Scintillator HCAL: LOI issues Felix Sefkow ILD meeting Seoul, Korea, 17. February 2009

Felix Sefkow Seoul, 16. February 2009 AHCAL Felix Sefkow Seoul, 16. February 2009

Cost drivers, optimization The main cost driving parameters are The choice of the absorber material The overall depth in terms of interaction lengths L The longitudinal sampling s The transverse segmentation d The dependence of PFLOW performance on geometrical parameters has been comprehensively studied with Pandora for stainless steel Near plateau region for L and d Shallow dependence for s, seems to be sensitive to algorithm Other materials: brass mechanically less attractive, but back-up if µ too large Tungsten: probably too costly; study just started, not for LOI AHCAL Felix Sefkow Seoul, 16. February 2009

Felix Sefkow Seoul, 16. February 2009 Optimization studies AHCAL Felix Sefkow Seoul, 16. February 2009

Felix Sefkow Seoul, 16. February 2009 R&D status CERN FNAL The first generation ‘physics prototype” is running in test beams since 2006, to be completed this summer Robust and stable operation, low noise, no ageing (< 0.5 permille) Test beam analysis Done: calibration, e.m. linearity, hadronic response, resolution, longitudinal profiles  support Geant4 based Pandora studies Still to come: shower radius, 2-particle separation, E+HCAL combined analysis, substructure and weighting  ~ 2011 AHCAL Felix Sefkow Seoul, 16. February 2009

(Birks law, pulse shape) Test beam results Essential: Corrections to data (temperature) and Monte Carlo (Birks law, pulse shape) π e Ongoing analysis A.Kaplan Ongoing analysis B.Lutz AHCAL Felix Sefkow Seoul, 16. February 2009

Felix Sefkow Seoul, 16. February 2009 R&D plans 2nd generation technical prototype underway Embedded electronics New ASICs: power pulsing, auto-trigger, zero-suppr. + digit. Several options for scint-SiPM/MPPC-electronic coupling New operational challenges Timeline PCB with tiles in March Full layer and e.m. tower end 2009 HCAL 2011 L.Raux 2m M.Reinecke K.Gadow AHCAL Felix Sefkow Seoul, 16. February 2009

Felix Sefkow Seoul, 16. February 2009 Dead zones Detailed implementation of sector boundaries in Mokka Too conservative with respect to most recent active layer design Replace aluminum frame by srews, 99% filling possible Variations simulated, not too critical for PFLOW Space for external electronics at barrel end face, between cable routes; can be made small, like ECAL M.Reinecke AHCAL Felix Sefkow Seoul, 16. February 2009

Felix Sefkow Seoul, 16. February 2009 Background Radiation damage: Only issue: neutrons in the very inner region of the end caps Radiation hardness subject of photo-sensor R&D (sLHC) Scintillator not affected Occupancy: Relevant for DAQ front end buffer depth and band width Would like to study gamma gamma and mini-jet events I recall from 2004 studies: 1 event every 3rd BX with 6 GeV in main calorimeters AHCAL Felix Sefkow Seoul, 16. February 2009

Felix Sefkow Seoul, 16. February 2009 Calibration Temperature-induced variations of photo-sensor: Monitor: single ph.e peaks Control: compensate by adapting voltage Possible long-term variations of light yield Scintillator ageing, optical coupling instability,..? Use track segments in hadron showers F.Simon AHCAL Felix Sefkow Seoul, 16. February 2009

Felix Sefkow Seoul, 16. February 2009 ILD simulation study Use algorithm developed on test beam data 1000 hits / cell  50 years @ 500 GeV  10 days @ 90 GeV 1000 hits / m2  2 weeks @ 500 GeV High granularity: insensitive to statistical cell to cell variation Need clever averages to control trends And good design, optical stability S.Lu, F.Simon 9 tracks AHCAL Felix Sefkow Seoul, 16. February 2009

Felix Sefkow Seoul, 16. February 2009 Support structure K.Kschioneck K.Gadow Following FEM calculations, support should be at 4 and 8 o’clock HCAL stands on the tip! AHCAL Felix Sefkow Seoul, 16. February 2009

This and following slides: Integration, step 1 This and following slides: K.Gadow AHCAL Felix Sefkow Seoul, 16. February 2009

Felix Sefkow Seoul, 16. February 2009 Integration, step 2 AHCAL Felix Sefkow Seoul, 16. February 2009

Felix Sefkow Seoul, 16. February 2009 Integration, step 3 AHCAL Felix Sefkow Seoul, 16. February 2009

Felix Sefkow Seoul, 16. February 2009 Integration, step 4 AHCAL Felix Sefkow Seoul, 16. February 2009

Felix Sefkow Seoul, 16. February 2009 ECAL integration, step 1 AHCAL Felix Sefkow Seoul, 16. February 2009

Felix Sefkow Seoul, 16. February 2009 ECAL integration, step 2 AHCAL Felix Sefkow Seoul, 16. February 2009

Felix Sefkow Seoul, 16. February 2009 Conclusion Answers to IDAG questions reasonably well prepared Well motivated design, clear R&D path Status of LOI draft: still a lot to do AHCAL Felix Sefkow Seoul, 16. February 2009