april 26, 2006bill wisniewski1 run 5 progress operations and safety systems status svt intervention...
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April 26, 2006 Bill Wisniewski 1
Run 5 progress Operations and Safety Systems Status
SVT Intervention Decision
DCH Front-end electronics upgrade
DIRC EMC IFR
Barrel upgrade progress and plans Avalanche mode
Trigger Z tracking upgrade
MDI Identification of Needs Summary
Detector Operations
April 26, 2006 Bill Wisniewski 2
Run 5 Progress
Run 4 ended soon after last review: 112 fb-1 (9/17/03-7/31/04).
Run 5: started 4/16/05 Expected to end 7/31/05
not the full story…
ROD
MD
April 26, 2006 Bill Wisniewski 3
BaBar Weekly Operations
During running cycle, daily meetings at 7:45 and 3:45:
Work is authorized at both meetings, though the format and constituencies of the meetings differ.
Work Authorizers: Technical Coordinator, Operations Manager, Run Coordinators, Chief Engineer (who is IR2 Area Manager), with participation of Directorate Safety Officers.
April 26, 2006 Bill Wisniewski 4
BaBar Weekly Operations
7:45 meeting: Attended typically by: TC, Ops Mgr, at least one RC, at
least one of the DSOs, Building Manager, chaired by CE. Other attendees: External groups working in IR2 from/for
Accelerator Dept and CEF Work to be performed in IR2 (and IR12) reviewed.
work by Hall Crew under supervision of Chief Engineer work done by others for BaBar or Accelerator Department
Safety issues related to this work are discussed, for example:
new 480v feeder lines to be connected to Motor Control Center work plan, worker qualifications and training (JHAM, line supervisor signoff)
cable installation work plan, JHAM, RWCF (rad work) if protection devices disturbed
Permit Required Confined Space….
April 26, 2006 Bill Wisniewski 5
BaBar Weekly Operations
7:45 meeting (continued): updates of ongoing work, reports discussion of general lab safety issues as they pertain
to BaBar work: changes in regulations/training for work on elevated surfaces (fall restraint), use of scissors lifts, hoisting and rigging.
discussion of safety issues that may affect the upcoming major installation.
record of the meeting: BaBar Experiment Logbook reported in header of day shift log, lab daily report binder of copies of Work Authorization forms (extended
projects)
April 26, 2006 Bill Wisniewski 6
BaBar Weekly Operations
3:45 meeting: attended typically by: Spokesperson, TC, Ops Mgr, the Run
Coordinators, operations managers for all the systems including computing tasks, safety officer. Chaired by Run Coordinator on duty. This is primarily a meeting of physicists.
other attendees (rare): second shift crew representative, typically from Accelerator Department
review by system activities of preceding day (much prompt repair) as well as plans for the next day. Understanding of data taking efficiency losses. Safety issues discussion.
form of authorization: minutes of the meeting, which are retained in Hypernews posting.
monthly system reports on Wednesdays (rotate thru systems)
April 26, 2006 Bill Wisniewski 7
BaBar Weekly Operations
Prompt Repair: running systems break down and need immediate
repair work authorization can not wait for the next operations
meeting person performing the repair reports to the Shift
Leader (pilot). Run Coordinator on duty is involved if loss of beam time greater than 15 minutes (systems work); approves work by other agencies.
April 26, 2006 Bill Wisniewski 8
BaBar Weekly Operations
Interactions with Accelerator: Run Coordinators report on preceding day’s
performance/activities by BaBar at 8:00 MCC Operations Meeting
PEPII-BaBar daily coordination meeting (8:15) includes typcially Spokesperson, Tech Coordinator, Run Coordinators with PEPII opposite numbers to plan for the day.
PEPII Accelerator Meeting (M,Th; 3:00): SP,TC,RCs, MDI manager as active observers
PEPII-BaBar Weekly Meeting: SP, TC, OpsMgr, RCs, system ops mgrs and concerned individuals. Updates of weeks activities and performance, plans for upcoming weeks (machine development, repairs).
