Long Fruitful collaboration between DESY and Japanese institutes On High energy physics Initiated by professor Masatoshi Koshiba since 1973 JADE at PETRA 1976- ZEUS at HERA 1992- DASP at DORIS 1973- LHC 2009- Katsuo Tokushuku KEK

ATLAS Detector: construction and commissioning Superconducting Central Solenoid (Japanese contribution:100%) End-cap muon triggering system (TGC) (~50%) Silicon microstrip tracking system (SCT) (~20%) <- collaboration with DESY Trigger (Muon/Tau HLT) Tracking (||<2.5, B(solenoid)=2T) : -- Si pixels and strips -- Transition Radiation Detector (e/ separation) Calorimetry (||<5) : -- EM : Pb-LAr -- HAD: Fe/scintillator (central), Cu/W-LAr (fwd) Muon Spectrometer (||<2.7) : air-core toroids with muon chambers Length : ~ 46 m Radius : ~ 12 m Weight : ~ 7000 tons ~ 108 electronic channels ~ 3000 km of cables 2018/11/20

ATLAS-KEK (active) members Updates from last year K. Tokushuku (Leader, HLT) TGC H. Iwasaki, (M. Ishino left to Kyoto) <- new open position TGC LVL-1 (+ upgrade) Trigger O. Sasaki + 1 student + 1 student SCT (+upgrade(pixel/strip)) Y. Unno, S. Terada, Y. Ikegami, Y. Takubo (IBL) + 1student(graduated) (J. Tojo left to Kyushu) K. Nakamura HLT K. Nagano(muon), S. Tsuno(tau) Physics S. Tsuno,　K. Nakamura ( Tau ) K. Nagano ( W+c , etc.) + 3 students J. Kanzaki (Top) + 1 student (graduated) Generators J. Kanzaki (Madgraph on GPU), S. Odaka (gamma gamma; GRACE) permanent staff only (+ few students) No post-docs! -> Close collaboration with JP universities 2018/11/20

Trigger related issues

Some highlights from KEK-ATLAS muon trigger activities Better performance if we can get information from small wheel. -> Phase 0 : Add Small-wheel TGC information in the trigger logic. -> Phase 1: Use the new small wheel information

KEK-ATLAS activities on Muon Trigger Upgrade Phase 2: R&D studies for Level-1 Muon trigger by using Monitored Drift Tubes (precision chambers)

KEK-ATLAS activities on HLT L1 Tau trigger improvement: with topological trigger -> S. Tsuno HLT muon: -> K. Nagano. Re-structuring the LVL2 Muon trigger with more transparent and modular software framework. -> easier for the collaboration with several groups (UK, US)

Tracker related issues

ATLAS detector upgrade plan 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 High-Luminosity LHC 5x1034 cm-2s-1 ultimate design luminosity 1-2x1034 cm-2s-1 toward design luminosity 14TeV -1x1034 cm-2s-1 Phase 1 minor upgrade: An additional pixel layer Replacement of Inner Endcap muon chambers Phase 2: Major upgrade: Complete replacement of the inner trackers (All-silicon tracker) R&D activities in Japan R&D of radiation- tolerant sensors Development of short strip detector module R&D of pixel sensors development of muon and combined triggers. Good collaboration with DESY and German institutes is essential

Activities on accelerator upgrade KEK is contributing to the R&D for the two key technologies: High-field magnet for the IP regions High-power injector in close collaboration with CERN and the other labs

HL-LHC Luminosity Leveling: various options Replace the forcusing magnets around ATLAS and CMS. Luminosity　Leveling: various options Crab crossing β* leveling And upgrades for LHC injectors.

LHC Injector RF Amplifiers: Possible KEK conributions LINAC4 （2018） PS booster PS SPS LHC ATLAS RF Amplifiers: Possible KEK conributions Magnetic arroys in the RF cavity. (developed at J-PARC)

Very fruitful collaboration with CERN J-PARC　neutrino beamline LHC magnets PSB: cavities J-PARC　RF cavities

Large aperture (φ130~150mm) 6 Tesla magnet: saturation, flux leakage International collaboration has started for the design work of the magnet system ～３００m D1: KEK Q1-3: US-LARP(Nb3Sn) or CERN(NbTi) D2: BNL Q4-6: CEA/Saclay JAEA Takasaki Cryogenic γ-ray irradiation Facility Epoxy (G10) CE BMI BT 14 Radiation test at J-PARC Challenges: Large aperture (φ130~150mm) 6 Tesla magnet: saturation, flux leakage High radiation dose: selections of rad-hard materials

International collaboration has started for the design work of the magnet system D1: KEK Q1-3: US-LARP(Nb3Sn) or CERN(NbTi) D2: BNL Q4-6: CEA/Saclay Last year Latest design

Toward the futher LHC upgrade Nb3Al has better performance then Nb3Sn at the high stress condition. (But now it turned out that R&D took longer. -> R&D for HE-LHC) Nb3Al cable produced by NIMS-KEK collaboration.

Summary In the ATLAS collaborations, KEK is responsible for TGC, Endcap LVL1 muon trigger, SCT and HLT. For ATLAS upgrade, KEK is working for LVL1 muon trigger upgrade and tracker upgrade. R&D for the silicon trackers (strips and pixels) are the most important activity in the next several years. In this area, a lot of collaboration between KEK and DESY are possible and plausible. KEK-CERN collaboration on the LHC accelerator upgrade is in place.