Assembly of Multi-Sample Probe to Measure Critical Current (I c ) of - - PowerPoint PPT Presentation

Name: Andre Merille Affiliation: SIST(Grambling State Univ.) Division: Technical Division Supervisor [IB3A]: Dr.Tengming Shen

Assembly of Multi-Sample Probe to Measure Critical Current (Ic) of Superconducting Material

August 5th 2013 9:40 am

Overview:

 Why Build?  Materials used  Probe Assembly  Heat Transfer Analysis  Data Acquisition  Results  Conclusion  Acknowledgements  Questions?

Why Build?

 Can hold 8 Superconducting strands at a time.

 Opposed to previous models which held 1 or 2.

 Faster Turnover rate of Test Samples.  Saves precious time.  Reduces Cryogen Consumption.  $6.00 per Liter  50-80 Liters per Sample  Four fold decrease in Helium consumption.  Receive better statistics on sample behavior.

Materials used:

Su Suppo pport rings t rings Sam Sample ple-ho

• holde

lder r Insu Insulatio lation plat n plate

• G-10 Fiberglass-Laminate

Co Coppe pper le r leads ads

• G-1

G-10: im 0: impe pervio vious t s to mo moistu isture re, go , good insu d insulat lator and is e r and is easy t asy to car carve/grind. /grind.

• Silv

Silver is the r is the be best e st ele lectrical co ctrical condu nduct ctor o r of all me f all metals. tals.

 Use

Used whe d when high do n high dose ses o s of cu f curre rrent are nt are re require ired d

• Brass is be

Brass is best f st for pre r preventing spar nting sparks. ks.

G-1 G-10 sam sample ple ho holde lder r Silv Silver-plat

• plated brass so

d brass sock cket t co conne nnect ctors s

Materials used:

 Stainle

Stainless st ss steel tu l tube be: protects the instrumentation wire which runs trough probe.

 Stainle

Stainless st ss steel casing l casing: Protects probe.

 Instru

Instrume mentatio ntation wire n wire:

 Copper alloy.  12 pairs of insulated wire through

center of probe.

 Serves as voltage tap (Bo

Bott ttom e m end nd).

Probe Assembly:

 Co

Coppe pper t r to co coppe pper Brazing r Brazing

 Har

Hard and So d and Soft So t Solde ldering ring

 Co

Coppe pper Be r Bending nding

Be Before Af After er

TO TOP

BO BOTT TTOM M

Probe Assembly:

 Lower joining temperature than welding.  Best used in tight situations [less access to surfaces].  Results in non-ferromagnetic joint (best for high-magnetic-field

apparatus).

How?

 Brazing metal Sil-F

Sil-Fos (15): (5%) 5%)phosphorus, (80%) 80%)copper and (15 15%)silver .

 Applied around joint; heated; fills gap by capillary action.  Fitted with very low tolerance [sleeve].

Why Brazing?

Heat Transfer Analysis:

) ( ) ( ) (

2 2

= + − ⎥ ⎦ ⎤ ⎢ ⎣ ⎡ A I T dx dT A T c m dx dT T dx d

p

ρ κ 

• Soldering of superconducting

YBCO.

• To reduce Joule Heating.

[V [Vapo apor-Co

• Coole

led Co d Coppe pper Cu r Curre rrent Le nt Lead] ad]

Temperature Profile: Standing Heat Input (I=0)

• Measurement of

temperature increase along copper leads .

• Determine where

YBCO should be soldered. Graph o Graph of T f Tempe peratu rature re vs. distance

• vs. distance

YBCO strip

Data Acquisition:

• Labview software
• Graphic user

interface

• Enables user to

control instruments, store, interpret and analyze data.

He Hewle wlett P tt Pack ackar ard d 668 6681A DC po 1A DC power r su supply pply Keithle ithley 200 2001 1 digital mu digital multi-me lti-meters s Su Supplie pplies 600 Am s 600 Amps ps Shu Shunt nt

Results: (Room temperature tests)

y = 0.0017x - 4E-05

• 0.002

0.002 0.004 0.006 0.008 0.01 0.012 0.014 0.016 0.018

• 2

2 4 6 8 10

Voltage(V) Current (A)

Voltage vs. Current

Ω

Results: Liquid Nitrogen (77K) tests

Sample# Superconducting Material IC Ω Value 1 YBCO 107 30 2 YBCO 103.3 28 3 YBCO 109.7 30 4 YBCO 107 29 5 YBCO 57* 17 6 YBCO 104 25 7 Bi2212 0.14 3 8 Bi2212 0.7 3

Conclusion:

 Multi-sample probe assembly was a success.  Commissioned room temperature and liquid nitrogen tests.

Future Work:

 4.2K tests in high-magnetic-field.

Other Projects: (ANSYS)

• 2 dime

2 dimensio nsional mo nal mode del l

• f a co

f a coppe pper wire r wire with with Bi22 Bi2212 po 12 powde wder r within the within the f filame ilaments. nts.

• APDL co

APDL code de. .

• ANS

ANSYS. S.

• Fiji so

Fiji softw tware are. .

Study of BSCCO conductor.

• In

Investigatio stigation o n of f 52 521, 522, 523, 52 , 522, 523, 524 4 co condu nduct ctors. s.

• Pho

Photosho shop (me p (merge rge pictu picture res fr s from SEM). m SEM).

• Liq

Liquid, AEC and CF id, AEC and CF phase phases. s.

What did I learn?

 Never grow to attached to the design or project.  Stay critical and strive for perfection.  Yes! even if it means going back to drawing board.  Always think 3 steps ahead.  Be the biggest optimist but remember things do go wrong

sometimes.

 How to be more productive in a lab.

Acknowledgements:

 Fermilab SIST Committee  Ms. Dianne Engram  Dr. Elliott Mccrory  Ms. Linda Diepholz  Mentor:  Dr. David Peterson  Supervisor:  Dr. Tengming Shen  Co-workers:  Pei Li, Yang Wang and Liyang Ye.  Special thanks: Dr. Davenport

Qu Questio stions? ns?