sPHENIX discussion of the superconducting solenoid

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

Hi,

This morning, Frank Toldo (primary worker !), Achim and I have installed the 
Hall probes.  At one point, we
saw 9 G on X and couldn't get rid of it when doing "zero-field" calibration.  
But later Achim realized that
when we do the zero-field calibration, we need to do it channel by channel 
(X/Y/Z).  After that, it's all below
1 G.

I've zipped Achim's photos here :
https://collab.external.bnl.gov/sites/sPHENIX-Magnet/Pictures/High%20Field%20Test/2017-12-8%20Hall%20Probe%20Installation.zip

that you may take a look.

We've used a magnet and got >1 kG so that we know the probe responds :-)  

The cable was not long enough and we've tried a couple arrangement.  At the 
end, we put the 2nd table 
(that Dave Phillips provided)  next to the steel wall and put the Gauss-meter 
put on a table.

... Just now, Jon Hock reminds us that we can hook up the two temperature 
sensors so that we can see whether the temperature are.  
Frank is going to do it at 1 pm (today).

 *********************************************************

I talked with Jon Hock, Dave and Rob Karl ... Ed Dabrowski is still drilling 
some holes at the moment.  
Rob Karl told me that during this morning's scheduling meeting, they've 
scheduled such that they'll finish doing the "preparation works"
(shim-ing) on Monday and then put the End-walls on Tuesday only once --- 
that's Rob's plan.  

==>  So, we have to wait until then (next Tuesday) to start cool-down.     
Yesterday, a Cryo tech (forgot his name) showed me that they're
hoping for a temperature to go below ~100 K (after a night's cooling) so that 
the plant can really start working.   This morning, I saw something
like between 120 and 130 K.

 *********************************************************

I'm going to send an email to urge Paul Giannotti to help guide Frank to 
install all the strain gauges and linear pots (including 4 from Jon Hock).

Kin

-----Original Message-----
From: Franz, Achim 
Sent: Friday, December 08, 2017 10:28 AM
To: Haggerty, John <haggerty AT bnl.gov>
Cc: Yip, Kin <kinyip AT bnl.gov>; O'Brien, Edward <eobrien AT bnl.gov>
Subject: Hall probes

Hi, 

Here are some pictures from the inside. And the readout with a magnet next to 
the probe and without.