Recent Progress with APC Nb3Sn Conductors [Slides]
1.Development of APC-PIT multi wires started in 2017. Since then progress has been fast; 2.Tests up to 31 T at 4.2 K show that Birr is 26-27 T, Bc2 is 27-28 T, ~1-2 T higher than RRP; 3. R&D in the past two years has led to significant improvement of wire recipe and quality. The non-Cu Jc is on similar level with present RRP wires, in spite that the Nb3Sn % is still low and grain size is not fully refined due to unoptimized wire recipe and heat treatment; 4.The Nb3Sn layer Jc at 16 T is ~2.5 times of RRP despite grain size not fully refined; 5.The improvement is still ongoing. The following levels are expected: 1) By improving conductor recipe and quality and heat treatment, the fine-grain Nb3Sn fraction can be increased to ~40%, as in standard tube type and PIT wires; 2) By optimizing O content and heat treatment, the grain size can be reduced to 50-65 nm or less, which leads to a Nb3Sn layer Jc of 5000-6000 A/mm2 for 4.2 K, 16 T. If so, this means the 4.2 K, 16 T non-Cu Jc can reach 2000-2400 A/mm2. This will surpass the FCC spec and also provide >30% margin. Above 16 T, the APC conductors should give extra Jc gain due to higher Birr and shift in Fp-B curve peak to higher fields.
- Research Organization:
- Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), High Energy Physics (HEP)
- DOE Contract Number:
- AC02-07CH11359
- OSTI ID:
- 1508015
- Report Number(s):
- FERMILAB-SLIDES-18-129-TD; oai:inspirehep.net:1730278
- Resource Relation:
- Conference: 2. Workshop on Current Challenges in Cosmology, Bogota (Colombia), 29 Oct - 02 Nov 2018
- Country of Publication:
- United States
- Language:
- English
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