Detector Operations 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.
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Transcript Detector Operations 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.
Detector Operations
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
April 26, 2006
Bill Wisniewski
1
Run 5 Progress
Run 4 ended soon after last review: 112 fb-1 (9/17/03-7/31/04).
R
O
D
April 26, 2006
Run 5: started 4/16/05
Expected to end 7/31/05
not the full story…
M
D
Bill Wisniewski
2
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
3
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
4
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
5
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
6
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
7
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
8
BaBar Weekly Operations
PEPII-BaBar Meeting
account for
downtime/lost
efficiency
review
backgrounds
experience of the
week
4/17
4/24
April 26, 2006
Bill Wisniewski
9
The Run 5 Wall of Shame
SVT
34.9 hours
ODC
15.4 hours
DRC
21.0 hours
ODF
6.1 hours
IFR/LST
10.0 hours
DAQ
3.6 hours
DCH
5.2 hours
TRG
3.3 hours
EMC
6.1 hours
ORC
2.0 hours
IFR/RPC
3.0 hours
OEP
0.4 hours
SVTRAD
5.5 hours
COMP
0.7 hours
+ Solenoid (12 hrs), Gopher (8 hrs), power glitches(2 hrs), Gas shack (1.5 hr), VESDA (1 hr)
Total BaBar down time (with PEP up) in Run 5 = 142 hours (~3%)
(~110 hrs in Run 5a, 4.4%; balance Run 5b)
10
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
st two are required of all SLAC employees
1
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
11
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
12
BaBar Training
SLAC Training Assessment (for BaBar)
April 26, 2006
Bill Wisniewski
13
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
14
SVT Radiation Dose
scrubbing
April 26, 2006
Bill Wisniewski
15
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
16
SVT Occupancy
Hit Efficiency Effects
Resolution
April 26, 2006
Bill Wisniewski
17
BL1M04 (Backward West)
DOSE
5Mrads
BEAM
OCCUPANCY
20%
DOSE
5Mrads
BEAM
OCCUPANCY
20%
DOSE
BEAM
OCCUPANCY
DOSE
BEAM
OCCUPANCY
5Mrads
20%
5Mrads
20%
April 26, 2006
Bill Wisniewski
18
FL1M01 (Forward East)
DOSE
BEAM
OCCUPANCY
DOSE
BEAM
OCCUPANCY
5Mrads
20%
5Mrads
20%
DOSE
5Mrads
April 26, 2006
BEAM
OCCUPANCY
20%
DOSE
5Mrads
Bill Wisniewski
BEAM
OCCUPANCY
20%
19
Summary of chips affected by
radiation/occupancy
2005
2006
2007
2008
April 26, 2006
Dose only
Occupancy only
Both
0
11
0
15
0
0
4
15
2
8
14
4
Bill Wisniewski
20
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:
Set E =
2 midplane
B J/Y Ks
35.3%
chips off in
L1& 2 (32 ICs)
34.5%
Scenarios with
mid-plane L1-2
modules off:
(UNREALISTIC)
56%
51%
Example among the most sensitive modes: soft p from B D*X
April 26, 2006
Bill Wisniewski
21
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
22
SVT Vicissitudes: Pedestal Shift
Bullet dodged: Can compensate for this dose related shift
Pedestal shift vs dose (krad)
Inefficiency vs position
after the threshold change
BL1M4z
25
RED = old thr
BLACK = new thr
April 26, 2006
Bill Wisniewski
23
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!
300 uA
Bias current
(uA)
FL4M11
200
uA
FL4M16
Bias current
(uA)
25 uA
10 uA
April 26, 2006
Bill Wisniewski
24
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
25
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
26
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
27
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
28
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
29
DCH Electronics Upgrade
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
April 26, 2006
Bill Wisniewski
30
DCH Electronics Upgrade
Phase 1: waveform
decimation
used in Run 5a
April 26, 2006
Phase 2: new readout board
uses FPGA
downloads allow code updates
Bill Wisniewski
31
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
32
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 went less smoothly than expected:
Installation of balance of modules planned for October down.
