Extraction of the Time Spectra For the E-Counters

The data relating to the E-counter TDCs are collected, at the present, into two BOS BANKS named RC11 (the raw bank), and TAGE (the 'bossified' bank). The analysis presented here only relies on the decoding of the raw data bank RC11. The analysis program is based on the RECSIS package used at Jefferson Lab. Finally, after decoding, the events are analyzed and histogrammed using the CERNLIB packages from CERN .

Decoding the raw event.

The decoding of the event is performed in the user_evnt.F routine. For each data event, the slot location is decoded first, and then, in order, the channel number, the actual value of the data, and finally, whether the edge triggered on was a leading or a trailing edge (1=leading, 0=trailing).

In the following analysis, an event had to satisfy the following conditions to be retained:

• Slot number had to be 6, 10, 14 or 18.
• Channel number had to be between 0 and 95 (done in histogram).
• Data had to be between 0 and 4095 (done in histogram).
• Leading edge (edge=1)

The events were thus histogrammed for each E-counter individually. The image below shows, as an example, the raw spectra as a function of High Voltage for E-counter 30. The entire set for all 384 E-counters is also available as a postcript file under /work/clas/disk1/tag.aug.97/e_counters.ps ( or here ). Just be aware that it is 16Mb long.