Detector Decommissioning Related Activities at DØ

George GintherFermilab and University of Rochester 23 January 2012

Secure and StabilizeRecent Events

• Routine recording of cosmics ended before 0730 on Thursday 22 December

• Began warm-up of Silicon Microstrip Tracker – Raised chiller setpoint to 16C– Recording IV curves and monitoring annealing of Layer 0 sensors

• Ramped down muon chamber high voltages• Shutdown of muon chamber gas systems• Powered down Level 1 Calorimeter Trigger system• North dry engine failed during the early morning of

Friday 23 December– East dry engine not able to keep up with demand– Liquid helium inventory dwindling– Started warm-up of solenoid early to reduce demand on helium

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More Recent Events• Blown fuse in ODH system closes valves on

calorimeter during the early morning of Saturday 24 December

• LCW pumps off and system drained• Disconnected solenoid and toroid power supplies• Powered down Silicon Track Trigger• Collision hall permit (intentionally) dropped

– Transition to supervised access mode• Configured detector to allow access to pump down

vacuum jackets on liquid argon transfer lines• Power down lumi system

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Even More Recent Events• Ramped down calorimeter high voltages and terminated

calorimeter bias current monitoring• Transferred 11100 gallons for liquid argon to

underground storage tank• Recondensing residual argon as it evaporates from the

calorimeters• Drained liquid helium inventory• Shutdown liquid helium plant• Began warm-up of Visible Light Photon Counter cryostats

(readout for Central Fiber Tracker)– Turn off VLPC bias and temperature control

• Turned off VLPC cryostat lid heaters• Powered down Level 1 Muon and Central Track Trigger

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Next Steps• Start purge on VLPC cryostats

– Verify cold block above dewpoint– Extract a cassette from the east cryostat and install a blank

with purge inlet– Replace a blank on west cryostat with a blank equipped

with purge inlet• Power down Central Fiber Tracker readout• Power down Calorimeter readout

• Complete rad survey of collision hall to update postings

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As conditions (and resources) permit

• Power down rack infrastructure• Continue preparations of online computing cluster

for transition to offline cluster– Identify, backup and archive critical information

• Shut down silicon chiller and purge system• Drain Deionized Chilled Water detector systems and

purge• Decommission Trane Chiller• Secure halon fire suppression systems• Continue high bay preparations• Continue harvesting components for re-use• Continue preparations for basic exhibit

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Clean Out and Harvest• The mechanical crew is well into the process of

preparing the DØ Assembly Building high bay to accommodate MicroBooNE TPC assembly

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High Bay 22-Nov-2011

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High Bay 9-Dec-2011

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High Bay 19-Dec-2011

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High Bay 16-Jan-2012

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Preparing the Basic Exhibit• Cleared north sidewalk area and moved current

collection of artifacts into that area

• Next steps– Prepare for dismantling of concrete shield block wall

• Clear top of wall and dismount bus work as needed• Support helium cryo lines• Disconnect air handling units

– Take down much of concrete block wall– Install barriers to control access to collision hall– Configure detector for exhibit

• Move north toroid onto sidewalk and open west central iron and move north end calorimeter back to expose gap

– Aim to be ready with basic exhibit prior to Tevatron symposium in early June 2012

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Detector Decommissioning Summary

• DØ successfully collected supporting data samples during the post-collider operations period

• The detector is in the process of warming, being stabilized and secured• Monitoring of SMT annealing in progress

• Making significant progress in preparing the Assembly Building to accommodate additional operations– High bay was ready for installation of MicroBooNE TPC assembly clean room

well in advance of the project’s required milestone• Anticipate resources will be sufficient to secure the detector and

provide the basic detector exhibit in 2012– Constraints generated by broader lab plans are being integrated into the

decommissioning effort may impact the schedule• This flexible plan should provide the opportunity to maximize the

productivity of the lab’s staff while ensuring that the DØ detector is put into a safe and secure state and transitions into a valuable educational exhibit

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DØ Mechanical Operations Team

DØ Operations SupportTeams

PPD Electrical Engineering Department members Mike Cherry,

Victor Martinez, Tim Martin, Mike Matulik, and Bruce Merkel also provide essential support

Russ Rucinski

Pete Simon

Bob Barger

John Najdzion

Bob Kubinski

Mike Sarychev

Bryan Johnso

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Pat Healey

Bill Frank