1 Online data quality and monitoring M. Ellis Daresbury DAQ Meeting 31 st August 2005

2 Disclaimers  I’ve not really thought about this in any serious way yet (concentrating on KEK test beam)  Mostly thinking about the tracker  However, from the detector point of view the KEK test beam is probably a reasonable starting point...

3 Tracker Hardware Monitoring  For the tracker, the VLPC system requires monitoring.  VLPCs require the correct temperature and bias voltage which are set and read back through the AFE boards.  Correct set points are determined from calibration data of VLPC cassettes and AFE boards (stored in a database).  1553 interface (VME) allows control of AFE board, including ability to read back measured bias voltage, temperature (resistance) and heater current in between spills.  During data-taking, would need to regularly read back set points and compare to wanted values. Monitoring heater setting versus time allows us to check how stable the temperature control is.

4 Online Data Monitoring  A first thought of parameters to monitor based on KEK test.  Only looking at the tracker. TOF, CKOV and EmCAL are probably simpler.  Broken down by reconstruction level: Number of reconstructed objects Number of reconstructed objects Raw hit level (channel number, ADC, TDC) Raw hit level (channel number, ADC, TDC) DoubletCluster level (per plane) DoubletCluster level (per plane) SpacePoint level (per station) SpacePoint level (per station) Track level (per tracker) Track level (per tracker) Higher level? Higher level? Extras? Extras?

5 Number of reconstructed objects  Integrated per tracker: Number of doublet clusters, space points and tracks Number of doublet clusters, space points and tracks  Per plane Number of doublet clusters Number of doublet clusters  Per station Number of double clusters Number of double clusters Number of space points Number of space points

6 Raw Hit Level  Low level electronic space, no attempt to convert to {Tracker,Station,Plane,Fibre}  Important as some problems could show up in terms of a given MCM or channel on each MCM, or a given board, etc...  At the most extreme case, ADC and TDC distributions per channel (probably too many)  Perhaps per MCM is a reasonable compromise?

7 Doublet Cluster Level  Show distributions per plane: ADC distribution expressed as PhotoElectrons ADC distribution expressed as PhotoElectrons TDC distribution TDC distribution Central fibre number for hits above some threshold (probably 2.0 PE) Central fibre number for hits above some threshold (probably 2.0 PE)  Allows us to check distribution of hits across each plane and look for any change in light yield or timing across each plane.  Requires online access to database of decoding and calibration information

8 Space Point Level  Show distributions per station: Position profiles (1D and 2D) – beam monitor Position profiles (1D and 2D) – beam monitor Time distribution of points Time distribution of points Distribution of internal residual of triplet space points? Distribution of internal residual of triplet space points?  Allows us to monitor the beam profile as it goes through each tracker, as well as look for any variation in the timing or space point recognition that could be a signal of a change in the RF background.  Requires online access to geometry information

9 Track Level  Show distributions per tracker:  2 per NDF of track fit  2 per NDF of track fit Reconstructed Momentum (P, P X, P Y, P T, P Z ) Reconstructed Momentum (P, P X, P Y, P T, P Z ) Extrapolations to reference surfaces??? Extrapolations to reference surfaces???  Show distributions per station: Residuals from track fit Residuals from track fit  Requires online access to magnetic field map information for track fit and extrapolation.

10 Higher Level  We probably wish to have some sort of online emittance calculation?  If so, need to define analysis technique to select tracks for a bunch and how many tracks per bunch.  Can think of a plot showing data in bins of (say) 10k tracks showing evolution of emittance over the run so far. Of course can also display emittance calculated with all tracks read so far.  As we move up each level, of course the amount of CPU required is increasing if we want to keep up with the data-taking rate!

11 Extras?  First thing that comes to mind is an event display. Already part of the planning. An idea of what functionality and interface is preferred will be needed before a proper choice of technology and coding can begin.  What other parameters or tools for monitoring have I missed?