# Presentation: 891526

## STAR FTPC and Run V

- Terence Tarnowsky
- Purdue University
- February 23,2005

## Outline

- I. FTPC parameters in Run V
- II. Operational Status
- III. Calibration Status
- IV. Summary

## FTPC Group

- Volker Eckardt (MPI)
- Alexei Lebedev (BNL)
- Markus Oldenburg (LBL)
- Jörn Putschke (MPI)
- Janet Seyboth (MPI)
- Peter Seyboth (MPI)
- Frank Simon (MPI)
- Brijesh Srivastava  (Purdue)
- Terry Tarnowsky (Purdue)

- _Thanks to:_
- Michael DePhillips
- Lidia Didenko
- Eric Hjort
- Jerome Lauret
- Jeff Porter
- .........
- For invaluable technical support!

## Run Parameters

- FTPCs operational for both Cu-Cu and upcoming pp running.
- Cu-Cu:
- 200 GeV, 62.4 GeV, injection energy.
- pp:
- 200 GeV polarized, 500 GeV (?).
- Based on cluster properties, anodes at 1775 V for 200 GeV Cu-Cu
- Early data taken at 1800 V. Change is mostly transparent to end users.
- Appropriate settings for other energies/species TBD from initial data.

## Electronics

- Alexei Lebedev installed protection boards for all FTPC FEEs during summer shutdown.
- Purpose was to mitigate destructive energy discharge to pad plane during anode trip.
- All FEEs retrofitted.

## Electronics II

- Status @ end of Run IV                      Status @ start of Run V

## Electronics III

- Beam backgrounds very high in this Cu-Cu run  fairly frequent anode trips.
- Fewer large scale losses compared to this time in Run IV.
- Electronics more stable and reliable .

-     Run V, Day 041        Run IV, Day 053

## Extra Temperature Sensors

- During summer shutdown additional FTPC body temperature sensors installed.
- Improves detector reliability. Accurate temperature readings are ***essential*** to reconstruction.
- New sensors operate on a completely autonomous system (no readout through FTPC RDOs).
**Even if original temperature readings are non-functioning, new sensors provide temperature readout.**

## Gain Scan

- Data runs w/ anode voltages ranging from 1725-1825 V.
- Compare cluster and charge distributions.
- Compare cluster r,  residuals.
- View raw clusters as function of pad vs. time using FTPC Pad Monitor.

## Gain Scan II

- _AuAu 5033089, 1775 V_       _CuCu 6012007, 1775 V_

- _AuAu 5033089, 1775 V_     _CuCu 6012007, 1775 V_

## Laser Calibration

- FTPC uses lasers to check drift velocity, t0, and            corrections.
- This requires (bare
- 	minimum):
- Inner and outer straight
- 	tracks.
- One inclined track.

## Laser Calibration II

- Laser run 6048026, 1400 V

- Laser run 6034019, 1200 V

- Along with gain, alignment can be adjusted.

## Laser Calibration III

- Unlike the TPC, FTPC does not continuous laser runs for calibration.
- Only need one (minimum) “good” run for calibration purposes.
- More is always better (of course!)
- Work in progress. Odds of success relatively high.

## Transverse Vertex Offset

- Align FTPC x,y vertex position w/ TPC vertex.
- Requires completed TPC calibration and fixed vertex.
- In Run IV data, a B-field dependent effect led to the calculation of offsets after every field change

## Vertex Offset II

- Initial Run IV offset calculated from RFF data only.

- Produced RFF data OK

- Produced FF data shows uncorrelated shift in x or y.

## Vertex Offset III

- After correcting for each specific B-field configuration, x,y vertex position is OK.
- For Run V, will repeat this procedure.
- Cause of field dependent effect still unidentified, but additional corrections more thorough anyway.

## Future Improvements

- Will receive two, 40x70mm SSD modules to install at a fixed position between FTPC body and electronics.
- This absolute position reference will allow independent verification of drift velocity and t0 measurements.
- SSD group has graciously provided modules and use of their readout electronics.
- Installation planned for Summer 2005.

## Summary

- FTPCs are operating well, no major problems to report.
- Some difficulty achieving good laser tracks, but work on alignment will continue.
- Improvements to FEEs and temperature measurement provide valuable extra reliability  more useable data!
- Future improvements (such as fixed position SSD modules) will add another level of reliability to calibration process.