The STAR Pad Monitor

Paper: 232
Session: A (poster)
Presenter: Schambach, Joachim, University of Texas at Austin
Keywords: object-oriented methods, data presentation, graphics, GUI's

The STAR Pad Monitor

Jo Schambach
Physics Department, University of Texas, Austin, TX 78712
STAR collaboration


We developed an X-Windows application that displays raw
TPC and other 3-dimensional drift detector data called the
"Pad Monitor". The purpose of this application is to guide
in the debug process of the STAR TPC and SVT detectors by
providing an easy to use tool which gives a graphical
representation of the raw pixel data, and quickly guides the
eye to problems with these data with the help of color
schemes in the display. This project was started for the
EOS TPC (at LBLs Bevalac) and has gone through several
iterations improving the interface since then. The current
version is based on the Motif User Interface Definition and
is customizable through an ASCII script for different
hardware configurations. The application is written in C
and uses only standard libraries available on any UNIX
workstation with the Motif Graphical User Interface.
The Pad Monitor displays a 2-dimensional representation of
the TPC pad plane, where each pad is color coded according
to some cut criteria. Clicking on any pad in this window
displays the time spectrum of this pad in a separate window;
the histogram can be manipulated with simple mouse clicks.
Additionally, a 3-D display of a whole pad row can be
displayed in a separate window, with the third dimension
represented by a simple color scheme. This display allows
visual inspection of hot spots within a pad row and even
simple identification of space point clusters. Graphical
tools allow changing the pad row, thus making it
possible to follow the transversal of a cluster through
different rows.

Future plans for this application include implementing a
method to display geographical electronics data (retrieved
from a database) in a way that shows the interconnect of
front-end electronics to the geographical position of the
pads. We would also like to connect the Pad Monitor to the
3-D event display applications available within the STAR
collaboration to allow moving back and forth graphically
between the raw data and the reconstructed space point and
track display. The same program was also easily customized
to serve as an anode monitor for the Silicon Drift Detector
Array of AGS experiment E896.