Step 1: Install a version of Geant on your computer +++++++ Step 2: Create an application code writing 5 classes and the main program: +++++++ Detector construction: ====================== Element Name Z A Density Ar 18 39.948*g/mole 1.662*mg/cm3 C 6 12.011*g/mole 2.265*g/cm3 Ce 58 140.12*g/mole 6.637*g/cm3 Cu 29 63.546*g/mole 8.96*g/cm3 F 9 18.998*g/mole 1.108*g/cm3 H 1 1.00794*g/mole 70.8*mg/cm3 N 7 14.007*g/mole 1.165*mg/cm3 O 8 15.999*g/mole 1.3315*mg/cm3 Si 14 28.005*g/mole 2.33*g/cm3 Zn 30 65.39*g/mole 7.112*g/cm3 Material Name Density Composition (by weight) Air 1.214*mg/cm3 N: 0.75 O: 0.24 Ar: 0.01 Brass 8.53*g/cm3 Cu: 0.70 Zn: 0.30 CeF3 6.16*g/cm3 Ce: 0.71085768 F: 0.28914232 Scintillator 1.032*g/cm3 C: 0.91512109 H: 0.08487891 One layer of 43.0 cm thick CeF3 of size 18.2 cm x 18.2 cm. Divide each layer into cells of size 2.6 cm x 2.6 cm Make 20 layers of 10 mm thick plastic scintillators of size 80 cm x 80 cm interleaved with brass plates of same size with first 10 layers of 50 mm thickness and the remaining layers of 56 mm thickness. Each scintillator is divided into cells of size 10 cm x 10 cm Hit Class with attributes: ========================== ID of CeF3 crystal or scintillator cell Energy deposit (all particles) Time of the first hit Sensitive Detector class: ========================= Attach to the logical volumes corresponding to: Each CeF3 crystal (combine row & column numbers) or scintillator cell (combine cell position along x, y axes and layer number) For CeF3, combine he crystal # in each direction (along x and y) to get cell ID (100*cell IDY + cell IDX). For scintillator, use the layer #, cell position along each direction for ID (layer*10000 + 100*cell IDY + cell IDX). Search, within the hit collection class of either type, a hit with the same ID. If not found, store cell ID, time, and energy deposit as a single hit else, if the time matches with the stored time within 1 ns, add energy deposit to the corresponding hit energies else create a new hit with the cell ID, new time and energy deposits Event Action class: =================== At the beginning of the event define a ROOT tree where o/p is saved At the end of each event, fill the tree with the information from the hit collection Primary Generator Action: ========================= Create a primary vertex at the left most edge of the world volume (must be just inside it) Create a particle of given type going along +z direction with a predefined energy Step 2: +++++++ o Generate 1000 events with 20 GeV muon(-) varying the primary vertex positions along x,y to be centered on each cell and save the outputs as ROOT tree o Generate 1000 events of negative pions of energies 5, 10, 20, 50, 100 and 200 GeV with the vertex facing the middle of the detector. Step 3: +++++++ Select all hits which satisfy a timing cut o Analyze the muon sample to determine what a minimizing ionizing particle deposits energy in each layer o Use the MPV (most probable value) for each cell to have relative calibration of each cell o Now use the 50 GeV pion run and see number of MIPs in each cell. Scale total MIPs to 10 GeV to get overall energy scale factor for each type of hit energy o Analyze all pion samples Get # of MIPS and convert to energies using the scale factor obtained from the previous step. From the energy distribution, compute most probable value and its mean dispersion to measure linearity as well as resolution. o Separate events where shower starts in ECAL or HCAL. Check if one can improve resolution by treating the two samples separately. o Also separate energy deposits due to electrons/positrons (which can produce Cerenkov as well as scintillation signals) or due to charged hadrons (which can generate signals only due to scintillation) and see if suitably combining the two components one can get back lineaarity in response and improve energy resolution.