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 planarity After 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 water tanks (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

6 Measure the red-glass resistivity in 5 points position (cm) MΩ/□MΩ/□ LabVIEW DAQ system

7 Planarity 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 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 3 kV HV test in air at ± 3 kV 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 telescope Trigger with coincidence of at least 4 FAST-OR signals from FEE Coincidence unit START TDC Cosmic-ray telescope in Bologna laboratory T i – T j T j – T k T k – T w T w – T z T z – T i Time resolution computed from 5 time measurements σ ij 2 = σ i 2 + σ j 2 σ jk 2 = σ j 2 + σ k 2 σ kw 2 = σ k 2 + σ w 2 σ wz 2 = σ w 2 + σ z 2 σ zi 2 = σ z 2 + σ i 2 σ i = √(σ ij 2 + σ zi 2 + σ kw 2 – σ jk 2 – σ wz 2 )/2 MRPC assembly monitoring

16 The first 18 MRPCs from mass production tested at PS in July/October HV scans in 4 positions along the strips