Transcript Progress and plans on PID simulation and reconstruction Yordan Karadzhov Sofia university St.

Progress and plans on PID
simulation and reconstruction
Yordan Karadzhov
Sofia university St. Kliment Ohridski
Description of PID Simulation, Digitization
and Reconstruction in G4MICE
• Simulation – Geant4 simulation of interactions of the
particles with the materials of the MICE detector system.
The wanted information from this simulation is stored in
objects called “hits”, for example TofHit, CkovHit, etc. . In
these “hits” we store numbers representing energy,
position, time, momentum etc. of the particles.
• Digitization – the “hits” output from the Simulation are
used to simulate the response of the detectors. The
information for the detector response is stored in objects
called “digits” (TofDigit, CkovDigit, etc. ). Usually in the
“digits” we have things like TDC counts, ADC counts etc.
The “digit” objects are designed to be used also to store
in them the real response of the detectors (real data).
• Reconstruction – the information from the “digits”
(simulation or real data) is used to reconstruct the event.
TOF sector
• Simulation and Digitization of the TOF sector are
completed;
• Reconstruction for the simulated data is
completed;
• TofHit, TofDigit, TofSlabHit and TofSpacePoint
objects with the relevant pointer links between
them are present in the output of the
reconstruction.
Positions of the hits in the TOF stations taken
from the Simulation
• 50 000 events are simulated
• TURTLE beam is used
Comparison of the times from Simulation and
Reconstruction
• This time difference is obtained by using 100 ps intrinsic time
resolution for each PMT.
• This means that we expect 100/sqrt(2) ~ 70 ps intrinsic time resolution
for each bar
• and 70/sqrt(2) ~ 50 ps intrinsic time resolution for each station.
Simulation of the Cherenkov detector in
G4MICE is going forward
•
•
Optical processes are implemented : G4Cerenkov, G4OpAbsorption,
G4OpBoundaryProcess, G4OpRayleigh
Optical properties for some of the materials of the detector.
The materials with optical properties are OptAIR and AEROGEL_1 and the
properties are refractive index and absorption length. The property Rayleigh
scattering length is not implemented for the moment and because of this the
Rayleigh scattering process is not active
The surface of the mirror is defined to be a G4OpticalSurface
•
Visualization of 240 MeV electron passing through the aerogel
•
Progress after the last collaboration meeting
• Definition of the ckov sensitive
detectors. We take the decision
only the windows of the four
PMTs to be sensitive detectors.
This means that hits will be
created only if a photon passes
through these windows. For the
moment the windows are
spherical with arbitrary radius
and thickness.
• Definition of CkovHits.
The class CkovHit derives
from the standard class
MICEHit. The new data
members are:
1. Plane number
2. PMT number
3. Wavelength of the photon
4. Angle of incidence of the
photon and the PMT
window
• Definition of CkovDigit. Data
members of the class CkovDigit are :
1. Plane number
2. PMT number
3. ADC counts
4. TDC counts
5. Vector with pointers to the mother
CkovHits
6. Number of photoelectrons
• Definition of the class CkovDigits.
This class manages the calculation of
the CkovDigit objects from the
CkovHit objects. For the moment we
take into account only the
dependence of probability to have
photoelectron on the wavelength of
the photon but not on the angle of
incidence.
Still open questions
• Description of the shape of the PMT windows;
• Precise description of the dependence of Rayleigh
scattering length of the aerogel on the energy (or
wavelength) of the photons;
• Precise description of the dependence of the
probability to have photoelectron on the wavelength
of the photon;
• Description of the dependence of the probability to
have photoelectron on the angle of incidence.