carla distefano for the nemo collaboration
DESCRIPTION
Carla Distefano for the NEMO Collaboration. KM3NET ‘Physics and Simulation (WP2)’ Oct 24 – 25, 2006. NEMO software. The NEMO Software. The simulations performed by the NEMO Collaboration are carried out using the OPNEMO and ANTARES software. - PowerPoint PPT PresentationTRANSCRIPT
C.Distefano KM3NET ‘Physics and Simulation (WP2)’ Oct 24 – 25, 2006
LNS
NEMO software
Carla Distefanofor the NEMO Collaboration
KM3NET ‘Physics and Simulation (WP2)’ Oct 24 – 25, 2006
C.Distefano KM3NET ‘Physics and Simulation (WP2)’ Oct 24 – 25, 2006
LNS
The simulations performed by the NEMO Collaboration are carried out using the OPNEMO and ANTARES software.
By the end of 2002, ANTARES software modified for a km3 detector by D. Zaborov was installed in Catania
In parallel: development of simulation software OPNEMO with new track and energy reconstruction algorithms (work mainly conducted in Rome)
The NEMO Software
C.Distefano KM3NET ‘Physics and Simulation (WP2)’ Oct 24 – 25, 2006
LNS
Using the ANTARES software several issues important for the km3 detector feasibility and performance were addressed:
- Dependence on environmental parameters (depth, optical background, optical proprieties …) (see talk by R. Coniglione)
- Dependence on detector structures (towers, strings, lattice ….) and geometries (distance between towers, storeys, PMT orientation …) (see talk by R. Coniglione)
- Effect of directional-sensitive optical modules (see talk by K. Fratini)
- Detection of the Moon Shadow (this talk)
-Detector sensitivity for diffuse and point sources (see tomorrow talk by C.D.)
NEMO Simulations
C.Distefano KM3NET ‘Physics and Simulation (WP2)’ Oct 24 – 25, 2006
LNSThe ANTARES Software
Detector generator
gendet
Geomety file
GentraGenneu
Muon tracks
km3
modk40
Hits on PMs
Hits on PMs + back hits
reco
Reconstructed tracks
Muon Generatoror
Neutrino Generator
Light simulator and propagator
Track reconstructor
Background and electronicssimulator
code
I/O
C.Distefano KM3NET ‘Physics and Simulation (WP2)’ Oct 24 – 25, 2006
LNSSimulated NEMO-km3 detector
Simulated Detector Geometry:
• square array of 81 NEMO towers
• 140 m between each tower
• 18 floors for each tower
• vertical distance 40 m
• storey length 20 m
• 4 PMTs for each storey
• 5832 PMTs
• Depth = 3500 m (Capo Passero site)
PMT location
and
orientation
(PMT=10”)
DETECTOR LAY-OUTThe ANTARES code gentra v1r2
has been used to generate the
detector geometry file.
C.Distefano KM3NET ‘Physics and Simulation (WP2)’ Oct 24 – 25, 2006
LNSThe ANTARES Software
Detector generator
gendet
Geomety file
GentraGenneu
Muon tracks
km3
modk40
Hits on PMs
Hits on PMs + back hits
reco
Reconstructed tracks
Muon Generatoror
Neutrino Generator
Light simulator and propagator
Track reconstructor
Background and electronicssimulator
code
I/O
C.Distefano KM3NET ‘Physics and Simulation (WP2)’ Oct 24 – 25, 2006
LNSMuon tracking and light generation
The same package (codes gen and
hit) has been used to generate new
photon tables simulating the
absorption length profile measured in
the Capo Passero site by the NEMO
and ANTARES Collaborations.
Light scattering has been simulated
according to the –partic-0.0075-
model, with Lb~50 m @440 nm (see
the ANTARES documentation).
The ANTARES simulation package km3 v2r1 is used to simulate the
passage of muons inside the detector and to generate the PMT hits
C.Distefano KM3NET ‘Physics and Simulation (WP2)’ Oct 24 – 25, 2006
LNSThe ANTARES Software
Detector generator
gendet
Geomety file
GentraGenneu
Muon tracks
km3
modk40
Hits on PMs
Hits on PMs + back hits
reco
Reconstructed tracks
Muon Generatoror
Neutrino Generator
Light simulator and propagator
Track reconstructor
Background and electronicssimulator
code
I/O
C.Distefano KM3NET ‘Physics and Simulation (WP2)’ Oct 24 – 25, 2006
LNS
Optical background was measured
in Capo Passero @ 3000 m depth.
