ESPERIENZA%20di%20Commissioning%20a%20CDF

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ESPERIENZA di Commissioning a CDF

• Anna Maria Zanetti
• INFN Trieste

Bologna - 23 Novembre 2006
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CDF
Run I first data in 1985 (prehistoric
organization detector) ? not too
much to learn. (L 2 x 1031 cm-2 s-1 ) Run II
Official Start march 2001 almost New Detector!
(10-20xLrunI) From CDF I
solenoid, central calorimeter, part of muon system

• All the rest is NEW!
• Endplug Calorimeter
• Tracking
• -SiliconSVXII,ISL,Layer00
• -Central Outer Tracker
• Front End Electronics
• Trigger
• DAQ System
• Muon systems
• TOF
• Offline/Online Software

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La Sfida di LHC
La SFIDA di LHC
Energy 14 TeV 7 x Tevatron Length 27 km
4 x Tevatron Magnetic Field 8.3 T 2
x Tevatron Beam Energy 350 MJ 250 x
Tevatron Bunch Collisions 40 MHz 20 x
Tevatron Instantaneous Luminosity 60 x
Tevatron of Collisions in an event 10 x
Tevatron of Detector Channels 100 M 100 x
Tevatron of Scientists (2500/expt) 3 x
Tevatron
Tevatron proton-antiproton 7 accelerators
LHC proton-proton
LHC
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Commissioning CDFII
Tevatron LHC
Begin Cosmic Ray Run Commissioning Run with Partial Detectors Late 1999 2000 Oct. 2000 2006
Detector Completion Jan. 2001 Summer 2007
Commissioning Period Mar. 2001 - Feb. 2002 Nov 2007 (1 TeV) Start Spring 2008 (14TeV)
Beginning of Physics Run Feb. 2002 ?
but 2002 still struggling with fully
commissioning some detectors/electronics/software
and with problems in detectors and Beam.
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First Phase Late 1999-2000

• CDF non yet completed
• Integration of components into DAQ
• Daily running pedestals, calibration runs
• November 1999 Three system readout test (DAQ w/
  multiple readout systems Calorimeter/TDC/Si DAQ
• January 2000 L1 calorimeter trigger
  established. Sum Et, Single tower, Missing Et
  triggers
• Cosmic Ray Running
• Once L1 trigger established, begin Timing-in of
  Electronics
• Across all detector subsystems, and across
  trigger subsystems
• Basic Level 3 filtering established
• Development of detector monitoring
• Calorimeter thresholds/noise rates
• A lot of work accomplished in debug and
  commission all the trigger
• systems and the Electronics
• Essential to be able to inject data/ read your
  system, test it indipendently by the others and
  in final environment

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Commission Trigger Electronics

• A lot accomplished with standalone test (no beam
  or cosmics)
• Take Silicon Vertex Tracker (SVT) as example
  (100 custom VME boards
• and a complex task) - but applies to all complex
  trigger systems.
• Note SVT was well thought on testing capability
  and monitoring
• the data flow on each board. Probably the best in
  CDF
• Independency from CDF DAQ (data driven device)
• Common data communication protocol
• Boards as building bricks that can be combined at
  will (lego)
• Can adapt SVT configuration to various test needs
• Ability to inject/read data from every board
• Can test most board functions with no additional
  hardware
• Software with board objects (ram, regs) in
  common framework
• Still it was not enough !!!
• System missing all these-gt struggle, building on
  the fly
• boards for testing purposes, suffered delays, etc

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..so what was missing?