April 26, 2006 Bill Wisniewski 9
BaBar Weekly Operations
PEPII-BaBar Meeting account for
downtime/lost efficiency
review backgrounds experience of the week
4/17
4/24
10
The Run 5 Wall of Shame
SVT 34.9 hours
DRC 21.0 hours
IFR/LST 10.0 hours
DCH 5.2 hours
EMC 6.1 hours
IFR/RPC 3.0 hours
SVTRAD 5.5 hours
ODC 15.4 hours
ODF 6.1 hours
DAQ 3.6 hours
TRG 3.3 hours
ORC 2.0 hours
OEP 0.4 hours
COMP 0.7 hours
Total BaBar down time (with PEP up) in Run 5 = 142 hours (~3%) (~110 hrs in Run 5a, 4.4%; balance Run 5b)
+ Solenoid (12 hrs), Gopher (8 hrs), power glitches(2 hrs), Gas shack (1.5 hr), VESDA (1 hr)
April 26, 2006 Bill Wisniewski 11
BaBar Training
Training for BaBar members authorized to work: Shifters:
gatekeepers: Run Coordinators tool for RCs: SLAC Training Assessment adapted for BaBar must have Safety Intro, Electrical, GERT (rad training)
Training 1st two are required of all SLAC employees
review IR2 Area Hazards Analysis go over Shifter JHAM with Run Coordinators who are the line
supervisors for this activity shifter training session by RCs:
review ESH issues for IR2; walk the site specific training for pilot (lead) and navigator (data
quality) shadow shifts
level of training helps with shifter responsiveness to detector problems; denser blocks/student training
April 26, 2006 Bill Wisniewski 12
BaBar Training
Training for BaBar members authorized to work: System Workers:
gatekeepers: system managers (or their system ops manager if delegated)
systems specific manuals for repairs and maintenance (web available): OJT
job specific hazards: DCH: PRCS (permit required confined space training) DCH: LOTO (lock-out tag-out) SVT: backward cabling: PRCS IFR & EMC: fall restraint training
April 26, 2006 Bill Wisniewski 14
SVT
Issue confronting BaBar at the end of 2004:
Does the SVT have to be removed from BaBar in the next long down for repairs?
Limiting factor to the lifetime of the SVT is radiation damage.
Damage to the sensors: instantaneous (p-stop short: efficiency) & integrated (increase in leakage current, decrease in charge collection efficiency)
Damage to the electronics: increase in noise & decrease in gain decrease S/N; inefficiency from digital failures
Sensors tested ok to 9 Mrad: non-mid-plane modules will reach ~1-1.5 Mrad in 2009 (not a problem), mid-plane modules have problems earlier.
April 26, 2006 Bill Wisniewski 16
SVT
Limiting factor to the usefulness of the SVT is occupancy.
Extrapolate background studies to future running conditions:
YEAR 2004
YEAR 2007
April 26, 2006 Bill Wisniewski 18
BL1M04 (Backward West)
5Mrads
5Mrads
5Mrads 20%20%
20%
DOSE
DOSE
DOSE BEAM OCCUPANCY
20%5Mrads
DOSE
BEAM OCCUPANCY
BEAM OCCUPANCY
BEAM OCCUPANCY
April 26, 2006 Bill Wisniewski 19
FL1M01 (Forward East)
DOSE
DOSE
DOSE
DOSE
5Mrads5Mrads
5Mrads 5Mrads
20%20%
20% 20%
BEAM OCCUPANCY
BEAM OCCUPANCY
BEAM OCCUPANCY
BEAM OCCUPANCY
April 26, 2006 Bill Wisniewski 20
Summary of chips affected by radiation/occupancy
Dose only Occupancy only Both
2005
2006
2007
2008
0
0
4
8
11
15
15
14
0
0
2
4
April 26, 2006 Bill Wisniewski 21
Physics Consequences
Studies on the impact of physics results have been performed for a number of scenarios where we lose the functionality of a different number of chips in the mid-plane:
35.3%
34.5%
B J/s
Example among the most sensitive modes: soft from B D*X
56%51%
Set E = 2 midplanechips off inL1& 2 (32 ICs)
Scenarios with mid-plane L1-2modules off:(UNREALISTIC)
April 26, 2006 Bill Wisniewski 22
SVT Repair Conclusion
The SVT group concluded in July 2004 that there was insufficient benefit to warrant replacing SVT modules in the next long shutdown: Occupancy in the dying regions would make the replacements useless.
The physics cost of failure to replace the modules is modest and acceptable, given the complexity and risk in replacing the modules. Conclusion endorsed by the physics team.
