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User name Markowitz
Log entry time 06:06:36 on July 05, 2010
Entry number 330163
keyword=Giving up on optics at 2 pass
The rates with the sieve out were only a factor of 2 higher than with the
sieve in. With the sieve in, T1 was 5 KHz. 2 KHz was from cosmics. Of
the remaining 3 KHz, 1 KHz was T5 (or electrons. T5 is S0+gas cerenkov).
That 1 KHz (we hoped) was the good electrons traveling through the
sieve. However, with sieve out, the rate was only 2 KHz. So the
conclusion we reached was that the actual number of electrons was much
less (a few Hz) and that the optics calibration could not be done in
Bogdan is still hoping that T5 triggers might allow optics running by
using the coincidence and the gas cerenkov to better select good electrons.