Log entry time 11:10:29 on November 22, 2008

Entry number 250313

This entry is a followup to: 250310

Following JP's suggestion, we did a study on ADC only. Here, we have the
correlation cut. We did not apply the TDC cut, since it is biased. See
fig. 1, the red one is "pion" and the black one is "electron".  The
sample is reasonable. 

Then we applied a cut at 200 to see the pion rejection and electron
efficiency.  From this study and my previous log entry, we can see
clearly that the Gas Cerenkov somehow still miss a lof of electrons. The
pion signal in ADC is due to background (not clear what). The pion does
not fire the cerenkov, but the random background will.

number of electron,  electron eff,  number of pions,   pion percentage
left within cut.

869     0.168009        4350    0.0643678

2287    0.390905        10566   0.308726

2600    0.327692        2452    0.257341

3711    0.156292        2243    0.0994204

7017    0.142654        3806    0.0987914

6481    0.13825 3575    0.067972

30270   0.104063        25872   0.0903293

5277    0.111806        2500    0.0788

30270   0.115857        25872   0.104205

600     0.223333        179     0.0893855

273     0.216117        1344    0.00818452

1400    0.254286        5067    0.00414446

1833    0.270049        1597    0.0125235

2177    0.205788        1350    0.00296296

3067    0.0798826       1981    0.00504796

3194    0.0491547       2219    0.0144209

15293   0.000196168     14277   0.000560342

2460    0.331707        1574    0.160737

15293   0.147715        14277   0.134902

282     0.180851        89      0.0337079

Figure 1