Contact Name

Jeff Hartnell.


The LI system outputs summaries, these summaries are an average of all the LI flashes occurring in 1 timeframe (1 second) of data. The LI summaries are in the LightInjection stream of the DAQ file (e.g. F00020021_0000.mdaq.root).

This package has two modes of operation: Reconstruction and Analysis.

The reconstruction part of this package takes all the summaries from each individual LED and averages them all together so that the average is typically of 1000 flashes. In addition, the reconstruction uses the Plex database tables to determine the led to stripend mapping  and the led to pin diode mapping among other things. This information is all written out at the end of the job so that database access is not necessary when doing analysis.

The analysis part of this package consists of a class containing many analysis methods that make various plots and have various outputs. The analysis part can also do the LI tuning and write out database tables of PMT gains etc.

See the further links section below to much more documentation of this package.


Input Objects

For reconstruction part: A simple DAQ data file (e.g. F00020021_0000.mdaq.root).

For analysis part: The LIData*.root file (e.g. LIDataF00020021_0000.root), which contains the li_tree TTree with lots of branches.

Output Objects

From reconstruction part: The LIData*.root file (e.g. LIDataF00020021_0000.root), which contains the li_tree TTree with lots of branches.

From analysis part: Various plots: sometimes as ps files or just displayed on the screen as graphics or as text.

Database Access

The reconstruction part of the package uses the Plex which pulls in the required database tables. This can be fairly slow when pulling in 200,000 stripend to led mappings so it's only done at the reconstruction stage. For the analysis part all the information is in the TTree so can be easily accessed by using Draw() at the command line or by using the prewritten analysis methods in the CDAnalysis.cxx class.

There are also various methods for accessing other database tables and plotting the information in an easy to understand fashion. See the LIPlexMaps.cxx class.

Also, there is code to write to the database, e.g. the CALADCTOPE table. Again it's in LIPlexMaps.cxx.

Configuring & Running

There is not much configuration to do for the reconstruction. See the LIReco.C macro. The only slight complication is deciding whether you want to write out all the LI summaries or would rather skip certain leds if they are repeated (the LI system periodically takes drift point data and is independent of run boundaries so one DAQ data file can contain 0, 1, 2, 3 or more drift points; you can choose whether to write out all the data or just a specific drift point).

The analysis part uses the general purpose macro LIAna.C. This macro creates an LIAnalysis object and then by uncommenting the various methods you can run the analysis you want.

Additional macros to do specific tasks are available in the LISummary/macros directories.

Further Links

Jeff Hartnell Last Modified: $Date: 2004/07/13 11:50:10 $