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3 Test Detector A scintillator cell 1cm x 1cm x 2mm 1 m 100 Layers 1 cm Total number of cells 1,000,000 Z X Y
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1
Hadronic calorimeter simulation
S.Itoh, T.Takeshita ( Shinshu Univ.)GLC calorimeter group
Contents- Comparison between Scintillator and Gas- Digital and Analog Hadronic calorimeter
2
Introduction
Our plan of Hadronic calorimeter(HCAL) is a Lead/Scintillator sampling type.We study the HCAL by GEANT4 simulation.Hadronic model is GEISHA based.
Lead : 8mm Scintillator : 2mm
3
Test Detector
A scintillator cell 1cm x 1cm x 2mm
1 m
1 m
1 m10
0 Lay
ers
1 cm
Total number of cells1,000,000
ZX
Y
4
Test of PFASet up for Multi particles
Iron Block
50cm
10cm
Multi particle event to simulated jet is generated.
pi-100GeV
5
Multi particle event
Iron Block
pi –100GeV
Hit cell energy ( >0.1mips ) in the HCAL
There are hit cells apart from the track.We try to study these cells.
6
Simulation for Gas
You can see the track clearer in Gas than in Scintillator.
Iron Block
pi –100GeV
Hit cell energy( >0.1mips )
7
Purpose of this study
Scintillator is our choice for the HCAL.
We study• The hits apart from the track in the scintillatorand• The difference in the measurement of the
scintillator and the gas.
8
A single pion
0.1
1
10
100
1000
0 20 40 60 80 100z position ( cm )
Hit
time
( ns
)pi-4GeV
The green cells are neutron hits. (by G4Track Information)
E(neutron) = 50MeV
Z
The hits are due to neutron scattering.
9
The effect of neutronsScintillator Gas(Xenon)neutron 50MeV
The box size: 1m x 1m x 1m
Neutrons incident at random positions to the pure scintillator and the gas.
10
Time cut parameter
0.1
1
10
100
1000
0 20 40 60 80 100z position ( cm )
Hit
time
( ns
)The neutron hit time is slower than other hits.
We study from the view point of the hit cell time. 2ns
5ns10ns
no time cut
11
Number of hit cells (Time Cut Dependence)
020406080100120
1 10 100 1000 10000
4GeV pion
Time cut ( ns )
Nhi
t
Nhit distribution Hit cell energy > 0.1mip
5
It stands for no time cut.
12
Hit time distribution
The hit time distribution for the scintillator is similar to that of the gas after the time cut(5ns).
Lead/Sci
Lead/Gas
Hit time ( ns )
13
Shower radiusTo see the effect of the time cut parameter to the hits, we define Shower radius as the mean of the distribution of r(i).
wherer(i) = for Cell position ( x(i), y(i), z(i) )
1m
22 )()( iyix r(i)
Z
14
Shower radius (Time Cut Dependence)
012345678
1 10 100 1000 10000
r(i) distribution
Time cut ( ns )
Show
er ra
dius
( c
m )
4GeV pion
Two SR approach as the time cut is small.
(Hit cell energy > 0.1mip)
15
Energy resolution - analog (Time Cut Dependence)
00.050.10.150.20.250.30.35
1 10 100 1000 10000
ScintillatorGas
The total energy
Time cut ( ns )
Ener
gy R
esol
utio
n 4GeV pion
It is independent of the time cut.
(Hit cell energy > 0.1mip)
16
Cell energy v.s. r(i)( @Time cut 5ns )
Lead/Sci Lead/Gas
Fluctuation of cell energy is large in the gas.
r(i) ( cm ) r(i) ( cm )
Cel
l ene
rgy
( m
ip )
Cel
l ene
rgy
( m
ip )
(Hit cell energy > 0.1mip)
17
Summary of analog HCAL(For 4GeV pion)
• We can cut the neutron hit cells in the scintillator by the time cut parameter.
In using the time cut parameter( 5ns )• Shower radius Scintillator : 4.2 cm Gas : 3.8 cm• Energy resolutionScintillator : 0.27 Gas : 0.31
18
Digital calorimeter
We have 1,000,000 cells in the HCAL.We can try to digital readout.
The measurement of the Digital HCAL only count the number of hit cells (Nhit).It is independent of cell energy.
19
Linearity for pion (1, 2, 4, 16, 32 GeV)
02004006008001000
0 10 20 30
pion
Incident energy (GeV)
Data by J.Yamada
We can use the digital readout for the HCAL.
Nhi
t for
dig
ital
Mip
for a
nalo
g
20
Resolution of Digital and Analog
-0.10
0.10.20.30.40.50.60.7
0 0.5 1
Res
olut
ion
E/1
ResolutionDigital 0.62 Analog 0.63
(incident,GeV)
21
Nhit distribution(With the time cut parameter : 5ns)
Lead/Sci Lead/Gas
Nhit Nhit
(Hit cell energy > 0.1mip)
22
Nhit Resolution - digital(Time Cut Dependence)
00.10.20.30.4
1 10 100 1000 10000
Nhi
t Res
olut
ion
Time cut ( ns )
4GeV pion
Nhit distribution (Hit cell energy > 0.1mip)
23
Summary of Digital HCAL
• The ability of Digital HCAL is similar to that of Analog HCAL for pions.
In using the time cut parameter( 5ns )• Nhit resolution (for 4GeV pion)Scintillator : 0.28 Gas : 0.32
24
Summary• We can control the neutron events in the
scintillator by the time cut parameter.
In using the time cut parameter • Resolution(analog/digital) of the scintillator
is similar to that of the gas.• Shower radius of the scintillator is similar to
that of the gas.
25
Outlooks
Time cut
Thank you very much.
The time cut parameter may help for the clustering in PFA.