WIP: start the development of Drift Chamber for CEPC

[mirguest]

• detector description (DD4hep)
  • The dimensions are defined as the constants (See commit 2d3a664)
  • Envelope for the Drift Chamber
    • radii: 235 mm, 1716 mm
    • z: -2225 mm, 2225 mm
  • inner chamber
    • radii: 235 mm, 909 mm
    • z: -2225 mm, 2225 mm
  • outer chamber
    • radii: 1085 mm, 1716 mm
    • z: -2225 mm, 2225 mm
  • silicon between inner and outer chamber
  • B-Field: 3 Tesla, uniform: See commit a663edc
• detector response (Geant4 Sensitive Detector)
  • register the Tracker SD for Drift Chamber as the first step.
  • need a specific SD for Drift Chamber to simulate: (See PR WIP: start to design the dE/dx simulation tool. #40)
    • the drift distance and time
    • dE/dx Tool Interface (See PR WIP: start to design the dE/dx simulation tool. #40)
      • Check the units. ⚠️ The units for the dE/dx follows the Geant4 convention.
  • Need a DD4hep Segmentation to calculate the CellID
• digitization
• Definition of the cellID
  • system: 8bit
  • chamber: 1bit (0: inner, 1: outer)
  • layer: 7bit (for inner: 67 layers, for outer: 63 layers)

Progress:

• PR WIP: development of Drift Chamber for CEPC #13 : a very simple implementation of two tubes.