Stato dell’analisi del Test Beam
Consorzio 11 Ottobre 2002
• Nuovi risultati al PSI
– Dead time (Domenico e Nicola)
– Fake clusters (Jacopo)
• Risultati preliminari ad X5
– Hip rate (Simone)
– Baseline recovery (Jacopo)
11 Ottobre 2002
1
Domenico e Nicola: dead time
• Nuovo algoritmo
combinatoriale per trovare
le tracce
 maggiore statistica
 efficienza ~1
11 Ottobre 2002
Confidence
region for the
1st track
Confidence
region for the
2nd track
2
Track statistics
How many tracks are
found in the spill?
CMmedian<-30
How many tracks are
found for each frame?
Entries 2877
11 Ottobre 2002
3
Track samples
CMmedian<-30
number of tracks if a
cluster is found near
the expected hit
hipped apv
good apv
total number of
tracks in the
sample
11 Ottobre 2002
4
APV efficiency: CM<30
CM subtraction on 16 strips
CM subtraction on 128 strips
e
e
5 out of only
6 events
5 out of only
6 events
It looks better!
11 Ottobre 2002
5
CM subtraction methods
Raw data-Pedestal
11 Ottobre 2002
CM subtraction on
128 strips (CMmedian)
CM subtraction on 16
strips (without the
first and the last two)
6
APV eff. for each Rinv: CM30
CM subtraction on 128 strips
CM subtraction on 16 strips
Hipped APV eff. in mod. with Rinv =50 Ohm is better!
11 Ottobre 2002
7
Inefficienza
Inefficienza media nei 750 ns dopo la hip
Hip
cut
Rinv
128
16
Pisa
(64)
< –30
50
100
0.19
0.44
0.13
0.41
0.17
< –90
50
100
0.30
0.47
0.24
0.40
0.22
I risultati di Bari indicano una inefficienza
maggiore di un fattore 2 circa rispetto a
quanto trovato da Pisa
11 Ottobre 2002
8
Jacopo: fake clusters…
• Clusterizer
1. Three cuts : seed, neighbours, cluster charge
2. Absolute cuts (in ADC counts)
•
1.
2.
3.
Studies
CM < -30,-90 to search HIPS
Different topologies of CM calculation (128,64,32,16,8)
Different cuts on clusters
•
Plotted Quantity
NHipped
number of clusters found on Hipped chip while it’s recovering
NnoHipped
11 Ottobre 2002
NHipped / NnoHipped
number of clusters found on chip in front of the Hipped one
9
(same column of APVs)
…vs hip cut
11 Ottobre 2002
10
…vs clusterization cuts
11 Ottobre 2002
11
Simone P. - Aug2002 X5
Multi-mode acquisition of Aug2002 X5 tests:
single frame, with 10 consecutive triggers.
counter (75 ns spacing)
first trigger
1
2
3
4
...
10
hip found
frame N.
run60519 --> Dec.
run60525 --> Peak
run60526 --> Peak
run60527 --> Peak
run60537 --> Dec.
run60538 --> Dec.
0
1
Inv.OFF
Inv.OFF
Inv.OFF
Inv.OFF
Inv.ON
Inv.ON
9
multi-mode
single-mode
multi-mode
multi-mode
single-mode
multi-mode
(117files, 1.878.433 evts)
(1 file, 15.601 evts)
(4 files, 48.147 evts)
(60 files, 881.956 evts)
(17 files, 257.929 evts)
(66 files, 1.000.468 evts)
At PSI main running mode was Peak Inv. ON: difficult to make comparisons!
11 Ottobre 2002
12
First results
run 60537: single-mode, Dec., Inv. ON 258000 evnts, with mean cluster
multiplicity ~ 2
Events with CM < -60:
apv0
apv1
apv2
apv3
total
module 4
module 5
module 6
module 7
module 8
234
236
292
238
241
37
158
158
147
156
103
95
109
112
138
435
457
520
508
486
809
946
1079
1005
1021
Average hip (CM<-60) rate ~ 1.8 x 10-3
 Good agreement with PSI (Peak, Inv ON) = (1.5 ± 0.3)x10-3
11 Ottobre 2002
13
Jacopo: baseline recovery
• Each frame correspond to 75 ns
• Deco, Inv ON, has a slower
recovery than at PSI
 Opposite to what expected from
“offline” deconvolution !
 Much faster without the inverter
HIP cut: CM < -90
Aug2002 X5
550 ns instead of 400 ns
11 Ottobre 2002
14
Conclusioni
• Analisi del PSI test “quasi finale”
– Rinv = 50 Ohm ha una inefficienza minore (e un rate
minore…)
– Calcolo del CM su < 16 strips migliora l’efficienza e
diminuisce i fake clusters
• Risultati MOLTO preliminari di Aug2002 X5:
– Hip rate trovato al PSI confermato anche per pioni di
120 GeV (come aspettato)
– La baseline in deconvoluzione recupera piu’ lentamente
– Difficile fare uno studio di efficienza perche’ il trigger
rate sembra essere troppo basso… non ci sono tracce
nei frames successivi al primo trigger…
11 Ottobre 2002
15