Data are consistent with 30 kHz
background on 10”PMT at 0.5 s.p.e.
Optical background in Capo Passero
The ANTARES code modk40 v4r8 is used to add optical background
hits and to simulate the electronics.
** gain randomisation (0-off, 1-on)
GAIN 1
** K40 frequency (Hz) and time offset (ns)
FK40 30000 1000
** raw hit production from SPE integration with 2 ARS, 25 nsec integration, 250 nsec
** dead time chosing the last number negative, the 'hit' tag can be suppressed from output
RAWH 2 25 250 -1
C.Distefano KM3NET ‘Physics and Simulation (WP2)’ Oct 24 – 25, 2006
LNSThe ANTARES Software
Detector generator
gendet
Geomety file
GentraGenneu
Muon tracks
km3
modk40
Hits on PMs
Hits on PMs + back hits
reco
Reconstructed tracks
Muon Generatoror
Neutrino Generator
Light simulator and propagator
Track reconstructor
Background and electronicssimulator
code
I/O
C.Distefano KM3NET ‘Physics and Simulation (WP2)’ Oct 24 – 25, 2006
LNSMain modifications by Zaborov for a km3
Reco V4r3 modified by Zaborov (AartStrategy)• Causality filter respect to the hit with the highest charge (|dt|<dr/vlight + 20ns) AND (||dt|-dr/c|<500ns)
• Hit selection for prefit-> at least 3 hits with charge > 2.5 p.e.
Some parameters in include files has been changed in order to take into account the high number of PMTs, clusters,strings…
C.Distefano KM3NET ‘Physics and Simulation (WP2)’ Oct 24 – 25, 2006
LNSMain modifications by LNS in RECO
Recov4r4km3 (LNS version)Same as v4r3km3 (Zaborov version) with:• Some internal conditions in AartStrategy.cc have been relaxedIf(mest_hits[0].size() <15) continue; modified intoIf(mest_hits[0].size() <6) continue;If(ndof<5) continue; modified into If(ndof<1) continue;
• Hit selection for prefit-> at least 3 hits with charge higher than 2.5 p.e. or in concidence (at least two hits with Dt<20ns in a LCM)
• Modifications for gcc3.X
Recov4r5km3Same as v4r4km3 with:• Hit selection for prefit-> at least 3 hits with charge higher than 2.5
p.e. or in concidence (at least three hits with Dt<20ns+dr/vlight in a LCM)
C.Distefano KM3NET ‘Physics and Simulation (WP2)’ Oct 24 – 25, 2006
LNSComparison between different RECO versions
Nemo detector(5832 PMT81 Towers 140m distant)
20kHz background
Median vs E
Aeff vs E
vs Ev4r3km3 (Zaborov Version)
v4r4km3 (LNS version with coinc)
v4r4km3 (LNS version with coinc)+quality cuts
C.Distefano KM3NET ‘Physics and Simulation (WP2)’ Oct 24 – 25, 2006
LNS
log10E(GeV)
Main modification by LNS
Recov4r6km3: Starting from v4r6 ANTARES version we applied the same
modifications of v4r4km3 version
Documentation for v4r6 improvements in antares.in2p3.fr/users/stolar/internal/recoco
v4r6km3v4r4km3 (LNS version with coinc)Nemo detector(5832 PMT 81 Towers 140m distant)35kHz background
ratio
Aeff(v4r6km3)/Aeff(v4r4km3)
quality cuts
reconstruction
C.Distefano KM3NET ‘Physics and Simulation (WP2)’ Oct 24 – 25, 2006
LNS
Detection of the Moon shadow
C.Distefano KM3NET ‘Physics and Simulation (WP2)’ Oct 24 – 25, 2006
LNSDetection of the Moon shadow
The detection of the deficit (The Moon Shadow) and of its
position in the sky provides a measurement of:
• the detector angular resolution;
• the detector absolute orientation.
The Moon is opaque to Cosmic Rays and thus causes a deficit in the
CRs and therefore in the atmospheric muon flux reaching the detector.
This approach has been already adopted in several cosmic ray
detectors as MACRO, SOUDAN, MILAGRO….
C.Distefano KM3NET ‘Physics and Simulation (WP2)’ Oct 24 – 25, 2006
LNSSimulation of the Moon shadow: OkadaMoon code
The code OkadaMoon (C++ gcc3.X):• calculates the Moon position in the sky at a given
time and transforms the Moon astronomical
coordinates in the detector frame;• generates the muons in a circular window around
the Moon position with radius R=10°;• simulates the lack of atmospheric muons in
correspondence to the Moon disk;• weights the muons to the Okada parameterization
but any other parameterizations could be easily
implemented.
