Difference between revisions of "IAC 1-7-08"

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We will move the Aluminum brick in front of the first scintillator.  
 
We will move the Aluminum brick in front of the first scintillator.  
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Aluminum block in front of first scintillator between experimental side wall and large scintillator.
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Rates:   
 
Rates:   
 
:First PMT singles =6128/2 min = 3064/min
 
:First PMT singles =6128/2 min = 3064/min
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:PMT Coinc Both PMTs & Metallica DC =3/2min = 1.5/min
 
:PMT Coinc Both PMTs & Metallica DC =3/2min = 1.5/min
  
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Now take the brick out.
  
Aluminum block in front of first scintillator between experimental side wall and large scintillator.
+
Rates: 
 +
:First PMT singles = min = /min
 +
:PMT Coinc both PMTs= min = /min
 +
:PMT Coinc Both PMTs & Metallica DC =min = /min
  
  
 
[http://www.iac.isu.edu/mediawiki/index.php/Mini-prototype#IAC_Runs Go Back]
 
[http://www.iac.isu.edu/mediawiki/index.php/Mini-prototype#IAC_Runs Go Back]

Revision as of 21:33, 7 January 2008

Accelerator: 100 ns, 60 Hz, 15 MeV

Configuration: Collimated rear scint + 2" Aluminum brick

Rates:

Coinc both PMTs =484/4min = 121/min
PMT Coinc Both PMTs & Metallica DC =25/4min = 6/min


Configuration: Collimated rear scint

Rates:

PMT Coinc both PMTs = 308/2min = 154/min
PMT Coinc Both PMTs & Metallica DC =17/2min = 8/min

The ratio of double/triple =36/1054 = 3.1%

Configuration: Collimated rear scint+ 2" Aluminum brick + 2" lead brick

Rates:

PMT Coinc both PMTs=105/10min = 10/min
PMT Coinc Both PMTs & Metallica DC =4/10min = 0.5/min


We see a lot of events in the Scintillator and very few in the Chamber. There is no clear electron signal so let's debug the beamline.

Our tests on Friday showed that inserting an Aluminum brick in front of our first collimator decreased the first scintillator's count rate by approximately 60 %. A 15 MeV electron should stop in 2cm of Aluminum. We believe our 2" (5 cm) thick Aluminum brick will stop electrons but not photons. We do not observed the same change in rate when we insert the Aluminum brick in front of the rear scintillator. We believe our collimation system is blocking most of the electrons.

We will move the Aluminum brick in front of the first scintillator.


Aluminum block in front of first scintillator between experimental side wall and large scintillator.

Rates:

First PMT singles =6128/2 min = 3064/min
PMT Coinc both PMTs=132/2 min = 66/min
PMT Coinc Both PMTs & Metallica DC =3/2min = 1.5/min

Now take the brick out.

Rates:

First PMT singles = min = /min
PMT Coinc both PMTs= min = /min
PMT Coinc Both PMTs & Metallica DC =min = /min


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