A systematic study of rate capability in MWPCs (final analysis)

A systematic study of rate capability in MWPCs

(final analysis)

D. Gonzalez-Diaz

16-10-2008

Set-up

Gain measurements (I)

Gain measurements (II)

The Mathieson model (I)

The Mathieson model (II)

Blanc's Law:

Rate capability at fractional gain drop F:

Typical rate curves

Correction for beam-size dependence (I)

Correction for beam-size dependence (II)

Correction for beam-size dependence (III)

Comparison with theoretical curves

Global fit to all curves: 6 (3mixtures x 2 pitches) parameters

Comparison with measured mobilities

Extrapolation to mips

Comparison with data from mips

Conclusions

Once one corrects for beam-size effects and if the nature of the drifting ion is known, the Mathieson formula has an enormous predictive power.

There is room for a further increase of pion suppresion without sacrifying the rate capability (increasing the gap h).

Appendix

Dead time correction

Beam-size dependence

All in a nut-shell

rate capability extrapolation