Performance of Performance of Compton Alignment Compton Alignment

in OPERA CS, 2008 run in OPERA CS, 2008 run

Seigo Miyamoto

Jan., 2009, MIZUNAMI.

April, 2003 20092004 2005 2006 2007 2008

Refreshing OPERA Films

Fundamental training to see track with my eyes,treatment,develop emulsion

electron showerenergy calibration

in ECC(10~20GeV)

history of my study (The way to establish this technology)

The balloonanalysis

High energyCosmic rays

analysis of atmospheric

muon flux

I got important data and Idea of

MeV electron detection

Test experiment and analysis of

Compton Alignment

momentumcalibration

in ECC (~1GeV)

Development of automatic programs for OPERA CSD

Application forReal OPERA CSand quality check

CS Manual Check

Making

Refresh

Chamber

MakingBalloon

Chamberand

Launching

Hardware

data analysis

deformation of the filmsdeformation of the films

Emulsion film have very good position resolution in the very small area.

In 10cm x 10cm position resolution decrease ~20um because the films deform in exposure -> develop -> drying.

In the case of CS doublet, bad alignment makes many fake coincidence.

Electron from natural R.I.Electron from natural R.I.~ 1 MeV

~ 100 keV

Deformation CalibrationDeformation Calibrationby finding MeV electron peak by finding MeV electron peak

10μmΔx from X-ray Alignment

SCANSCANSCAN

CS1 CS2

SCAN

micro track micro track micro track micro track

Making base track Making base trackCompton Alignment

base track base trackcalibration map

Doublet Track Selection (4hold, 3hold, muon selection)

Manual Confirm

These processes performs fully automatically , which is controlled by Morishima .

TT Hit

Automation of CS track selectionAutomation of CS track selection

Automation of getting the Automation of getting the deformation mapdeformation map

1. Division of scanning area (5mm x 5mm)2. Peak search Detection of Compton

electrons in the Shift_x,y map for all divided areas

3. Estimation that each alignment is successful or not in each divided areas.

4. Linear interpolation for not successful areas

5. Estimation performance for all areas.

Evaluation performanceEvaluation performanceof Compton Alignmentof Compton Alignment

Samples are 425 CSDs scanned in Japan (~early Dec., 2008.)

No available alignment in any scanning region

5 (1%)

Getting good alignment pattern map (at least 5cm2 , and they are adjoining ) , and # of pattern = 1

347(82%)

# of pattern is >= 2 73(17%)

Ratio successful areaRatio successful area Samples are 420 CSDs

(at least 5cm2 is available , and including multiple pattern)

# of CSD ratio successful is more than 80% is about 360(85%).

The Areas couldn’t get available alignments are almost due to large gaps.

~85%

Alignment accuracyAlignment accuracy Samples are 163 muon track that observed in CSD

( ratio successful is more than 80% ) from beginning to early Dec. , 2008.

Residual from X-ray Alignment

5.5um 7.6um

Alignment accuracyAlignment accuracy Samples are 163 muon track that observed in CSD

( ratio successful is more than 80% ) from beginning to early Dec. , 2008.

Residual from Compton Alignment

2.0um 2.0um

SummarySummary

Compton Alignment is applied for all CSDs full automatically in 2008 RUN.

99% CSD succeed to get alignment at least 5cm2, and multi pattern is about 17%.

CSD - its ratio successful is more than 80% - is about 85%.

Alignment accuracy is 2um, BG reduction power is around 1/10.

Future Plan: Future Plan: General MeV electron DetectorGeneral MeV electron Detectorwhich has micron position resolutionwhich has micron position resolution Material Science-Study of Structural Phase Transitions ( Dr. Tanimura (Osaka univ.) presented

in Emulsion WorkShop 2008.)

Any other ideas ( It’s secret. )