sPHENIX discussion of the superconducting solenoid

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

Hi,

Roberto just called me (23:40) and explained the situation.   As Rosi Reed hinted to me earlier, the Cryo technicians (Tom Wozniak et. al.) couldn't solve the problem of a valve of the 400 L reservoir in the coldbox at the top platform in our IR.

The valve in question is H3668 (picture attached) and the problem is that it can't be closed completely when it's needed to.  In this case, there will be overflow into the reservoir and flood the cryo lines.  Apparently, we had problem last year but they could make it close after some manoeuvre.  But this time, they really couldn't get it to move properly.

So, Roberto has started the steps to warm up the vessel inside the coldbox so that they can pull out the valve and fix.  As helium is boiled off, cooling to the Magnet will be stopped and magnet temperature will drift up naturally ... maybe to 80 K or so.

After the fix, the Magnet will be cooled down again.   It may take a couple/few days.  Roberto has already starting the "boiling off" and the Cryo group will work over the weekend.

 

 

 

From: sPHENIX-magnet-l <sphenix-magnet-l-bounces AT lists.bnl.gov> On Behalf Of Yip, Kin
Sent: Thursday, April 18, 2024 6:29 PM
To: Than, Yatming (Roberto) <ythan AT bnl.gov>; Van Kuik, Brian <vankuik AT bnl.gov>; Tenreiro, Louis <tenreiro AT bnl.gov>; Riker, Kenneth D <kenr AT bnl.gov>; Martin, Daniel <martin AT bnl.gov>; Lederle, Dewey L <lederle AT bnl.gov>
Cc: sphenix-magnet-l AT lists.bnl.gov
Subject: [Sphenix-magnet-l] Magnet ramped down to ~0 A

 

Hi,

 

I got a call from Roberto (who took the necessary step) and he told me to ramp down as one of the 400 L reservoir valve was stuck and the reservoir level was going down.   He’s asking a technician to find an I/O card

to swap with the bad one.   But he’s afraid that his technician wouldn’t be able to come to swap it in time before we ran out of He.

 

So, I did the “slow ramp down/discharge” (i.e., through the freewheeling diode).   Somehow, the valve came back 10-15 minutes later ☹😊   But Roberto asked the technician to swap it out anyway (to avoid similar problem).

Had we known that the card would be good in 15 minutes or so, we didn’t need to ramp the Magnet down.    But we didn’t know.  Last time, a Cryo personnel called me to ramp down was on Aug. 1, 2023 while there was

Helium leak in 1004B and the Cryo Room needed to shut down the He to prevent further leak and called me to ramp down the Magnet.  In that case, it’s too late as the quench system forced the Magnet fast-discharge.

 

After consulting with my colleagues in 1008, the Magnet will stay off tonight and we’ll think about whether to turn it on or not   tomorrow / for the weekend.

 

I attach a plot of the complete ramp-up and ramp-down for today. 

( I’ve been looking at the gas-cooled lead voltage tap.   It rose to 40 mV (compared to our threshold of 50 mV) during the ramp-down.  It’s slightly better than >45 mV during ramp-down last year.  )

 

Kin

 

 

-------- Original message --------

From: "Than, Yatming (Roberto)" <ythan AT bnl.gov>

Date: 4/18/24 16:38 (GMT-05:00)

To: "Yip, Kin" <kinyip AT bnl.gov>, "Van Kuik, Brian" <vankuik AT bnl.gov>, "Haggerty, John" <haggerty AT bnl.gov>, "Mills, James A" <mills AT bnl.gov>, "Tenreiro, Louis" <tenreiro AT bnl.gov>, "Riker, Kenneth D" <kenr AT bnl.gov>, "Martin, Daniel" <martin AT bnl.gov>, "Lederle, Dewey L" <lederle AT bnl.gov>

Cc: "Feder, Russell" <rfeder AT bnl.gov>

Subject: Re: Ramping now ...you can watch lead flow

 

Kin,

We had an I/O card failure for valves on the 400L reservoir.

I think we need to rampdown.

Reservoir is dropping.

Roberto

 

 

---

From: Yip, Kin <kinyip AT bnl.gov>
Sent: Thursday, April 18, 2024 4:22 PM
To: Van Kuik, Brian <vankuik AT bnl.gov>; Than, Yatming (Roberto) <ythan AT bnl.gov>; Haggerty, John <haggerty AT bnl.gov>; Mills, James A <mills AT bnl.gov>; Tenreiro, Louis <tenreiro AT bnl.gov>; Riker, Kenneth D <kenr AT bnl.gov>; Martin, Daniel <martin AT bnl.gov>; Lederle, Dewey L <lederle AT bnl.gov>
Cc: Feder, Russell <rfeder AT bnl.gov>
Subject: RE: Ramping now ...you can watch lead flow

 

Almost 3 hours later ...The ices didn't seem to be any different.

