AIDA GELINA BRIKEN nToF CRIB ISOLDE CIRCE nTOFCapture DESPEC DTAS EDI_PSA 179Ta CARME StellarModelling DCF K40
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Message ID: 4     Entry time: Mon Feb 20 10:01:06 2017
Author: DK 
Subject: F0, PPAC, and DSSD signal checks 
Today the following was performed:

===F0===

Chamber pumps were turned on (though the chamber was still under marginal vacuum from previous exp of ~10 mbar).

H2 gas was filled to check the windows at 551 Torr.  After >6 hours, leak rate is ~1 Torr (~4 Torr / day).

===F3 PPACs===

The F3 chamber pressure was below 5 x 10^-4 Pa, extremely good for F3.  Even with PPACs having gas, the baseline did not change.

Strange behavior was seen with the evacuation of the gas system and connecting the gas system to the PPACs.  There appeared to be pressure backflow frmm the pump.  This causes 
minor jitter in the current when bias was applied at first, and also strange temporal data.

After lunch, we found the input to the pump has a very severe leak.  Once it was replaced, the PPACs could be operated normal, including the expected spectra.  It could be 
possible the high discharge frequency and lower bias settings used, e.g., in 7Be THM exp in 2016.11 was partly due to this issue of contaminants in the gas.

Now the chamber pumps were turned off, in case we open the chamber tomorrow.

===F3 DSSDs===

Now all the cabling is connected in both E7 and J1.  Many more things are properly labeled.  

We had trouble to find all the signals generated via pulser in the DAQ.  PSD1 data showed up right away.  We could find PSD2 data after a change to the camac init script 
inputs.  The issue of PSD3 remains to be resolved (but at least there are no longer encoding errors, so perhaps it is a problem in ANAPAW.
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