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March 9, 1999. Status of the CERN/NIKHEF Microscope Project. Ioannis Papadopoulos. ( representing the CERN-Microscope group ). Chorus Collaboration Meeting 8-10 December. Overview. Status of scanning CS/SS data bulk calibration, scan-back. speed and efficiencies White Kink
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March 9, 1999 Status of the CERN/NIKHEF Microscope Project Ioannis Papadopoulos ( representing the CERN-Microscope group ) Chorus Collaboration Meeting 8-10 December
Overview • Status of scanning • CS/SS data • bulk calibration, scan-back. • speed and efficiencies • White Kink • scanning strategies • first vertices, kinks! • CET • analysis • preliminary results • Outlook
CS/SS scanning Module 27/3 28/3 CS events scanned 2924/4580 248/570 tracks scanned 4635/10085 639/2669 <efficiency> 64% ~64% <views> 25 25 #images 16 16 track-regions No No SS events scanned 655/927 0 tracks scanned 1349/3178 - <efficiency> 71% - <views> 5 - #images 16 - track-regions No - track-region: All grains in the track neighborhood
3 mm 3 mm plate n+2 plate n+1 bulk calibration track maps of beam on eight different positions (full sheet) 6 mm plate n Module 27/3 36 plates aligned 8 maps/plate 4000 tracks/map (together with track-regions) >1,000,000 tracks stored together with grains • Current problem: • alignment SS-bulk only possible for half plate
bulk scan-back • Strategy • if a track is lost, take grain maps over the full thickness and send it to General Tracking (GT) “farm”, to decide between: • inefficiency ( the track was there ) • vertex • kink • Scanning results • 9 half plates scanned. • GT recovered inefficiency from online. • 20 vertices found. • Our current concern: • To improve efficiencies before continuing.
Efficiency-speedoptimization • Procedural improvements • Track-regions: all grains close to the track are saved in the database. • DAQ with more than 16 images. • All layers fully covering the emulsion layer. • Surface detection eliminated (positions continuously updated). • Handles to improve efficiencies • From track-regions optimize tracking parameters. • Using more layers increase S/N. • Current working speed • 4 s per view: • 2 s data taking ( 25 layers ) • 2 s movement of the stage
WSK: strategy • 1st iteration • 2 SS + 111 bulk plates already scanned • 112 pairs matched • σ < 4 μm. GT • 2nd iteration • GT for last and missed segments • Following down tracks from vertices/kinks.
WSK: first kinks! • Starting with ~3500 tracks: • Results from 1st plate: • 168 “predictions” sent for GT • ~99% of straight tracks recovered. • 7 vertices • 5 black kinks • 2 white kinks • ( 133 and 290 mrad, 3 GeV π-) • Current efforts • Classify all the output possibilities from GT. • Tune GT with unbiased sample. • Very useful for CHORUS bulk scanning
CET analysis • Importance of the CET for the WK: • Measure momenta of outgoing tracks • distinguish between elastic and inelastic events. • Step 1 • Match the 8 plates using tracks of the non interacting pions ( 3, 5 GeV). • Step 2 • Create set of reference tracks. (Lack of fiducial marks) • Step 3 • Measure position of outgoing tracks w.r.t. the reference tracks: Measure P, Pt.
CET preliminaries 3 GeV set Plate 1 Plate 1 - Plate 2 10 GeV 5 GeV • Momentum measurement with 10% accuracy is achievable.
Outlook • CHORUS emulsion scanning • Rescan CS/SS of 28/3 with new programs. • Tune parameters of online and general tracking with existing data, increasing efficiencies. • Implement improved calibration procedures. • Complete 27/3 and 28/3. • WSK • Finish bulk scanning. • Measure momenta. • Hardware • Receive new DSP and implement the 30 Hz operation mode. • Receive shutters with improved design. • Plans for Phase II • See Jaap’s talk.