sPHENIX discussion of the superconducting solenoid

[Kin Yip <kinyip AT bnl.gov>]

Hi,

Pasquale has provided some certication for the Aluminium stabilizer (the coil), RRR etc.

https://collab.external.bnl.gov/sites/sPHENIX-Magnet/Shared%20Documents/Documents%20introduced%20or%20sent%20to%20us%20by%20Pasquale%20Fabbricatore/2016-2-9%20BABAR%20-%20EUROPA%20METALLI%20Al%20certification.pdf

and some test results :

https://collab.external.bnl.gov/sites/sPHENIX-Magnet/Shared%20Documents/Documents%20introduced%20or%20sent%20to%20us%20by%20Pasquale%20Fabbricatore/2016-2-9%20BABAR%20-%20EUROPA%20METALLI%20Tests.pdf

the smallest value there was > 23 MPa (in the bond strear test).   Other tests had higher yield strengths at 77 K.

Kin

-------- Forwarded Message -------- Subject: Re: no certification for Al aluminium Date: Tue, 9 Feb 2016 17:51:20 +0100 From: fabbric <Pasquale.Fabbricatore AT ge.infn.it> To: Yip, Kin <kinyip AT bnl.gov>

Hi Kin,
yes this week I am back in office.
Next week I will be away again.

Regarding the pure Al, you should have among the Ansaldo
documents the material certification.

All I have are  pieces of information,
which I am sending you.

2) Al certificate (Not sure all certificates)

3) Some tests done on final conductor

Let me see if I find anything more. However the bonding test
giving a failure of 23 MPa gies somew information.

Best regards

Pasquale



Il 09/02/2016 16:13, Yip, Kin ha scritto:

Dear Pasquale,

 

I hope you’re back …  Kind of the same questions that we’ve asked you but we need exact numbers

this time.    

 

My colleagues think strongly that there should be some certification exactly what

Aluminium stabilizer (coil) that Ansaldo/BaBar has used in manufacturing all the coils.   And there

should be some stress analyses which said that stress on the coils is < 20 MPa everywhere.   ( Our own analyses had some high stress points > 20 MPa in corners/edges and they seem to be due to sharp edges in modelling and we’re varying the models in ANSYS to convince ourselves that edges/corners are the main reason for high stress points. )

 

But we couldn’t find anything like certification … nor explicit analysis which stated that the stress < 20 MPa

for the coil (Al stabilizer which makes up most of the coil).

 

From the email that you sent me on July 12 last year with the attached D0 document, it indicates that

the yield strength of pure Al is sensitive to its composition or how it was made.

 

Do you know of (any certification for) the exact composition of the Al stabilizer (coil) or the exact yield strength of the Al (coil) ?   Any analysis which shows the it’s < 20 MPa  anywhere (even before the coils

were manufactured, such as in BaBar Note 233 etc. etc…. we couldn’t find) ?

 

Kin

 

From: fabbric [mailto:pasquale.fabbricatore AT ge.infn.it]
Sent: Sunday, July 12, 2015 5:37 AM
To: Yip, Kin <kinyip AT bnl.gov>
Subject: Re: 20 MPa or 30 MPa or ??? on Aluminium (stabilizer)

 

Hi Kin.
about your questions:
1) Coil, G10 flanges and mandrel were impregnated
    together.  No releasing agent was used.
2) The plot reports a measurement done in Cortaillod
    (Ch) where the BaBar conductor was coestruded. It is
   a document I personally stored. May be I have other, but I have
  to look inside old boxes. It is possible that it is not included
  in the QA documents because it is a document of a sub-suppliers.
3) Regarding pure Al I am attaching an old publication of Rich Smith
   (Fermilab) about D0 magnet. There are a lot of information about
   very pure Al.
  I can summarise the main points. When we speak abour very pure Al
  we are dealing with 99.997 (or better )purity. The RRR is 1000 or higher.
 The yield stress for these materials is very low, but there is an increase
  of mechanical strength with mechanical and thermal cycles.
 As the mechanical strength increases the electrical resistivity increases too.
This material has also the properties to anneal at very low temperatures.
You can find a lot of information looking at the works of K.T.Hartwig.
In some way our decision to set at  20 Mpa the yield stress  could be
considered arbitrary. However the measurement odf the RRR showed that
the resistivity was quite low in operating conditions, sign that the mechanical
strength was low too.

