Report on the PHENIX by Yu Maruyama 5/6~5/30 Ｙｏｓｈｉｈｉｒｏ　Ｉｗａｎａｇａ Ｙｕ　Ｍａｒｕｙａｍａ 2018/12/31

Done at PHENIX 5/6~5/15 ・ Shift worksの習得。 ・ PHENIX実験のSub Systemの勉強。 5/16~5/31 　・　PWG, Focus Seminar, uBNLへの参加。 　・　BBCのCalibration。 　・　BBCに起きた問題について。 2018/12/31

Shift works (1) Shift Leader ・ Answer telephone 　・ Put shift summary in Elog 　・ Explain about shift summary in shift change meeting Shift Assistant 1 　・ Ramp high voltage between beam fills and for certain calibrations 　・ Fill out Low Voltage checklist every 4 hours 2018/12/31

Shift works (2) Shift Assistant 2 　・ Fill out gas system checklist every 4 hours Data Monitoring 　・ Online Monitoring of data from each subsystems DAQ Operator 　・ Operate Run Control, starting and stopping runs during beam fills 　・ Do daily calibration runs 2018/12/31

Online Monitoring 2018/12/31

About DAQ(1) Buffer Box PRDF 2018/12/31

Event Size :実際に取っているデータ About DAQ(2) Event Size :実際に取っているデータ 2018/12/31

ビームの状態を示す モニター カウンティングハウス の風景 2018/12/31

Sub System ZDC BBC EMCal RICH HBD (Hadron Blind Detector) ACC TOF TEC Mu ID Mu Tracker 2018/12/31

HBD( Hadron Blind Detector) relativistic electrons 多くの粒子がe+e- decay channelsを持っている。 Dalitz decay electronは2memp からなるはっきりとした質量をつくる。 Photon conversionはさらに鋭いピークを2me付近につくる。 pads φ π Dalitz と Photon conversionはどちらも小さなopening angleである。 Major problem: 多くの組み合わされたbackground、つまりγ-conversions とπ0 Dalitz decays がある中から、 electron　ID、そしてmomentum directionの決定を行う。 そのためにbackgroundを減らす必要がある。 2018/12/31

Gas Electron Multiplier (GEM) The original idea by F.Sauli (mid 90s) US Patent 6,011,265 Traditionally CHARGED PARTICLE detectors (not photons) 150μ 80μ Two copper layers separated by insulating film with regular pitch of holes HV creates very strong field such that the avalanche develops inside the holes Just add the photocathode By the way: no photon feedback onto photocathode 2018/12/31 11 Jason Kamin Jan 23rd, 2007

HBD( How to work) Start with a GEM Put a photocathode (CsI) on top HV photoelectron from Cherenkov light avalanches in the high density E-field ~150 μm Use more GEMs for larger signal Pick up the signal on pads What about ionizing particles (hadrons)? We need a mesh with a reverse voltage on it to blow electrons away!!! We have a detector sensitive to UV and blind to ionizing particles! 2018/12/31 12 Jason Kamin Jan 23rd, 2007

BBC Calibration(1) FEM Calibration ・ QScan : Check ADC using internal charge injecter ・ TScan : Check TDC using internal charge injecter 2018/12/31

BBC Calibration(2) Online Calibration ・ Check ADC and TDC distridution ・ Get MIP peak, TDC overflow, Slewing correlation, Timing offset, Z-Vertex offset -> Calibration constant 2018/12/31

BBC Problems (Laser) Lack of laser hitrate This problem occurred because of changing new flash lump. 2018/12/31

BBC Problems (QScan) In QScan, slope of ch[6],ch[76],ch[126] is unstable. Daughter card had problem. 2018/12/31

BBC Problems (QScan) BBC experts changed Daughter card in access day. before after replacement 2018/12/31

BBC Problems (QScan) We investigated temperature vs QScan’s slope. 2018/12/31

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BACK UP 2018/12/31

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