L. Ferrari, Diploma Thesis
Moon below the Horizon
C.Distefano KM3NET ‘Physics and Simulation (WP2)’ Oct 24 – 25, 2006
LNSObservation of the Moon shadow
(simulation normalized to 1 year of data taking)
2
2
2
D
2
2moon
2 e2
1kdD
dN k= 659 ± 8 deg-2
= 0.19 ± 0.02 deg
Event Selection*:
Nhitmin= 20
cut= -7.6
S1year=5.5
days 100~)3(2
minminmin
S
StSt gen
Minimum time needed for observation:
Moon rest frame
Moon disk
Event density
* Events selection criteria will be discussed tomorrow.
C.Distefano KM3NET ‘Physics and Simulation (WP2)’ Oct 24 – 25, 2006
LNSEstimate of the detector angular resolution
= 0.19 ± 0.02 deg
Event Selection:
Nhitmin= 20
cut= -7.6
S1year=5.5
median angle of selected events:
estimated angular resolution:
= 0.22 deg
Reconstructed
Selected
C.Distefano KM3NET ‘Physics and Simulation (WP2)’ Oct 24 – 25, 2006
LNS
0.2
0.4
0.6
Study of the telescope absolute pointing
We introduce a rotation around the Z axis to simulate a possible systematic error
in the absolute azimuthal orientation of tracks.
(1 year of data taking)
• for 0.2 (expected accuracy), the shadow is still
observable at the Moon position;
• for 0.2 (pessimistic case), systematic errors could be
corrected;
• the presence of possible systematic errors in the absolute
zenithal orientation is still under analysis.
Moon rest frame Moon rest frame
Moon rest frame
C.Distefano KM3NET ‘Physics and Simulation (WP2)’ Oct 24 – 25, 2006
LNSMoon shadow: CORSIKA-Music muon generation
Corsika (http://www-ik.fzk.de/corsika) has been modified to
simulate the Moon Shadow:
• We implemented the calculation of Moon position in the sky;
• We restricted the generation of primaries in a circular window around
the Moon position with radius R=10°;
• The lack of primaries in correspondence to the Moon disk is simulated;
• The produced muons are propagated up to the detector using the
MUSIC code (Antonioli et al, 1997).
Study of the effect of multi-muons events in the detection of the
Moon Shadow a full simulation of atmospheric muons.
C.Distefano KM3NET ‘Physics and Simulation (WP2)’ Oct 24 – 25, 2006
LNS
Primary ions -> p, He, N, Mg, Fe
Primary energy -> 10-105 TeV/nucleon
Primary zenith angles –> 0° 85°
Energy threshold for muons at sea level -> 0.5 TeV for ions between 0° and 60° and 1 TeV for ions between 60° and 85°
Slope primary spectrum E-2
Isotropic angular primary distribution
CORSIKA input
Corsika version: CORSIKA version 6.2 (http://www-ik.fzk.de/corsika) +
Sheffield modifications to get output files in the ANTARES format +
modifications to simulate the Moon Shadow
Hadronic interaction model -> QGSJET and GHEISHA
“curved” version for horizontal showers and “flat” for vertical showers
Simulation input
C.Distefano KM3NET ‘Physics and Simulation (WP2)’ Oct 24 – 25, 2006
LNSCosmic Ray Primary Spectrum
0 00 0
0
1ˆ
c z
c c
z
HorandelZ
Z
z
EdE E
dE E
The generated events are weighed to the Cosmic Ray Primary Spectra
provided by J.R. Horandel Astr. Phys. 19 (2003) 193.
Total numbers of
Generated Primaries: 2.7 109
Muons reachingthe detector can: 1.9 108
Reconstructed Events: 3.4 106
Present statistics
C.Distefano KM3NET ‘Physics and Simulation (WP2)’ Oct 24 – 25, 2006
LNSCORSIKA-Music generation: preliminary results
Corsika + Music
Events statistics too poor: preliminary results
Okada
Event Selection:
Nhitmin= 20 cut= -7.6
Fit results:
= 0.19 ± 0.02 deg
k= 659 ± 8 deg-2
Event Selection:
Nhitmin= 26 cut= -7.1
Fit results:
= 0.26 ± 0.04 deg
k= 230 ± 2 deg-2
PRELIMINARY