A Nb + 75% Zr superconducting magnet for 85 kg

✍ Scribed by I.N. Goncharov

• Publisher: Elsevier Science
• Year: 1968
• Tongue: English
• Weight: 321 KB
• Volume: 8
• Category: Article
• ISSN: 0011-2275
• DOI: 10.1016/0011-2275(68)90093-3

✦ Synopsis

THE GREAT majority of superconducting solenoids are made of the alloy Nb + Zr containing less than 50~Zr. 1-3 This is because, for these alloys in the cold worked state, the critical current density (je) in fields of 30 to 40 kG is (5-8) x 104 A/cm2. 4,5 Alloys which are mainly Zr have much lower Je in the cold worked state and higher upper critical field than alloys which are mainly Nb. 6,7 Heat treatment would lead to such great current instabilities that it would appear that they could not be used in ordinary solenoids. 8 However, special heat treatment can increase je tens of times and instabilities are practically non-existent. 9,1° It turned out that for these alloys a low temperature treatment (400-500°C) was best, and the precipitation, stabilizing je, 11,12 is very finely divided.

The solenoid consists of two concentric sections wound on separate formers (see Figure 1); section B can easily be taken out of the solenoid. Section CHARACTERISTICS OF Nb+75% Zr SOLENOID Connection and Critical Section supply T, °K current H, kG