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. 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 Absorber ： Tungsten alloy (Thickness 3.5 mm ) Gap : Scintillators (Thickness 2.0 mm ) 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. A particle passed common square area of these two scintillators.

ReflectorScintillator ・ 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 fiber no 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 ) Count of events ADC Count ： the difference between peak and peak Average Photo Electron ( ) → divided into the average of ADC count more than 36 scintillators efficiency test (use ) Average Photo Electron (p.e.) Scintillator number Average : Standard deviation : 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 calorimeter A side view

The relation between trigger scintillators and hadron calorimeter ①②③④⑤⑥⑦⑧⑨⑩⑪⑫⑬⑭⑮⑯⑰⑱ ① ② ③ ④ ⑤ ⑥ ⑦ ⑧ ⑨ ⑩ ⑪ ⑫ ⑬ ⑭ ⑮ ⑯ ⑰ ⑱ 1st layer 2nd layer Trigger 1 Trigger 2 When cosmic rays pass this common area, the ADC gate is opened. ⑩⑪⑫⑬⑭⑮⑯⑰⑱ ⑩ ⑪ ⑫ ⑬ ⑭ ⑮ ⑯ ⑰ ⑱ ① ②③④⑤⑥⑦⑧⑨ ① ② ④ ⑤ ⑥ ⑦ ⑧ ⑨ ③ I can get data from No.1 ~ 9 scintilator of each layers. 2nd layer 1st layer

Curtain box Circuit diagram

Results of experiment I measured cosmic rays times. I changed ADC count into photo electron. 1st layer 1st2nd3rd4th 5th 6th7th8th9th This is an example of one of the events. This data shows point where a cosmic ray passed. 2nd layer

P.E. distribution P.E. distribution (Landau fit) the peak of Landau fit : Count of events

Sum of events about scintillators of 2nd layer Sum of events about scintillators of 1st layer Histogram of point passed by cosmic rays Detection rate : Scintillator number of 2nd layer Scintillator number of 1st layer Count of events

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 ） I researched energy resolution through simulation that shoots, and particles for this hadron calorimeter.

Results of simulation I require my hadron calorimeter to satisfy this resolution I research how many layers will need by using Genat4 simulation. Energy Resolution

My Hcal : 100 layers Comparing resolution ILD Hcal ： 48 layers absorber ： pure iron （ thickness ） gap ： scintillator (thickness ） Energy Resolution Energy Resolution absorber ： tungsten alloy （ thickness ） gap ： scintillator (thickness ）

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. I constructed two layers of hadron calorimeter.

Tasks I Investigate how much photo electron increases by using Scintillators which are in thickness. I make a histogram of point passed by particles through simulation that shoots them for hadron calorimeter whose each gap are divided into 18 bars.