sPHENIX discussion of the superconducting solenoid

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

Hi Roberto,

> So I will do this when I get back from MSU. Week of Oct 8

Have you started doing this "backfilling with N2" ???  I'm just wondering.   I saw Pat (the group leader for the electricians) and chatted with him really quickly.
I told him that the Cryo personnel have turned off the vacuum pump and the electricians can disconnect all the power sockets any time they like.  He said that it'd
take a day only.     I'm still waiting and not sure when Dave Phillips will be able to arrange the Valvebox to be taken off ....

Each of these above three things can happen any time (without waiting for each other), as far as I understand.   { Let me know if I'm wrong. }

Kin

On 09/26/2018 05:43 PM, Than, Yatming (Roberto) wrote:

 

Backfilling with N2 is easy.

I am worried about oxydation/corrosion of anything. [pin connectors] If you have all soldered joints then no worries, but…

So better to do it, and refresh once in a while with brand new dry N2.

I have N2 gas at the cryoplant from our 11,000Gal LN2 storage dewar economizer N2 gas feed, so I can just connect a polytube from there[cryoplant] to where vacuum valve is.

No need to bring in 2200 psi N2 bottles.

Once we are done with the 650MHz cold test, we will eventual loose all LN2 inventory in our storage dewar, since no more cold test for a while.

So I will do this when I get back from MSU. Week of Oct 8

Roberto

 

From: sPHENIX-magnet-l <sphenix-magnet-l-bounces AT lists.bnl.gov> On Behalf Of Yip, Kin
Sent: Wednesday, September 26, 2018 4:53 PM
To: sphenix-magnet-l AT lists.bnl.gov
Subject: [Sphenix-magnet-l] Brief Summary of sPHENIX Magnet Meeting (Sept. 26, 2018) at 1:30m pm @ 902 Conference Room

 

Agenda and other materials :  https://indico.bnl.gov/event/5077/

 

P. Kovach did an ANSYS analysis on the 2 doghouses and the conclusion was that we don’t need additional shipping fixtures during transport.   Paul put 100 pounds on the end and the bend was only a fraction of an inch.
So, he told us that after the Valvebox is taken off, the extension pipe (with the doghouses but not the doors --- Ray Ceruti reminded us about this as the doors are quite heavy) may be left in air.   Paul said that it can deal with 2-3 g accelerating movement during transport.

People were very happy that this analysis was done.  Jim Mills and others think that to make ourselves feel even better, we may do something simple (Unistrut) to protect the extension further from accidental damage during the transport.

P. Kovach/M. Anerella said that during transportation (from 912 to 1008), it is mandatory that the truck has both tractor & trailer BOTH in air ride suspension since the shipping restrain frame has no shock absorbing features. 

 

Jim Mills asked whether we should rotate the magnet so that the doghouses would be near the floor.  People discussed that there didn’t seem to be any compelling reason to do so.   And of course, rotating it creates a risk. We also discussed about putting in dry nitrogen or not, or running vacuum pump, for the years that the Magnet Cryostat may sit in 912 before we move it to 1008.  From the experience of many magnets that the Magnet Div. people have dealt with or the RHIC spare magnet being only wrapped with plastic bag, nobody really thought that it’s absolutely necessary to do put in dry nitrogen or keep pumping.  Paul Orfin has agreed to cap all the openings to prevent any foreign substance (like oil) or animals going into the Magnet to do any damage.

It’s suggested whether keeping it in vacuum/putting in nitrogen may save us some major time when we do the installation I 1008.  But, after we bring it to 1008, there will be some time during installation that the Magnet is open to air.   Paul Orfin commented that the most (time) that it may take to pump it down is 4 weeks and should be shorter. I’ve modified a Microsoft project file that Dave Phillips (by changing the starting date to Mar. 1) and uploaded it to the indico page (listed at the top of this email), “Magnet Repair. mpp”.   From that schedule, if we start to move the valvebox on Mar. 1, we finish the repair and move the Magnet to the frame by the middle of May.   But Mar. 1 may be the latest day which was due to the fact that we don’t have electricians --- who are busily working for the RHIC project --- as it’s not entirely unlikely that we may get the electricians before that time.  If so, we’ll proceed as soon as possible. We or I realized in the meeting that we can actually open up the doghouse underneath the Valvebox before the Valvebox is removed.  Right now, Paul Orfin told us that the vacuum pump had been turned off.  We see the current pressure as 0.56 Torr which was only due to the fact that the system was still closed.   We can open up the doghouse once Paul Orfin can open up the system and put in some dry nitrogen to atmospheric pressure.   Paul Orfin said that he’s busy until mid-Dec.  

So, the agreement is that as soon as Paul Orfin raise the Magnet pressure to  atmospheric pressure (before or in Dec.)
=>  we call Ray Ceruti to open the doghouse door ;
=>  then Carl/Sonny can come to check/repair.

6. Ray Ceruti told us that we really need to take good care of the things that we take apart and should take video/photo of the process. 
   => Brian Streckenbach has volunteered to take video picture of the process.
   => John Haggerty said that John C Biggs’ group can take care of storing the components of the Magnet (that we take apart from the Valvebox and doghouse) in a safe place.

 

7. Next meeting is happen before Thanksgiving.