# Presentation: 118078

## Detector and Trigger Plans - Overview

- Accelerator
- Plans
- “October” shutdown
- D0 Control Room shifts
- Experiment technical support
- Sub-detectors plans
- Trigger
- D0 operating efficiency
- Commissioning and data collection
- Data quality monitoring
- Summary
- Thanks for the input from many individuals!

- Dmitri Denisov

## Accelerator Operation

- Tevatron peak luminosity is around 2.1031 over past two months
- Improvements in peak luminosity are expected soon due to installation of cooling tanks in antiproton accumulator during June shutdown
- only about 30% of antiprotons are reaching final collisions for now
- transverse beam sizes are more then expected
- Detailed plan of increase of Tevatron luminosity is developed
- studies periods each week
- Beams Division plans to split weekly 2 days of studies into smaller intervals
- periodic shutdowns

- Dmitri Denisov

## Accelerator Performance

- There is slow improvement in “per week” delivered luminosity
- higher initial luminosity value
- better operating efficiency
- ~70% of stores end gracefully
- Run Ia goal is ~15pb-1 per week
- January 2002 plan is to deliver ~300 pb-1 to each of the experiments by the end of 2002
- as of today delivered luminosity about twice lower then planned
- revision of the plan is expected soon
- How can D0 “help”
- utilize luminosity more efficiently
- reduce number of interruptions in accelerator operations
- there is no 10 minutes access!

- Dmitri Denisov

## “October” Shutdown

- “It is a bad plan which admits of no modifications...”
- Original plan was 6 weeks shutdown starting September 30th 2002
- Single major reason for the October shutdown
- Improvement in vacuum and other elements of recycler
- Considerations
-  Last(!) prolonged shutdown for the recycler
- Are 6 weeks enough?
- Far from perfect accelerator performance even without recycler
- Prolonged interval needed to get accelerator to “pre-shutdown” conditions
- Experiments desire to collect decent data samples for Winter 2003 conferences
- Current “plan”
- Not earlier then October 2002
- Not less then 6 weeks

- Dmitri Denisov

## Accelerator Backgrounds

- D0 benefits greatly from extensive shielding installed during Run IIa upgrade
- Much lower backgrounds on muon detectors
- less then 0.1% occupancy
- Reduced beam halo
- D0 beam halo is stable and affects ~1-2% of crossings
- Beam related backgrounds are affecting primary forward proton detector
- Task force (with CDF) is formed
- Late March CDF believed to experience high (~1Mrad/sec) dose rate irradiation which caused 6 silicon ladders to fail
- Abort of partly de-bunched beam
- Not confirmed by booster studies
- CDF is located close to the Tevatron abort
- D0
- Located favorably
- D0 silicon High Voltage did not even tripped
- Typical integrated dose during store shot setup for D0 is 5-10 rads
- Low in comparison with silicon radiation hardness

- Dmitri Denisov

## D0 Control Room Shifts

- Over last ~6 months achieved reasonably stable shifts sign up
- ~5.103 shifts per 6 months are needed
- This year requires peak number of shifters
- Still many systems are in commissioning stage
- Require extensive trainings and active work during data taking
- Introducing extra shifters as “systems” become available
- L2
- Global monitor (planned)
- Starting combining shifts for different sub-detectors
- Forward Proton Detector (FPD) and Calorimeter
- Based on relative success of current shift duties rules only minor modifications are adopted for July-December 2002 period
- 8 shifts for each “non-resident” on Masthead per 6 months
- 10 shifts for each “resident” (> 6 months at Fermilab) on Masthead per 6 months
- Thanks to all shifters who keep the experiment running: it is fun, experience, understanding of your detector performance, and a must to get our data sample

- Dmitri Denisov

## D0 Experiment Technical Support Groups

- Two teams of electrical and mechanical professionals are reliably supporting operations of the D0 experiment
- Mechanical – Russ Rucinski group
- Electrical – Rick Hance group
- Perform extensive amount of 24/7 duties
- All cryo control and monitoring
- Power supplies and magnets
- Heating and cooling
- Emergency responses
- Detector opening and closing
- Can you move 5000 tons with 0.5mm precision?
- We plan to continue 24/7 presence of Ops shifter for the duration of Run II
- Let D0 control room crew concentrate on high quality data taking
- Will provide support for commissioning/installation/operation jobs
- Requests should be made in advance