• Plan for lack of input/output (done, but not
  enough)
• Must be able to test SVT in place, with proper
  timing and data flow, even without
  SVX/COT/L2/beam
• Not only hw test, also operating/monitoring
  software
• More functions and flexibility for board/system
  testing added on the road
• Plan for long, demanding, integration/commissionin
  g
• Should have invested much more in software much
  sooner
• More features could be implemented
• More people easily trained (?less expert demand)
• When come to integrating electronics be
  creative.
• Any way to bypass/emulate other
  system/boards must
• be pursue and strongly looked for.

be creative
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First Phase Organization

• CDF has early established shifts/DAQ always
  running ? once IN, a system must work and be
  correctly monitored and checked
• Sometimes testing activities not so easy.
• The payoff is a system kept working, running and
  steady growing
• Very important Fight hard the Entropy
• Train Shift Professionals ACEs. Stay in shift
  for 3 monthes- overlap 1 monthes. CDF still works
  this way.

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Begin Commissioning with Beam

• Oct 2000 Commissioning Run
• Si Barrel 4 only
• Many other systems partial
• COT recently on-line (seen 1st
• cosmics few days before roll-in)
• Nov. 2000-March 2001
• Complete the detector
• Continued integration work
• Daily cosmic running
• March 2001-February 2002
• Commission for physics data

Commiss.Run had some of everything enough to
shake down much of systems
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The Commissioning Run
Crucial event of CDF commissioning
Date 5/9 18/9
Ottobre 2000 Week -2
-1 0 1 2 3 4
5 6 Period Roll-in A
B C
Lum.
1029 1030
Bunches proton 1 x 8
1 x 8 36 x 8 36 x 36

• Period A Proton only beam (1.5 wks)
• Period B Observe first collision (1 wk)
• Period C Subsystem commissioning (3.5 wks)

Y.K. Kim/Sep.2000
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Commissioning Run Plan

• Period C (1x8, 36x8, 36x36 bunches)
• Understand operation of COT with colliding beam
• Stability of the chamber with a large amount of
  ionization
• Determine hit occupancies / efficiencies per
  superlayer
• Begin to understand tracking issues / t0, drift
  velocity
• Synchronous noise from Silicon readout ?
• Understand operation of Si Barrel-4, new
  endplugs.
• Commission calorimetry and muon systems.
• Commission DAQ system (Hardware Event Builder,
  L3, Data Logger )
• Establish operation of L1 Trigger system
  functionality
• Calorimeter muon stubs triggers
• Tracking slice COT XFT XTRP to Muon /
  Calorimeter
• Capture data in L2 processors, simple
  tagging/prescaling
• Read-in L1 and XFT info, Cluster and ISO cluster
  operation
• SVT for instrumented region
• Take a few hundred k good events for the COT for
  the post-run

Y.K. Kim/Sep.2000
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The First Collisions!!

L1
Beam profile Good Tracks
L2
Non dimentichiamo!! A volte pochi giorni di
collisioni producono risultati straordinari
Impulso alla collaborazione
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From the Commissioning Run

• some data

K short peak
SET500 GeV di-jets
Cambiare plots

• a lot of work accomplished
• and a better understood list of the work to be
  done

Still 4 monthes to go Begin Run II March 01
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Downtime logger

• Detailed accounting of the reason CDF is not
  taking data (loosing luminosity)
• Very powerful tool to immediately identify what
  systems are causing inefficiency (not always so
  obvious)
• Used by operation/commissioning manager to
  prioritize and decide work schedules
• Identify weakness/limitations of systems

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Silicon Commissioning

• Only prototype Si installed for commissioning run
• Allowed Si DAQ commissioning.
• Si readout did not cause noise problems
  elsewhere.
• BUT most of Silicon commissioning still to be
  done!
• Si was installed in Jan 2001 with just 2 months
  to start of Run II (722K channels)
• - shifts 24 hours a day, 7 days a week
• But Installation completed
• in May 2001 (beam in Mar 01)
• Access to collision hall restricted before
• connection completeschedule complicated

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E iniziato il run II..Commissioning with Data

• Early J/y data (few pb-1)
• basic momentum scale for tracking
• measure muon chamber efficiencies
• SVX vertex resolution

