sPHENIX discussion of the superconducting solenoid

[Kin Yip <kinyip AT bnl.gov>]

Hello John Haggerty,

You may find the 4 Gaussmeter measurement on the GPM under the tree:

/Development/sPHENIX/magField.mon

( Winston had a typo in his email: "com" -> "mon"   and  you may need to choose "All Monitor Files" in GPM to see it.  )

Winston told me that it's still running in his machine acnlin75 as he's got a little problem moving into the server.  So, he's working on that.
After it's all working, we'll start logging it in the "LogView" (ie. starting to log).

I attach a plot of the GPM fields (around 1 G).

Kin

-------- Forwarded Message -------- Subject: RE: [Sphenix-magnet-l] one bad RTD ... but I found a replacement from Len Masi Date: Fri, 8 Dec 2017 17:31:28 -0500 From: Pekrul, Winston <wpekrul AT bnl.gov> To: Yip, Kin <kinyip AT bnl.gov>

Kin,

Gaussmeter GPM is running at /Development/sPHENIX/magField.com.

Winston

---

From: sPHENIX-magnet-l [sphenix-magnet-l-bounces AT lists.bnl.gov] on behalf of Kin Yip [kinyip AT bnl.gov]
Sent: Friday, December 08, 2017 5:27 PM
To: sphenix-magnet-l AT lists.bnl.gov
Cc: Masi Jr, Leonard; Toldo, Frank A; Biggs, John C
Subject: [Sphenix-magnet-l] one bad RTD ... but I found a replacement from Len Masi

Hi,

This afternoon, Frank Toldo tried to read the temperature sensors attached to the surface of the cryostat surface (which are supposed to monitor the seasonal temperature changes).   He's puzzled why it said "OPN" (opened) for a while.    Long story short, after Paul Giannotti and I came to help set things and investigate, we finally realized that one RTD is good which give us ~75 F ~ close to 110 ohm or so ... whereas the other was reading 7k ohm --- explaining why the meter said "opened".   That bad RTD was inside the inner radius of the cryostat and Frank was able to measure the resistance and confirmed that the RTD was broken (huge resistance).

So, Frank called Omega to order 2 (and each cost $139) but it'll be shipped on Monday and arrived at BNL on Tuesday, kind of late for our schedule.  So, I asked a few colleagues including Tony Curcio and Len Masi Jr.    Len has just given me an Omega RTD : SA1-RTD-4W-SB, and another cheap one.

I've learnt a little about these RTD's in the last couple of hours.   Though the one that we have is STRD-1 (https://www.omega.com/pptst/SRTD-1_SRTD-2.html) and is slightly different the one that Len gave me --- SA1-RTD (https://www.omega.com/pptst/SA1-RTD.html), they're both 100 ohm platinum and both use the so-called European curve (temp coefficient = 0.00385 Ω/Ω/°C).  They're just packaged differently.
One is polymide insulated whereas the other is silicon-based.   Roberto Than and Len have both believe that they're interchangeable.   After reading all the specifications, I'm convinced too that they're the "same" to us, especially that we just try to measure the temperature to see whether they'd be different for 10 F or something.   I've discussed with Jim Mills who also agrees.


So, on Monday, I'll try to ask Frank to install the one that Len gave us.  We may just need short 2 of the 4 wires to become 3 wires
(as Len advised) or we can actually use 4 wire.


 ***********


Roberto told me that their plant seems to be working normally at the moment ... Sometime tomorrow, it'll start to produce liquid He ... A day later, we will have a curve and Roberto et. al. can then tell us whether the Plant is working near 100% capacity or not.


Kin

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