Download - Status of the OPERA simulation software
Status of the OPERA simulation software
• Introduction: – generator, simulation, digitization status
• Recent development in OpRoot – detector geometry implementation– Tracking of the tau
• Conclusions
D.DuchesneauLAPP, Annecy
OPERA collaboration meeting May 19th, 2003
NEGN / Jetta OpTreeConvertOpRoot
Inputs for track reconstruction
Physics ...
Simulation Digitisation
Reconstruction
Software chain: Actual development: main goal is to provide a working chain from
Event generation to the digit level for production:
Detector simulation relies on Geant 3 in the OpRoot framework
Hitsroot
OpDigit
Hitsroot
ASCIIbeamfile
digitsroot
TTree structure TFolder structure
OpDigit nearly ready!Complete chain will be finalized in about 2 weeks
Evt generator
Event generator: NEGNOPERA adaptation of the NOMAD event generator (Dario)
Official release: v1.00 on april 24th 2003 available on LXPLUS, standalone package
Characteristics: • DIS interactions described by modified LEPTO6.1• QE process: based on Llewellyn-Smith formulation• RES process: based on Rein & Seghal model• Coherent interactions• Hadronization according to JETSET 7.4 retuned with Nomad data
Includes:Neutrino DIS, QE and Resonant processesOptions: Nuclear interactions, …..
READY for production. The program produces standard OPERA event beamfiles.
Simulation Software: OpRoot Detector simulation relies on Geant 3 in the OpRoot framework
Major changes done recently consist of: •implementing and uniformising all the sub-detector geometry descriptions (odd files)•check the compatibility between the different OPERA parts (volume position etc…)•Tracking of short lived particles like the tau in the emulsion films•Update the hit structures to keep mother and primary references
Version 5 READY for production. It produces root trees event by event with hits for each subdetector .
DTLY
OPERA geometrical tree in OpRoot 48 different volumes
All the positioning along the Z axis is based on this drawingRef: Frascati drawing 12/11/02
Z (cm)-823.4 -452.62 44.88 104.4 etc……
For the target section: •the support structure for the Scintillators and the bricks are not described (2nd order…)
For the spectrometer section:•Only the SRPC chambers include supporting structures, screws, profiles, spacers….•The XPC and Drift tubes have no support described
Geometry description in this OPERA implementation
From OpRoot
the distances between emulsions layers and scintillator strips are based on numbers available in february 2003.
TT:
•the CS emulsion layer position takes into account additional separation due to packaging , CSS etc… = 0.2766 cm distance with last emulsion
•Ref: Document LAPP, H. Pessard et al., january 10th 2003,
Emulsion bricks:
Spectrometer part:
Uniform B = 1.55 T
Spectrometer RPC planes: 21 chambers / plane
screws
spacers
8.76 m
7.98
m
Drift tube planes: 4 layers of 192 tubes
Tube: outer radius 1.85 cminner radius 1.7 cmlength: 8m
Wire diameter: 60m
2.03 cm
5.67 cm
4.2 cm
Spectrometer XPC planes: 21 chambers / plane
spacers
8.75 m
8.06
m
To verify: position of the second XPC plane? Before or after the DT plane?
OpRoot final setup:Hits are saved along particle tracks in active volume
Scintillators, DT, XPC, RPC: 1 hit per strip or gas volume per track middle point between entrance point
and stopping or exiting point
Emulsions:
2 hits per emulsion layer per track entrance point and stopping or exiting point
Hit visualization: interaction with
emulsions
SRPC
Drift tubes
XRPC
Scintillators
Hit description: (example)
Scintillators: 1 hit per strip per track
•fX, fY, fZ coordinate of the hit•fPartPx, fPartPy, fPartPz Momentum of the particle at the hit position•fEdep energy loss•fPartId Pdg number of particle•fParMass Mass of the particle•fPrimary Id of the primary particle•fMother Id of the mother particle•fTrack track number in Geant•fSciSM SuperModule number•fSciWall Wall number•fSciBox Scintillator module•fSciBar strip number
Hit distributions in the spectrometer sections
XPC driftSRPC
SM 1
SM 2
Z position (cm)
Hit distributions in the target section vs Z
emulsions
scintillators
CS
Tracking the (or any short lived particle leading to a second vertex)
In OPERA we use to have the flight length given by the generator
Solution:•Set the lifetime to large values •Track it in the bricks until it has travelled a distance equals to the distance between the 2 vertices
Result:
interaction with
Hits are now recorded in the emulsions
Conclusions
NEGN generator is ready for production
The detector geometry description follows the actual OPERA design (apart from support structures and veto chambers). A summary note is being prepared
Each sub-detector has hits defined to allow digitization
’s leave hits in emulsions
No major upgrade of this version is foreseen since the next generation of software is under construction (OpVMC)
OpRoot is ready to be used for the coming simulation campaign. Need a new version release
Still some work needed in OpDigit package.