 

I attach a picture.   I will try to find Roberto to discuss a bit.

 

Kin

 

 

 

-------- Original message --------

From: "Van Kuik, Brian" <vankuik AT bnl.gov>

Date: 4/18/24 15:28 (GMT-05:00)

To: "Than, Yatming (Roberto)" <ythan AT bnl.gov>, "Yip, Kin" <kinyip AT bnl.gov>, "Haggerty, John" <haggerty AT bnl.gov>, "Mills, James A" <mills AT bnl.gov>, "Tenreiro, Louis" <tenreiro AT bnl.gov>, "Riker, Kenneth D" <kenr AT bnl.gov>, "Martin, Daniel" <martin AT bnl.gov>, "Lederle, Dewey L" <lederle AT bnl.gov>

Cc: "Feder, Russell" <rfeder AT bnl.gov>

Subject: RE: Ramping now ...you can watch lead flow

 

Do we need to lower the flow rate a smidge?

 

From: Than, Yatming (Roberto) <ythan AT bnl.gov>
Sent: Thursday, April 18, 2024 1:51 PM
To: Yip, Kin <kinyip AT bnl.gov>; Van Kuik, Brian <vankuik AT bnl.gov>; Haggerty, John <haggerty AT bnl.gov>; Mills, James A <mills AT bnl.gov>; Tenreiro, Louis <tenreiro AT bnl.gov>; Riker, Kenneth D <kenr AT bnl.gov>; Martin, Daniel <martin AT bnl.gov>; Lederle, Dewey L <lederle AT bnl.gov>
Cc: Feder, Russell <rfeder AT bnl.gov>
Subject: Re: Ramping now ...you can watch lead flow

 

The heaters are maxed out, and frost will keep forming.

258K is the flange surface temperatures.

---

From: Yip, Kin <kinyip AT bnl.gov>
Sent: Thursday, April 18, 2024 1:40 PM
To: Than, Yatming (Roberto) <ythan AT bnl.gov>; Van Kuik, Brian <vankuik AT bnl.gov>; Haggerty, John <haggerty AT bnl.gov>; Mills, James A <mills AT bnl.gov>; Tenreiro, Louis <tenreiro AT bnl.gov>; Riker, Kenneth D <kenr AT bnl.gov>; Martin, Daniel <martin AT bnl.gov>; Lederle, Dewey L <lederle AT bnl.gov>
Cc: Feder, Russell <rfeder AT bnl.gov>
Subject: RE: Ramping now ...you can watch lead flow

 

Hi,

 

I like that the gas-cooled voltage tap is low ...

 

I just took a picture.  So far, there is no big ice ball.

 

Kin

 

 

 

-------- Original message --------

From: "Than, Yatming (Roberto)" <ythan AT bnl.gov>

Date: 4/18/24 13:28 (GMT-05:00)

To: "Yip, Kin" <kinyip AT bnl.gov>, "Van Kuik, Brian" <vankuik AT bnl.gov>, "Haggerty, John" <haggerty AT bnl.gov>, "Mills, James A" <mills AT bnl.gov>, "Tenreiro, Louis" <tenreiro AT bnl.gov>, "Riker, Kenneth D" <kenr AT bnl.gov>, "Martin, Daniel" <martin AT bnl.gov>, "Lederle, Dewey L" <lederle AT bnl.gov>

Cc: "Feder, Russell" <rfeder AT bnl.gov>

Subject: Re: Ramping now ...you can watch lead flow

 

Kin,

Definitely too much flow.

Roberto

---

From: Yip, Kin <kinyip AT bnl.gov>
Sent: Thursday, April 18, 2024 11:34 AM
To: Than, Yatming (Roberto) <ythan AT bnl.gov>; Van Kuik, Brian <vankuik AT bnl.gov>; Haggerty, John <haggerty AT bnl.gov>; Mills, James A <mills AT bnl.gov>
Subject: Ramping now ...you can watch lead flow

 

Hi,

 

We are ramping now.  You can watch lead flow if you want.

 

Kin

 

Attachment: This Valve.png
Description: This Valve.png