Difference between revisions of "HM 2014"
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| − | Determine best | + | Determine best Cathode HV that produces the largest separation of the source ON/OFF signal. |
Then perform a set of measurements (shutter open/closed and source ON/OFF) to establish reproduceability. Make sure you record the scaler count rates. | Then perform a set of measurements (shutter open/closed and source ON/OFF) to establish reproduceability. Make sure you record the scaler count rates. | ||
Revision as of 03:41, 18 September 2014
9/18/14
Determine best Cathode HV that produces the largest separation of the source ON/OFF signal.
Then perform a set of measurements (shutter open/closed and source ON/OFF) to establish reproduceability. Make sure you record the scaler count rates.
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
- CATH 3.1 KV
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
- 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.