Technische Universität München Status report on SADC feature extraction.

Technische Universität München

Status report on

SADC feature extraction

Technische Universität München

Outline

• Feature extraction fitting pulses– General idea– Parameter sets– Implementation

• AC noise suppression• Performance (comp. to std. alg.)

– Energy spectrum for e- calibration

– “0” mass spectrum

• Conclusion

Technische Universität München

Feature extraction using functional parameterization

• Describe pulses by analytic function (Silicon, J. Friedrich)

• Fix function parameters (calibration)• Fit/Calculation of time and amplitude

Technische Universität München

Typical pulse and its description

Technische Universität München

Result of fit (first parameter)

Using three parameter sets for ECAL02

Parameter sets depend on shaper not on cell type!!

Technische Universität München

Signals on two different channels

Analytic calculation of function variables due to large amplitude error not desirable

Technische Universität München

AC coupling

Technische Universität München

AC Coupling suppression (ACS)

• AC coupling signals have amplitude independent length

• Remove all signals with a half-width ≤ 5

• Problems for small signal introduce threshold to apply cut

Technische Universität München

40 GeV e- Beam – ECAL calibration(std: green, pf: red)

Technische Universität München

40 GeV e- Beam – ECAL calibration(std: green, pf: red)

Technische Universität München

40 GeV e- Beam – ECAL calibration(std: green, pf+acs: blue)

Technische Universität München

M(0) (PulseFit & AC suppresion) VS std. FE

• slightly improved energy resolution (~ 4%)

• slightly improved signal to bg ratio ~ (0.2%)

• reduced signal integral (~ 8%)

Technische Universität München

Deeper analysis:

Feature of shower reconstruction (“instable” against small changes )

M(0) PulseFit VS std. FE

• increased signal integral (~ 4%)

• decreased energy resolution (~ 50%)

• decreased signal to bg ratio (~ 20%)

Technische Universität München

Conclusion

• Alternative method for feature extraction available• Electron beam performance (without calibration

adaption) promising• Reconstruction problems for 0 observed

Improvement by adaption of shower reconstruction possible?

• Increased CPU usage (for physics runs 20% of total runtime)

• Fine tuning needed (dep. on shower reconstruction) For the moment std. reconstruction is the preferable

option!!!

Technische Universität München

Thank you.