# Presentation: 261087

## SUMMARY FROM THE SVT WORKSHOP

- CDF Collaboration Meeting
- Stefano Belforte
- for the SVT group

- Stefano Belforte - INFN Pisa

- November 5, 1998

## The 1st SVT Workshop

- Goals
- finalize hardware design
- review & finalize error handling protocol
- prepare for next year test (vertical slice)
- review mechanical alignment issues
- review where we stand on patterns issues
- what goes in the AM
- what do the Track Fitters do
- a dozen SVT workers attended in person + 5 on video
- managers, spokespersons ...
- other people too (perspective SVTers, physics convenors, trigger experts)

- Stefano Belforte - INFN Pisa

- November 5, 1998

## Hardware Status & Schedule

- All SVT boards (8 different kinds) are now fully specified.
- Few small details will be adjusted as implementation allows
- None is waiting external input, boards design rolls to completion by end of year
- Pre-production prototypes have started arriving.
- Will have one of each board by March.
- XTRP fanout will come later (not a problem)
- Production will start in June, installation completed by end of year
- 3 month window in March-June to assemble 1/12th of SVT and test full operations before production start
- vertical (phi) slice test
- not just a test: a step in a continuos process to build full SVT hardware and software and integrate it in the Trigger/DAQ

- Stefano Belforte - INFN Pisa

- November 5, 1998

## Vertical Slice Test

- Board debug at home in Jan/Feb
- Vertical slice test is mainly infrastructure test
- we have now:
-  schedule, coordinators, list of tasks, estimate of manpower, plan for software development, more already done software then it looked, green light for crates, power, cpu’s etc., confidence of meeting the goals
- Goals:
- Build a team of SVT experts (not just single boards)
- Extensive and intensive tests of the hardware (look for subtle bugs)
- Connect with SVX readout and Level 2 (XFT later on)
- Interface with R_C and demonstrate the SVT startup, control, error-handling and recovery procedures

- Stefano Belforte - INFN Pisa

- November 5, 1998

## Error Handling

- Years long debate. We now have a final agreement.
- Two kind of errors:
- SVT_Error for internal use. Details spared.
- CDF_Error for error that requires full DAQ re-sync
- one month ago: SVT does not pull CDF_Error, just passes   error flags to Level2 in the data stream
- now: each SVT board will pull CDF_Error as soon as it detects a severe error condition (if it can)

- Stefano Belforte - INFN Pisa

- November 5, 1998

## Mechanical Alignment

- SVX builders could not come, but William Trishuck managed to put together a talk from Canada that Giovanni showed us on video from Pisa ! Thanks to both for the effort !
- He reviewed April alignment fest and October special topic meeting
-  SVT spec: everything (including the beam) line up to 100 rad
- situation as hardware is being finalized
- SVX mechanics should be OK
- COT can not be moved, 300 rad expected at installation, may be OK but more studies are needed
- SVX adjustment (inchworms) is promising, wait for more tests with full mechanical  weight
- potential worry: 100rad is a maximum range, not RMS
- but looks under control

- Stefano Belforte - INFN Pisa

- November 5, 1998

## Beam Alignment

- It was NOT a workshop topic
- Still surfaces every time
- Liason with Beam Division must be strengthened, agreement spelled out (verba volant, scripta manent)
- Our plan:
- we will provide real time feedback on beam angle & position
- we expect the beam to be put where we want it at each store
- we will not adjust dynamically to beam movement
- we expect the beam to be kept still in place
- The SVT hardware will NOT be able to adjust in real time to beam center movement

- Stefano Belforte - INFN Pisa

- November 5, 1998

## Increasing SVT efficiency

- It is has become a general request, but vague.
- Clear statements are welcome: When ? How much ? Why ?
- Two sources for inefficiency:
- incomplete pattern coverage (AM has a finite size)
- SVX single layer efficiency: 0.9 ~0.95
- Two basic rules agreeded upon at the workshop:
- we do not deal with 3-hit tracks
- if a track has 5 hits, use only 4 in the fit
- Solution: require 4/5 SVX layers
- two methods possible (details spared )
- detailed comparison in progress to pick best approach (not hardwired anyhow)

- Stefano Belforte - INFN Pisa

- November 5, 1998

## How to do Majority Logic in SVX (4/5)

- Not a straightforward  issue. Still we take it seriously.
- Several people in SVT are working on it.
- 4/4 always possible (baseline from TDR, 	well suited for B triggers)
- Going to 4/5:
- can we do 4/5 ?			Yes
- do we need hardware changes ?	No
- is there a price tag attached ?	Yes
- what is it ?			Level 2 Time
- why ?				Replicates (roads & fits)
- how bad is it, and what should we do ?		Next slide

- Stefano Belforte - INFN Pisa

- November 5, 1998

## SVT efficiency with 4/5

- Target (efficiency = 1) is to find in SVT all tracks with 4 hits in SVXII
- This plot is for 20 GeV ISAJET bbar simulation

- Stefano Belforte - INFN Pisa

- November 5, 1998

## Track Replicates

- Same 4-hit combination may appear in more roads (up to 1.4)
- One 5-hit track fires up to five 4-hit combinations
- What to do with track copies ? Maybe Level2 can not handle them, so we need to build more SVT hardware...
- How many clones we have ? How long does it take to deal with them ?
- What will Level2 processor have to do with these tracks ?
- Cut on d ? Easy and fast.
- Find vertex ? Jet-probability algorithm ? How long does it take ?
- It all depends a lot on the kind of event (20Gev jet ? 2-track ?)
- Time to think in terms of integrated triggers, L1 + SVT + L2:
- if SVT takes longer  less time for Level2
- proposals for triggers requiring higher SVT efficiency should include understanding of what to do in Level 2 processors

- Stefano Belforte - INFN Pisa

- November 5, 1998

## Ways out of 4/5 troubles

- Decide we do not need it. Back t	o 4/4 (the SVT TDR)
- Take the hit: Level 2 will have to wait.
- Limit 4/5 to high Pt tracks (e.g. displaced high Pt lepton for exotic) ?
- Threshold will be adjustable at any time (4 GeV looks a good one)
- Work in progress within SVT, but needs input from collaboration.
- Decide what to do according to which Level 1 trigger fired.
- Looks interesting
- Too bad we have no way of doing now
- Not clear if it may ever be possible
- But “Necessity is the mother of invention”

- Stefano Belforte - INFN Pisa

- November 5, 1998

## Online software

- Various tasks needed to properly monitor the SVT operation have been listed. The list is long and will grow.
- Some will require “standard” monitoring a’ la TRIGMON
- Some will require our own special DAQ.
- Likely dedicated computing hardware as well
- “The SVT workstation”
- Definitely a lot  of work
- Interface with Run_Control is starting to be addressed
- DataBase requirements are being layed down (looks OK)
- You will hear more about this as time goes by

- Stefano Belforte - INFN Pisa

- November 5, 1998

## online

- Here I will show the two cartoons with the hardware mountain and the software ocean

- Stefano Belforte - INFN Pisa

- November 5, 1998

## Conclusions

- It was a very intense meeting
- Some very positive results:
- hardware finalized
- schedule & organization for next year test
- start acting as a single group
- beginning to grasp how to handle 4/5
-  throw back work to do to the collaboration
- start looking beyond hardware building
- Next step:
- integrate more the various institutions
- put in place a structure to deal with common issues
- tackle software more aggressively
- add more collaborators

- Stefano Belforte - INFN Pisa

- November 5, 1998