Difference between revisions of "IAC 1-7-08"
| Line 21: | Line 21: | ||
:PMT Coinc both PMTs=105/10min = 10/min | :PMT Coinc both PMTs=105/10min = 10/min | ||
:PMT Coinc Both PMTs & DC =4/10min = 0.5/min | :PMT Coinc Both PMTs & 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 lets debug the beamline. | ||
| + | |||
| + | We move the Aluminum brick in front of the first scintillator. Our tests on Friday showed inserting an Aluminum brick in front of the collimator decrease the scintillator count rate by approximately 60 %. A 15 MeV electron should stop in 2cm of Aluminum so we believe our 2" (5 cm) thick Aluminum bricks are stopping 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. | ||
| + | |||
| + | |||
| + | |||
[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 20:44, 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 & DC =25/4min = 6/min
Configuration: Collimated rear scint
Rates:
- PMT Coinc both PMTs = 308/2min = 154/min
- PMT Coinc Both PMTs & 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 & 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 lets debug the beamline.
We move the Aluminum brick in front of the first scintillator. Our tests on Friday showed inserting an Aluminum brick in front of the collimator decrease the scintillator count rate by approximately 60 %. A 15 MeV electron should stop in 2cm of Aluminum so we believe our 2" (5 cm) thick Aluminum bricks are stopping 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.