# Presentation: 349379

## Superconductor Developmentin Europe

**Arnaud Devred**
**CEA-DSM-DAPNIA-STCM**
- VLHC Magnet Workshop
- 24-26 May 2000

## Contents

-  **NbTI**
** ****Nb****3****Sn**
** ****ITER**
** ****CEA/Saclay-Alstom**
** ****INFN/Milan-Europa Metalli**
** ****PIT in the Netherlands**
** ****HTS**

## Contents

-  **NbTI**
** ****Nb****3****Sn**
** ****ITER**
** ****CEA/Saclay-Alstom**
** ****INFN/Milan-Europa Metalli**
** ****PIT in the Netherlands**
** ****HTS**

## NbTi Production

** ****NbTi production is mainly driven by LHC: 474 t (2370 km) of inner cable, 736 t (4025 + 575 km) of outer + quad. cable**** **
** ****Requires ~50% increase in wire and cable production over the next five years (yearly production will become ~1/3 LHC, 1/3 IRM and   1/3 other)**** **

## LHC Inner Cable

_**CABLE CHARACTERISTICS**_
**Rutherford-type cable**
**28 strands**
**Thick-edge thickness: 2.064 **_**+**_** 0.006 mm**
**Thin-edge thickness: 1.736 **_**+**_** 0.006 mm**
**Width: 15.1 + 0/-0.02 mm**
**Critical Current (4.2 K, 7 T):  ******** 14140 A**
**Critical Current (1.9 K, 10 T): ******** 13750 A **

_**STRAND CHARACTERISTICS**_
**Diameter: 1.065 **_**+**_** 0.0025 mm**
**1.6 ******** Cu/Sc ******** 1.7**
**Filament diameter : ~7 μm**
**Number of filaments: ~8900**
**Stabrite coating (between 0.4 and 0.6 μm)**

**Courtesy**

## LHC Outer Cable

_**STRAND CHARACTERISTICS**_
**Diameter : 0.8250 **_**+**_** 0.0025 mm**
**1.9 ******** Cu/Sc ******** 2.0**
**Filament diameter: ~6 μm**
**Number of filament: ~6400**
**Stabrite coating (between 0.4 and 0.6 μm)**

_**CABLE CHARACTERISTICS**_
**Rutherford-type cable**
**36 strands**
**Thick-edge thickness: 1.598 **_**+**_** 0.006 mm**
**Thin-edge thickness: 1.362 **_**+**_** 0.006 mm**
**Width: 15.1 + 0/- 0.02 mm**
**Critical Current (4.2 K, 6 T): ******** 13230 A**
**Critical Current (1.9 K, 9 T): ******** 12960 A**

**Courtesy**

## Sharing of LHC Production

## Status of LHC Production

** ****Contracts signed during second semester of 1998 **
** ****Production is gearing up at various manufacturers**
** ****First 45 unit batches of inner wires  (28x460 m) and first 31 unit batches of outer wires (36x750 m) ready to be cabled**
** ****Production to be completed by 2004**

## LHC Production at

**Clean room for billet assembly**

**Drawing bench**

**Cabling machine**

## Tyical Results of LHC Production (after L. Oberli)

** ****Critical current on virgin wires **
** ****Inner: *****J*****c**** (4.2 K, ****7 T****) ******** ****1550-1600 A/mm****2**
** ****Outer: *****J*****c**** (4.2 K, ****6 T****) ******** ****2300 A/mm****2**
** ****Cabling degradation between ****2 ****and**** 3%**

## Main challenges of LHC Production (after G. Grünblatt)

** ****Control of Cu-to-NbTi ratio (±0.03 from billet to billet)  **
** ****Control of crossover resistances (15 to 20 ********for inner cable and 30 to 40 ********for outer cable): stabrite (SnAg) coating + heat treatment on final cable**
** ****No cold welds allowed**

