FCAL Munich October W.M. Morse 1 U.S. FCAL Efforts William Morse - BNL

FCAL Munich October W.M. Morse 2 U.S. Interests BNL – BeamCal, GamCal Yale – GamCal Colorado – SUSY studies Morse is the SiD forward coordinator Have submitted GamCal R&D Proposal to DOE Preparing BeamCal R&D Proposal to DOE

FCAL Munich October W.M. Morse 3 U.S. Interests BNL PI: W. Morse F. Lanni, D. Lissauer: BeamCal readout issues Z. Li: radiation damage issues B. Parker: machine interface issues Yale PI: M. Zeller G. Atoian, V. Issakov, A. Poblaguev: GamCal design issues Colorado PI: U. Nauenberg: SUSY studies

FCAL Munich October W.M. Morse 4 BeamCal Radiation Damage 10MGy/yr from electrons 2  n/cm 2 per yr, mainly from giant dipole resonance (10-40 MeV  N  nN*) Zheng Li (BNL Instrumentation) recommends high resistivity MCZ Si cooled to -10C

FCAL Munich October W.M. Morse 5 SiD 14mr with anti-solenoid

FCAL Munich October W.M. Morse 6 SiD Anti-Solenoid Magnet Brett Parker (BNL) design – see VLCW06 talk Lower B affects pairs and also backsplash to vertex detector

FCAL Munich October W.M. Morse 7 Fast Feedback The ILC fast feedback team requests a signal at 3MHz with low latency almost proportional to actual luminosity for fast optimization Comprehensive info at 5Hz to a data base (still to be defined)

FCAL Munich October W.M. Morse 8 Achieving the Design Luminosity Will Be a Challenge Bunch P - (t) {N, E, x, y, z,  x,  y,  z,  xy,  x,  y } Bunch P + (t) {N, E, x, y, z,  x,  y,  z,  xy,  x,  y } Instantaneous Luminosity: x y

FCAL Munich October W.M. Morse 9 Run Time Measurements Beam-beam deflections (pickup electrodes) Beam-strahlung gammas (GamCal) Beam-strahlung pairs (BeamCal) We need robust and complementary information

FCAL Munich October W.M. Morse 10 Beam-strahlung F = e(E + c  B). B max  1KT Instantaneous power radiated: P   3% P e N   1.5N e Bethe-Heitler:  e → e e + e -  BH  38 mb  1GeV Landau-Lifshitz: ee → ee e + e -  LL  19 mb  0.15GeV Other processes much smaller C. Rimbault et al., Phys Rev ST AB 9, (2006).

FCAL Munich October W.M. Morse 11 Bethe-Heitler Pairs  e → e e + e - For left and right detectors separately: N + /  x  y and N - /  x  y. Question: How well does this really work? Answer: Needs simulation.

FCAL Munich October W.M. Morse 12 Landau-Lifshitz Pairs ee → eee + e - For left and right detector equally 1 GeV

FCAL Munich October W.M. Morse 13 Simulations W. Morse (BNL) W. Lohman, E. von Oelson, and M. Ohlerich (DESY Zeuthen) To Be Submitted as an ILC Note Guinea Pig simulations varying some of the 500 GeV ILC bunch parameters around nominal values

FCAL Munich October W.M. Morse 14 Vertical offset E BeamCal (TeV)

FCAL Munich October W.M. Morse 15 Vertical Offset R (10 -6 )

FCAL Munich October W.M. Morse 16 Bunch Width BeamCal E (TeV) R 10 -6

FCAL Munich October W.M. Morse 17 Comparison Sign of dE/d(bunch characteristic) at design values. Note that all five lines are different, which means complementary information. ParameterPairsGammasRatio X offset0 (max) zz -- 00 yy 00 xx --- Y offset0 (max)0 (min)0 (max)

FCAL Munich October W.M. Morse 18 Bunch Height

FCAL Munich October W.M. Morse 19 Bunch Length

FCAL Munich October W.M. Morse 20 Is There More Info in BeamCal? T.Tauchi,K.Yokoya Phys Rev E51,6119(95) 6<r<7cm azimuthal dist But, Moliere dia.  2cm! Also,  1 Bhabha/BX! Thus we need more simulation to show that it is robust enough.

FCAL Munich October W.M. Morse 21 Robust and Complementary DetectorX offsetY offset xx yy PUE xx yy Normal E GamCalLowHighLowNormal E BeamCalLow Luminosity, ie. R, is low. Note that all columns are different, ie. complementary information.

FCAL Munich October W.M. Morse 22 Large Crossing Angle GamCal Gas jet followed by a 1m long 1.5T dipole magnetic field. Trajectories of positrons of momentum 0.1, 1, and 10 GeV/c are shown.

FCAL Munich October W.M. Morse 23 GamCal Backgrounds

FCAL Munich October W.M. Morse 24 Conclusions We need robust, redundant information: Beam-beam deflections Beam-strahlung gammas Beam-strahlung pairs E(pairs)/E(gammas) particularly valuable Largely proportional to instantaneous luminosity

FCAL Munich October W.M. Morse 25 Extra Slides

FCAL Munich October W.M. Morse 26 1  21  2 + - y z

FCAL Munich October W.M. Morse 27 Perfect Collisions