MiniPrototype SinglesCosmicRuns 2008

Goal

Use singles Cosmic events to measure rate differences between Metalica and Plastica

Apparatus

• Plastica and Metalica are stacked on top of each other. High Voltage and ionization gas are connected in parallel.
• A discriminator is connector to the amplified output (an on board preamp and the VPI Post amp) of sense wire 4.
• The discriminator output is connected to a VME scaler.

Proposed Tests

1. Measure the singles rate as a function of DC high voltage
2. Measure the singles rate as a function of Discriminator Threshold

30-04-2008

The DC high voltage is on. The DC outputs of Plastika and Metalica from sense wire 3 are connected to the Model 777 Octal Variable Gain Amplifier.

HV settings
Wire	Volts
Sense	1700
Field	-800
Guard	800

Scope picture below shows the Noise level on the DC measured in infinite persist time mode.
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Scope pictures representing the cosmic signals from Plastika and Metalica(Amplifier is connected)

• Plastika

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• Metalica

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OUTPUTS FROM DISCRIMINATOR

Discriminator Threshold=450MV

Rate -vs- Discriminator Threshold

Gas is ArCo2 . 75/25 mixture

HV settings
Wire	Volts
Sense	1700
Field	-850
Guard	850

Threshold (mV)	Metalica (Events/hr)	plastika (Events/hr)	Coincidence
300	701 [math]\pm \sqrt{\frac{1.04194}{730}}[/math]	627 [math]\pm \sqrt{\frac{1.04194}{653}}[/math]
300	560 [math]\pm \sqrt{\frac{1.01639}{569}}[/math]	570 [math]\pm \sqrt{\frac{1.01639}{579}}[/math]
350	511 [math]\pm \sqrt{\frac{1.00028}{511}}[/math]	454 [math]\pm \sqrt{\frac{1.00028}{454}}[/math]
350	382 [math]\pm \sqrt{\frac{1.02222}{390}}[/math]	334 [math]\pm \sqrt{\frac{1.02222}{341}}[/math]	27(?)
350	427 [math]\pm \sqrt{\frac{1.05222}{449}}[/math]	409 [math]\pm \sqrt{\frac{1.05222}{430}}[/math]	74
350	427 [math]\pm \sqrt{\frac{1.13083}{437}}[/math]	409 [math]\pm \sqrt{\frac{1.13083}{424}}[/math]	56

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