## Wire Short Sample Tests

** ****It is foreseen to perform  ~30 000 wire short sample tests at CERN**

**(Bldg. 163 at CERN; courtesy A. Verweij)**

## Cable Short Sample Tests

** ****It is foreseen to perform  ~3000 cable short sample tests at BNL and ~1000 tests at CERN**

**(9.5-T, 30-kA cable test facility at CERN; courtesy A. Verweij)**

## Contents

-  **NbTI**
** ****Nb****3****Sn**
** ****ITER**
** ****CEA/Saclay-Alstom**
** ****INFN/Milan-Europa Metalli**
** ****PIT in the Netherlands**
** ****HTS**

## ITER Production

-  **The production of Nb****3****Sn wires has been fueled in the 90’s by the ITER program, which required two different wire types:**

## ITER Production (Cont.)

-  **One Western European vendor (****Europa Metalli**** in Italy) was qualified for ****HP1**** production (along with IGC and TWCA in the USA)**
-  **One western European vendor (****Vac**** in Germany) and one Russian vendor (****Bochvar Institute**** in Moscow) were qualified for ****HP2**** production (along with Furukuwa, Hitachi and Mitsubishi in Japan)**
-  **Bochvar did produce some small quantity that was OK, but had to stop because of the financial problems of the Russian Federation**
-  **ITER wire production was completed in 1997 **

## Results of ITER Production

**(Courtesy P.J. Lee)**

## Contents

-  **NbTI**
** ****Nb****3****Sn**
** ****ITER**
** ****CEA/Saclay-Alstom**
** ****INFN/Milan-Europa Metalli**
** ****PIT in the Netherlands**
** ****HTS**

## CEA/Saclay-Alstom Collaboration

** ****CEA/DSM/DAPNIA/STCM has started in 1996 a collaboration with Alstom to develop high performance Nb****3****Sn wire and cable and to build a short quadrupole magnet model**
** ****The wire specification was inspired from ITER/HP1**
** ****The program has been slow moving at CEA/Saclay because of lack of manpower, but Alstom has completed its share of the R&D work and is ready to start the production of the final cable lengths (5x60 m)**

##  Nb3Sn R&D at Alstom

** ****The collaboration has enabled Alstom to produce:**
** ****an “internal-tin” Nb****3****Sn wire with a *****J*****C****(non-Cu) of ****750 A/mm****2**** ****at 4.2 K and 12 T and an effective filament size of ****18 ********m**
** ****a Rutherford-type cable with a ****25-********m-thick**** stainless steel (annealed 316L) ****core**

**(Courtesy R. Otmani)**

##  Nb3Sn R&D at Alstom (Cont.)

- x Alstom

**(Modified from P.J. Lee)**

## New CEA/Saclay-Alstom Collaboration

** ****Discussions are now underway with Alstom on a new collaboration to develop a wire with a *****J*****C****(non-Cu) of ****2000 A/mm****2**** ****at 4.2 K and 12 T and no specification on effective filament diameter (except that the wire should be stable against flux jump) **
** ****Such wire could be used to build a second quadrupole magnet model that would be suitable for the final focusing of TESLA          ****(see my other talk at this workshop)**

## INFN/Milan-Europa Metalli Collaboration

** ****INFN/MILAN (LASA) has worked from 1995 to 1999 with Europa Metalli to develop Nb****3****Sn wires for accelerator magnet applications**
** ****The goal was to achieve a *****J*****C****(non-Cu) of      ****1800 A/mm****2**** ****at 4.2 K and 12 T, to meet the requirements of a conceptual design for a large-aperture (70 mm), high-field-gradient (300 T/m) quadrupole magnet to upgrade the LHC inner triplets ****(see my other talk at this workshop)**** **
** ****The program is presently on hold due to lack of funding**

## Nb3Sn R&D at Europa Metalli

** ****The best *****J*****C**** values were obtained in 1998 for a 0.9 mm, “internal-tin” wire of the so-called “high-field” layout: ****~1975 A/mm****2**** ****at  4.2 K and 12 T (non-Cu)**

**(Courtesy L. Rossi)**

## Nb3Sn R&D at Europa Metalli (Cont.)

** ****However the high-*****J*****C**** wire exhibits signs of instability and the effective filament diameter is ****108 ********m**

