ORCA 8 EcalPlusHcalTower Geometry ================================= Hcal Tower Eta Size Depth -------------- --------- Segments EcalPlusHcalTowers Index Low High Det eta phi Num-Crystals 1 0 0.087 HB,HO 0.087 5 deg HB=1,HO=1 25 2 0.087 0.174 HB,HO 0.087 5 deg HB=1,HO=1 25 3 0.174 0.261 HB,HO 0.087 5 deg HB=1,HO=1 25 4 0.261 0.348 HB,HO 0.087 5 deg HB=1,HO=1 25 5 0.348 0.435 HB,HO 0.087 5 deg HB=1,HO=1 25 6 0.435 0.522 HB,HO 0.087 5 deg HB=1,HO=1 20 7 0.522 0.609 HB,HO 0.087 5 deg HB=1,HO=1 25 8 0.609 0.696 HB,HO 0.087 5 deg HB=1,HO=1 30 9 0.696 0.783 HB,HO 0.087 5 deg HB=1,HO=1 25 10 0.783 0.870 HB,HO 0.087 5 deg HB=1,HO=1 20 11 0.879 0.957 HB,HO 0.087 5 deg HB=1,HO=1 25 12 0.957 1.044 HB,HO 0.087 5 deg HB=1,HO=1 30 13 1.044 1.131 HB,HO 0.087 5 deg HB=1,HO=1 25 14 1.131 1.218 HB,HO 0.087 5 deg HB=1,HO=1 20 15 1.218 1.305 HB,HO 0.087 5 deg HB=1,HO=1 25 16 1.305 1.392 HB 0.087 5 deg HB=1 30 17 1.392 1.479 HE 0.087 5 deg HE=1 25 18 1.479 1.566 HE 0.087 5 deg HE=1 19 19 1.566 1.653 HE 0.087 5 deg HE=1 18 20 1.653 1.740 HE 0.087 5 deg HE=1 15 21 1.740 1.830 HE 0.090 10 deg HE=1 24 22 1.830 1.930 HE 0.100 10 deg HE=1 21 23 1.930 2.043 HE 0.113 10 deg HE=1 19 24 2.043 2.172 HE 0.129 10 deg HE=1 17 25 2.172 2.322 HE 0.150 10 deg HE=1 16 26 2.322 2.500 HE 0.178 10 deg HE=1 13 27 2.500 2.650 HE 0.150 10 deg HE=1 10 28 2.650 3.000 HE 0.350 10 deg HE=1 10 *29 2.853 2.964 HF 0.111 10 deg HF=2 0 30 2.964 3.139 HF 0.175 10 deg HF=2 0 31 3.139 3.314 HF 0.175 10 deg HF=2 0 32 3.314 3.489 HF 0.175 10 deg HF=2 0 33 3.489 3.664 HF 0.175 10 deg HF=2 0 34 3.664 3.839 HF 0.175 10 deg HF=2 0 35 3.839 4.013 HF 0.174 10 deg HF=2 0 36 4.013 4.191 HF 0.178 10 deg HF=2 0 37 4.191 4.363 HF 0.172 10 deg HF=2 0 38 4.363 4.538 HF 0.175 10 deg HF=2 0 39 4.538 4.716 HF 0.178 10 deg HF=2 0 40 4.716 4.889 HF 0.173 10 deg HF=2 0 41 4.889 5.191 HF 0.302 10 deg HF=2 0 Actual HCAL Geometry ==================== Hcal Tower Eta Size Depth -------------- --------- Segments Trigger Tower Index Low High Det eta phi Num-Crystals 1 0 0.087 HB,HO 0.087 5 deg HB=1,HO=1 25 2 0.087 0.174 HB,HO 0.087 5 deg HB=1,HO=1 25 3 0.174 0.261 HB,HO 0.087 5 deg HB=1,HO=1 25 4 0.261 0.348 HB,HO 0.087 5 deg HB=1,HO=1 25 5 0.348 0.435 HB,HO 0.087 5 deg HB=1,HO=1 25 6 0.435 0.522 HB,HO 0.087 5 deg HB=1,HO=1 25 7 0.522 0.609 HB,HO 0.087 5 deg HB=1,HO=1 25 8 0.609 0.696 HB,HO 0.087 5 deg HB=1,HO=1 25 9 0.696 0.783 HB,HO 0.087 5 deg HB=1,HO=1 25 10 0.783 0.870 HB,HO 0.087 5 deg HB=1,HO=1 25 11 0.879 0.957 HB,HO 0.087 5 deg HB=1,HO=1 25 12 0.957 1.044 HB,HO 0.087 5 deg HB=1,HO=1 25 13 1.044 1.131 HB,HO 0.087 5 deg HB=1,HO=1 25 14 1.131 1.218 HB,HO 0.087 5 deg HB=1,HO=1 25 15 1.218 1.305 HB,HO 0.087 5 deg HB=2,HO=1 25 16 1.305 1.392 HB,HE 0.087 5 deg HB=2,HE=1 25 17 1.392 1.479 HE 0.087 5 deg HE=1 25 18 1.479 1.566 HE 0.087 5 deg HE=2 ?? 