Dan Bauer CDMS Collaboration Meeting February 11, 2005 Soudan Overview Highlights of work since July...

Dan BauerCDMS Collaboration MeetingFebruary 11, 2005

Soudan Overview• Highlights of work since July 2004 meeting

Ended R119 on Aug 9 and warmed upCryogenics upgradesBackgrounds, shield, veto upgradesDAQ/electronics/computer upgradesThree new detector towers

• Short-term scheduleIVC-OVC leak is fixed!Finish leak checks and cooldownCommission five towersInitial calibration dataBegin Run 120

• Schedule for the rest of CDMS IIRun through 2005

• Some issues to discuss this afternoon


IVC-OVC Leak• Massive leak discovered last Friday

– Opened OVC/LN lids, restrained IVC can and pumped out

– Radial sealing o-ring broken at end of e-stem

– Replaced ‘in-situ’ (NOT EASY)

– Pumped IVC to 7E-5 torr last night; leak checking this morning

– Will close OVC and pump out both IVC and OVC over weekend


Cryogenics Upgrades• Cryo Cooler

– Proved difficult and time-consuming to install on e-stem• Mechanical problems and electrical isolation

– Finally finished in December, 2004– Tested operation briefly last week

• Vacuum– Tightened bath/OVC and IVC seals in tails– Added low-impedance tail pumpout

• May reduce or eliminate ‘burps’, reduce Lhe consumption

• New Ebox– Much better vacuum bulkhead connectors

• But mechanical problems with box itself led to delays– Now installed and leak tight– Should allow routine connection of detector cables


Cryo Pictures

• Cryocooler and ebox


Cryogenics Upgrades• Icebox

– Added 600 mK, and modified 4K, IR shields• Shields not well sealed around towers• 600 mK caused problems when it cut tower wires

– Added 600 mK, 4K IR absorber paddles• Try to absorb any stray heat from e-stem

– Installed more thermometry at 4K• Si diode thermometer on each tower, 1 on 4K flange• Si diodes on both 4K and 77K stages of cryocooler

– Cleaned cans as best we could w/o disassembly• Removed discrete particles and a kevlar string

– Checked alignment of cans• Within 0.01” of where they were before


Icebox Pictures

• 600 mK shield and 4K shield/IR absorbers


Cryogenics Upgrades• Transfer systems

– Improved LN transfer efficiency (50 PSI dewars)– Will fix Lhe transfer line resistors (keep water out)– New, longer Lhe slow-transfer line

• UPS– Have same UPS, but installed automatic transfer switch

• Will buy diesel generator to backup crucial vacuum pumps

• Intellution/APACs– New PCs

• Some issues with mine networking

– New version of software (compatibility with FNAL)– Better LR700 interface– Improved historical record

• Move variables, better sampling


Backgrounds, Shield, Veto• Radon

– Now have 6 purge tubes instead of 1• Allows much better purge between icebox and mu-metal

shield

• Also can purge area of inner poly

– Can insert sources along both c-stem and e-stem• Sources below and above level of detectors

• Veto– Upper layers of veto removed and stored

– Interference problems with paddles around cryocooler

• Shield– Pb rings around stems notched for new tubes


Radon Purge

• White tubes (2 on each stem) purge between icebox and mu-metal can– These can also accept all radioactive sources

• Yellow tubes (1 on each stem) purge inner poly shield region


Electronics Upgrades

• FEBs– Problems with new FEB power supplies, fans

• Mostly sorted out but few spare FEBs or supplies available

• RTFs– Small fraction of triggers not registering on some

boards• Have one such board at FNAL to debug

• Remote control/monitoring– New box installed to allow remote control/monitoring

of FEB and RTF power supplies and FEB fans


DAQ and Computing Upgrades• DAQ

– 5 tower DAQ working• Still some work to improve data writing and tracking• Need some work on detector tuneup software• Need some improvement in online diagnostics

• Offline computing– DarkPipe processing works for 5 towers

• But need some work on logistics

– New SAC - 30 dual-cpu machines from FNAL• Not installed yet; need surface building upgrades• Should be ready in time for massive data sets

• Networking– Movement on both upgraded LAN (GigE) and WAN (T3)

• Target date for T3 is March 17• Should improve speed to Soudan by at least x4


Five Towers (Finally)• Installation

– Installed T3-T5 in October/November– Had to repair T3Z5 (tower wires cut by 600 mK shield)– Also repaired T1Z4 (side coax)

• Blown coupling capacitor, probably from ESD• Installed copper grounding platform around icebox

– T1Z1 has only two functioning phonon channels• But charge channels should work => veto detector

– Maintained Rn purge of inner can for the whole time– Installed 31 striplines (one for diode thermometry)

• Electrical checkout– FEDUP works well at Soudan (thanks to Dennis)– A few detector I/O cables need modifications


Detector Pictures

• Tower 3 Face 5 repair


Detector Pictures• ESD platform for work around icebox


Short-term scheduleWeek of February 14

Close icebox and ebox again, after reconnecting stripline warm ends

Redo detector checks.

Recheck IVC-air, OVC-air, IVC-OVC; check fridge-IVC, fridge-OVC

Begin LN cooldown

Week of February 21

Electrical checks of detectors at 77K

Begin slow transfer and go to 4K

Begin cryocooler operation

Make sure autofill systems working correctly

Electrical checks at 4K


Short-term scheduleWeek of February 28

Clean mix, establish circulation and tune mix

Reach base temperature

Begin turning on T1

Week of March 7

Continue turning on and tuning detectors

Close shield and reinstall veto

Rest of March

Continue tuning detectors

Take calibration data sets

Prepare for WIMP search running

April 1, 2005

Begin Run 120


CDMS-II Schedule

BeginSoudan Science

UCB/Case T2

Full Science Running

T1 T1-2 Soudan

BeganScience

T1 SUF

Select best detectors for T3-5; studyany remaining detectors at TFs

T1

2000 2001 2002 2003 2004 2005

T1-5


Some discussions for this afternoon

• Soudan Operations– Detector tuning strategies and software– Best strategy to maximize WIMP livetime– Amount and type of calibration (gamma, n)

• Analysis– Role of Pipefitter – Analysis code maintenance and FNAL reprocessing– Optimization of beta rejection, nuclear recoil acceptance– R118 PRD content– When do we unblind for R119?



• Detectors and Test Facilities– How can we use TFs to understand T1-T5 at Soudan?

• What improvements are needed to do this?

– Is any detector fabrication justified under CDMS II?• Agencies have said we cannot use CDMS II $$ for future work!

• Backgrounds– What tests can we do at Soudan to understand gamma, beta

backgrounds?– What screening work falls within CDMS II?

• Alpha, neutron counters at Soudan• Continued surface analysis• Some additional gamma screening



• Cryogenics– Need to develop contingency plans for further leaks or failure to

cool to base– Also need operational strategy in the cryocooler era

• Collaboration– Do the video meetings work well enough?– How can we improve communication and documentation?– What can be improved for people at Soudan?

• Other– Feel free to meet in parallel groups on any CDMS II issues– Reconvene in plenary session to discuss ideas at 4:00


People do manage some amusements at Soudan!

• Spicy Buffalo Wings/Hot peppers contest– Oh, this really hurts!

Dan Bauer CDMS Collaboration Meeting February 11, 2005 Soudan Overview Highlights of work since July...

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