Difference between revisions of "June,18,2007 Teachers in lab"
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== Tuesday , June 19, 2007 == | == Tuesday , June 19, 2007 == | ||
| − | Today our team of experimenters setup a discriminator to determine which of the PMT outputs | + | Today our team of experimenters setup a discriminator (LeCroy Model 821) to determine which of the PMT outputs would be used to define the presence of a charged particle passing through the scintillator. |
| − | + | The discriminator takes a signal from the PMT that is above the threshold (-30mV to -9V)and returns a voltage of -lV square pulse. | |
[[Image:Discriminator.jpeg]] | [[Image:Discriminator.jpeg]] | ||
| + | The voltage for each channel was set so that the trigger rates from the discriminator were the same (about 21 pulse/second). | ||
| + | Channel A voltage -1057V, Discriminator threshold -30mV, | ||
| + | Channel B voltage -1001V, Discriminator threshold -30mV. | ||
Revision as of 18:16, 19 June 2007
Experimenters:
- Jenette Briggs
- Keith Quigley
- Bettie Keetch
- Tony Forest
Monday, June 18, 2007
Out Quarknet Teachers had their first seesion experimenting with a coscmic ray test stand made up of two scintillators. Each scintillator was attached to a single PMT. A voltage of -900 Volts was applied and signals were observed using an oscilloscope.
First Cosmic ray scope pictures using PMT + Scintillator
First scope picture on a single detector
now look for a coincidence signal between two PMT detectors
Tuesday , June 19, 2007
Today our team of experimenters setup a discriminator (LeCroy Model 821) to determine which of the PMT outputs would be used to define the presence of a charged particle passing through the scintillator.
The discriminator takes a signal from the PMT that is above the threshold (-30mV to -9V)and returns a voltage of -lV square pulse.
The voltage for each channel was set so that the trigger rates from the discriminator were the same (about 21 pulse/second).
Channel A voltage -1057V, Discriminator threshold -30mV,
Channel B voltage -1001V, Discriminator threshold -30mV.