Micro Pixel Chamber 1 Introduction 2 MSGC and
大面積Micro Pixel Chamberの開発 京都大学 宇宙線研究室 永吉 勉 折戸 玲子 谷森 達 1: Introduction 2: MSGC and μ-PIC 3: Operation test of μ-PIC 4: Data acquisition system 5: Me. V gamma-ray imaging 6: Summary エレクトロニクスオンラインユーザーズワークショップ ＠KEK October 4, 2001
Introduction Requirement for micro pattern gas detectors • Position resolution ~ 100 μm • Incident particle capacity ~ 10 6 cps/mm 2 MSGC (Strip electrode) • Higher gas gain > ~ 1000 • Stable operation • Large area Pixel electrode based on PCB technology
Micro. Strip Gas Chamber 10 cm× 10 cm MSGC backstrips 512 ch anodes 512 ch Pre-amp & Discri. ECL Position encoder Control/ Memory 512 MB local bus CPU DAQ system on VME
dummy Photographs of MSGC and DAQ system
Real-time X-ray imaging using MSGC ex. X-ray crystallography time slice of diffraction pattern Rapid X-ray crystal structure analysis less than 1 second これまでは 数時間〜１日 かかっていた
Micro Pixel Chamber (μ-PIC)
Large area μ-PIC anode cathode read-out 400μm substrate (ceramic) 256 anodes and 256 cathodes 10 cm ~10 cm × 10 cm detection area anode read-out
Obtained signal • Gas Ar 8 : C 2 H 6 2 混合ガス • Source 55 Fe (5. 9 ke. V) anode • プリアンプ 8 ch 分のsum 読み出し領域 anode : 3. 2 mm × 100 mm cathode : 3. 2 mm × 100 mm 80 ns 10 m. V 55 Fe cathode アノード・カソードから ほぼ等しい大きさの信号が得られた (5. 9 ke. V)による信号 MSGCの場合 … backstrip < anode
Spectrum & gas gain spectrum gas gain (anodes 8 ch) escape peak • FWHM ~ 30% • Gas gain ~ 3000 • Escape peak is observed. Maximum gain ~ 5000
Data acquisition system
Imaging system 完成予想図 (開発中) AMP-Discri. Boards
Application Micro TPC based on μ-PIC Pre-amp + Discri. 8. 5 cm Scintillator + PMTs Position (2 D) + Timing 3 D Track
Simulation using EGS 4
Scintillation light 光量分布からγ線の入射位置 を算出 単純に重心をとると中心に ひきずられ、歪んでしまう。 Neural Network の活用 MLPfit(Multi-Layer Perceptron) http: //home. cern. ch/~schwind/MLPfit. html Used for ～ 10 years 57 Co (122 ke. V)による実験データ Cherenkov, Track reconstruct, particle identification, calorimeter position resolution etc…. .
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