• Photon conversions used to
• understand the radial material
• distribution

August 2001 1pb-1
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Tracking Chamber Alignment

• Cosmic ray based alignment Cell tilts/shifts
• Includes corrections for electrostatics and
  gravity

Impact parameter vs. phi
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First unexpected problems

• Early TeV beam had high losses
• Silicon frequently off for protection
• Muon chamber currents very high (installed
  shielding)
• Power supply failures with beam
• Transistor deaths due to single event burnout
• Reduced bias/more resistant transistors/shielding
• ISL cooling lines blocked
• Initially could not operate detector
• Blockage due to epoxy in 90o bends
• Cleared using Yag LASER prism

?Recovered June 02
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Beginning of Physics Run

• February 2002 is the START OF PHYSICS date
• Still 2002 was a painful year still a lot to
  learn and improve
• Unexpected problem in detectors
• Beam incidents
• Still in 2003
• The first run II paper published

D?,Ds???
?M 99.41?0.38?0.21 MeV PDG 99.2?0.5 MeV
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Silicon Jumper failure
Aging COT
A small but steadily growing number of CDF
silicon detector modules were dying. Breakage of
a wirebond
CDF central tracking chamber Aging ? resolved

• Some broke during a trigger test at 20 kHz
• Oriented orthogonal to 1.4 T B field
• Fundamental frequency for 2 mm
• Al bond 20 kHz

• Resonant oscillation from Lorentz forces during
  special trigger conditions!
• Reduced current through jumper
• Eliminated guilty trigger test mode
• Lost some sensors (z-side mainly)

Resolved!
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Beam Incidents CDF Safety

• Based on Run I experience
• Procedures for store fill and scrape, and store
  end
• hardware and procedures for minimizing radiation
  dose to silicon detector intended to lengthen
  life of detector
• Measure losses from p and pbar bunches
• NOT ENOUGH !!
• Not well protected
  against
• beam incidents. A run II
  news
• LHC beam power 250 x Tevatron!

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Beam related Problems

• Very Serious
• Fast beam loss (risk was known, but..) Damage
  Silicon
• Damage to silicon from low doses (100s of rads)
  at high rate (100 nsec) particular failure mode
  not reproduced in tests
• Serious
• Damage to various electronics in collision hall
  due to SEB (single event burnout) or similar
  single events ? abnormally high losses
• One bad example beampipe misaligned during
  access ? proton
• halo scraped ? Lost 12 crate power supplies
  over about an hour
• Actions
• Added shielding around low-b quads
• Reduced bias voltage in VME power supplies /
  modify power supplies
• Annoying
• Example Beam induced background in missing ET
  trigger ? halo scraping upstream of CDF

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Abort Kickers

• Kickers are very fast ? Danger of fast beam loss
• Kicker prefire

• Actions
• Reduce prefire rate (kicker conditioning)
• Add collimator for almost perfect shadowing ?
  needed full latticeMARS simulation

A11 collimator Already in place
a task force in AD end 2004
A0 proton abort kickers
Add .5 m Collimator at A48 to shield against
prefires
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The Abort Gap

• Kickers fire correctly, but beam in the abort gap
• Discovered beam in the abort gap when quenched
  and suffered silicon damage on abort!
• Monitor the gap
• CDF added monitoring of local losses in abort gap
  ? useful diagnostic for accelerator adopted
  jointly, in TevMon
• Accelerator added better instrumentation adopted
  jointly
• Failure of specific Accelerator systems can spill
  beam into the abort gap
• Early incident RF problem drove significant beam
  into abort gap ?1 of silicon detector lost
  (unable to talk to chips)
• Added beam abort interlock, monitored in TevMon
• Tevatron Electron Lens used to clean the abort
  gap, monitored in TevMon

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Important Lesson

• monitor state of potentially dangerous systems in
  the accelerator - RF system, electron lens etc
• Learned by analyzing each serious machine
  accident
• monitor the accelerator as if it were a detector
  system

