Transcript DOE_020212
CDMS II Shielding From Design To Construction To Installation Outer Polyethylene CDMS II Shielding The Layers Inner Polyethylene Outer Lead Layers Inner Ancient Lead Mu Metal Shield CDMS II Shielding The Polyethylene Lid Early Stage of Construction in UCSB HEP High Bay Lab August 1999 Completed Lid Assembled and Installed in Soudan Clean Room September 2000 CDMS II Shielding The Lead Lid Nearing Completion of Construction in High Bay Lab November 1999 Completely Assembled Lid as it’s Lowered onto the Soudan Clean Room Mezzanine September 2000 CDMS II Shielding The Poly & Lead Base In the midst of Construction at UCSB September 1999 Completion of Stage 1 of Soudan Installation September 2000 CDMS II Shielding Radon Protection Lead Lid in Aluminized Mylar Bag w/ Old Air Purge September 2000 Remainder of Lead Base in Mylar Bags June 2001 CDMS II Muon Veto 40+ High Voltage Lines 40+ Signal Lines Buffered PMT Signals Remote Controlled via Ethernet In-House Fan-Out & Charge Amp Circuit Amplified & Stretched PMT Signals Commercial NIM Discriminators Commercial VME Time History Module Commercial VME Scalers Multi-channel Digital Lines Commercial VME Digitizers CDMS II Muon Veto Construction (1999-2000) Bicron Plastic Scintillator Acrylic Light Guide Glued at 45o Angle Armored PMT & Sides CDMS II Muon Veto Light Collection Testing Summer 2000 241 Scintillator Length Scintillator Width Am Matlab DVM Collected Current (nanoAmps) CDMS II Muon Veto Cosmic Ray Calibration September 2001 • • Achieved large muon-gamma peak separation (> 40pC for all panels). After calibrating, a Cs137 source current measurement was made for each panel. This will allow offline re-tuning of the veto underground (w/o muons!) to within ~ 5% of the original calibration. Typical Side Panel Typical Top Panel 52pC 48pC CDMS II Muon Veto Custom Electronics 8 Channel Prototype for SUF Run 21 Run 21 Low Background Veto Charge Spectra CDMS II Muon Veto Pulser Monitoring System Blue light from cone travels 60’ of optical fiber to right angle prism Optically coupled prism reflects light into veto paddle PMT converts light pulses to trackable calibration peak EM Shielded Box Driver Circuit & LED Array CDMS II Shield & Veto Future Work • Shield – UCSB crew will finish passive shielding construction during next Soudan trip this spring. Stem deflection due to weight of lead and poly lids will be measured at this time. – Radon protection tent for detector installation to be designed, constructed and installed. • Muon Veto – Future trip planned for arranging muon veto paddles around outer poly shielding. High voltage, signal and fiber optic cables will be installed at this time. The veto will be re-tuned with the 137Cs source, and the pulser will be setup and tuned to give reasonable calibration peaks in all paddles (spring 2002). – Readout Electronics • First version of printed circuit board layout for custom electronics is complete. Once the layout is finalized, boards will be fabricated, stuffed and tested at UCSB (spring 2002). • NIM crates and LeCroy discriminators to be borrowed from Fermilab electronics pool. • Some commercial VME electronics and crates remain to be purchased. CDMS II Muon Veto Cool Pulser Pics!