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 * 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
SIGMA # sigmaX sigmaY sigmaTX sigmaTY DEGRAD 1 4# angular degradation: sig(tx) = sig(0)*(1+deg*tx) BINS # bin*sigma = acceptance CHI2MAX 13.5# chi2 simple CHI2PMAX 13.5# chi2 with puls weighting (ramp used) Up/down linking parameters: building the base-tracks CHI2MODE 0 3 SIGMA DEGRAD 0 4. BINS CHI2MAX 05.5 CHI2PMAX 05.5 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 Sasso Candidates for 6 european bricks 109 (102 with grains>=40) events in 16*6 = 96 cm 2 6x5=30µm3.4x5=17µm 5x5=25mrad 40 grains x = 6µm tx = 5mrad
CS1-to-CS2 alignment for brick Candidates: 93 (79 with grains>=42) events in 96 cm 2 (8.6x11.1cm2) x = 15µm y = 4µm tx = 4mrad ty = 4mrad 42 grains
Y residuals vs. X and Y position Y CS2 - Y CS1 - TY CS1 *300 Y (µm)X (µm)
X residuals vs. X and Y position X (µm) Y (µm) X CS2 - X CS1 - TX CS1 * 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 distributionAngle distribution
Data quality of films inside the brick high fog (>=10/1000 µm 3 ) and Compton Micro-tracks per view Clusters per view 3 inter-calibration areas 1cm2 ~500 base-tracks/mm2 ( <0.5) after quality cut ~15/mm2
Measured gap between CS and brick 4450 µm measured value (4700 µm nominal) 220 µm correction 270 µm correction
CS to brick connection position accuracy = 70µm = 54µm 12 cm x (µm) finding rate = 47/74 = (64±6)%
CS to brick connection angular accuracy = 9mrad = 12mrad
CS to brick connection position and angular distribution of candidates validated by manual check 12 cm 9 cm
Connection of plate 1 to 2 position accuracy all candidates validated by manual check x = 16µm y = 12µm = 41/47 = (87±5)%
Connection of plate 1 to 2 angular accuracy all candidates validated by manual check tx = 8.6mrad ty = 7.9mrad
Connection of plate 2 to 3: position accuracy all candidates validated by manual check tx = 7mrad tx = 6.4mrad y = 8µm x = 13µm = 39/41 = (95±3)%
Conclusions ● 74 tracks found on the CS doublet (~ 96 cm 2 ) but not manually checked ● Position dependence of the X offsets ● High fog density (10/1000 µm 3 ) 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)