April 26, 2006 Bill Wisniewski 23
25
Pedestal shift vs dose (krad)
BL1M4z
RED = old thrBLACK = new thr
Inefficiency vs position after the threshold change
SVT Vicissitudes: Pedestal Shift
Bullet dodged: Can compensate for this dose related shift
April 26, 2006 Bill Wisniewski 24
SVT Vicissitudes: Bias Current
Layer 4 Problem. Observed initially as an increase in occupancy. Tracked to bias current increase. Swift growth of current would find many L4 modules in trouble in a few months!
10 uA
300 uA 200 uA
25 uA
FL4M11 FL4M16
Bia
s cu
rren
t (uA
)
Bia
s cu
rren
t (uA
)
April 26, 2006 Bill Wisniewski 25
SVT Vicissitudes: Bias Current
Intense effort to understand the source of this problem
Direct IV measurements confirm it Not a radiation damage issue; geography is funny: L5 ~no
effect Beams off, bias on give current decrease; converse also
yields current decrease: limit damage source. Changing relative voltage between L4 & L5 has effect. (&
humidity)
April 26, 2006 Bill Wisniewski 26
SVT Vicissitudes: Bias Current
Changing relative voltage between L4 & L5 has effect. By properly adjusting the voltages, can fix the problem
Interpretation is static charge accumulation. Radiation ionizes the air between L4 & L5. The voltage difference drifts ions and electrons to the silicon surface.
Simulate layer of charge accumulating on oxide & effect on junction: increase of field at the edge of the junction, which is known to cause localized junction breakdown.
++++++ ++++++ ++++++++
April 26, 2006 Bill Wisniewski 27
SVT Humidity Tests
Bias voltage problems continue in some modules after center tap change: introduce humidity to reduce charge build-up.
First attempt coincides with damage to two modules, BL3M5, BL3M6. Conjecture is water condensed onto boards. Recovered 32 of 40 chips on these modules.
Second attempt under better controlled circumstances yields success. Set up more robust humidifying system in October 2005.
April 26, 2006 Bill Wisniewski 28
SVT Reliability Upgrades
Modify power supply boards to allow flexibility on changing the reference voltages
Add two new chillers to provide redundancy DAQ firmware upgraded to fix configuration issues
April 26, 2006 Bill Wisniewski 29
DCH Run 5 Experience
Test chamber aging studies (two studies)
indicate that DCH should be fine well
beyond the exposure received during the balance of the life of
the experiment.
April 26, 2006 Bill Wisniewski 30
Motivation: Reduce deadtime due to
serialization and shipping of data from DIOM to ROM
Upgrade in two steps:
Phase 1 (2004): Ship only half the waveform information (3216 bytes) firmware change
Phase 2 (2005): Modify electronics: FPGA to do feature extraction before transmission hardware change
DCH Electronics Upgrade
April 26, 2006 Bill Wisniewski 31
DCH Electronics Upgrade
Phase 1: waveform decimation
used in Run 5a
Phase 2: new readout board
uses FPGA downloads allow code
updates
April 26, 2006 Bill Wisniewski 32
Phase 1 in Run 5a
Ship 16 of 32 bytes Keeps timing stamp Reduces dE/dx sampling: no significant performance loss Worked fine except(!):
Feature extraction bug in ROM meant that 4.2% of DCH hits were labelled bad waveforms. Hits were lost. Losses were uniform. Cause: a typo in the assembler code in the ROMs. Problem fixed August.
Tracking fix implemented that compensates for the effects of lost hits.
April 26, 2006 Bill Wisniewski 33
Phase 2 Installation Three front end electronics modules, one of each
of three types, installed during Run 5a to gain experience with the new design. Waveform decimation implemented.
Installation of balance of modules planned for October down.
Installation went less smoothly than expected: after installation of the first dozen front end electronics
boxes, subtle thermal sensitivity problems were noticed with the outer boxes; the simple fix for this problem, the addition of a capacitor, was quickly implemented.
another system issue was discovered: greater sensitivity to uniformity of DIOM timing (trigger related); this problem was also quickly diagnosed and fixed.
Good planning for the installation included substantial float; installation was completed 2 November.
April 26, 2006 Bill Wisniewski 34
Phase 2 Performance
Phase 2 electronics appear to be performing well. Downloaded code ran in waveform decimation mode at start
of 5b. In order to get the full benefit of this phase of the
electronics upgrade, move front end feature extraction from the ROMs into the FPGA on the ROB.
