1 Cross section of a double-stack MRPC. 2 Clean room for MRPC strip production

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

6

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

16

The first 18 MRPCs from mass production tested at PS in July/October 2004

102 HV scans in 4

positions along the

strips