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

14.03.2013Dorothea Pfeiffer

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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