Construct two layers of hadron calorimeter and test Makoto Harada High Energy Physics Laboratory...
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Transcript of Construct two layers of hadron calorimeter and test Makoto Harada High Energy Physics Laboratory...
Construct two layers of hadron calorimeter and test
Makoto Harada
High Energy Physics Laboratory
Faculty of Physics
Department of Science
Shinshu University
The purpose of this study
I constructed two layers of hadron calorimeter and
tried to detect point where cosmic
rays passed.
mmmm 1010
I tested my hadron calorimeter by using Geant4
simulation.
Improve detection accuracy and energy resolution of
ILD hadron calorimeter
Hadron calorimeter
A detector which causes hadron shower to hadron
and measures its energy.
total track length of all generated particles
measuring total track length → measuring incidence particle energy
It is essential to detect the point where a particle passed accurately.
incidence particle energy
Two layers of hadron calorimeter
A particle
mm180
mm11
Absorber : Tungsten alloy (Thickness 3.5 mm )
Gap : Scintillators (Thickness 2.0 mm )
mm180
Scintillators are divided into 18 bars.
Scintillator bars of 1st and 2nd layer are orthogonal.
A particle
(point passed by a particle)
These two scintillators radiate light.
mm10
mm180
A particle passed common square area
of these two scintillators.
mmmm 1010
Reflector Scintillator
・ prevent light from escaping out of scintillators
・ get independent signal from each scintillators
→ wrap each scintillators in a reflector
I made 36 scintillators wrapped in a reflector
Scintillation light
using fiberno fiber
gathered by wave length shift fiber
detected by MPPC MPPC ・・・ a new type of photodetector
・ small size and reasonable price
・ photocounting efficiency
・ tolerance to magnetic field
MPPC
Constructing hadron calorimeter
Absorber side Gap side
Structure of absorber is tungsten alloy plates
Structure of gap is 18 scintillators
magnification
ADC distribution of MPPC (use )Sr90
d
..1 ep ..2 ep
..3 ep
..0 ep
Cou
nt o
f eve
nts
ADC Count )25.0( pC
: the difference between peak and peak d ..1 ep..0 ep
..5.0 ep
Average Photo Electron ( )
→ divided into the average of ADC count more than ..5.0 epd..ep
36 scintillators efficiency test (use )Sr90A
vera
ge P
hoto
Ele
ctro
n (
p.e.
)
Scintillator number
Average : Standard deviation :..53.7 ep ..56.0 ep
No.1 ~ 18 scintillator → 1st layer No.19 ~ 36 scintillator → 2nd layer
I detected scintillation light using MPPCs.
Then, I made ADC distribution about each MPPCs.
two layers of hadron
calorimeter
I set two PMTs up and down hadron calorimeter and used them as trigger.
Scintillator of trigger 1
Scintillator of trigger 2
Experiment with cosmic raysTwo layers of hadron calorimeterA side view
The relation between trigger scintillators and hadron calorimeter
① ② ③ ④ ⑤ ⑥ ⑦ ⑧ ⑨ ⑩ ⑪ ⑫ ⑬ ⑭ ⑮ ⑯ ⑰ ⑱
①②③④⑤⑥⑦⑧⑨⑩⑪⑫⑬⑭⑮⑯⑰⑱
1st layer
2nd layer
Trigger 1
Trigger 2
When cosmic rays pass this common area, the ADC gate is opened.
⑩ ⑪ ⑫ ⑬ ⑭ ⑮ ⑯ ⑰ ⑱
⑩⑪⑫⑬⑭⑮⑯⑰⑱
① ② ③ ④ ⑤ ⑥ ⑦ ⑧ ⑨
①②
④⑤⑥⑦⑧⑨
③
I can get data from No.1 ~ 9scintilator ofeach layers.
2nd layer
1st layer
Curtain box
tillatorScin MPPC
AMPASD BufferASD
2Trigger
natorDiscrimi eCoincidenc
ADCCircuit diagram
1Trigger
tillatorScin MPPC
ADC
AMPASDBufferASD
R Circuiteadout
R Circuiteadout
RayCosmic
Results of experiment
I measured cosmic rays 20000 times.
I changed ADC count into photo electron.
1st layer
1st 2nd 3rd 4th 5th 6th 7th 8th 9th
16.0 24.6
93.6
This is an example of one of the events.
This data shows point where a cosmic ray passed.mmmm 1010
20.0 25.0 10.0 09.0 08.0 14.0 04.0
07.0 04.0 04.0 06.008.0 01.0 16.0 01.02nd layer
P.E. distribution
ElectronPhoto
P.E. distribution (Landau fit)
the peak of Landau fit : ..08.7 ep
Cou
nt o
f eve
nts
Sum of events about scintillators of 2nd layerSum of events about scintillators of 1st layerHistogram of point passed by cosmic rays
Detection rate : %0.61
Scintillator number of 2nd layer
Scintillator number of 1st layer
Cou
nt o
f ev
ents
Geant4 simulation
Hadron calorimeter planned to be used in ILD
・ Absorber : Pure iron ( Thickness ,Density )
・ Gap : Scintillator ( Thickness )
・ Number of layers :
・ Size : ( To compare my hadron calorimeter )
mm20 3/874.7 cmg
mm2
mmmm 180180 48
I researched energy resolution through simulation that
shoots , and particles for this
hadron calorimeter.
GeV10 GeV30 GeV80
Results of simulation
I require my hadron calorimeter to satisfy this resolution
I research how many layers will need by using Genat4 simulation.
80
58.077.27 31.048.16 25.016.13
Energy 3010
Resolution
)(GeV
)%(
My Hcal : 100 layers
Comparing resolution
ILD Hcal : 48 layers
absorber : pure iron ( thickness )
gap : scintillator (thickness )
mm0.20mm0.2
80
58.077.27 31.048.16 25.016.13
Energy 3010
Resolution
)(GeV
)%(
80
45.009.19 39.012.10 48.050.11
Energy 3010
Resolution
)(GeV
)%(
absorber : tungsten alloy ( thickness )
gap : scintillator (thickness )
mm5.3mm0.2
Conclusion
My hadron calorimeter needs 100 layers to satisfy
energy resolution of ILD hadron calorimeter.
( thickness of hadron calorimeter will be half )
Using cross scintillators, I succeeded in detecting the
point where cosmic rays had passed.
My hadron calorimeter showed 7 photo electron.
mmmm 1010
I constructed two layers of hadron calorimeter.