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
33
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
34
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
35
EMC
Monitor Light Yield with
Source Calibration
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
monitor dose with radfets, leakage current
April 26, 2006
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
Bill Wisniewski
36
IFR (RPC)
April 26, 2006
Bill Wisniewski
37
Barrel RPC efficiency dropping ~1%/month,
but endcap RPCs doing well
Efficiency (July ’05)
RPC Forward End-cap Preservation Society
April 26, 2006
Bill Wisniewski
39
Humid gas since
June 8
Apr. 24
Humid IFR Gas
Jun 16
Layer 13
Layer 13
Humid gas
since Feb. 18
Layer 16
Layer 16
Humid gas
since May 5
April 26, 2006
Bill Wisniewski
40
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
41
RPC Forward End-cap Preservation Society
April 26, 2006
Bill Wisniewski
42
Efficiency Loss at Small Radii
Layer 1
Layer 4
Layer 8
Layer 10
Layer 12
Feb. 2003
Oct. 2003
Dec. 2003
Jan. 2004
Jun. 2004
Jun. 2005
April 26, 2006
Bill Wisniewski
43
RPCs & Avalanche Mode
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.
Forward end-cap services gap
April 26, 2006
Bill Wisniewski
44
Avalanche Mode RPCs
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.
Dark current reduced by factor of 6
April 26, 2006
Bill Wisniewski
45
Avalanche Mode RPCs
efficiency
Flexibility 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)
Streamer mode average
+FEC threshold is ~2x (–FEC) threshold
April 26, 2006
Bill Wisniewski
Increase
operating
voltage
200v
46
Barrel IFR Upgrade
New RPC belt
New layer
10cm steel
Barrel
5 layers of
2.5 cm brass
6
Brass layers
RPC LST
2 sectors in
2004
4 more in 2006
April 26, 2006
Bill Wisniewski
47
Summer 2004 Safety Plan Review
April 26, 2006
Bill Wisniewski
48
Summer 2004 Safety
April 26, 2006
Bill Wisniewski
49
Bottom sextant before and after installation
Forward side
April 26, 2006
Bill Wisniewski
50
Bottom sextant before and after installation
Backward side
April 26, 2006
Bill Wisniewski
51
Peter Kim & Charlie Young
LST Installation
New east platform
for electronics
Special tooling for
backward corner
block
April 26, 2006
Bill Wisniewski
52
LST Top Sextant Installation
Strips
Brass
Modules
April 26, 2006
Bill Wisniewski
53
HV supply
Enable and control box for HV
High Voltage system
provides 4 wires for
every tube
April 26, 2006
Bill Wisniewski
54
Readout electronics
A completely new electronics has been developed to
readout the signals from:
- strips (z coordinate – beam line direction)
positive signal
Daughter
board
- wires (phi coordinate – azimuthal angle)
negative signal
Mother board
Single ended signals are sent to Front End Cards
(outside the detector) and there amplified and
discriminated.
Ferrara
April 26, 2006
Bill Wisniewski
55
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
56
Summer 2004 Safety Experience
The plan:
Everyone working on the detector during the down period
receives IR2-specific training
Each shift has Safety Oversight
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).
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
57
Summer 2004 Safety Experience
Post-mortem on experience (LST engineering)
But…
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.
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
58
LST Modules at Collider Hall
2006
2004
April 26, 2006
Bill Wisniewski
59
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
60
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
61
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
62
Preparations for 2006 Down
EMC load transfer fixture
Pre-fit support beam pads
Check clearances from cables and services
at pins
April 26, 2006
EMC services survey
Bill Wisniewski
Coolant lines
Cable slack (no endcap un-cable?)
Replace aft cableways & rearrange
EMC cables for simpler LST install
63
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
64
LST October Cable Work
Conduit
(Backward East)
April 26, 2006
Bill Wisniewski
65
Draft Schedule for ’06 Installation
pg 1 of 16
April 26, 2006
Bill Wisniewski
66
Below-the-hook Fixtures for ’06
April 26, 2006
Bill Wisniewski
67
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
68
Installation Preps
April 26, 2006
Bill Wisniewski
69
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
70
Safety Plan for ’06
Plan based on ’04 safety plan
Plan takes into account current training requirements
April 26, 2006
Bill Wisniewski
71
Trigger: Level 1 Upgrade
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).
Beam background
events
Physics events
April 26, 2006
Bill Wisniewski
72
L1 Trigger Rate
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
April 26, 2006
Bill Wisniewski
73
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
74
MDI
How BaBar helps:
Simulations:
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>)
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
75
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.
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Identification of Needs: DCH
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Identification of Needs: DIRC
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Identification of Needs: Trigger
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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:
April 26, 2006
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
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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
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