FEX code was developed and tested. Deployment mid-February
Recalibration needed & completed for analysis
Fly-in-the-ointment: Single Event Upsets Experience ~1/day in December (recovery difficulties for
shifters) Scheme for quick recovery functioning implemented Long term: aim for redundant implementation/configuration
checks
April 26, 2006 Bill Wisniewski 35
DIRC
Robust system that now performs well. Front end electronics upgrade during 2004 down:
DCC modifications for rate handling. Got ahead of aging curve in 2005 down: replaced
front end electronics fan trays that were reaching the end of their service life.
PMT watch: effect of water on face of tubes monitored; no accelerated aging; ok for life of experiment.
PMT internal failures (“Christmas Trees”) continue at a low, acceptable rate.
April 26, 2006 Bill Wisniewski 36
EMC
radiation damage to CsI(Tl) crystals is via formation of color centers
monitor effects of radiation damage via source calibration
perform radiation tests, using an intense Cs source, of array of 16 crystals that simulate the barrel. Exposure comparable to expected dose over life of the experiment
check overall response: OK check effect on uniformity (more of a worry
since can not easily monitor this in situ): uniformity does change with dose, however it is small enough to be ignored, though a correction factor by crystal grower could be applied.
continuing offline activities: improvements to calibration
Monitor Light Yield with Source Calibration
monitor dose with radfets, leakage current
April 26, 2006 Bill Wisniewski 40
Humid IFR Gas
Apr. 24 Jun 16Layer 13 Layer 13
Layer 16 Layer 16
Humid gas since Feb. 18
Humid gas since May 5
Humid gas since June 8
April 26, 2006 Bill Wisniewski 41
Avalanche Mode RPCs
Forward endcap RPCs, currently run in streamer mode, see high rates. Rates highest at edge of middle chambers that is closed to beam line.
Lifetime of chambers limited by integrated charge. Limit charge by moving from streamer to avalanche mode on middle chambers. Challenge is smaller signal.
Strategy: install preamps on chambers where backgrounds most localized; test for noise, measure integrated charge reduction. Understand gas mix, voltages, efficiencies in situ. Determine if avalanche mode is worth extending in 2006.
April 26, 2006 Bill Wisniewski 43
Layer 1 Layer 4 Layer 8
Layer 10 Layer 12
Feb. 2003
Oct. 2003
Dec. 2003
Jan. 2004
Jun. 2004
Jun. 2005
Efficiency Loss at Small Radii
April 26, 2006 Bill Wisniewski 44
Running the RPCs in avalanche mode instead of in streamer mode will reduce the charge/unit area and extend the life of the RPCs. This may be especially crucial for layers 15, 16 and portions of the inner layers. Work has been done at Princeton and Ferrara to understand if it is possible to install preamps in critical regions so that chambers can be run in avalanche mode: should work. Test on endcap inner layers.
RPCs & Avalanche Mode
Forward end-cap services gap
April 26, 2006 Bill Wisniewski 45
During the October shutdown we have inserted the preamplifier boards, and switched the gas mix for front endcap east door, layer #1, #3, #5 middle section RPCs. Total 6 RPCs are switched.
Disconnect the connector;
Add extension cables and insert the preamplifier board.
For the present test total 480 preamp channels are inserted.
Avalanche Mode RPCs
Dark current reduced by factor of 6
April 26, 2006 Bill Wisniewski 46
Avalanche Mode RPCs
Streamer mode average
Increase operating voltage 200v
efficiencyFlexibility from gas mixture:Red is current mix: R134A/Ar/Isob/SF6 (75.5/19.4/4.5/0.6)Purple is (75.5/19.4/4.5/0.6)
+FEC threshold is ~2x (–FEC) threshold
April 26, 2006 Bill Wisniewski 47
New layer
New RPC belt
10cm steel
5 layers of 2.5 cm brass
Barrel6 Brass layers RPC LST2 sectors in 20044 more in 2006
Barrel IFR Upgrade
April 26, 2006 Bill Wisniewski 52
LST Installation
New east platform for electronics
Special tooling for backward corner block
Peter Kim & Charlie Young
April 26, 2006 Bill Wisniewski 54
HV supply
High Voltage system provides 4 wires for every tube
Enable and control box for HV
April 26, 2006 Bill Wisniewski 55
Readout electronics
Single ended signals are sent to Front End Cards (outside the detector) and there amplified and discriminated.
