1 cross section of a double-stack mrpc. 2 clean room for mrpc strip production
TRANSCRIPT
1
Cross section of a double-stack MRPC
2
Clean room for MRPC strip production
3
Quality assurance tests:
Before strip assembly :• wash/rinse/dry glass plates • measure red-glass resistivity in 5 points• check honeycomb plates and PCB planarityAfter strip assembly : • measure global resistance of resistive glasses• measure gap size in 5 points• HV test in air (3 kV)• check soldering on r/o channels with pulser test • HV test in gas and measure efficiency and time
resolution with cosmic-ray telescope (for a random sample ~3%)
Fill the MRPC database (traveler ---> DCDB)
4
ultrasound tank
(wash)
cold watertanks(rinse)
water filtering system
oven(dry)
Glass-plates washing room
5
Washing the glass plates
Ivan Kiselevich and
Alexandre Zinine
ITEP (Moscow)
at Bologna INFN Section
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Measure the red-glass resistivity in 5 points
0
4
8
12
16
20
2.5 30 55 81 107
misure su 11 vetri
position (cm)
MΩ/□
LabVIEW DAQ system
7
Planarity checkPlanarity check
• all the honeycomb plates and PCBs are checked on a marble high-precision table
• largest accepted non-planarity ∆ = 0.2 mm
8
MRPC construction steps
• Preparation of the components: glueing honeycomb plates on cathode PCBs, inserting plastic screws in bottom PCB, cleaning the red glasses, ..............
9
• Glueing the red glass plates on the PCBs by using the marble precision table
Hyang-Nam Kim and Won-Woong Jung
Kangnung National University
Republic of Korea
at Bologna INFN Section
10
• Stack assembly procedure with “Penelope” (automatic fishing-line positioning machine)
11
• External-to-central PCB pins and connector solderings (1664/strip)
12
0
5
10
15
20
25
234 238 242 246 250 254 258 262 266 270
Gap width - strip b41
(μm)
MRPC assembly monitoring
Microscope + CCD camera + LabVIEW software to check gap width uniformity along a strip (250 μm ± 10 μm)
13
HV test in air at HV test in air at ±3 kV3 kV
0.0
0.2
0.4
0.6
0.8
1.0
0.5 1.0 1.5 2.0 2.5 3.0
corrente anodo
corrente catodo
current (μA)
HV (kV)universal
multichannel power supply CAEN SY3527
MRPC assembly monitoring
For 95% of strips, current is below 100 nA
14
MRPC assembly monitoring
Pulser test to check r/o channels soldering
pulser trace
15
Test with cosmic-ray telescopeTest with cosmic-ray telescope
Trigger with coincidence of at least 4 FAST-OR
signals from FEE
Coincidence
unit
START TDC
Cosmic-ray telescope in Bologna laboratory
Ti – Tj
Tj – Tk
Tk – Tw
Tw – Tz
Tz – Ti
Time resolution computed from 5 time
measurements
σ ij2 = σi
2 + σj2
σjk2 = σj
2 + σk2
σkw2 = σk
2 + σw2
σwz2 = σw
2 + σz2
σzi2 = σz
2 + σi2
σi = √(σij2 + σzi
2 + σkw2 – σjk
2 – σwz
2)/2
MRPC assembly monitoring
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The first 18 MRPCs from mass production tested at PS in July/October 2004
102 HV scans in 4
positions along the
strips