Il 10/07/2015 22:47, Kin Yip ha scritto:

Dear Pasquale,

(1) We're doing some ANSYS analysis ... A detailed question people have raised:  Near the end of solenoid (in lead-end or non-lead-end),
between coil and the G10  or between G10 and the mandrel, have you put any "mode release"/"releasing agent" in this BaBar Magnet ?  Or,
they coil/G10/Mandrel are directly stuck together ??

(2) Where did you get the plot (about the failure at 45 MPa) ?  They are in French (I see CH-...) and it seems to be done in Switzerland.
They're not in the 6-volume BaBar documents, right ?  I can never read them all ...

Eg. I try to find any quality control thing that you've alluded here:

http://www.c-ad.bnl.gov/kinyip/download/Volume%205.1%20Design%20and%20Quality%20Control%20Report%20GENERAL%20MAIN%20COMPONENTS.pdf

{ and a bit more here: http://www.c-ad.bnl.gov/kinyip/download/PCSS/, though many in the latter link are just things extracted from the above),

I couldn't find anything close to what you find.

(3) Apart from the Al-Rutherford joint, people also seem to give that Al stabilizer (the very pure Al ??) a strength limit of 20 MPa ????  Is it
also a design criterion for the Al-stabilizer at 20 MPa  (if it's really 20 MPa at all) ??

Kin

On 07/07/2015 03:16 PM, fabbric wrote:

Kin,
the 20 MPa of the table are related to the minimum requested
shear strength between Rutherford cable and pure aluminum stabilizer.

The co-estrusion process, which embeds the cable into pure aluminum,
shall be done in a way to guarantee a good mechanical bonding between
cable and pure Al. This bonding is quantified in specification to be > 20 MPa
(this number comes from mechanical analysis and thermal stability computations).
Depending on design we could ask more (e.g. 30 MPa). For CMS we ashed more than
40 MPa.

As soon as the co-estrusion is started, a sample is cut down and the shear strength
is measured by pulling the cable with respect the pure Al. I am attacching a typical
measurement done on one sample of Babar conductor. You can see that the failure
of the shear strength happens at about 45 MPa, which is a very good number.


May be you have the quality controls done on all samples taken from co-estruded
cables and can find these figures.

Best regards

Pasquale



Il 07/07/2015 18:27, Kin Yip ha scritto:

Hi,

Sorry to bug you again ....

In the BaBar paper published (after the Magnet after been operated), they mentioned the Aluminium (people often call stabilizer, I guess)
with the remark "> 20 MPa" (in p. 6, Table 2 of the attached document, for example).

Is this 20 MPa based on yield or some conservative assumption or what is it actually ?  Some colleagues mention 30 MPa (which I don't know
where they come from ...).

Any comments ?

Kin

-- 

Dr. Pasquale Fabbricatore

INFN Sezione di Genova

via Dodecaneso 33, 16146 Genova Italy

Direct tel  + 39 010 3536340

Laboratory  + 39 010 3536437

Secret.fax  + 39 010 313358

E-mail   pasquale.fabbricatore AT ge.infn.it

WEB page  http://www.ge.infn.it/~fabbric/

 

-- 

Dr. Pasquale Fabbricatore

INFN Sezione di Genova

via Dodecaneso 33, 16146 Genova Italy

Direct tel  + 39 010 3536340

Laboratory  + 39 010 3536437

Secret.fax  + 39 010 313358

E-mail   pasquale.fabbricatore AT ge.infn.it

WEB page  http://www.ge.infn.it/~fabbric/

-- 
Dr. Pasquale Fabbricatore
INFN Sezione di Genova
via Dodecaneso 33, 16146 Genova Italy
Direct tel  + 39 010 3536340
Laboratory  + 39 010 3536437
Secret.fax  + 39 010 313358
E-mail   pasquale.fabbricatore AT ge.infn.it
WEB page  http://www.ge.infn.it/~fabbric/