27/02/2002 M.D.P. - ATLAS Muon Week 1

First results of Atlas RPC cosmic First results of Atlas RPC cosmic rays testrays test

Massimo Della Pietra

Atlas RPC Group Napoli(M. Alviggi, V. Canale, M. Caprio, G. Carlino, F. Conventi,

R. de Asmundis, M.D.P., D. della Volpe, P. Iengo,

S.Patricelli, L.Romano, G. Sekhniaidze)

27/02/2002 M.D.P. - ATLAS Muon Week 2

OutlineOutline RPC cosmic rays test in Naples. Definitions. Test results.

Gap currents and single rates Full Plateau curves Cluster size

Conclusions.

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RPC Test in Naples RPC Test in Naples

First chamber under test in Naples: BOS-B-004.

32 strips or 32 strips were tested with cosmic rays using final receiversfinal receivers.

A complete scan of RPC performances with respect to HV and threshold values has been done.

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Splitter board

Shaper (50 ns)

Latch

Latch

Scaler

TDC

TDC

Shaper (50 ns)

VM

E

DAQ SetupDAQ Setup

Splitter board

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Current

0

0.5

1

1.5

2

2.5

9200 9400 9600 9800 10000 10200 10400 10600 10800HV

A

Gap 1

Gap 2

Gap 3

Gap 4

Gap currents Gap currents

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Single rate BOS-B 004

0

5000

10000

15000

20000

25000

9200 9400 9600 9800 10000 10200 10400 10600 10800

HV

Hz

Single ratesSingle rates

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Single ratesSingle rates

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Definitions (I)Definitions (I)

10000 muons have been triggered for each run with fixed HV and threshold.

To evaluate the RPC performances goldengolden tracks were selected (1 single hit for each layer in drift chambers) reducing the sample to about 5000 events.

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Definitions (II)Definitions (II)

Expected strip

Expected area

The RPC is considered to be efficient if there is an hit in the “expected area” (defined as the expected strip 5 mm).

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Definitions (III)Definitions (III)

Non physical cluster

Physical cluster

We define Physical

Cluster as the set of contiguous strips containing the expected one.

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Plateau efficiency: ~ Plateau efficiency: ~ 96%96% TDC e LATCH results are TDC e LATCH results are

identical within identical within 0,1 %0,1 % HV normalized HV normalized

@ 1013 mbar, 20.5@ 1013 mbar, 20.5ºCºC

Plateau efficiency: ~ Plateau efficiency: ~ 96%96% TDC e LATCH results are TDC e LATCH results are

identical within identical within 0,1 %0,1 % HV normalized HV normalized

@ 1013 mbar, 20.5@ 1013 mbar, 20.5ºCºC

strips: Efficiency vs. HVstrips: Efficiency vs. HV

27/02/2002 M.D.P. - ATLAS Muon Week 12

strips: Efficiency vs. Thresholdstrips: Efficiency vs. Threshold

Plateau efficiency: ~ Plateau efficiency: ~ 96%96% TDC e LATCH results are TDC e LATCH results are

identical within identical within 0,1 %0,1 % HV normalized HV normalized

@ 1013 mbar, 20.5@ 1013 mbar, 20.5ºCºC

Plateau efficiency: ~ Plateau efficiency: ~ 96%96% TDC e LATCH results are TDC e LATCH results are

identical within identical within 0,1 %0,1 % HV normalized HV normalized

@ 1013 mbar, 20.5@ 1013 mbar, 20.5ºCºC

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Mean N. of Clusters Mean N. of Clusters 1.01 @ (0.71mV,10500 V)1.01 @ (0.71mV,10500 V)

HV normalized HV normalized

@ 1013 mbar, 20.5@ 1013 mbar, 20.5ºCºC

Mean N. of Clusters Mean N. of Clusters 1.01 @ (0.71mV,10500 V)1.01 @ (0.71mV,10500 V)