- Dmitri Denisov

## “To do” for the D0 Detectors

- All major detectors are in operation
- Second order commissioning and improvements
- Luminosity detector
- Operates stable over many months
- Still with Run I electronics...
- Improvements in calibration constant
- On-line numbers for integrated luminosity
- Is CDF luminosity really ~6% higher?
- D0/CDF task force
- Silicon detector
- Reliability of the cathedral power supplies and cooling
- Understanding of “grassy noise” issue
-  High voltage leak currents
- Monitoring of the radiation dose

- 4 F Disks

- 6 Barrels

- 12 F Disks

- Dmitri Denisov

## “To do” for the Detectors

- Fiber tracker and preshowers
- Great progress since AFE boards became available
- Resolve AFE boards failures/problems
- Understand pedestal variations to reduce hits occupancy
- Monitor light output, VLPS, and AFE responses
- Provide calibrated thresholds/signals for CTT trigger
- Integrate forward preshower (and FPD)
- Calorimeter
- Fix noise on Level 1 trigger signals
- Stable pulser calibration
- Operation with 1.5 vs 2.5 zero suppression threshold
- COMICS based reliable parameters download and verification
- ~25 BLS low voltage power supplies have to be upgraded

- Dmitri Denisov

## “To do” for the Detectors

- Inter Cryostat Detector (ICD)
- Replace bad PMTs (+few electronics channels)
-  Updated ICD addressing and test using LED pulser
-  MIP calibration with data for every individual tile
- Solenoid
- Long term stability monitoring
- Corrections to field map
- Geometry, tracks fit based corrections
- Muon system
- Improve stability of readout (synhronization and other errors)
- Level 2 trigger signals issues
- Individual thresholds for central A layer counters
- T0s and time-to-distance for PDTs (momentum resolution)

- Dmitri Denisov

## “To do” for the D0 Detectors

- Forward Proton Detector (FPD)
- Connect dipole spectrometer to AFE boards
- Phase I (10 detectors/5 spectrometers) to be included in readout by October
- FPD Trigger Manager commissioning will proceed in parallel with DFE commissioning
- Commission luminosity monitor TDC boards to include trigger scintillator information

- Dmitri Denisov

## D0 Trigger 

- Trigger framework
- Existing prescaler logic could report mis-measured luminosity for prescaled triggers
- Plan on how to resolve this problem is developed
- Automated SCL inits
- To reduce downtime (see below)
- L1 trigger
- Fiber tracker (CTT) trigger
- Implementation is delayed due to higher then specified trigger decision time
- Different options of resolving this issue are discussed by experts
- Estimated delay is ~6weeks
- Calorimeter trigger
- Debug recently achieved eta coverage up to 2.4
- Dead and noisy towers, calibration
- Missing Et
- Extend eta coverage
- Muon trigger
- Optimize new trigger terms based on scintillator and wire detectors
- Re-establish data vs trigger simulator comparison
- Attempt to shave 132ns from FPGA logic
- To accommodate CTT trigger delay

- Dmitri Denisov

## D0 Trigger 

**Level 2 trigger**
**Increase processing bandwidth from current ~0.5kHz **
**Code speedup/max_opt:                  1-2 kHz**
**Multiple Alphas/Betas in crate          >2 kHz?**
**Silicon track trigger**
**In progress of installation**
**Expect beam commissioning later this year (fiber tracker trigger needed)**
**Fiber tracker**
**Waiting for inputs – expected in September**
**Calorimeter trigger**
**Running on-line (/eta/<0.8 for now)**
**Requires better understanding of efficiency, cuts, rejection**
**Muon trigger**
**Well developed: single muon, di-muon**
**Resolving problems with synhronization of signals coming from hundreds of front-ends**
**Detailed monitoring of the inputs is needed**
**Algorithms optimization (geometry for P****t**** cut, etc.) is in progress**

