Edge Scanning: new Edge Scanning: new plate design for the plate design for the European Scanning European Scanning
SystemSystemG. Sirri for Bologna group
22/17/17
Specifications of the glass window
10 cm
10 μm
THICKNESS TOLERANCE:< 10 μm per 10 cm length
FLATNESS:a few fringes per inch(~400 nm per cm)( local slope < 0.1 mrad)
PARALLELISM:< 3 arc min (1 mrad)
a few fringes per inch
Specifications:
• This window is produced by Silo (Florence) according to the following specifications:
44/17/17
““Standard” vacuum plateStandard” vacuum plate
125.1
99.8
118 mm
95 mm
D1 = 3.5 mm
D2 = 2.5 mm
~10% of the emulsion plate is outside the vacuum pipe.
groove for vacuum
55/17/17
New vacuum plate for the European Scanning Sysyem to scan the whole area of the emulsion plate.
125.1 (max 125.5, min 124.55)
99.8 (max 100.0, m
in 99.45)
128 mm
102 mm
The emulsion is glued on a larger adhesive support (similar to the Nagoya Plate Changer) in order to keep it steady during scanning.
66/17/17
groove for vacuum
Plate setting with adhesive Plate setting with adhesive support support
Adhesive support on the bottom side
Several adhesive support tested:
Type ThicknessNitto tape 31RH 72 μmNitto tape 31 BATR 71 μmNitto tape 5058A5 45 μm3M tape 76991 47 μm3M Electrostatic tape
150 μm
very adhesiveEnough adhesiveNot adhesive,
problems scanning with oilSufficiently adhesive
and very transparentSufficiently adhesive, problems on the edge
scaning with oil
Emulsions manually glued to the support, having care to minimize troubles in scanning the bottom side (as micrometric air bubbles).
Emulsion
(thanks to japanese collegues and N. D’Ambrosio to provide us a sample of the adhesive tapes)
77/17/17
Data setData setBrick exposed in the cosmic ray pit for 4.75 days. Ref. efficiency on the center of the emulsions:~80 % 5 plates have been glued to adhesive tapes:2021 Nitto tape 31 RH2223 Nitto tape 31 BATR2425 Nitto tape 5058A52627 3M tape 769912829 Electrostatic tape30
glass
All the others attached to the plate with a scotch tape (covering about 1 mm of the edge); some of them have been measured also using a “standard” plate.
glass
ODD PLATES
EVEN PLATES
emulsion
emulsion tape
tape
88/17/17
Data acqData acq
Y (m)
X(m)
99500
69000
3000060000
glass
3X3 cm2 on each plate
to test:
1. the scanning quality (distortions and efficiencies) with and without the adhesive support
2. base-track efficiency on the edge of the emulsions
99/17/17
DistortionsDistortionstop- base
position (m)
3 mm from the edge
P25
P22
P23
P20
P21
P24
-0.020 mrad
-0.020 mrad
-0.015 mrad
1010/17/17
Distortions near the edgeDistortions near the edge
Starting from 3 mm from the edge, distrortions are bad. We have 20 mrad for all plates, with or without the support.
1 cm from the edge
1111/17/17
Efficiencies vs Plate Efficiencies vs Plate (not edge)(not edge)(d>1 cm from the edge)(d>1 cm from the edge)
Nitto tape 31 RH
Nitto tape 31 BA TR
Nitto tape 5058A5
3M tape 76991
Electrostatic tape
No support
1212/17/17
Efficiencies Efficiencies (not edge)(not edge)
Average for all plates
1313/17/17
Base-track density near the edge Base-track density near the edge (d<1cm)(d<1cm)
X (m)
Y (
m)
“Standard” vacuum plate
The vacuum groove is visible as a zone with a huge number of fake tracks. Outside we can still measure some tracks but volume-tracks are not well reconstructed.
New vacuum plate (emulsions with adhesive support)
We can measure the whole area of the emulsions.
1414/17/17
Efficiencies Efficiencies near the edgenear the edge
Average for all plates with adhesive support
2927252321
1515/17/17
Efficiencies Efficiencies near the edgenear the edge
o New plate, emulsion with adhesive support (Nitto tape 31 BA TR)
“standard” plate
Vacuum groove
Outside the efficiency decrease to zero.
1616/17/17
New plate without supportNew plate without support
The emulsion is not stable enough on the plate. The tape on the top side of the emulsion is fine to scan far away from the edge. Close to the edge, specially with oil, the system looses surfaces and miss some fragments.
Plate 26 Plate 24
Plate 28
1717/17/17
ConclusionsConclusions• The new vacuum plate allows to use
emulsions glued on a larger adhesive support and to scan the whole area of the emulsion.
• All the adhesive tapes we tested don’t decrease the quality of the acq.
• Efficiency is good close to the edge, with respect to the “standard” plate.
• Strong distortions from 3 mm far to the edge, related to emulsion itself.
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