The design and preliminary tests of microstrip-microgap RPC ( M-M-RPC ). P. Fonte 1 , R. Oliveira 2 ,G. Paic 2,3 , V. Peskov 2,3 F. Pietropaolo 4 , P. Pichhi 5 1 LIP, Coimbra, Portugal 2 CERN, Geneva, Switzerland 3 UNAM, Mexico 4 INFN Padova, Padova, Italy - PowerPoint PPT Presentation
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The design and preliminary tests of microstrip-microgap RPC
(M-M-RPC)
P. Fonte1, R. Oliveira2,G. Paic2,3, V. Peskov2,3 F. Pietropaolo4, P. Pichhi5
Due to the time constrains the CsI coating was done by a spray technique
Gain calibr in current mode
0.01
0.1
1
10
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Voltage
nA
Series1
Series2
Series3
P. Fonte et al., NIM A431,1999, 154
R-R-RPC with spacers in corners
Preliminary estimations:no good plateau, charging up(?), space
charge( ?)…
Estimated gain, preiminary
1.00E-01
1.00E+00
1.00E+01
1.00E+02
1.00E+03
1.00E+04
1.00E+05
1.00E+06
1.00E+07
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Voltage (V)
Gain
Ar+10%ethnan0.5 mme,
X-rays and UV
Ar+25%CO2UV, 0.18mm
Ar+25%CO2X-rays
The highest gains were obtained among all resistive micropattern
detectors(to be discussed)
3.2.Charge profile measurements
The current prototype have not connectors allowing to readout all
strips independently
Induced signal profile measured with 0.5mm gap M-M-RPC in
Ar+25%CO2
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1
1.2
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
Step/strip number (250 micron each)
Sig
nal
am
pli
tud
e (a
r.
un
its)
Preliminary (step-strip scan)!
Anode strip
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-6 -4 -2 0 2 4 6
Step number (250 micron)
Sig
na
l a
mp
litu
de
(a
rb. in
its
) Cathode strip
I. Crotty et al., NIM A505, 2003, 203
Preliminary: R-R-RPC with pillars
More studies should be done(Changes in CsI? Problem with pillars?)
Gain with pillars 128 micron
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Voltage
Es
tim
ate
d g
ais
n
Region of current instability
Conclusions:•Preliminary it looks like M-M-RPC can be an interesting alternative to R-MICROMEGAS• Certainly more work should be done to prove this.• Potential advantages: good position and time (much below ns) resolutions, possibility to apply automatic procedure to build large area M-M-RPC (no mesh)
Nearest plans:More test with pillars and tests with Miranda CsITest of new designs (currently in manufacturing process)Large- area M-M-RPCTests in “standard” RPC gases ensuring high time resolution( in these studies Ar based mixtures were chosen to compare to PPAC and resistive MICROMEGAS )
Study CsI coating as a sec. electr. emitterWork more closely to J. Wotschack and P. Fonte group on applications for muon detection and TOF PET