OPTIONS PROGRESS-PRINT GLOBAL anode = -4100 GLOBAL wdiameter = 0.002 // 20um GLOBAL wypos = 0.0 GLOBAL wpot = 0.0 GLOBAL wtension = 70.0 // 70g GLOBAL wlength = 25.0*1.141 // 45grad Global gas_file `Arg-50-Eth-50.gas` Global gas_member `a50e50` //============================================= & CELL //============================================= opt cell-pr plane y=-1.3 v={anode} plane y=+1.3 v={anode} // we use cartesian system ROWS CARTESIAN S 41 {wdiameter} -8.46+(0.423*I) ... {wypos} ... {wpot} ... {wtension} ... {wlength} ... TUNGSTEN GRAVITY 0 0 1 WRITE DATASET vdc_cell.dat //============================================= & MAGNETIC //============================================= // at present: no B fieed here // whats about the earth B field ?! COMPONENTS 0 0 0 GAUSS //============================================= & GAS //============================================= // 1 atm 50/50 Argon-ethane mixture in your chamber. Call inquire_member(gas_file,gas_member,`gas`,exist) If exist Then get {gas_file,gas_member} Else write {gas_file,gas_member} // Loads the mixture Argon 50 %, ethane 50 % ARG-50-ETH-50 // temp + pressure def before Heed TEMPERATURE 300 KELVIN PRESSURE {1*1013.25} MILLI-BAR // Compute for electrons: drift velocity, diffusion coefficient etc // time comsuming: several hours on 2.4GHz Xeon MAGBOLTZ argon 50 ethane 50 // (Tong put it outside if-else-endif ?!) // Prepares cluster generation by Heed Heed argon 50 ethane 50 Endif !add meta type PostScript file-name "vdc.ps" !open meta !act meta plot-options drift-velocity nodiffusion notownsend opt gas-plot nogas-print //============================================= & OPTIMISE //============================================= //Prints the current potential settings DISPLAY //forces acting on a wire and the wire displacement SELECT 21 FORCES PRINT-SAG PLOT-SAG KEEP-SAG DETAILED ... ELECTROSTATICS GRAVITY //============================================= & FIELD //============================================= AREA -1.5 -1.5 +1.5 +1.5 // Plot electrical field track -1.3 0.0 -0.01 0.0 PLOT-FIELD GRAPH sqrt(EX**2+EY**2) track * * -0.3 * PLOT-FIELD GRAPH sqrt(EX**2+EY**2) track -0.3 * -0.05 * PLOT-FIELD GRAPH sqrt(EX**2+EY**2) track -0.05 * -0.0001 * PLOT-FIELD GRAPH sqrt(EX**2+EY**2) // Plot contour of Electrostatic potential grid 25 area * -.423 * .423 PLOT-FIELD CONTOUR -V RANGE 1200 4000 n=14 area -.423 * .423 * PLOT-FIELD CONTOUR -V RANGE 900 2100 n=24 //============================================= & DRIFT //============================================= //Sets the size and view of the drift area AREA -1.5 -1.5 +1.5 +1.5 //Number of drift lines used by x(t) etc. LINES 60 //Grid density for tables and contour plots GRID 10 20 // define area around wire #21 for possible plots SELECT 21 // select center wire INTEGRATION-PARAMETERS COMPUTE-IF-INTERPOLATION-FAILS // define single track: 45deg TRACK -1.5 -1.5 1.5 1.5 // Heed takes care of cluster generation, it simulates the ionisation of // the gas molecules by a particle. TRACK HEED ... NODELTA-ELECTRONS NOTRACE-DELTA-ELECTRONS ... NOMULTIPLE-SCATTERING ... NOENERGY-CUT ELECTRON ENERGY 0.85 GeV // drift line calculation: // will begin at some of the boundaries of the drift area as set by AREA. DRIFT EDGE notleft notright up down isochrone 0.020 // drift line calculation: // electrons or ions start to drift from the surfaces of the wires that // have been SELECTed. DRIFT WIRE lines 30 isochrone 0.020 // drift line calculation: will begin on the track. DRIFT TRACK TIME-GRAPH CONTOUR 0.020 // relation between the position of a track and the drift time. // This is a calibration curve used by the track reconstruction program XT-PLOT DATASET xt.dat xt1 ... PRECISION 1E-3 ... PRINT-XT-RELATION ... PLOT-XT-RELATION // TIMING: Computes the arrival time distribution of the n'th electron over // a given area. Unlike the ARRIVAL-TIME-DISTRIBUTION instruction, TIMING does // not produce calibration curves, but merely timing distributions. // TIMING ELECTRON 1 ... TIME-WINDOW 0.0 0.3 ... X-RANGE -1.3 0.0 ... Y-RANGE 0.0 1.5 ... ANGLE-RANGE 0.0 90.0 ... BINS 301 ... ITERATIONS 10000 ... RUNGE-KUTTA-DRIFT ... PLOT-OVERALL PLOT-SELECTED-ELECTRON ... PRINT-OVERALL PRINT-SELECTED-ELECTRON //Computes the arrival time distribution of the n'th electron that //reach electrodes from a series of tracks. //A by-product of this calculation is the x(t) relation and an estimate of //the arrival time spread. See XT-PLOT for a comparison with related commands. ARRIVAL-TIME-DISTRIBUTION ELECTRON 1 ... TIME-WINDOW 0.0 0.3 ... STEP X RANGE 0.0 1.4 INCREMENT 0.1 ... SCAN Y RANGE -0.20 0.20 ... ANGLE 47.34 ... DIFFUSION ... DATASET "arrival.dat" min1 ... ITERATIONS 10000 ... PLOT-SELECTED-ELECTRONS PRINT-SELECTED-ELECTRONS ... PLOT-ALL-ELECTRONS PRINT-ALL-ELECTRONS !deact meta !close meta !del meta