[Primex2] Found possible dead e-chanel in all compton runs

[Gan, Liping]

Hi, Franz,

Thanks very much for your correction. I did mix up with T-counters.

Jing, please check E-counter alignment as Franz suggested. Lingling did  the time  alignment earlier. You may discuss with her about it.

Cheers,
Liping

-----Original Message-----
From: Franz Klein [mailto:fklein at jlab.org] 
Sent: Tuesday, November 11, 2014 12:42 PM
To: Gan, Liping
Subject: Re: [Primex2] Found possible dead e-chanel in all compton runs

Liping,
I saw Jing's plot she sent to the primex group: I don't remember a time that so many E-counters were dead! I have not seen the data, maybe they have a large time offset and were therefore discarded?!
To your response: the T-counters have 2 PMTs (VME multihit TDCs with 25ps resolution), the E-counters have 1 TDC per channel (we had FASTbus multihit TDCs with 500ps resolution, they were exchanged wit VME multihit TDCs with 100ps resolution in early 2011).

Cheers,
Franz 

----- Original Message -----
From: "Liping Gan" <ganl at uncw.edu>
To: "Jing Feng" <fengj at jlab.org>, primex2 at jlab.org
Sent: Tuesday, November 11, 2014 11:47:09 AM
Subject: Re: [Primex2] Found possible dead e-chanel in all compton runs

HI, Jing,

Each E-counter should have two TDC's. You may check which TDC is dead. If the other TDC for the same E-counter is still alive, you may use the single TDC for that E-counter. 


Liping 

-----Original Message-----
From: primex2-bounces at jlab.org [mailto:primex2-bounces at jlab.org] On Behalf Of Jing Feng
Sent: Monday, November 10, 2014 7:29 PM
To: primex2 at jlab.org
Subject: [Primex2] Found possible dead e-chanel in all compton runs

Dear all and Ilya,
Please see the picture attached. All the compton runs have the problem of several e Channels dead(120/121/126/127/167/168). That may cause our yields lower than anticipation.Please commend on possible influence and remedy on our CS. I've just think of photon flux, MC simulation. If the problem also stay in pi0, we should also pay attention. 6 echannel is 1/30 of our numbers.more than 3% percent roughly. 
Thanks
Jing

_______________________________________________
Primex2 mailing list
Primex2 at jlab.org
https://mailman.jlab.org/mailman/listinfo/primex2

-- 
===============================================================
                  Franz J. Klein, Associate Professor 
                  CUA, Department of Physics
                  Washington, DC 20064
  office: Hannan Hall 206          phone: 202-319-6190 
  or: Jefferson Lab,CC F-243       phone: 757-269-6672 
---------------------------------------------------------------