- Dmitri Denisov

## D0 Trigger

- Level 3 trigger
- Running on-line for quite a while
- Development of fast and efficient algorithms with good rejection is driving the schedule
- Tracking Level 3 is coming on-line next week
- Improve electron and muon rejection
- Vertex for missing Et resolution improvement
- Calorimeter is one of the most advanced systems
- Efficiently filtering jets and em objects
- Coming in p12: missing Et, non-linearity corrections, hot cell killer
- Muon
- Filtering on limited sub-set of muon triggers
- Technical issues with muon geometry, efficiency to be better understood
- Level 3 trigger basic philosophy
-  Develop as much as possible inclusive single e, mu, tau, jet filters
- Combine tools into di-muon, muon+jet, etc. filters
- For all trigger levels
- After trigger is running on-line and commissioned
- ID and physics groups have to take the lead to optimize cuts, study efficiencies, and select optimal trigger terms for their analyses
- Trigger board will coordinate these efforts

- Dmitri Denisov

## DAQ

- Currently could utilize new DAQ system rate capabilities in a limited way due to complex system of distributed readout and front-end crates
- Multi-buffering operation in tracking crates just arrived
- Correct “tick and turn” operation to be verified
- With estimated DAQ rate capability in the range of ~1kHz we are currently limited to ~140Hz for reliable on-line operation
- Current most serious problem is loss of synhronization in muon scintillator crates
- Every ~10 minutes at 140Hz
- There are other concerns on the horizon
- Tracking crates  front-end busy fraction at 140Hz is ~4%
- DAQ rate “task force” has been organized (chaired by Ron Lipton)
- Very well defined goal
- Bring experts from different sub-systems together to resolve problems preventing us from running at full DAQ capabilities
- Support of the DAQ system operation will continue to be responsibility of the DAQ team and appropriate detector groups
- DAQ team has developed list of improvements related to core of the DAQ system
- Software bugs fixes (small annoyances)
- Complete Linux Port
- Supervisor, Monitor Server are still on Windows
- Improve shifter monitoring and documentation

- Dmitri Denisov

## On-line System and Controls

- Key system for data handling/transfer and on-line data quality monitoring
- Run II design rate of writing data to tapes at 50Hz has been achieved
- Operations
- get serious with Significant Event System (alarms)
- important issue for high quality data collection
- active participation from detector/trigger groups is required
- migrate detector groups to use COMICS downloads
- migrate detector groups to use Hardware Database
- improve support of Examines
- Applications
- deploy run configuration/quality database
- introduce global DAQ monitor application
- Software issues
- install, test Python v2.2 (update to t02.23 soon)
- support of software releases
- System issues
- solve nfs and static route problems
- add more Examine nodes
- control room monitor upgrades

- Dmitri Denisov

## D0 Operating Efficiency

- Definition
- % of collisions used
- Global runs (recorded)
- Special runs
- Commissioning
- Goals
- From Run I experience
- ~190pb-1 delivered ~120pb-1 recorded (~60%, Main ring vetoes, etc.)
- Should do better in Run II –> 90%
- Moving target
- Major reasons of luminosity loss are changing as more systems come on-line
- What was a concern  a few months/weeks ago is replaced by new “enemies”
- Steady increase in operating efficiency during February/March – “steady state” operation
- Recent numbers
- ~60% for the last ~2 months (lower before)
- ~75% last week (after implementation of mutli-buffer readout)

- Dmitri Denisov

## D0 Operating Efficiency

- Major components of the efficiency
- Dead time
- Sub-system is setting busy signal due to low bandwidth: L1, L2, L3, DAQ
- Adjustable and can be set at almost any value by adjusting trigger rates
- Due to lack of multi-buffering in tracking crates had to accept relatively large L1 front-end-busy fraction (~20%) to collect decent data sample before June shutdown
- Currently running at about 4% front-end-busy fraction (140Hz readout rate)
- Downtime
- Data collection is stopped (or could not be started) due to failure of a specific component (or components)
- Currently issues are
- Muon scintillator front-end crates errors
- High Voltage trips
- Redownloading of “problematic” crates
- Begin/end runs
- Operator errors
- Commissioning activities (prescales selection, trigger studies,...)
- SCL inits
- Used to synhronize trigger/DAQ system
- Over last 3 months we average ~3.103 SCL inits per month during global runs
- About 15% of luminosity blocks (but not events) is wiped out
- Will have to keep detailed track of automated SCL inits
- Experts are working on resolving all of the above issues
- Plan to keep efficiency at the ~70% level while new sub-systems are introduced
- Our steady state operating efficiency should be in the range of ~90%
- Reachable – D0 had ~85% operating efficiency during last weekend store!