HV normalized HV normalized

@ 1013 mbar, 20.5@ 1013 mbar, 20.5ºCºC

strips: N. of Clustersstrips: N. of Clusters

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Phys. cluster size Phys. cluster size 1.3 1.3 @ (0.71mV,10500 V)@ (0.71mV,10500 V)

HV normalized HV normalized

@ 1013 mbar, 20.5@ 1013 mbar, 20.5ºCºC

Phys. cluster size Phys. cluster size 1.3 1.3 @ (0.71mV,10500 V)@ (0.71mV,10500 V)

HV normalized HV normalized

@ 1013 mbar, 20.5@ 1013 mbar, 20.5ºCºC

strips: Cluster sizestrips: Cluster size

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Plateau efficiency: ~ Plateau efficiency: ~ 96%96% TDC e LATCH results are TDC e LATCH results are

identical within identical within 0,1 %0,1 % HV not normalized! (DCS HV not normalized! (DCS

problem.) problem.)

Plateau efficiency: ~ Plateau efficiency: ~ 96%96% TDC e LATCH results are TDC e LATCH results are

identical within identical within 0,1 %0,1 % HV not normalized! (DCS HV not normalized! (DCS

problem.) problem.)

strips: Efficiency vs. HVstrips: Efficiency vs. HV

27/02/2002 M.D.P. - ATLAS Muon Week 16

Plateau efficiency: ~ Plateau efficiency: ~ 96%96% TDC e LATCH results are TDC e LATCH results are

identical within identical within 0,1 %0,1 % HV not normalized! (DCS HV not normalized! (DCS

problem.) problem.)

Plateau efficiency: ~ Plateau efficiency: ~ 96%96% TDC e LATCH results are TDC e LATCH results are

identical within identical within 0,1 %0,1 % HV not normalized! (DCS HV not normalized! (DCS

problem.) problem.)

strips: Efficiency vs. Thresholdstrips: Efficiency vs. Threshold

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Mean N. of Clusters Mean N. of Clusters 1.05 @ (0.59mV,10500 V)1.05 @ (0.59mV,10500 V)

HV not normalized! (DCS HV not normalized! (DCS problem) problem)

Mean N. of Clusters Mean N. of Clusters 1.05 @ (0.59mV,10500 V)1.05 @ (0.59mV,10500 V)

HV not normalized! (DCS HV not normalized! (DCS problem) problem)

strips: N. of Clustersstrips: N. of Clusters

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Phys. cluster size Phys. cluster size 1.4 1.4 @ (0.59 mV,10500 V)@ (0.59 mV,10500 V)

HV not normalized! (DCS HV not normalized! (DCS problem)problem)

Phys. cluster size Phys. cluster size 1.4 1.4 @ (0.59 mV,10500 V)@ (0.59 mV,10500 V)

HV not normalized! (DCS HV not normalized! (DCS problem)problem)

strips: Cluster sizestrips: Cluster size

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Both curves reach Both curves reach 96%96% of of efficiencyefficiency

HV not normalized to HV not normalized to compare the two curves !compare the two curves !

Both curves reach Both curves reach 96%96% of of efficiencyefficiency

HV not normalized to HV not normalized to compare the two curves !compare the two curves !

and and EfficiencyEfficiency

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and and Cluster sizeCluster size

strips are a little noisier strips are a little noisier than than strips (under strips (under investigation).investigation).

HV not normalized to HV not normalized to compare the two curves !compare the two curves !

strips are a little noisier strips are a little noisier than than strips (under strips (under investigation).investigation).

HV not normalized to HV not normalized to compare the two curves !compare the two curves !

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ConclusionsConclusions

The results show a good RPC behavior for both and plane: Efficiency 96 % Cluster size 1.3 - 1.4

TDC and LATCH give identical results with shaped signals.

The analysis tools to fully test up to 8 RPCs together are ready.

We’re ready for massive tests.

@ working point.