HBD Answers to DC Questions

1. HBD Answers to DC Questions TK Hemmick for the HBD Crew

2. 1-3 • 1- DC member, resident experts and coverage plan; contacts for Online Monitoring and Online Calibration (OnCal) • DC Member: Itzhak Tseruyya. • Alternates: Craig Woody, Tom Hemmick • Resident Experts: Stony Brook Crew; BNL crew; Rotating WIS crew; UCR crew. • Online Monitoring & OnCal: Takao • 2- Detector upgrades and repair expected before 1/1/2009 • Expect installation of detector systems on two dates. • Preferred schedule: • 1st detector (goes in West) ~ Halloween • 2nd detector (goes in East) ~ December 1st • Are you on Don Lynch's shutdown schedule? • Yes • 3- Expected dead channels, bad high voltage channels, dead wires in FY09; impact of dead channels on physics signals in Run 9; are there adequate spares for replaceable electronics? • 1 known dead strip in West detector (less than 1%) • Will be repaired if in acceptance region. • Will be ignored if outside acceptance region.

3. 4-6 • 4- How necessary is the calibration procedure? • We will need to measure our pedestal values to prepare the zero suppression. This does not require beam and might be repeated on an infrequent basis (every few weeks) • Need sizeable sample (10-40 million events) for early gain calibration using “All triggers” to see scintillation. • Full list of Minicells on every event. • 5- How does this subsystem use OnCal?  If it doesn't, why not, and how could calibrations be ready sooner? • The HBD does not use OnCal since calibration requires reconstructed electron tracks originating from the origin. • This does not affect our readiness for reconstruction since we’ve agreed with Tony Frawley to an compact data format that stores raw hit channels that can be recalibrated upon being re-read. • HBD Minicell list is all pads for some number of events (TBD) and only in a filtered region for subsequent events (i.e. near a loosely defined electron track). • 6- What raw data is needed for monitoring detector performance during the run?  What analyzed data? • We need to have minimum bias events to show alive channel count. • We would like to also have reconstruction of electron tracks in ERT-electron triggers online as a set of data used to evaluate detector performance online. This should make specialized micro-DST files for subsequent analysis with many passes as we learn what we’re doing. • These files can be HIGHLY filtered to only keep the very best events for subsequent efficient analysis with minimal disk space usage.

4. 7-9 • 7- What special runs are needed (zero field, etc.)?  How often should they be taken, and how many events are needed? Any need to take 'Pre-Run' data? • We need runs to establish pedestals for zero suppression. This is Pre-run data. And is only every couple of weeks at most. • We need a single zero field run in the early days with ERT-electron trigger for alignment. • 10-40 million minimum bias events for scintillation gain. • 8- What "physics" signals can be used to monitor the detector on a weekly basis? • The detector can look at J/Psi yield with and without HBD veto (should mostly remain) and compare this to the level of the nearby continuum. • This kind of plot would only come “late” into the run as it requires a lot of learning on the detector. • 9- What should be modified for 500 GeV running in this system? • Nothing.