TEST GIF SPS OCTOBER 01

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TEST GIFSPSOCTOBER 01
Tested 2 RPCs RB (1342) double-oil
65X272 cm2 RS standard
50X50 cm2
? flux varied by means of absorbers abs10
5 Hz/cm2 abs5
10 Hz/cm2 abs1 30 Hz/cm2
Detectors in front of our chambers
?-beam from SPS 10000/burst max
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EXPERIMENTAL SET-UP
7.2 C4H10 41.3 C2H2F4 50.5 Ar 1 SF6 RB
70cc/min RS 30cc/min
952 mblt P lt964 mb 20.5Clt T lt22C P0953 mb
T0294K21C VeffVa P0/PT/T0

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THE BIG RPC
x
94 vertical strips (x-strips) 16 read-out (2.81
cm wide) 22 horizontal strips (y-strips) 8
read-out (2.81 cm wide)
4 1 56 23
y
3 1 2
Efficiency measurements - different ? fluxes -
different positions

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Efficiency with GIF OFF-1

Y
X

5
Efficiency with GIF ON-1

X
Y

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Efficiency with GIF ON-2

Y
X
30 Hz/cm2
10 Hz/cm2
5 Hz/cm2

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TEST GIFCOSMIC RAYS NOVEMBER-DECEMBER 01
RB (1342) double-oil RS
(1409,June 01) double-oil
? max 100-130 Hz/cm2 7.2 C4H10 41.3
C2H2F4 50.5 Ar 1
SF6 RB 70cc/min RS 30cc/min
957mbltPlt982mb 14.5CltTlt18C P0965 mb
T0289K16C VeffVa P0/PT/T0
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THE CHAMBERS
RS
RB
16 x-strips16 x-strips 14 y-strips
16 x-strips
H.V.8200 V
H.V.8300 V
Efficiency Current Counting rates
3 1 2

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Current and rates-GIF OFF


10
Current and rates-GIF ON

Veff-Va

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RB Efficiency-GIF OFF

?
?
Y
X

H.V.
H.V.
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Efficiency-GIF ON

Veff-Va

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Efficiency vs Rates
With GIF OFF - uniform efficiency - 10 Hz/cm2
pos.2 - 3 Hz/cm2 pos.1 - 1 Hz/cm2
pos. 3

With GIF ON - efficiency decreasing with rate -
efficiency decrease dependent on position

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The counting method

A Rate measured at a fixed V0 and abs1
B Expected rate at a fixed V0
and abs1 (rateabs10-rateGIFOFF)86001
0(rateGIFOFF)V0
EFFICIENCY for each strip A/B

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Efficiency by counting method-1

15 Hz/cm2
115 Hz/cm2

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Efficiency by counting method-2

15 Hz/cm2
115 Hz/cm2

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Efficiency by counting method-3

?
X
Abs10 15 Hz/cm2
Y
Abs1 115 Hz/cm2
H.V.8300

Strip number
Strip number
18
Laboratory test in Turin-1


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Laboratory test in Turin-2
efficiency by tracking
SY19
3
2
1
4
SY4
SX1
SX61
SX76
SX45
- Cosmic rays - Cosmic rays ? by 137Cs

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Efficiency by tracking-Pos.2
Y
Y
X
X
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Efficiency source on and off-1
( 70 Hz/cm2 measured)
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Efficiency source on and off-2
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Crowns
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Conclusion
- the efficiency is not uniform - the
efficiency decreases with rate (dry mixture?)
Outlook
- test in Turin of this RPC with humid mixture -
test at the GIF from April of a new real-size RPC