The PandaX-4T Experiment Ren Xiangxiang On behalf of PandaX-4T Collaboration ShangHai Jiao Tong University

ABSTRACT PANDAX-II EXPERIMENT RESULT

The PandaX-4T(Particle AND Astrophys- ical Xenon phase IV) project is a dark mat- ter direct detection experiment with dual-phase located in the China JinPing Under- ground Laboratory phase-II(CJPL-II). As the re- sult of 120kg PandaX-I has been released in May 2015 and the 500kg PandaX-II will stop data taking in 2018, the upgraded experimen- t, PandaX-4T, will contain 4 tons of xenon in the sensitive volume and we hope it will set the more stringent limit for WIMP.

PANDAX-4T EXPRIMENT DESIGN • Detector TPC: 1.2m drift length

• Drift voltage: 800V/cm

• Fiducial volume Xenon: ∼4T

• Gas Cooling System Detector shield: <0.05mDRU Gas Storage • Signal collection: 368 3-inch PMT and Top PMT Array 144 1-inch veto PMT DAQ Server & Disk arry PC

Online monitoring GUI software • ∼6T Xenon gas purification, cooling and 10Gbps Switch ×4 ×4 TPC field cage ×4 ATCA Crate (9U) 6U PXI Crate PandaX-4T SFP . RAM detector SFP #1 SFP storage system 125MSPS . SFP PreAmp 14bit . . . ×16 . 10Gbps ethernet anode #1 <10m .×8 ADC . . FPGA SFP PMT #1 . . . PreAmp . ADC Board . 1Gbps <2m . SFP #2 . . #13 . SFP 1Gbps FPGA SFP . . #14 . . SFP 1Gbps Water Shield . . SFP . #15 . . . SFP 1Gbps . SFP #16 . SFP Trigger Board . . . ×4 . . . anode PreAmp PMT #512 #512 • DAQ system: realtime data suppression and DAQ System Bottom PMT Array triggerless data taking

PANDAX-4T EXPECTED SENSITIVITY With a 5.6 ton-year exposure, the sensitivity to spin-independent WIMP-nucleon cross sec- tion limit is expected to reach 10−47cm2, more than one order of magnitude lower than the current PandaX-II limit. The sensitivity of the PandaX-4T experiment, together with curren- t leading exclusion limits, the mSUSY contour, and the ultimate neutrino “floor“. This experi- ment will also be a critical technology demon- strator for the next stage PandaX-xT detector.

REFERENCES CONTACT INFORMATION [1] Andi Tan et al. Dark matter results from first 98.7 days of data from the pandax-ii experiment. Physical • Web: pandax.physics.sjtu.edu.cn Review Letters, 117(12):121303, 2016. • Email: [email protected] [2] Andi Tan et al. Dark matter search results from the commissioning run of pandax-ii. Physical Review D, 93(12):122009, 2016. test LHCP2017 ,May15-20 ,Shanghai ,China