Sealed RPCs: The LIP approach

P.FonteLIP- Coimbra

Objective:

Develop a large area sealed RPC detector that may be used for cosmic ray experiments and Outreach activities.

InexpensiveModular (easy maintenance)TOF-quality timing

1st prototype built in August 2009Learning process ongoing…

Mechanics

External (independent)readout electrodes

2mm glass4 mm acrylic

10.004 mm acrylic

5mm

100.00

K7 approach

1st prototype

1m2Under test since August

Performance so far (example)

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12-01-10 14-01-10 16-01-10 18-01-10 20-01-10 22-01-10 24-01-10 26-01-10 28-01-10 30-01-10Date

Cor

rent

e (n

A)

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sure

(mba

r), T

empe

ratu

re (a

.u.)

Background currentCounting currentTemperaturepressure

Chamber sealed

The contamination is internal. We made VERY sure there is no macroscopic leakage.

Best guess (my version): air trapped in adesives and/or under foils. If so, should go away after a few cleaning cycles. Obvious alternative: outgassing from materials.