3 /////////////////////////////////////////////////////////////////////////////
5 //---------------------------------------------------------------------
6 // ALICE TPC sector geometry
7 //--------------------------------------------------------------------
9 const Float_t z_end = 250.; // position of the readout chamber
11 // Lower sectors (numbers 1-12), opening angle in radians
13 const Float_t alpha_low=0.523598775; // 30 degrees
15 // Upper sectors (numbers 13-36), opening angle in radians
17 const Float_t alpha_up=0.261799387; // 15 degrees
19 // Pad size 2.05 x 0.35 cm
21 const Float_t pad_pitch_l=2.05;
22 const Float_t pad_pitch_w=0.35;
24 // number of pad rows per sector
26 const Int_t nrow_low = 23;
27 const Int_t nrow_up = 52;
29 // Lower sector, pad row radii
31 const Float_t pad_row_low[23]={
32 89.445, 91.495, 93.545, 95.595, 97.645, 99.695, 101.745, 103.795,
33 105.845, 107.895, 109.945, 111.995, 114.045, 116.095, 118.145, 120.195,
34 122.245, 124.295, 126.345, 128.395, 130.445, 132.495, 134.545};
36 // Upper sector, pad row radii
38 const Float_t pad_row_up[52]={
39 143.72, 145.77, 147.82, 149.87, 151.92, 153.97, 156.02, 158.07,
40 160.12, 162.17, 164.22, 166.27, 168.32, 170.37, 172.42, 174.47,
41 176.52, 178.57, 180.62, 182.67, 184.72, 186.77, 188.82, 190.87,
42 192.92, 194.97, 197.02, 199.07, 201.12, 203.17, 205.22, 207.27,
43 209.32, 211.37, 213.42, 215.47, 217.52, 219.57, 221.62, 223.67,
44 225.72, 227.77, 229.82, 231.87, 233.92, 235.97, 238.02, 240.07,
45 242.12, 244.17, 246.22, 248.27};
47 // Lower sector, number of pads per row
49 const Int_t npads_low[23]={
50 129, 133, 135, 139, 143, 145, 149, 151, 155, 157, 161, 165,
51 167, 171, 173, 177, 179, 183, 187, 189, 193, 195, 199};
53 // Upper sector, number of pads per row
55 const Int_t npads_up[52]={
56 101, 103, 103, 105, 107, 109, 111, 111, 113, 115, 117, 117,
57 119, 121, 123, 123, 125, 127, 129, 131, 131, 133, 135, 137,
58 137, 139, 141, 143, 145, 145, 147, 149, 151, 151, 153, 155,
59 157, 157, 159, 161, 163, 165, 165, 167, 169, 171, 171, 173,
63 // Number of wires per pad and wire-wire pitch
65 const Int_t nwires = 5;
66 const Float_t ww_pitch = 0.41;
68 /////////////////////////////////////////////////////////////////////////////
70 //---------------------------------------------------------------------
71 // ALICE TPC Cluster Parameters
72 //--------------------------------------------------------------------
76 const Float_t a_rphi=0.41818e-2;
77 const Float_t b_rphi=0.17460e-4;
78 const Float_t c_rphi=0.30993e-2;
79 const Float_t d_rphi=0.41061e-3;
81 const Float_t a_z=0.39614e-2;
82 const Float_t b_z=0.22443e-4;
83 const Float_t c_z=0.51504e-1;
84 // Cluster width in rphi
85 const Float_t ac_rphi=0.18322;
86 const Float_t bc_rphi=0.59551e-3;
87 const Float_t cc_rphi=0.60952e-1;
89 const Float_t ac_z=0.19081;
90 const Float_t bc_z=0.55938e-3;
91 const Float_t cc_z=0.30428;
96 /////////////////////////////////////////////////////////////////////////////
98 //---------------------------------------------------------------------
99 // ALICE TPC Gas Parameters
100 //--------------------------------------------------------------------
103 // Diffusion constants
105 const Float_t diff_t=2.2e-2;
106 const Float_t diff_l=2.2e-2;
108 // Lorentz angle (omega_tau)
110 const Float_t omega_tau = 0.125;
112 // Electron drift velocity
114 const Float_t v_drift=2.85e6;
115 /////////////////////////////////////////////////////////////////////////////
117 //---------------------------------------------------------------------
118 // ALICE TPC Electronics Parameters
119 //--------------------------------------------------------------------
123 const Float_t t_sample = 2.e-7; // sampling time
124 const Float_t fwhm = 2.5e-7; // width of the Preamp/Shaper function
128 const Float_t gas_gain = 1.e4; // gas gain
129 const Float_t q_el = 1.602e-19; // elementary charge
133 const Float_t adc_sat = 1023; // dynamic range (10 bits)
134 const Float_t zero_sup = 5.; // zero suppression
135 const Float_t sigma_noise = 500.; // electronics noise (no. of electrons)
136 const Float_t chip_gain = 24.; // conversion gain (mV/fC)
137 const Float_t dyn_range = 2000.; // output dynamic range (mV)