1 TPC Meeting Institute of Physics, Academia Sinica Jia-Ye Chen 2 Outline Pile-up Pulse Decomposition Study Pulse Identification, Fitting (Well & Failure) Statistics, Efficiency, Residual and Further more... Pad Response Function (PRF) Smearing Effect and Parameterization of PRF Experimental Measurement & Analysis 3 Pile-up Pulse Decompisition Algorithm for Identification Single Pulse & Shape Parameterization Pile-up Pulse, Shoulder Pulse and Coupled Failed Fitting (small pulse, plateau pulse) Efficiency : Percentage of Pulse Residual Question & Problem 4 Algorithm for Identification Pile-up Pulse peakAdc > threshold (dynamic threshold) Separation of peakTdc > 2 clocks Pulse valley away from prevPeakTdc > 2 clocks Shoulder Pulse ( By Su-Yin Wang ) (ADC ) < -8. Separation to neighboring peakTdc > 3. 5 Single Pulse 6 7 Pile-up Pulse 8 9 Shoulder Pulse 10 Shoulder Pulse 11 Shoulder Pulse 12 Pile-up & Shoulder Pulse 13 Failed Pulse : Saturated 14 Failed Pulse : Saturated 15 Percentage of Pulse ID old definition number of pulse = number of single pulse = 43383(56.38%) number of multiple pulse = 22086(28.70%) number of no definition pulse = 11477(14.92%) number of defined pulse = ( ) number of single pulse = 43383(66.26%) number of multiple pulse = 22086(33.74%) old multiple, new single number of pulse = 3989 (18.06%) in number old defined multiple pulse old single, new multiple number of pulse = (34.50%) in number old defined single pulse 16 Percentage of Failure number of pileup pulse = number of single pulse = 30534(56.24%) number of double pulse = 22563(41.58%) number of triple pulse = 956( 1.76%) number of quadruple pulse = 247( 0.46%) number of (1)pulse =18(0.0074%) (percentage in double pulse (0.0177%)) (chi_square>4, single pulse) number of ( )pulse =89 (0.16%) (percentage in double pulse (0.39%)) (chi_square>4, single pulse) 17 Efficiency & Residual Run : First 500 Events & only double-pulse event w/o triple-, quadru-, OLD 6 Events/sec NEW 1.5 Events/sec 18 Question & Problem Can we believe the fitting? Yes, which should be fitted, which not? Polynomial Approximation, instead of exact Error Function Fitting? Computing Time : much slower than previous one. 19 Smearing Effects to PRF transverse diffusion coefficient drift velocity of electron drift length wire spacing Lorentz angle due to ExB effect 20 FWHM of the PRF TRIUMF TPC Pad rows are parallel to the sense wire. 21 Angle(T,W) vs Angle(P,W) 22 Angle(T,W) vs Angle(P,W) 23 Angle(T,W) vs Angle(P,W) 24 Angle(T,W) vs Angle(P,W) 25 Angle(P,W) Slices 26 Angle(P,W) Slices 27 Angle(P,W) Slices 28 Angle(P,W) Slices 29 Angle(P,W) Slices 30 Angle(P,W) Slices 31 Angle(P,W) Slices 32 Angle(P,W) Slices 33 Angle(P,W) Slices 34 Angle(P,W) Slices 35 Angle(P,W) Slices 36 Angle(P,W) Slices 37 Parameterization of PRF 38 Parameterization of PRF 39 Backup Slices 40 Pad Response Function The induced charge distribution is called Pad Response Function . Width of PRF 1.Direct measure of the power to distinguish between two close-by coordinates. 2.Determine the two-track resolution. 41 : chamber-specific pad response width, often normalized to the pad width P by Parameterization of PRF Under the optimal design of pad width G : the distance between sense wire and cathode plane 42 Smearing Effects to PRF The transverse diffusion The angular wire effect The angle under which the tracks cross the wire- normal. The E B effect close to the sense wires The angular pad effect If tracks cross the normal on a pad-row under a non- zero angle. If more than one wire contributes to a pad signal. 43 Experimental Measurement New TPC By Nakatsugawa Yohei Line Fitting (Lab. Frame)