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User name Reitz
Log entry time 13:53:57 on August 2,2001
Entry number 68620
keyword=HRSR_S2R_1 TDC peak/ prog width fan out
About the TDC peak at channel 3000 in S2R1 in HRSR:
again an artefact of one of those Prog. Width ECL Fan Outs.
This peak only occurs, if there was a particle crossing
the overlap region of the first and the second scintilator paddel
of S2 and firing all four PMTs. In this special case, the
signal from S2R1 got truncated in the mentionned module:
it started 130 ns later and was only 70 ns long (instead of 200 ns),
whereas the signal on S2R2, S2L1 and S2L2 remained as they should.
Again, only the TDC is affected. And one still has a reasonable
timing from three other ones.
I now removed all remaining modules of this kind in both spectrometers,
therefore I had to increase the output width of all discriminators
to 105 ns. (on the left arm the have been at 50-60ns before)