Background Workshop: why & how. W. Kozanecki, CEA-Saclay. Three themes.... In-depth review of radiation-abort policies Monday 9/22 Harnessing the run-4 backgrounds (oper’l issues) Tuesday 9/23 Long-term projections Experimental extrapolations Tuesday 9/23
Background Workshop: why & how W. Kozanecki, CEA-Saclay • Three themes.... • In-depth review of radiation-abort policies Monday 9/22 • Harnessing the run-4 backgrounds (oper’l issues) Tuesday 9/23 • Long-term projections • Experimental extrapolations Tuesday 9/23 • Background simulations & new IR design Wed. 9/24 • ...in a wider context • Machine-background experience @ Belle/KEKB • PEP-II parameter projections Tuesday 9/23 • IR upgrade strategy Wed. 9/24
In-depth review of radiation-abort policies: the goals • Push the envelope: where are the hard limits? • How much reserve do we have in the radiation budget? • What happens if we relax some threshold(s)? What are the implications for • detector damage (SVT, DCH, EMC) • integrated dose (SVT, EMC) • data quality (all) • What could SVTRAD change in its modus operandi (e.g. algorithms, thresholds, abort the ‘bad’ beam only...) that would • make life easier/more efficient (for PEP-II & BBR considered as a whole) .... • ...while preserving the safety & the performance of the detector • Share the pain between • running efficiency • detector integrated dose • BaBar data quality
In-depth review of radiation-abort policies: the issues • SVT radiation hardness • damage mechanisms (slow, fast) & pain thresholds • measurement results; tests in progress/upcoming; uncertainties • Radiation exposure, past & future (mostly SVT, EMC) • accumulated dose to date, characterization (MID vs T/B, sources) • dose transfer from pin diodes SVT modules, ATOM chips • updated experimental projections on integrated dose (incl. injection asspt’s) • comparison of measured dose rates vs Ibeam, normalized to extrapolations • SVT maintenance/rotation scenarios • SVTRAD upgrade plans • Data quality measures • define an ‘occupancy meter’ in each subdetector • cross-calibration of data quality & pin-diode dose? • Beam-abort algorithms • stable beams: fast aborts, timer aborts, fast/slow thresholds, flexibility • injection (inhibit/abort)
Long-term projections (2003-2009) • experimental extrapolation of ‘traditional’ backgrounds(in present geometry)valid 2006 ? • b* ==> Coulomb still OK? ( simulate present machine) • how does one extrapolate beam-beam backgrounds? • BTW...how believable are these extrapolations? • any limitations/vulnerabilities in Babar hardware or physics performance? • SVT radiation hardness? SVTRAD reliability ? • background ==> • power supply limitations? • dataflow BW? • p0 reconstruction ? • tracking occupancy?
Harnessing the run-4 backgrounds • Stored-beam tails • Trickle injection • recent experience, open issues, work in progress • Injection backgrounds • strategy (possible experimental / monitoring actions) ? • Radiation bursts • strategy (possible experimental / monitoring actions) ? • How else can we improve the overall (P-II +BBR) operational efficiency? • fast monitoring, P-II BaBar on-line info exchange • ‘new’ liaison (??),...
Background simulations new IR design (primarily) • Synchrotron radiation (SR) • overview of new IR design • [summary of past SR simulations for the SVT] • status of SR simulations for new IR design • Beam-gas • Overview of simulation architecture • Summary of past background simulation studies (SVT, DCH, EMC) • Status of Turtle decks • Status of GEANT-4 geometry implementation • Strategy, plans, timeline, milestones validation of P-II upgrade design • Beam-beam tails • new (or relocated) collimators? (simulations + experiments) • modelling collimation secondaries
Conclusions • “You cannot collimate electrons: you can only make them mad!” • However.... Lots of people in this room know how to handle “bees” ! Have a great workshop!