- Dmitri Denisov

## Commissioning and Data Collection

- Many important Run IIa systems are coming late (some are still in pipeline)
- Seriously complicates data collection
- Commissioning requires substantial amount of devoted beam time
- Requires often changes to operating conditions (trigger list, etc.) and documentation
- We operate balancing between physics data collection and commissioning activities
- Data are needed for Reco development and physics analysis
- We have decent luminosity sample which is providing interesting results
- Our detector is much better then in Run I
- Even with available on tapes luminosity data samples in some channels (J/ -> , etc.) are orders of magnitude above Run I
- Long term we need full D0 detector capabilities we planned for
- Since the beginning of the Run II we perform above mentioned activities in parallel
- All control room activities are coordinated by the Run Coordinator
- Priorities are based on Collaboration goals defined together with D0 Spokes
- Goal is to minimize global data taking disruptions (do whatever could be done without beam) providing necessary time for sub-systems commissioning

- Dmitri Denisov

## Data Quality Monitoring

- This issue was discussed at different meetings during this Workshop
- Basic outcome is that we need “multilayer” data quality checks
- Significant Event Server (“alarms”), different GUIs (HV, readout, ...), check lists,...
- Examines and event Display
- Detector, trigger, physics (Global Monitor)
- Bad run lists
- Off-line “physics based” monitoring
- Checks everything from detectors, triggers, luminosity to reco, cuts, and databases
- Run quality database which will combine (most) of the above results is under development
- The sooner in the above list the problem is discovered the better
- Fix problem and mark data set with appropriate flag
- Sub-system experts are working hard optimizing monitoring without overloading shifters and physics analysis groups
- Size of minimal unit for monitoring was discussed: event? Luminosity block number? Run?
- Complexity is drastically increasing with reduction in segmentation
- Some physics studies may not require every system working perfectly
- Stability of data collection is a key issue
- In many cases it is easier to fix the problem then develop monitoring tools
- Success on all levels (including analysis) strongly depends upon stability
- Last time forward muon parameters were changed in January 2002
- Currently changes in detector/trigger parameters happening “when ready”
- Plan to introduce “no changes” data samples
- Most probably linked to trigger list version

- Dmitri Denisov

## Specs, Reliability, and Schedule

- In such large experiment as D0 with many independent groups involved following written specifications is absolutely critical
- CTT trigger decision time appeared to be above specs (most recent example)
- Delayed CTT trigger implementation
- Could cause considerable amount of work for all sub-systems for re-timing the experiment
- Considerable amount of the experiment downtime is due to low reliability of different systems
- We plan to run for many years with limited number of accesses
- Reliability should be taken into account at the design and construction/testing stage
- Recent examples (serious in terms of downtime and potential damage)
- Muon VME power supplies
- Silicon low voltage power supplies
- Interface boards water heat exchangers
- Schedule is not what you “might” do, it is what you “will” do
- Lab and funding agencies approach is changing (Run IIb)
- Mixture of different “cultures” in the experiment
- Wrong time estimates are causing considerable manpower losses and reduce prioritizing efficiency

- In cathedral area

- Dmitri Denisov

## Summary

- Incredible progress in the D0 detector capabilities over last year
- All detectors are working and down to second order improvements
- No show stoppers!
- All trigger levels are in operation with rapidly improving capabilities
- New DAQ is performing well
- Data collection monitoring is advancing
- Data collection efficiency is reasonable
- We have to finish installation of a few critical systems and commission recently installed equipment
- Will provide necessary support for these activities
- Steady high efficiency operation with in depth data quality monitoring is becoming highest priority for most of the sub-groups
- Accelerator performance is critical for success of the D0 physics program
- We should provide feedback and minimize disruptions to accelerator commissioning and operations
- Current plan is to deliver ~300pb-1 by the end of the year 2002
- Strong support of the control room shifts and detector/trigger/on-line activities by the Collaboration is critical in getting interesting physics results soon

- Dmitri Denisov