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

2. April 9, 2000 ALICE-STAR Joint Meeting Manuel Calderón de la Barca Sánchez TPC Simulators @Simulate response of TPC Detector volume @Relevant processes  Ionization Drift  Amplification in Sense Wires  Pad Plane Signal Generation  Readout Electronics Rem. Sl. 8

3. April 9, 2000 ALICE-STAR Joint Meeting Manuel Calderón de la Barca Sánchez Current Simulators @Fast Simulator : TFS  Fortran based  Extensively exercised  Fast, but not very detailed @Slow Simulator : TRS  C++ based  More detailed breakdown of interesting processes Rem. Sl. 7

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

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

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

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

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

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

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