【正文】 cs and beamgas events ? Systematics and understanding will be the key issue: – Bringing together the knowledge from survey, tracking and ongoing FSI monitoring – Detector (thermal) stability will bee important below 100 ?m (initial running conditions will probably be unstable) 11 Solenoid field mapping ? Understanding magic field is important for mass scale – W mass requires overall field integral to %, other physics processes % ? Shape more difficult – understand local variations to %. ? Strategy for Bfield determination – Mapping field before ID installation using mapping machine with Hall probe array ? Intrinsic precision better than %, measure many points (few days mapping) – Fit field map using Maxwell equations ? Field shape can be described to ~ % using Bessel function expansion ? May improve precision by constraining Hall probe measurements – Monitoring using NMR probes during running ? 4 NMR probes installed outside barrel TRT at z=0 (region with low field gradient) ? Use for checking overall scale and monitoring time stability (probe intrinsic precision of ~ 5 ppm – frequency measurement) – Final check using particles of known masses (J/?, ?, Z) ? But this also brings in alignment and material effects – corrections hopefully small 12 Electromagic calorimeter Pbliquid argon sampling calorimeter with Accordion shape, covering |?| H ? ?? : to observe signal peak on top of huge ?? background need mass resolution of ~ 1% ? response uniformity (. total constant term of energy resolution) ? % over |?| 13 ? The constant term c=cL ? cLR。 – The local constant term, cL: 1. Geometry (residual Accordion modulation) 2. Mechanics (absorber amp。 gap thickness) 3. Calibration (with pulse test: amplitude uniformity, etc …) – The ―longrange‖ constant term cLR (from moduletomodule miscalibration)。 ? The absolute energy scale Use test beam measurements, cosmic ray run, pp collisions Calorimeter calibration 14 1. Geometry: (. deviation from Accordion modulation): ~ %。 2. Construction phase: thickness of all 1536 absorber plates ( long, wide) within ~ 10?m ? response uniformity ~ %。 3. PulseTest: calibration accuracy of each module ~ %。 Overall “l(fā)ocal” constant term: %. ? Testbeam: 4 (out of 32) barrel modules and 3 (out of 16) endcap modules。 Uniformity over units of size D? x D? = : ~ %。 Scan of a barrel module with 245 GeV e . ? % over ~ 500 spots = mm ? ? 9 ?m Testbeam data 15 ? Cosmic muons: ? find dead/noisy channels。 cabling errors。 pare with test beam data。 ? check calibrations。 with 3 months of cosmics runs we can correct the calorimeter response variations vs ? to % 。 S(?) / ?(noise) ? 7 Muon signal in barrel ECAL Testbeam data ? Testbeam data 16 ? Beamhalo and beamgas。 ? reconstruct muons in the endcap ? rate: ~ 1 Hz for Etot 5 GeV。 open problem: how to trigger? ? measure p0 in EM calo and check shower shapes。 ? Few usable electrons: try to use other tracks to check calibrations If no correction are applied: ? cL ~ % ? cLR~ % The calorimeter will behave sufficiently well already at the startup to allow some physics. 17 With pp collisions ? Use min. bias and ―some‖ electron trigger (pT 10 GeV) – Adjust/setup timing of calorimeters – Measure ―overall‖ energy spectrum in EM calo – Measure EM cluster energy spectrum – Study response uniformity of calo‘s in ? ? Start tuning/adjusting eidentification procedure – Check calo shower shapes for electrons