Event Conversion Program
Event data (List Mode Data) are sets of correlated numbers (parameters)
representing a physical measurement.
Data acquisition systems
usually collect many variables constituting one physical measurement.
Such groups of data are read out as a list and stored as an event for
There exist as many event formats as acquisition systems.
For our analysis we have adopted a special
event format to which all externally taken data are converted.
EVC is an X window based application to the event
format conversion for data
taken at WNSL (Yale University), HRIBF (Oak Ridge National Lab)
and LBL(88 Inch Cyclotron), where the Rutgers Nuclear Physics Group
has measured magnetic moments of short lived excited nuclear states.
The experiments make use of 4 Clover detectors and involves the
measurement of one or
more gammas in coincidence with particles up to 33 parameters per
The analysis requires
gain matched gamma energies for each clover segment. This gain
matching is built into the event conversion.
The user interface is simple and intuitive. The final parameter
ranges can be specified in the "setup" menu. Gain match information
has to be provided or is automatically obtained for a given set
of peak positions.
Open Data File: event data file
Reopen: resets the read pointer to the begin of a event data file.
Does not work for ORNL files !
Read Peak File:
This file contains all gain match information.
The format is fixed (sample .pks file).
The gain match factors are calculated and displayed in the text window.
Useful for gain matching of already converted event files.
Peak position Information:
The input requests are energies for two peaks, a center for
the aligned tac spectra and
a file containing the
approximate peak positions for each detector including limits
for the tac center search (conveniently created as .win file
The automatic gain matching procedure makes gamma energy and tac
histograms for all gamma detectors Then find the peak centroids
for the given peak positions (±4 channels), searches for
the maxima of the tac spectra in the given range.
In a second run though the event file the actual gain matching
This procedure is repeated for each event-file, small drifts
are automatically adjusted.
The actual experimental setup, total gain settings, which adc or tdc
has which input is contained in a configuration file. This
file may have
to be updated (edited) to refect the current experiment.
Convert: Conversion including gain matching when enabled.
If no peak positions or gain match factors are input, the
conversion proceeds without gain matching.
gain match: Only gain match for already converted data
show event: for diagnostic purposes (converted data only)
Experiment setup:can be modified and saved. The tac spectra
can be shifted in addition to being compressed.
(/2 500 divide each channel by 2 and shift 500 channels left).
Last modified: Fri Jan 14 12:14:38 EST 2005