16 February 2009CLIC Physics & Detectors Konrad Elsener 1... some issues regarding the forward region... (“picking up” from Lucie Linssen, 29 Sept 2008) not mentioned today: PairMonitor + GAMCAL

16 February 2009CLIC Physics & Detectors Konrad Elsener 2 from the ILD LoI (“top view”) X 14 mrad 2.5 m3.5 m NB. “mask”

16 February 2009CLIC Physics & Detectors Konrad Elsener 3 earlier pictures – thesis D. Schulte 1996

16 February 2009CLIC Physics & Detectors Konrad Elsener 4 earlier pictures – thesis D. Schulte 1996

16 February 2009CLIC Physics & Detectors Konrad Elsener 5 earlier pictures – TESLA TDR March 2001 – X 0 mrad ( mrad)

16 February 2009CLIC Physics & Detectors Konrad Elsener 6 earlier pictures – CLIC Physics report 2004 – X 20 mrad

16 February 2009CLIC Physics & Detectors Konrad Elsener 7 recent pictures – Adrian Vogel thesis ILC – X 14 mrad

16 February 2009CLIC Physics & Detectors Konrad Elsener 8 recent pictures – Adrian Vogel thesis 2008

16 February 2009CLIC Physics & Detectors Konrad Elsener 9 recent pictures – Adrian Vogel thesis 2008 [m] 210 mm Be steel

16 February 2009CLIC Physics & Detectors Konrad Elsener 10 “all the work is done” for ILC - why should CLIC be different ? CLIC 500 GeVCLIC 3 TeVILC nominal 500 GeV particles per bunch bunch separation0.5 ns 370 ns number of bunches per train length of bunch train 177 ns156 ns1 ms repetition rate50 Hz 5 Hz Beamstrahlung energy loss 7 % 29 %2.4 % incoherent pairs1.7 x x x 10 5 coherent pairs0.001 x x

16 February 2009CLIC Physics & Detectors Konrad Elsener 11 recent work for CLIC – Andrey Sapronov, 2008 (inspired by 2004 CLIC report and work on ILC) “dummy volume” to count background particles

16 February 2009CLIC Physics & Detectors Konrad Elsener 12 Preliminary background studies: mask effectiveness, spatial distribution of background hits in the dummy volume: no mask with mask 12 recent work for CLIC – Andrey Sapronov, 2008

16 February 2009CLIC Physics & Detectors Konrad Elsener 13 recent work for CLIC – Andrey Sapronov, 2008 (latest data file) NB. mask centered on detector symmetry axis; LumiCal + BeamCal centered on outgoing beam axis 1m2m3m 20 cm 10 cm

16 February 2009CLIC Physics & Detectors Konrad Elsener mrad

16 February 2009CLIC Physics & Detectors Konrad Elsener 15 # config file for CLIC detector forward region simulation (CFR) # general options CrossingAngle = 20 # mrad InputDataFile = "Pairs.root" DataFileName = "../data/cfr.root" StoreTrackerBg = "yes" PhysicsList = "standard" # Mask parameters Mask = "on" MaskInnerTheta = 80 # mrad MaskConeThk = 10 # mm MaskCylThk = 100 # mm MaskStartPoint = 1000 # mm MaskJointPos = 2270 # mm MaskEndPoint = 3350 # mm MaskPolyethThk = 200 # mm # LumiCal options LumiCal = "on" LcNLayers = 30 LcInnerRad = 80. # mm LcSensrThkns = 0.5 # mm LcAbsbrThkns = 3.5 # mm # BeamCal options BeamCal = "on" BcNLayers = 30 BcPos = 3100 # mm BcInnerRad = 20 # mm BcOuterRad = 160 # mm BcSensrThkns = 0.5 # mm BcAbsbrThkns = 3.5 # mm # field options FieldType = "solenoid" FieldValue = 4.5 # T FieldMapFile = "LDCantiDID_3Oct05.txt"

16 February 2009CLIC Physics & Detectors Konrad Elsener work to do... w.r.t. background in all sub-detectors include vacuum pipes + surrounding material (approx.) include final quadrupole (approx.) -> more realistic backscattering optimise all dimensions / thicknesses in terms of background hits in detectors (conical part needed?) change opening angle in BeamCal (-> 10 mrad ?) attempt to have an ILD-style LumiCal (symmetric, mrad) modify magnetic fields ? (presently 4.5 T, anti-DID*) integrate calorimeters / mask into support structure NEUTRONS: “hook up” with post-collision line (Michael Salt, Cockcroft) *Detector Integrated Dipole

16 February 2009CLIC Physics & Detectors Konrad Elsener work to do... w.r.t. functions of LumiCal attempt to have an ILD-style LumiCal ( mrad) 30 layers of W / Si - background vs. Bhabha at 500 GeV and 3 TeV (cf. D. Schulte: coherent pairs inside 6 mrad BUT... incoherent pairs, etc....) - need to change acceptance angles ? - functionality w.r.t. CLIC bunch train time structure - can we use the ILC LumiCal at 3 TeV ? - or do we need to change something (angular acceptance ? detectors/readout ?) ??? study of non-perfect collisions ???

16 February 2009CLIC Physics & Detectors Konrad Elsener 18 LumiCAL acceptance - ILD (from W. Lohmann + LoI) Fiducial volume for event counting Events  (rad) 32 – 74 mrad -> precision mechanics and monitoring of relative positions

16 February 2009CLIC Physics & Detectors Konrad Elsener work to do... w.r.t. functions of BeamCal detailed investigation on BeamCal 30 layers of W / diamond + GaAs (R&D on-going) - background from beam-beam interaction at 500 GeV and 3 TeV - radiation issues, as function of radius diamond detectors (CLIC>10 MGy?) - useful for feedback to accelerator ? - useful for background rejection in new particle search ? - functionality w.r.t. CLIC bunch train time structure

16 February 2009CLIC Physics & Detectors Konrad Elsener m3.5 m

16 February 2009CLIC Physics & Detectors Konrad Elsener 21 first step: address “basic” LumiCal issues (with Andre Sailer (Doct), Iftach Sadeh (visitor)) -> use Andrey’s files / machinery (but modify to have ILD LumiCal acceptance; check acceptance angles vs. fiducial volume) -> check input from GuineaPig at 3 TeV -> use GEANT4 model to score background particles hitting LumiCal (particle type, distribution, energies, etc.) -> compare 3 TeV background hits in LumiCal with 500 GeV ILC situation -> then conclude on next steps (10 cm graphite layer – degrades LumiCal performance?)