**(Courtesy L. Rossi)**

**Close-up view of a bundle (“high-field” layout)**
**Before HT                                     **** ****After HT**** **

## Nb3Sn R&D at Europa Metalli (End)

** ****Stable performances are obtained on lower *****J*****C****-wires of the so-called “3-sector” layout: ****1450 to 1500 A/mm****2**** ****at  4.2 K and 12 T (non-Cu) with ****60 to 70 ********m**** effective filament diameter**
** *****I*****C**** degradation for various types of Rutherford-type cables made from these strands has been measured to be between 10 and 20% (in the 12    to 14 T field range)**
** *****I*****C***** *****vs. tranverse stress**** ****measurements, performed at Twente University on a 1°-keystoned cable, showed less than 7% degradation at 200 MPa **

## Contents

-  **NbTI**
** ****Nb****3****Sn**
** ****ITER**
** ****CEA/Saclay-Alstom**
** ****INFN/Milan-Europa Metalli**
** ****PIT in the Netherlands**
** ****HTS**

## Contents

-  **NbTI**
** ****Nb****3****Sn**
** ****ITER**
** ****CEA/Saclay-Alstom**
** ****INFN/Milan-Europa Metalli**
** ****PIT in the Netherlands**
** ****HTS**

## Nb3Sn Developement at ECN

** ****In the 1980’s, ECN (Netherlands Energy Research Foundation) has developed a quite successful “Powder In Tube” (PIT) process for Nb****3****Sn wires**
** ****The production was stopped in 1992 after internal restructuring at ECN and reorientation on core activities**

## ECN Process

** ****The ECN process is in two-steps:**
** ****production of mono-filaments by compaction of Nb****2****Sn and Sn powders inside a Cu liner fitted within Nb and Cu tubes **
** ****stacking of hexagonally drawn-down mono-filaments inside a Cu can**
** ****It only requires short heat treatment (<48 hours)**

**(Courtesy A. den Ouden)**

## Best Results of ECN Process

** ****The best results were obtained in 1987 with a *****J*****C****(non-Cu) of ****1600 A/mm****2**** ****at  4.2 K and 11 T (physical filament diameter of 20 ********m)**** **
** ****ECN-processed wires were used in the dipole magnet model built at Twente University and tested at CERN in 1995, which reached 11.03 T on its first quench at 4.4 K**

**(Courtesy H.H.J. ten Kate)**

## Nb3Sn R&D at Twente University

** ****Twente University has signed in 1998 a 3-year contract with CERN and NIKEF to build a 88-mm-aperture dipole magnet model, with a 10 T operating field (at 4.4 K), that could be used as a second-generation, beam-separation magnet in the LHC interaction regions.  Test is scheduled at CERN in June 2001.**

**(Courtesy A. den Ouden)**

## Resumption of PIT production   at ShapeMetal Innovation

** ****With Twente University support, ShapeMetal Innovation (SMI) has acquired ECN tooling and know-how and has resumed PIT production in the late 1990’s**
** ****SMI has recently achieved a record *****J*****C****(non-Cu) of ****2300 A/mm****2**** at 4.2 K et 12 T with an effective filament diameter of ****50 ********m**** (50 kg billet)**

**(Courtesy A. den Ouden)**

## Contents

-  **NbTI**
** ****Nb****3****Sn**
** ****ITER**
** ****CEA/Saclay-Alstom**
** ****INFN/Milan-Europa Metalli**
** ****PIT in the Netherlands**
** ****HTS**

## HTS Production in Europe

-  **Bi-2212 Tape**
** ****Alcatel (France)**
** ****Bi-2223 Tape**
** ****Nordic Superconductor Technologies (NST, Denmark)**
** ****Vacuumschmelze (Germany)**

## Alcatel Production

-  **Alcatel has set up a production facility at Jeumont (France) for Bi-2212 PIT tape**

** ****Engineering *****J*****C**** presently achieved are:**
** ****775 A/mm****2**** (at 4.2 K, self-field) on short lengths **
** ****450 to 500 A/mm****2**** (at 4.2 K, self-field) on kilometric lengths**

**(Courtesy P.F. Herrmann)**