Diego González-Díaz

Tsinghua 1m-long counter with walls

~∞..

.. 6 gaps (g=0.22mm, εr=1)

~∞grounded at FEE input grounded at RPC end

d=0.7mmεr=7.5

HV, hHV~0

insulator, hins~0

hpcb=1.5mmεr=4.7

w=25mm

~∞wgap =4mmwwall =1mm

electrical scheme of the RPC in working conditions

FEE

L=94 cm

transverse section

....

grounded at LEMO cable

R=50Ω

floating

sourcevictims

electrical scheme used for validation of simulation

transverse section

cathode 1anode 1

cathode 2anode 2 50

cathode 350 anode 3 50

cathode 4anode 4 50

cathode 5anode 5

cathode 5anode 5

50

Zdet~37.5

USTC 0.5m-long counter without wallsand mirrored

~∞..

.. 5 gaps (g=0.22mm, εr=1)

~∞

d=0.7mmεr=7.5

HV, hHV~0

insulator, hins~0

hpcb=0.8mmεr=4.7

w=25mm~∞

wgap =6mm

electrical scheme of the RPC in working conditions

FEE

L=52.5 cm transverse section

.... 5 gaps

grounded at FEE input

cathode 1anode 1

cathode 2anode 2 50

cathode 350 anode 3 50

cathode 4anode 4 50

cathode 5anode 5

cathode 5anode 5

50

Zdet~20.5

Preliminary results: only charge sharing

Tsinghua 1m-long counter with walls

weighting field

Efficiency profile (I)

Efficiency profile (II)

Efficiency profile with broad trigger (1cm) (I)

Efficiency profile with broad trigger (1cm) (II)

average charge (I)

average charge with broad trigger (1 cm) (II)

Not so preliminaryresults

Scan in HV

Free parameters:

Qth=30fC

reportedQth=[10-30fC]

P. Fonte's long counter

Tsinghua's short counter

Free parameters:

Qth=150fC

Not reported! for slow electronics Qth=[50-150fC] are not strange (NINO).

USTC 50-cm counter

Free parameters:

Qth=150fC

Qth=60fC(measured)

Free parameters:

1kV effective drop in the appliedvoltage must be assumed (?)

Heidelberg counter

Scan in transverse coordinate

(cross-talk is included from APLAC simulations in each particular configuration!)

Free parameters:

•trigger region(2 cm – nominal)

•Cross-talk fuzzy factor x1.7

Tsinghua's short counter

Tsinghua's short counter

Free parameters:

•trigger region(2 cm – nominal)

•Cross-talk fuzzy factor x1.7

USTC 50-cm counter

USTC 50-cm counter

Free parameters:

•trigger region(2 cm – nominal)

•Cross-talk fuzzy factor x0.6

cross-talkfuzzy factor:0.4

P. Fonte's long counter

Conclusions

A new RPC simulator is available:

•The simulator can approximate the behavior of a large range of systematic measurements for completely different detector geometries.

• A first quantitative description of charge-sharing has been attempted. Detectors with little inter-strip spacing and/or shielding can be reasonably described by the used analytical formulas. Accurate comparison in other cases requires to use different tools (work in progress).

• A first quantitative description of charge-sharing has been attempted by using APLAC to estimate the fraction of signal coupled to the neighbors. The data can not be described unless extra factors amounting to x0.4 (Fonte-large), x0.6 (Heidelberg) and x1.7 (Tsinghua/USTC) are introduced. The cross-talk simulation is very sensitive to the whole structure + electronics and it is still difficult to make safe predictions. The best practical approach seems to be to simulate the situation and ensure that the cross-talk is not a problem even for x2-3 more cross-talk than simulated (engineering approach). This is not yet my final word!.

• There are plenty of things that can be done with existing data still in order to help us understand what is going on and debugging the simulator.