Film Storage and book-keeping

1
WG4 summary

• Film Storage and book-keeping
• Scanning Quality Control
• Cosmic Ray Density
• Vertex Confirmation
• Vertex Location

2
WG4 summary

• Film Storage and book-keeping
• First version Brick Tracer ready to use ( C.
  Bozza )
• Scanning Quality Control
• SUTS ( K. Morishima )
• ESS ( C. Bozza )

3
Brick tracer
http//operaweb.web.cern.ch/operaweb/internal/inde
x.shtml
4
WG4 summary

• Cosmic Ray Density
• Aim of cosmic ray exposure is to provide
  alignment for momentum measurement and decay
  search.
• Data shows we can go down to 1/5 while keeping
  alignment accuracy. ( A. Ariga )
• Brick deformation can be corrected using Cosmic
  Rays during transportation ( S. Takahashi )
• now 6micron rms whole OPERA film WITHOUT cosmic
  rays
• Further improvement is being studied.
• One can apply this method for Bricks with black
  CS to have have NO cosmic ray exposure.
• For normal bricks we can use cosmic rays in
  larger area for alignment.
• This method requires a brick should be made of
  emulsion sheets in a single pack.

5
1.4cm x 1.4cm x 11plates 369 tracks in scanning
area

• From the point of alignment.
• Higher cosmic density doesn't give higher
  resolution.
• 1/31/5 of current exposure is enough to get same
  alignment accuracy(1micron).

6
WG4 summary

• Cosmic Ray Density
• Aim of cosmic ray exposure is to provide
  alignment for momentum measurement and decay
  search.
• Data shows we can go down to 1/5 while keeping
  alignment accuracy. ( A. Ariga )
• Brick deformation can be corrected using Cosmic
  Rays during transportation ( S. Takahashi )
• now 6micron rms whole OPERA film WITHOUT cosmic
  rays
• Further improvement is being studied.
• One can apply this method for Bricks with black
  CS to have have NO cosmic ray exposure.
• For normal bricks we can use cosmic rays in
  larger area for alignment.
• This method requires a brick should be made of
  emulsion sheets in a single pack.

7
Deformation map between film 1 - 2
_at_transportation
50micron
8
Deformation mapbetween film 1 2 _at_brick
50micron
9
difference (transportation - brick)(film 1 2)
RMSx2.4micron
RMSy1.4micron
10micron
Deformation seems conserving between
transportation and brick.
10
Virtual alignment

• ?Used several films of brick36565
• exposed CR
• ?Scanned full area
• ?Important to read X-ray mark accurately
• for accurate alignment
• Trying now
• ?Instead of X-ray mark,
• used tracks at area near the X-ray mark
• ?Global correction is used tracks at area
• near the X-ray mark.
• ?Local correction is used tracks
• at transportation
• ?After virtual alignment,
• I check position difference using brick tracks.

1cm
X-ray mark
y
x
film
d
Lead
film
11
Position difference
plate 25 - 26
dx
dy
micron
micron
offsetmicron ( -13.2, 2.2 ) RMSmicron
( 5.8, 5.8 )
Position difference have offset.
12
Prospect for offset
If films curl at transportation offset appear.
transportation
after scanning
CR
If curl effect contribute offset should be had
same value.
13
Offset for several combinations
film1 film2 offset dxmicron offset dymicron
25 26 -13.2 2.2
26 27 -17.2 -2.4
27 ? 28 -9.7 1.4
Offset is same within several micron.
14
WG4 summary

• Worries about reducing cosmic ray density
  exists but
• Some scan back using X-ray marks were tried also
  in Europe side.
• Lyon ( L. Arrabito )
• Cross check can be done soon using brick data
  taken so far.

15
WG4 summary

• Vertex Confirmation
• Volume scan procedure using SUTS ( T. Fukuda )
• Summary of events
• Nagoya ( U. Kose, N. Kitagawa )
• Bern ( C. Pistillo )
• Lyon ( L. Arrabito )
• Vertex Location
• NO cosmics for bricks with Black CS
• Presentations in A. Ariga and S. Takahashi -gt
  Alignment w/o cosmics
• Bern NC event ( I. Kreslo )
• One vertex related to cosmic rays
• One vertex outside a brick
• No CSD tracks
• TT match
• No Veto tracks
• Shift management and human organization
• Homework for each lab

16
ECC with black CS(current Nagoya strategy.)?

• General scan the downstream plates(35).
• search vertex candidates.
• Scanback or Direct vertexing.
• Strong worry about the 2nd, 3rd, vertex by cosmic
  ray.
• --gt no cosmic on the ECC with black CS.
• Next talker, Takahashi.

ECC downstream
17
NC event 179312944
18
Volume scan around vertex
577
748
1211
2938
450
Tracks are visible in veto gt This is NOT a
neutrino event, but HE cosmics reaction
19
After scanback of 1300 tracks two interesting
vertices found
20
After scanback of 1300 tracks two interesting
vertices found