9064f4a4b01a6788cc307f4a0707ae37.ppt
- Количество слайдов: 15
The Daya Bay Reactor Antineutrino Experiment Christopher White, IIT PHENO 2010 1
Backgrounds Christopher White, IIT PHENO 2010 2
Water Shield and Muon Tagging System A 2. 5 m active water-shield around the antineutrino detectors is instrumented with 8 -inch PMTs experimental hall The high-purity water shield is divided into inner and outer regions separated by Tyvek water pool Christopher White, IIT RPCs are positioned on top of the water pool to improve eff. RPCs muon veto system The combined system has A muon tagging efficiency of >99. 5% PHENO 2010 3
RPC Detectors • Bakelite RPC detectors cover the water pools plus one meter of rock. • Each module has four 2 m x 2 m layers of RPCs, each consisting of two bare chambers. There a total of 81 modules in the far hall and 56 in each near hall. • The RPC gas system provides each RPC module with a controlled non-flammable gas mixture. • The RPC high-voltage (HV) system provides an ~8 k. V voltage gap. Each HV channel provides power to 9 RPC planes split by a multiplexing box. • A muon is characterized by hits in 3 of 4 RPC layers (across modules is allowed). The efficiency of each layer should be greater than 95%. Christopher White, IIT PHENO 2010 Production of RPCs 4
PMTs for ADs and the water pool 192 Hamamatsu 8” PMTs per AD (new) AD Ladder All new tubes have been tested at DGUT Some MACRO tubes are being potted for use in the water pools (supplemental). PMT testing station Christopher White, IIT PHENO 2010 5
Automatic Calibration Units (ACUs) 68 Ge, 60 Co: Positron Energy 241 Am-13 C: Neutron Energy LED: Timing Prototype Am. C neutron sources fabricated and tested ACU construction is now in “factory mode”. Christopher White, IIT PHENO 2010 6
Readout and DAQ Progress Christopher White, IIT PHENO 2010 7
Offline development is progressing well • Regular tutorials, workshops, enhanced documentation & tools. • Completed validating the analysis framework – Release available on IHEP, LBNL, and BNL clusters – Developing realistic detector system simulation & analysis chain • Mock Data Challenge → On/Offline Integration → AD Dry Run • Tape archive @ LBNL online and being used; 150 TB allocation for Daya Bay Hall commissioning. • PDSF and BNL Coop clusters online and heavily used. • Automated IHEP↔LBNL network testing in place. • Evaluating data movement and management software. Christopher White, IIT PHENO 2010 8
Mini-Dry-Run and Dry-Run Christopher White, IIT PHENO 2010 9
Mini-Dry Run Results – December, 2009 one “ladder” of PMTs was instrumented and readout. Muons LED Flasher Christopher White, IIT PHENO 2010 10
Status of Civil Construction May 2010 Christopher White, IIT PHENO 2010 11
Daya Bay Is Moving Forward Quickly Groundbreaking Ceremony: Oct 13, 2007 First Blast: Feb 19, 2008 Christopher White, IIT PHENO 2010 12
Christopher White, IIT PHENO 2010 13
Schedule • March 2009: Surface Assembly Building occupancy • Dec 2009: mini-dry run • Summer 2010: begin installation activities in the DB Near Hall • Summer 2011: begin installation activities in the Far Hall Sensitivity in sin 22 13 (90%CL) • Sometime in 2012: Begin physics operations 0. 05 0. 04 0. 03 90% C. L. 0. 02 0. 01 0. 0 1 2 3 4 Number of years of data taking Christopher White, IIT PHENO 2010 5
The Daya Bay Collaboration Christopher White, IIT PHENO 2010 15
9064f4a4b01a6788cc307f4a0707ae37.ppt