A completely new electronics has been developed to readout the signals from:
- strips (z coordinate – beam line direction) positive signal
- wires (phi coordinate – azimuthal angle)
negative signal
Daughter board
Mother board
Ferrara
April 26, 2006 Bill Wisniewski 56
Successful Milestones
Plan Actual
Start bottom sextant 8/16/04 8/15/04
Finish bottom sextant 9/8/04 9/2/04
Start top sextant 9/18/04 9/16/04
Finish top sextant 10/5/04 9/29/04
April 26, 2006 Bill Wisniewski 57
Summer 2004 Safety Experience
The plan: Everyone working on the detector during the down
period receives IR2-specific training During April Safety Stand-down, July collaboration
meeting & whenever there was a need during the down time (e.g. weekly sessions, special training sessions for newly arrived techs).
Each shift has Safety Oversight Dedicated team led by Sandy Pierson, including Frank
O’Neill, Joe Kenny, Karen Holtemann, Michael Scharfenstein, John Shepardson, Rick Challman (aside from Frank and Sandy, borrowed from other divisions).
Procedures prepped by Jim Krebs and Bill Sands for disassembly of magnet steel, installation of LSTs and reassembly of the magnet. These procedures include Job Hazard Analyses.
Tailgate safety meetings held for each shift to discuss the work to be done and safety.
April 26, 2006 Bill Wisniewski 58
Summer 2004 Safety Experience
Post-mortem on experience (LST engineering) Overall the program was successful Engineers and technicians
Initial fears: safety oversight might be too intrusive and cause inefficiencies
Actual events: the team moved into a comfortable working relationship
Instances of unsafe practice typically quickly identified and stopped.
But… Block dropped when hall crew members ignore procedure for
moving a corner block; nylon sling broke and block dropped ~1 ft to floor
Lesson learned: procedures for complicated lifts must be followed, no shortcuts.
April 26, 2006 Bill Wisniewski 60
LST 2005/6 Progress
All modules are at SLAC All HV cables, long and short haul, at SLAC All brass at SLAC, machining and layer selection done Two ‘day long’ engineering workshops held including safety
planning Fab of fixtures, platforms, mock-ups almost complete
IFR slow controls integral of RPC & LST Simulations have been validated Geometry has been validated, new sextants aligned to DCH Muon ID: cut based selector checked & tuned; NN selector
tuned on simulation, in process for data
April 26, 2006 Bill Wisniewski 61
Preparations for 2006 Down
LST installation in the diagonal sextants of the barrel requires substantial disruption of detector services.
For SVT, cables will need to be pulled back to the outer edge of the detector. This was allowed for in the original system design to accommodate pulling back the EMC endcap.
For EMC, the disruptions are greater: load transfer of the forward end of the calorimeter; very extensive uncabling of the calorimeter, and disruption of cooling services and source calibration system.
April 26, 2006 Bill Wisniewski 62
EMC Load Transfer Review
Held 22-23 September at SLAC with presentations by engineering team of Krebs, Boyce and Dittert. Presentations included design and analysis of the EMC load transfer fixture, installation of the EMC load transfer hardware, and written load transfer procedures.
Reviewers from SLAC: Metcalfe, Skarpaas VII, Doyle, DeBarger
Outcome of review: The design looks good, but some details needed to be improved.
April 26, 2006 Bill Wisniewski 63
Preparations for 2006 Down
EMC load transfer fixture Pre-fit support beam pads Check clearances from cables and
services at pins
EMC services survey Coolant lines Cable slack (no endcap un-cable?)
Replace aft cableways & rearrange EMC cables for simpler LST install
April 26, 2006 Bill Wisniewski 64
Preparations for 2006 Down
LST’s will be installed in 4 sextants during the scheduled 2006 down.
Only 4 months available to do more than twice the work done in 2004: very tight schedule with 10 or 11 hall crew shifts a week, owl shift for testing+.
Perform substantial prep work in October October work:
LST HV cable runs under EH platforms and on walls redone so that there is space for next year’s installation, as well as re-routing cables to supplies in the electronics racks on top of the EH
LST on-detector racks installed under the detector west mezzanine
April 26, 2006 Bill Wisniewski 68
Readiness Task List for ’06
169 item list. Items not completed typically load tests, mock up tests, final procedures. These should be complete by ’06 down, though it will be tight.
April 26, 2006 Bill Wisniewski 70
Hoisting and Rigging for ’06
There are more than 400 crane related tasks on the project schedule that involve on the order of 2000 crane lifts.