19 1.566 1.653 HE 0.087 5 deg HE=2 ~17 20 1.653 1.740 HE 0.087 5 deg HE=2 ~14 21 1.740 1.830 HE 0.090 10 deg HE=2 ~12 x 2 22 1.830 1.930 HE 0.100 10 deg HE=2 ~11 x 2 23 1.930 2.043 HE 0.113 10 deg HE=2 ~10 x 2 24 2.043 2.172 HE 0.129 10 deg HE=2 ~8 x 2 25 2.172 2.322 HE 0.150 10 deg HE=2 ~7 x 2 26 2.322 2.500 HE 0.178 10 deg HE=2 ~6 x 2 27 2.500 2.650 HE 0.150 10 deg HE=3 ~5 x 2 28 2.650 3.000 HE 0.350 10 deg HE=3 ~10 x 2 *29 2.853 2.964 HF 0.111 10 deg HF=2 0 30 2.964 3.139 HF 0.175 10 deg HF=2 0 31 3.139 3.314 HF 0.175 10 deg HF=2 0 32 3.314 3.489 HF 0.175 10 deg HF=2 0 33 3.489 3.664 HF 0.175 10 deg HF=2 0 34 3.664 3.839 HF 0.175 10 deg HF=2 0 35 3.839 4.013 HF 0.174 10 deg HF=2 0 36 4.013 4.191 HF 0.178 10 deg HF=2 0 37 4.191 4.363 HF 0.172 10 deg HF=2 0 38 4.363 4.538 HF 0.175 10 deg HF=2 0 39 4.538 4.716 HF 0.178 10 deg HF=2 0 40 4.716 4.889 HF 0.173 20 deg HF=2 0 41 4.889 5.191 HF 0.302 20 deg HF=2 0 Notes: HF tower 29 is completely shadowed by HE tower number 28, and hence the energy in HF tower 29 comes dominantly from lateral shower spreading from HF tower 30. HE segmentation confirmed by Alexei Volkov, 17-May-2005. Tower 28 in the HE has complex eta segmentation. The 1st and 2nd depth segments are divided in eta at eta=2.868 (sometimes called tower 28a and tower 28b or HCAL Tower 28 and HCAL Tower 29) but the 3rd depth segment behid them both is not divided in eta. The 1st segment is scintilating layers 0, 1, 2, the 2nd depth segment is layers 3 and 4, and the 3rd is layers 5 through 17. Tower 15 in the H0 part has half the eta coverage of Tower 15 in the HB. The depth segments in the HF are really 1) long fibers that run from front to back. 2) short fibers that start 12 X0 deep and run to the back. The numbers above for eta and phi in the HF are measured at the front face of the calorimeter, and that is what is used currently for jet clustering. Since the geometry in the HF is x-y, a more correct approach would be to measure them at an appropriate depth (shower maximum). The number of crystals per EcalPlusHcalTower is determined in ORCA by matching them to their nearest HCAL cell, and hence is not fixed at 25 in the Barrel. The number of crystals per Trigger Tower in the endcap is estimated from a drawing in the DAQ TDR.