Screen printed MicroMEGAS, tests and

plansAtsuhiko Ochi, Yuki Edo, Yousuke Kataoka

ATLAS MicroMEGAS meeting, 11/12/12

Features◦ Main board was manufactured (including

screen printing) by industrial company (Laytech Inc.)

◦ Build up by bulk MM method.◦ Resistive strips are formed by screen

printing.◦ Readout is connected to panasonic

connector. Dimensions

◦ Size : 10cm x 10cm effective area◦ Readout : 1-Dimensional, 400um pitch◦ Gas gap : ~ 100 um (estimated)◦ Drift length : ~ 1.5cm◦ Resistivity : ~ 100MW/cm

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Screen printed MM @ Kobe

Gain measurements using 55Fe (5.9keV).◦ Maximum gas gain ~ 10000 (using Ar:CO2 = 93:7)◦ Operation voltage is 15% smaller than CERN MMs (T

series, Z series) Due to difference of amplification gap?

Basic property tests at labo.

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High rate capability test (8keV XG at CERN labo.)◦ Small gain degradation are found in 107

counts/cm2 irradiation (~ 10%)

Basic property tests at labo.

Histogram of qmax from APV25

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Just now, we have a beam time for fast neutron at Kobe.◦ I am participating this meeting from beam site.

We will put the same chamber in fast neutron beam, and test the properties under HIP circumstances (e.g. spark probabilities)

This week … neutron test

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We will make a second prototype◦ Printing method

Screen printing is good method, but engineer in industrial company suggests that, it will be easy to print large size pattern (with same accuracy) using dispenser.

We have a small dispenser system in KEK, and we will try to use this for next prototype.

◦ Resistive strip pattern We should modify it like a zebra chamber, or some other pattern.

◦ Two dimensional readout.◦ Variable drift space.

Next Plan for prototypes

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The Bulk MicroMEGAS prototype using screen printed resistive strips have been tested at Kobe RD51 labo and CERN H6 beamline.

The maximum gain with Ar-CO2 gas was 11000. Results of beamtest will be given by Yousuke. We will test the chamber under fast neutron just

now! Next prototype will be produced and tested at

beginning of next year.◦ Modifying the resistive value, printing pattern and

printing method.◦ Two dimensional readout.

Conclusion & future prospects

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