Detailed lifting procedures (~20) for ~100 critical lifts. Remaining lifts are ordinary lifts, which would require a
couple of hundred lift plans. Project schedule threatened by H&R requirements
uncertainty, possible requirement to generate a large number of lift plans for ordinary lifts.
April 26, 2006 Bill Wisniewski 71
Safety Plan for ’06
Plan based on ’04 safety plan Plan takes into account current training
requirements
April 26, 2006 Bill Wisniewski 72
Level 1 DCT selects tracks with high Pt (PTD) DCZ allows selection on track Z0
reduces L1 rate due to beam related background by cutting on the Z0 of the track.
Essential for running at luminosities ~1034 to keep event rate low enough to avoid deadtime from bottlenecks (see later talks).
Physics events Beam background events
Trigger: Level 1 Upgrade
April 26, 2006 Bill Wisniewski 73
DCZ does its job just as well as we hoped Finding tracks and measuring z0 and pT
How is this information used? ZPD counts tracks with cuts on |z0| and |1/pT|
Have tried |z0| < 15(12)cm, |pT| > 200(800) MeV
GLT can combine “Z tracks” with other trigger objects
It’s a delicate balancing act Physics efficiency (which physics?) and robustness Maximum reduction of L1 trigger rate
L1 Trigger Rate
April 26, 2006 Bill Wisniewski 74
Trigger
Ironed out new DCZ trigger during Run 5a: commissioned in parallel with DCT TSF firmware problem diagnosed and ‘repaired’ TSF ZPD transmission errors fixed DCH-DCT calibration problem fixed DCZ power cycle sequencing understood DCZ configured out of the database nagging power sequencing problem almost ironed
out
EMT has had fast monitoring updates IFT timing aligned better than Run 1-4
(problem between LST and RPC resolved) Great progress in trigger simulation
April 26, 2006 Bill Wisniewski 75
MDI
How BaBar helps: Background diagnostics ( doses <doses as in past>, aborts
<1/day vs 3/day>, neutron background sources <region .5 to 2m forward; DIRC & RPC susceptibility>)
BaBar based accelerator diagnostics ( trickle performance, background rate along train, real-time luminous region monitoring, IP parameter measurements )
New diagnostic instrumentation (LER x-ray beam size monitor <6% precision>)
Simulations: Bhabha generator incorporated GEANT4 model to Q2 septum LER Turtle + G4 simulations for subsystems NEED: HER Turtle + G4 rays; vacuum model; neutron
validation; more details in G4 model (Q4…etc) Much accomplished, but luminosity will increase by >2x.
Need to increase effort in MDI.
April 26, 2006 Bill Wisniewski 76
Identification of Needs
In December the Technical Board reviewed mid and long term plans for the detector systems and online.
hardware improvements expected? Fallout: online upgrade; return to dataflow bottlenecks. changes/ improvements to reconstruction envisioned?
What are the systems long term manpower needs? minimum number of FTEs needed in years after 2006
challenge: can you continue to turn out high quality data with much less manpower?
Fallout: round of discussions between Spokesperson-elect, Technical Coordinator and System Managers to explore service task coverage and to identify key positions to be filled. Drop seen in TC’s annual service task audit (FTE per capita) for some institutions adds impetus to this identification of open positions.
Result: develop system task tables to carry through to the end of BaBar.
April 26, 2006 Bill Wisniewski 80
Summary (I)
BaBar has: demonstrated ability to efficiently take data with low
overall down time: even at 1x1034 we have been able to take data with low deadtime.
identified obstacles in the path to efficient data-taking: trigger upgrade that substantially reduces
backgrounds while retaining interesting physics Drift Chamber electronics upgrade to remove a data
flow bottleneck promptly dealt with in a sequenced approach that stayed ahead of luminosity increases
upgrade(d) online compute farms to deal with higher data rates, and to avoid hardware end-of-life problems
see Weaver & MacFarlane talks later: backgrounds and future risks for data flow
April 26, 2006 Bill Wisniewski 81
Summary (II)
BaBar has: adopted a phased approach to IFR upgrades
that make use of experience gained with detector performance and installation experience to complete the task safely and effectively and to schedule
RPC upgrade for endcap extension of RPC endcap life via avalanche
mode two campaign LST upgrade for barrel to
take advantage of lessons learned developed tools for understanding and
applying manpower resources and safety going into the final years of the experiment