1. Review of PID simulation & reconstruction in G4MICE Yordan Karadzhov Sofia university “St. Kliment Ohridski” Content : 1 TOF 2 Cerenkov

2. TOF sector Simulation – the position and the time of the hits in the TOF bars and the energy deposition are stored. No simulation of any optical processes. Digitization – the time of the hit is converted into TDC counts by taking into account the distance between the position of the hit and the PMT. The energy deposition is converted into ADC counts again taking into account the reduction of the signal because of the light absorption. Reconstruction – for the moment there is a reconstruction only for the simulated data. For the real data we will need t 0 constants and a time walk correction.

3. Work done The Simulation and the Digitization are tested and cleaned from bugs. The Reconstruction for the simulated data is implemented. The Persistence of the simulated TOF data is completed.

4. Time of flight between TOF0 and TOF1 for electrons, muons and pions with momentum 240 MeV in case of 100 ps time resolution of the PMTs Electrons Muons Pions

5. Ckov sector Simulation The emission, the Rayleigh scattering inside the aerogel, the reflection/refraction and the absorption of the Ckov photons is simulated. The time, the position, the wavelength, the incident angle and the angle between the plane of incidence and the electric vector of the photons which hit the PMTs are stored.

6. Still open problems We are using a simplified geometry for the conical mirror (normal cones instead of elliptical cones). Many details in the definition of the optical materials have to be clarified. Aerogel 1 Aerogel 2 Density = 0.251*g/cm3 Density = 0.430 g/cm3 Refractive Index = 1.08 Refractive Index = 1.12 Absorption length = 245.0*mm Rayleigh scattering length is calculated by the formula : Where C = 1e-24 m3 Optical glass (the material for the Glass window) Density = 2.6 g/cm3; Refractive Index = 1.4 The absorption length is shown in the plot No Rayleigh scattering in this material

7. Optical air (only the vessels of the Cerenkov detector are filled with this material) Density = 1.29e-3 g/cm3; Refractive Index = 1.0 No absorption in this material. No Rayleigh scattering in this material One bug in Geant4 tracking of the photons is found and temporally fixed but the Simulation is still unstable. Digitization The emission of the photoelectrons is simulated by taking into account the quantum efficiency of the PMT. The time of the first photoelectron is digitized (threshold discriminator + TDC). There is no digitization of the shaper + FADC response for the moment. Reconstruction – no reconstruction for the moment.

8. 240 MeV electrons are passing along the symmetry axis of the detector Energy and wavelength of the photons which hit the PMTs The time of the hits in the PMTs for Vessel 1 (n=1.08) and Vessel 2 (n=1.12) Latest Results

9. Number of photoelectrons in a PMT for one electron crossing Vessel (n=1.08) 1 and Vessel 2 (n=1.12)

10. The time of the first photoelectron in Vessel 1 and Vessel 2 The time of the photoelectron minus the time of the first one

11. Performance of the shaper – the worst case scenario The response of the shaper is simulated in case of normal signal from the PMT and in case of a double peak signal.