[Halld-pid] [Revised Logentry] TOF Shielding Study

[eugenio at jlab.org]

Logentry Text:
--
For the last day of the run we were able to install one configuration of TOF acrylic shielding.  Run after 12:00 on Oct 20 have the TOF shielding in place.  Initial results are below.

[See updated figure in later log post]

[Text from figure]
Discriminator Scalers:    TOF:S:T:#:scaler_t1

TOF South PMTs for paddles 18, 19, 20, 21(closest to beam)
paddles 18 & 19 are 6cm wide 
paddles 20 & 21 are 3cm wide


Without shielding

                     Dec-19         Dec-19         Dec-19         Dec-19
                     00:00           00:00            23:00            18:00
   [MHz]
Beam             200nA         300nA           400nA           500nA
S:21               2.3               3.3               3.7                4.7
S:20               1.6               2.2               2.6                 3.6
S:19               1.7               2.4               2.9                 3.7
S:18               0.8               1.2               1.5                 2.1

With shielding

                     ------             Dec-20          Dec-20          
                     --:--               18:00            18:45           
   [MHz]
Beam             200nA         300nA           400nA           
S:21               -                   2.0               2.4                
S:20               -                   1.15             1.5                 
S:19               -                   2.0               2.5                 
S:18               -                   1.2               1.5      

Shielding configuration: 2.25" thick acrylic 25cm x 25cm with beam hole
           shielding cover paddles 21, 20, and part of 19
           

---

This is a plain text email for clients that cannot display HTML.  The full logentry can be found online at https://logbooks.jlab.org/entry/3448864
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