CS LNGS Current status and perspectives Luigi Esposito (European CS Scanning Team)

20/01/2009 OPERA Collaboration Meeting in MIZUNAMI 2 CS scanning protocol 1.CSd are scanned according to fog level – different cuts are applied for the two samples 2.Double base-track search (STANDARD) 3.Manual check validation 4.Event validation 5.In case of null (double bt) result: (MICRO) – Compton alignment – ¾ search 6.In case of null result after ¾ search: – we rescan the event according to its topology we expect to do it in 10% QE events (see Natalia’s talk) 7.request second brick and send the first back to detector (only after positive result of the second) 8.Support to the labs when the event is not located in ECC Automatic See Fabio’s talk

20/01/2009 OPERA Collaboration Meeting in MIZUNAMI 3 Current situation Currently using up to 7 microscopes for the scanning + 1 devoted to manual check 24/7 shift – coverage was around 85% before Christmas, significantly reduced afterwards Scanning Station is able to digest 50÷60 CSd/week in this condition SySal2000 (VS6, ST8.5) – Improvements excepted from the release made by Cristiano, tests foreseen

20/01/2009 OPERA Collaboration Meeting in MIZUNAMI 4 Present numbers of the 2008 run The status as of :00 LNGS time From , 72 development batches not uniformly distributed in time CS_DEVELOPED818 EVENTS712 CS_MEASURED709 BRICK_DEVELOPED *417 BLACK_CS25 BRICK_BACK8 * Including some ¾ search

20/01/2009 OPERA Collaboration Meeting in MIZUNAMI 5 Event classification 417 bricks were developed after positive result from the CS scanning: – STANDARD search: 402 – MICRO search: 15 Relative ratio may change since the micro-track search is in progress

20/01/2009 OPERA Collaboration Meeting in MIZUNAMI 6 Black CS 1154 is black!

20/01/2009 OPERA Collaboration Meeting in MIZUNAMI 7 High fog CS

20/01/2009 OPERA Collaboration Meeting in MIZUNAMI 8 High-fog CS scanning N (Fog > 10) = 104 (12.9 %) N (Fog > 20) = 44 (5.4 %) N (Fog > 30) = 18 (2.2 %) Current protocol: use ScanGrid when Fog > 10 grains/µm 3

20/01/2009 OPERA Collaboration Meeting in MIZUNAMI 9 CS scanning trend 3 weeks to complete the scanning of the 1 st extracted CSd (  140 remaining) 2 nd probable bricks being extracted (4 weeks for  200)

20/01/2009 OPERA Collaboration Meeting in MIZUNAMI 10 Estimates from the previous slide The scanning rate is 50÷60 bricks/week, enough to follow the extraction/development rate  to be doubled for 2009 run (including second brick extraction) The success rate ~ 60% can be slightly improved  ¾ routinely applied but still lengthy

20/01/2009 OPERA Collaboration Meeting in MIZUNAMI 11 Scanning speed Standard scanning ScanGrid Data from 7 microscopes, 2 microscopes are used with ScanGrid For the low fog CS, the nominal speed is affected by the reduction of scanning thresholds Scanning speed is strongly affected by fog level ScanGrid will be extensively used. Increasing computing power is planned: an upgrade of the LNGS planned in the coming weeks

20/01/2009 OPERA Collaboration Meeting in MIZUNAMI 12 Data quality: impact of the rescanning Scanning data quality (micro-track per view, emulsion thickness, reconstructed base-tracks) is monitored with an “online” tool Appropriate actions are taken when DQ is not satisfactory, such as CSD rescan on small areas Progressive reduction of rescanning while keeping constant the effectiveness

20/01/2009 OPERA Collaboration Meeting in MIZUNAMI 13 CS scanning data quality notch

20/01/2009 OPERA Collaboration Meeting in MIZUNAMI 14 CS track multiplicity

20/01/2009 OPERA Collaboration Meeting in MIZUNAMI 15 CSd-TT comparison: NC events Nearest CS track with respect to the centroid of the electronic prediction Accuracy ~ 9 mm in both projections

20/01/2009 OPERA Collaboration Meeting in MIZUNAMI 16 Analysis of the second extracted brick to evaluate the improvement in the location efficiency Events with a 2 nd brick extracted105 passing through track in 1 st brick11 1 st brick still under analysis19 1 st brick developed8 Both CS black1 Not measured…yet14 2 nd CS scanned52 2 nd brick developed20

20/01/2009 OPERA Collaboration Meeting in MIZUNAMI 17 Preliminary results MeasuredDevelopedRatio (%) 1 st brick  nd brick  st & 2 nd brick75.9 These estimations are VERY PRELIMINARY for the following reasons: some manual check not yet concluded some event validation not yet concluded 3/4 search not yet applied in case of null double base-track result So the value has to be considered as a lower limit

20/01/2009 OPERA Collaboration Meeting in MIZUNAMI 18 Complicated event #1 Two CSd measured: no convincing track to develop a brick

20/01/2009 OPERA Collaboration Meeting in MIZUNAMI 19 Complicated event #2 First brick extracted

20/01/2009 OPERA Collaboration Meeting in MIZUNAMI 20 Complicated event #2 Second brick extracted

20/01/2009 OPERA Collaboration Meeting in MIZUNAMI 21 Improvements and conclusions Shift coverage 24/7 (+15%) Increase number (+3 from Lyon) of microscope (+43%) Increase scanning speed (+13%) Total rate increase: + 85% Data quality improvements – Test new SySal2000, released by Cristiano – Procedure improvements: – Compton alignment and ¾ search