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Important Lesson

• Experiment must worry about its own safety and
  work closely with Accelerator Division to ensure
  it
• CDF enjoyed good communications with AD
  Operations Manager and Tevatron experts this is
  important
• Joint CDFAD instrumentation for monitoring
• Determine the cause of every serious beam
  incident and take corrective action (bullet may
  not miss you next time)
• Corrective actions may require significant work
  from the Accelerator Division
  (quoting J. Spalding)
• LHC
• LHC, ATLAS, CMS failure modes will not be the
  same.
• But potentially all loss issues will be more
  severe
• Importance monitoring, diagnostic tools,
  collimater,
• shielding, communication between machine and
  exp. teams

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A Physics Heaven?a Very Complex Trigger!
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Trigger L

• Principle physics process trigger cross section,
  s B (const)
• Reality a trigger cross section, s A/L B
  CL DL2
• CDF has worked a lot on trigger
• rates -gt still failed to correctly
• predict how they grow with L.
• It is a difficult task!
• A good trigger system allows one to easily
  adopt
• (CDF trigger has lot of features L enable,
  Dyn.Presc. etc)
• ?Still hard choices could be needed
  (drop some physics)
• ?Still one of the top CDF headaches today

MET252JET
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Trigger Summary

• A flexible trigger table handling is essential
  to cope with the continuous changes and
  increasing performance demand
• Work to insert relevant physics channels in the
  trigger table since the beginning. Late insertion
  can turned to be painful
• A very good trigger simulation is an essential
  tool be sure all you need is in since early days

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and now Where can I run my jobs?

• While in the commiss. period (2001) it became
  clear the Computing model for data analysis was
  not good anymore. Needed CPU x10 painful tape
  access -gt Old system trashed
• 2002? a new model (CAF). In 6 monthes a small
  CAF was working -gt In 1 year users enjoyed our
  beloved CAF
• ?First impact with data (and users) could destroy
  all your planning -gt Dont panic there is some
  time -gt A complete
• revolution is possible and sometimes desirable
• Are CPU and human energy waisted? Yes - CDF did
  not provide
• simple tools to manage the analysis of large
  datasets
• strong set of easily available debugging and code
  analysis tools
• Motivation/organizations to more centralized
  processing
• When conference pressure-gt too late. Users find
  their way

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Non manca molto al passaggio del testimone

• ? It is time to begin running together!
• Still CDF has his best years of physics
• production ahead. Should get 4 X Lint.
• CDF work for LHC in many areas (backgrounds, MC
  tuning, QCD, Wtop mass etc) dont overlook the
  possibility to learn something today of your
  favorite physics channel.
• Put your request on the table now but this does
  not mean you will get it (manpower) The best
  attitude do it yourself!

Why not begin to commission LHC using CDF ??
Join CDF as a Visitor you could play with
your favorite CDF data with no duties
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..ce il rischio (o la speranza!) che qualcuno
esageri un po
TEVATRON
LHC
Dont tell me you discovered Higgs!!
Cartoon courtesy of Young Kee Kim
Many thanks to Y.K.Kim, T. Liss, T.Liu, J.
Spalding and many others
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BACKUP
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Beam Loss Monitor snapshot for a messy abort
D0
low b quads
CDF
note CDF shields D0
abort dump
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Run II
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Tevatron Run-II

• Data set has doubled every year

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Triggering in Run 2

45 kHz
300Hz
60 Hz 20MB/s
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Commissioning with Data

• Additional J/y data used to understand material
• And alignment

M(J/y) vs. Pt
Additional 0.455 g/cm2
Corrected for nominal material in simulation
No corrections
Residuals in 5 SVXII layers
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Abort Gap

• Tevatron has 3x12 bunch trains and 3 abort gaps
  (2 ms long)

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Average Luminosity
0.9 fb-1
1E32cm-2s-1
By fiscal year