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)