sPHENIX discussion of the superconducting solenoid

["Yip, Kin" <kinyip AT bnl.gov>]

Hello,

 

Thanks for Zeynep’s message.   From our discussion slightly earier last Friday and Winston’s multiple messages this weekend, the timestamps seem to be screwed up a bit …

But I still went to the SDDS (quench data A and B) to look and made two plots POS_GC_Lead.*.gif.  

 

The red line is the quench-signal  (Intlk_Quench_Event) whereas the black curve is the Postive-Gas-Cooled-Lead signal.

 

In POS_GC_Lead.1.gif, this Postive-Gas-Cooled-Lead has been flirting with 5 mV    while   POS_GC_Lead.2.gif clearly shows that it’s just 5 mV.    Is this it ?

 

From LogView.gif (120 Hz data), it doesn’t look like it was over 5 mV.  ( Carl would give me a lecture of noise and filtering ..... )

 

Kin

 

From: Altinbas, F. Zeynep
Sent: Sunday, February 04, 2018 12:17 PM
To: Yip, Kin <kinyip AT bnl.gov>; Schultheiss, Carl <carls AT bnl.gov>; Rosas, Pablo J <rosas AT bnl.gov>
Cc: Theisen, Charles <ctheisen AT bnl.gov>; Lambiase, Robert <lambiase AT bnl.gov>; Marusic, Aljosa <marusic AT bnl.gov>
Subject: sPhenix - Quench explained

 

Hello everyone,

 

Late Friday, I figured out the reason for the quench trip happened on Thursday. 

Before we ramped to 500A that day, we did a manual quench from 1000A. To generate the fake quench, I lowered the Positive Gas Cooled Lead threshold from 50mV to 5mV. Unfortunately, I forgot to revert the setting to 50 before our second ramp. All these thresholds are saved in the header of the PXIe log file. Though, it seems to be missed during analysis.

 

Even though this investigation led us to discover a few other issues, I'm sorry for the false alarm and not catching this early enough.

 

Zeynep

Attachment: POS_GC_Lead.1.gif
Description: POS_GC_Lead.1.gif

Attachment: POS_GC_Lead.2.gif
Description: POS_GC_Lead.2.gif

Attachment: LogView.gif
Description: LogView.gif