GIF++ cosmic and beam trigger systemand Geant4 flux simulations
Dorothea PfeifferGIF++ SBA Presentation14.03.2013
Flux simulations
• Detailed study with FLUKA dose and flux simulations by Bart Biskup
(B. Biskup, "Studies for GIF++," CERN, 30 11 2011. [Online]. Available: http://indico.cern.ch/getFile.py/access?resId=1&materialId=1&confId=115583.)
• Opening of angles upstream and downstream to +/- 37 degrees vertically and horizontally made recalculation necessary, since a lot more scattering occurs
• Further the shielding request of the cosmic trigger and the beam trigger groups necessitated new simulations
• After several iterations the flux for all chambers is at or under the requested maximum values
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GIF++ Geometry
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roof chamberIrradiator with filter frame
floor chamber
Steel floor (2 cm)
Finetracking chamber
• Irradiator with lead filters• RPC chambers surrounded by 4 cm of steel• Floor chamber also covered by 17 cm of steel• Beam trigger shielded by 5mm Tungsten rubber• Roof chamber shielded by 2 cm lead plate in air
Lead shield for roof chamber
Beam trigger
Beam trigger
GIF++ projection yz
roof chamber
Lead shield
steel platefine tracker
floor chamber
Average flux above source 4.7e5 s^-1 cm^ -2
GIF++ projection xz
roof chamber
Average flux 1.0 e5 s^-1 cm^ -2
floor chamber
Average flux 1.2 e3 s^-1 cm^ -2
Downstream beam trigger:average flux 1.8 e4 s^-1 cm^ -2
Upstream beam trigger:average flux 5.9 e4 s^-1 cm^ -2
fine tracker
Average flux 5.1 e5 s^-1 cm^ -2
Cosmic and beam trigger
• Beam trigger uses 40 cm x 60 cm TGC quadruplets and will be used during muon beam time and when muon halo is available
• Beam trigger uses 5 L of mixture of CO2 and flammable n-Pentane (heated stainless steel pipes needed -> n-Pentane liquid at room temperature)
• Upgrade with larger chambers is foreseen to improve halo triggering and enable triggering of horizontal cosmics
• Cosmic trigger uses RPCs and will be used for vertical to ~ 45 degree cosmics when beam or halo are not available
• Gas mixture 95% C2H2F4. (tetrafluoroethane) and 5% C4H10 (isobutane)
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Cosmic triggger: top tracker• Trigger and high time resolution.
– 4 independent detectors area 1x0.5 m2. Gap structure to be finalized– strips 3 cm wide;
• The 1 m long strips (16 per read-out panel) in all 4 RPCs• 0.5 m long strips in 2 out of 4 chambers. • # strips: 64 x 2 = 128 strips
• Fine tracking. – One or 2 RPC 30x30 cm2 with 1 cm strips in both direction ( 32 strips vertically
+ 32 strips horizontally). Centroid reconstruction in both directions. # strips: 64
40 cm
100 cm50 cm
• Y-Z readout• Y only readout• Y-Z readout• Y only readout
Fine trackers
30 cm
30 cm
View from bottomSlide: courtesy G. Aielli
Cosmic trigger: bottom tracker• Trigger and high time resolution:
– One chamber 1x0.5 m2 as for the top tracker: strips: 16 + 32 = 48– Fine tracking: 1 chamber 30x30 cm2 as in the previous point. # strips: 64
• Underground detector– One doublet chambers: size 2.8 x 2.4 (=2x1.2) m2 (two chambers; bi-dimensional read out with
40 mm strips. . # strips: 224 (20 E/ channel)
50 cm
100 cm30 cm
Fine trackerY-Z readout
280 cm240 cm
30 cm
Iron shielding
Concrete
Concrete
Slide: courtesy G. Aielli
Beam trigger: test beam setup
Monitor chambersFor external referenceNeeded to select parallel tracks
sTGC quadruplets within the Mechanical frame. Allows to
Adjust the quadruplet position
Slide: courtesy G. Mikenberg
Beam trigger: layout
Slide: courtesy G. Mikenberg, Y. Benhammou
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