Evolution of Beam- Beam-Background Simulation at CLIC André Sailer(PH-LCD) May 12,2010
Feb 23, 2016
Evolution of Beam-Beam-Background Simulation at CLIC
André Sailer(PH-LCD)May 12,2010
Content
• Beam-Beam Simulation with GuineaPig• Simulation and Background in the Full
Detector
Simulation with GuineaPig(GP)
• Initial distribution of Particles (bunch shape, charge density)– Largest impact on
number of pairs– Provided by Beam
Physics Group (B.Dalena, D.Schulte)
• Two data sets, different horizontal emmitance
Incoherent Pairs from GP
• Wider beam, less particles (350k 310k)
• But energy distribution per angle very similar
Detector Simulation
• Using Geant4 based Mokka
• Based on ILD concept• Different– Crossing angle– Magnetic field (4 Tesla)– Beam pipes– Calorimeters
André Sailer, LC Physics/Detector Meeting 621st July, 2009
Vertex Detector
• CLIC01_ILD • Vertex Detector
• 3 double Layers at R=31/46/60mm
• All layers 25cm long• 50 µm Active Silicon• Threshold: 3.4 keV
• 4 Tesla Magnetic Field• Hadronic Calorimeter
• 8.5λ• Absorber: Tungsten, 1cm
thick, 77 layers
Vertex Detector
Forward Region
• First Simulations done with geometry right bottom
• Different magnetic Field options– AntiDID, Solenoid, DID
only– Hits in VXD (all Layers)
(10BX)– 19000 71000 33000
Changes I
• AntiDID not an option, because it costs to much Luminosity, from now on only Solenoid field
• Using “real” CLIC QD0• Hits in the Vertex
Detector (all layers, 10BX)– 70k down to 60k
Changes II
• Larger inner radius for BeamCal– 20 to 25 mm
• Beam pipe with a single radius
• Hits in the VXD increases (all Layers, 10BX)
• From 60k to 93k
Changes III
• Using Racetrack profile• Not an option, because
of QD0 design• Reduces number of
backscatters from beam pipes
• Hits in VXD (all Layers, 10BX)
• From 93k to 41k
Changes IV
• Conical beam pipe that fits with QD0 design
• Hits reduced again• 41k to 21k
Changes V
• Moved BeamCal forward, decreased inner radius
• Space for Intra-Train-Feedback
• Hits:– 21k to 27k
• Same geometry new Beam Profiles– Hits 24k