Log entry time 04:50:59 on November21,2008

Entry number 250136

BB Cherenkov TDC Signal

It is the run#3711 which was taken by me in Nov20 owl shift, after Brad corrected the channel mapping error. 
Beam current was 0.5uA and has 0.8M events. The target is empty target.

In the plots black line is the counts which are only trigged by T1 or T6 and is really a track, 
while the red line has an additional cuts as total preshower energy large than 500, which is only a rough cut to choose good electons. 
Here are the counts and ratio for different lines in each channel:

4840  / 10932 = 0.442737

4923  / 10432 = 0.471913

9614  / 21146 = 0.454649

8879  / 19432 = 0.456927

21173  / 46722 = 0.453170

7010  / 15139 = 0.463042



5653  / 12490 = 0.452602

9639  / 21835 = 0.441447

7227  / 15553 = 0.464669

207  / 438 = 0.472603

742  / 1214 = 0.611203

1067  / 2150 = 0.496279

386  / 643 = 0.600311

1274  / 2221 = 0.573615

1092  / 1581 = 0.690702

13987  / 30735 = 0.455084

951  / 1816 = 0.523678

234  / 510 = 0.458824

1158  / 2451 = 0.472460



Another thing I want to mention is that the first 10 channels are located at the beam line side. So they have more junk, compared with the next 10 channel. 

PS: The 19th channel is the witness PMT, which are not connected with our Cherenkov tank. So it only has some noise or radiation background there. The 7th channel does not exist in my database, so I cannot find anything in it.