[Halld-pid] TOF Lucite Shield

[Shepherd, Matthew]

Paul,

Best to consult with Adesh on sample size for calibration.

At 18 cm x 18 cm you are only covering 3/4 of the innermost "ring" of blocks.  The beam hole is 3 x 3 (4 cm blocks).  I think it is going to be hard for us to get a handle on calibration of those particular blocks.  At 25 cm you extend just into the second ring.

I'm afraid that the systematic errors on calibration of these blocks might make it hard to see any effect, but we can try.

Adesh:  what is the typical event sample you use for calibration?

Matt

---------------------------------------------------------------------
Matthew Shepherd, Professor
Department of Physics, Indiana University, Swain West 117
727 East Third Street, Bloomington, IN 47405

Office Phone:  +1 812 856 5808

> On Nov 10, 2016, at 2:32 PM, Eugenio, Paul <peugenio at fsu.edu> wrote:
> 
> Matt,
> 
> Below is a link to TOF logbook entry of the TOF Lucite Shield.  The entry includes the shield dimensions.  
> 
> Our plans is to start off without any shielding to obtain some baseline data, followed data taken with the configuration shown in the log entry(3+3 layers: 2.25” thick for 18x18cm and 1.125” from 18x18cm out to 25x25cm), and then possible some data with 2+2 layers:  1.5” thick for 18x18cm and 0.75” from 18x18cm out to 25x25cm. 
> 
> https://logbooks.jlab.org/entry/3437900
> 
> FCAL question:  How much data is need to perform a quick photon calibration?  
> 
> Paul
> 
> --
> Prof. Paul Eugenio
> Florida State University
> Department of Physics
> Tallahassee, Florida,  USA 32306
> 
> (850) 325-0314
> eugenio at fsu.edu
>