HM 2014

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Revision as of 18:31, 17 September 2014 by Abdehait (talk | contribs) (→‎9/17/14)
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9/17/14

Measure the charge for several values of the Cathode HV keeping the GEM preamplifier voltage and gas flow rate constant.

CATH 3.2 KV

QDC source on off 7728 7729.png

CATH 3.1 KV

QDC source on off 7736 7737.png

All the runs have the same duration 20 min.

CATH 3.4 KV

Try to take scope picture to show difference between source on and off signal that are being measured by the QDC.

9/16/14

QDC source on off 7724 7726.png

Condition of above results

Shutter is Open

Red is Cf-252 source ON Run 7724

Green is Cf-252 source OFF run 7726

HV_GEM= -2930 Volts HV_Cathode=-3400 Volts

Gas Flow rate = 0.1 ft^3/hr

Goal
Can the Cf-252 source ON signal be changed?

Change the Cathode voltage to try and turn off the signal when the source is on.

Result

Yes, when the cathode voltage is decreased to -3200V, QDC histogram does not show any difference in the collected charge as the shutter is open with the source on it, and when the shutter is open without the source.

QDC source on off 7728 7729.png


Neutron_TGEM_Detector_Abdel