TPC Detector Simulators TPC Fast Simulator TPC Response

TPC Detector Simulators TPC Fast Simulator & TPC Response Simulator April 9, 2000 ALICE-STAR Joint Meeting

TPC Simulators @ Simulate response of TPC Detector volume @ Relevant processes HIonization Drift HAmplification in Sense Wires HPad Plane Signal Generation HReadout Electronics April 9, 2000 ALICE-STAR Joint Meeting Manuel Calderón de la Barca Sánchez Rem. Sl. 8

Current Simulators @ Fast Simulator : TFS HFortran based HExtensively exercised HFast, but not very detailed @ Slow Simulator : TRS HC++ based HMore detailed breakdown of interesting processes April 9, 2000 ALICE-STAR Joint Meeting Manuel Calderón de la Barca Sánchez Rem. Sl. 7

VERY Fast slide on TFS @ Geant Hit Signal @ 2 Widths: prf & z W Intrinsic Pad Response W Drift Length W Pad Crossing Angle W Sense Wire Spacing W Diffusion, Trans. & Lon. W Electronics Shaping Time & Sampling Frequency April 9, 2000 @ Geant Hit Positions W Gaussian Smear = f( prf ) W Hit Merging = f( prf , z ) @ TFS Output Tracking ALICE-STAR Joint Meeting Manuel Calderón de la Barca Sánchez Rem. Sl. 6

TRS: Factorization & OO @ Is it possible to factorize the processes occurring in the chamber? @ Study each process individually HEach process a different base class HAlgorithms for a particular process are implemented in derived classes April 9, 2000 ALICE-STAR Joint Meeting Manuel Calderón de la Barca Sánchez Rem. Sl. 5

TRS : Processes @ Charge Transport @ Charge Collection @ Analog Signal Generation @ Electronics Response & Digitization April 9, 2000 ALICE-STAR Joint Meeting Manuel Calderón de la Barca Sánchez Rem. Sl. 4

Charge Transport @ Transport charge (sub-)segments to sense wires. with field cage electrostatics. . . HField Cage Structure HE & B Field Maps HWire Grid Transparency @ … and Gas properties HDrift velocity HDiffusion & Absorption April 9, 2000 ALICE-STAR Joint Meeting Manuel Calderón de la Barca Sánchez Rem. Sl. 3

Analog Signal @ Induced Charge on Pad H Gas Gain Amplification H Gas Gain Saturation H Cross coupling between adjacent rows H Noise generation @ Implementations, e. g. induced charge: H “Slow” W Image charge integral at the single electron level’ H “Parameterized” W Pad response function April 9, 2000 ALICE-STAR Joint Meeting Manuel Calderón de la Barca Sánchez Rem. Sl. 2

Electronics Response @ Amplification & Gain H Analog shaping response & time W Gaussian, Asymmetric Gaussian, convolution of shaper response funct. w/ longitudinally diffused cluster. @ Digitization H Analog to Digital Conversion H Zero Suppression H Sampling of signal H Distribution of charge into time bins April 9, 2000 ALICE-STAR Joint Meeting Manuel Calderón de la Barca Sánchez Rem. Sl. 1

Status & Summary @ Algorithms being tested, debugged & refined (comparison w/ cosmic ray data) @ Separation of Parameters & Algorithms HDB Geometry, Gas, Calibration parameters HCoordinate Transformations WPlaced DB Utilities area for general use @ Speed up Algorithms April 9, 2000 (~20 min/Central Hijing) ALICE-STAR Joint Meeting Manuel Calderón de la Barca Sánchez Rem. Sl. 0