cs to brick and track follow-up ● cosmic ray test ● cs scanning ● cs to brick connection ●...
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CS to brick and track follow-up
● Cosmic ray test● CS scanning● CS to brick connection● Track following
Napoli Scanning Lab
Cosmic ray test performed in November
● Brick with CS brought out of the gallery
● Kept for about 4 minutes at the surface
● Integrating about 100 tracks on the whole surface
● Going back to the underground lab
● Attach a second CS doublet and expose to cosmic rays in the pit for 24 hours
CS doublet
Cosmic rays
Scanning of the cosmic-ray test bricks
● CS doublets (European part) were scanned at Gran Sasso
● After the first area scanning performed at Gran Sasso, one CSD was sent to Naples
● Enlarged the statistics (all the surface)● CSD scanning and results● CS to brick connection● Brick scan-back
Scanning station for 6 bricks
CS1 and CS2 scanning:● minimum number of grains = 7● “expansion” filter● fixed cutoffs● 15 layers
Up/down linking:● minimum number of grains = 7● Delta X,Y = 30 µm● Delta TX,TY = 40*(1+4*) mrad
CS1/CS2 tracking● Delta X,Y = 40 µm● Delta TX,TY = 25 mrad● N = N
CS1 + N
CS2 = 40 grains
● quality cut: SIGMA < N * 0.13 - 1.3
Napoli laboratory: brick #973
CS1 and CS2 scanning:● minimum number of grains = 7● “expansion” filter● cut-offs tuned on the CS2● 16 layers
Candidates in the CS sheets:● Delta X,Y = 120 µm● Delta TX,TY = 50 mrad
CS1 and CS2 scanning
SIGMA0 1 6. 6. .010 .010 # sigmaX sigmaY sigmaTX sigmaTYDEGRAD 1 4 # angular degradation: sig(tx) = sig(0)*(1+deg*tx)BINS 1 5 5 5 5 # bin*sigma = acceptanceCHI2MAX 1 3.5 # chi2 simpleCHI2PMAX 1 3.5 # chi2 with puls weighting (ramp used)
Up/down linking parameters: building the base-tracks
CHI2MODE 0 3SIGMA0 0 40. 40. .005 .005DEGRAD 0 4.BINS 0 3 3 5 5CHI2MAX 0 5.5CHI2PMAX 0 5.5
CS1/CS2 tracking parameters: building the doublet tracks
xy= 40µm 3 cut txty = 5mrad 5 cut
degrading with the track slope
xy= 6µm 5 cut txty = 10mrad 5 cut
degrading with the track slope
CS1-to-CS2 alignment with data scanned at Gran SassoCandidates for 6 european bricks
109 (102 with grains>=40) events in 16*6 = 96 cm2
6x5=30µm 3.4x5=17µm
5x5=25mrad5x5=25mrad
40 grains
x = 6µm
tx = 5mrad
CS1-to-CS2 alignment for brick 3000973Candidates: 93 (79 with grains>=42) events in 96 cm2
(8.6x11.1cm2)
x = 15µm y = 4µm
tx = 4mradty = 4mrad
42 grains
Y residuals vs. X and Y positionYCS2 - YCS1 - TYCS1*300
Y (µm)X (µm)
X residuals vs. X and Y position
X (µm) Y (µm)
XCS2 - XCS1 - TXCS1*300
12 cm 10 cm
X residuals vs. X and Y position (2D view)
mark #1
mark #2
mark #3mark #4
30 µm offset
Summary of CS to CS connection● After a cut on the number of grains (42 out of 64) 74
tracks remained predicted onto the brick after the extrapolation of 4700 µm
Position distribution Angle distribution
Data quality of films inside the brickhigh fog (>=10/1000 µm3) and Compton
Micro-tracks per viewClusters per view
3 inter-calibration areas 1cm2
~500 base-tracks/mm2 (<0.5)after quality cut ~15/mm2
Measured gap between CS and brick4450 µm measured value (4700 µm nominal)
220 µmcorrection
270 µmcorrection
CS to brick connectionposition accuracy
= 70µm = 54µm
12 cm
x (µm)
finding rate= 47/74 = (64±6)%
CS to brick connectionangular accuracy
= 9mrad = 12mrad
CS to brick connectionposition and angular distribution of candidates
validated by manual check
12 cm
9 cm
Connection of plate 1 to 2position accuracy
all candidates validated by manual check
x = 16µm y = 12µm
= 41/47 = (87±5)%
Connection of plate 1 to 2angular accuracy
all candidates validated by manual check
tx = 8.6mrad ty = 7.9mrad
Connection of plate 2 to 3: position accuracyall candidates validated by manual check
tx = 7mrad tx = 6.4mrad
y = 8µmx = 13µm= 39/41 = (95±3)%
Conclusions● 74 tracks found on the CS doublet (~ 96 cm2) but not manually
checked
● Position dependence of the X offsets
● High fog density (10/1000 µm3) on the films inside the brick
● 47 tracks found in the first plate of the brick and manually confirmed
● 65% of connecting efficiency (physics, instrumental, etc.)
● 41 tracks found on the second plate (manually confirmed)
● 39 tracks found on the third plate (manually confirmed)
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