proper thermal contact to the Al-plate. A controlled water-flow either through grooved channels or through 6 mm Al-pipes winding inside the Al-plates will provide the cooling for the FEBs. Each module will be read-out by 18 FEBs, i.e. about 2200 channels. For the GEM modules single-mask triple GEM foils will be used having 24 segments each. Each of these segments will be powered by a resistive chain via an opto-coupler interface. Modules based on this approach are currently under fabrication for lab tests. These will also be used in the forthcoming beam test at CERN-SPS in November 2017.

Welcome to Figure 7: Left side - the Muon present System web used by CbmMuonGroup CbmRoot : To connect to geometry of three GEM modules forming the CBM Muon Group send an email to mMUCH subsystem. Right side - photograph of a trapezoidal module mounted on a Aluminum plate used during the CERN-SPS test in 2016. cbm-much@gsi.de

List of MUCH working group members:

IAttachmentActionSizeDateWhoComment
CBM_MuonW.jpgjpgCBM_MuonW.jpgmanage 47.0 K 29 Nov 2006 - 15:55IouriVassiliev CBM Much detector

Need to be added the full list along with institutes.

Physics

Di-muon measurements constitute a central part of the CBM research program, as they are very sensitive diagnostic probes of the conditions inside the fireball. At low invariant masses, dileptons provide information on the in-medium modification of vector mesons, which can be connected to the chiral phase transition. At intermediate invariant masses, the dilepton spectrum is dominated by thermal radiation from the fireball reflecting its temperature. At invariant masses around 3 GeV /c2, dileptons are the appropriate tool to study the anomalous charmonium suppression in the de-confined phase. The Muon Chamber (MuCh) detector system is designed to identify muon pairs which are produced in high-energy heavy-ion collisions in the beam energy range from 4 to 40 A GeV. These di-muons are expected to provide useful information about the in-medium modification of hadrons, chiral symmetry restoration and de-confinement phase transition inside a dense baryonic medium.

MUCH detector layout

The di-muon measurements would require a sophisticated muon detector system located down stream the dipole magnet housing Silicon Tracking System (STS), required determination of particle momentum. The experimental challenge for muon measurements in heavy-ion collisions at FAIR energies is to identify low-momentum muons in an environment of high particle densities. The CBM strategy is to track the particles through a hadron absorber system, and to perform a momentum-dependent muon identification. This concept is realized by an instrumented hadron absorber, consisting of staggered absorber plates and tracking stations. The hadron absorbers vary in material and thickness, and the tracking stations consist of detector triplets based on different technologies.