Details

Autor(en) / Beteiligte

• den Ouden, A
• van Weeren, H
• Wessel, WAJ
• ten Kate, HHJ
• Kirby, G A
• Siegel, N
• Taylor, T

Titel

Normal zone propagation in high-current density Nb sub(3)Sn conductors for accelerator magnets

Ist Teil von

• IEEE transactions on applied superconductivity, 2004-01, Vol.14 (2)

Erscheinungsjahr

2004

Quelle

IEEE Xplore

Beschreibungen/Notizen

• Self-absorbing quench protection schemes for accelerator magnets mainly rely on longitudinal and turn-to-turn normal zone propagation (NZP) immediately after the occurrence of a quench and subsequently on the effectiveness of protection heaters. Especially for impregnated Nb sub(3)Sn coils the protection should not only aim at limitation of the hot spot temperature and internal voltages but also at avoidance of large temperature gradients and local stress accumulation. Considering Rutherford types of cable based on present high current density Nb sub(3)Sn wires with a relatively low stabilizer content, a priori knowledge about their NZP properties is mandatory. Especially the medium and low-field properties appear to be critical for coil protection. The longitudinal NZP velocity of PIT-type Nb sub(3)Sn conductors are investigated both experimentally and numerically in nearly adiabatic conditions typical for impregnated coils. Numerical simulations are extended to extremely high current density Nb sub(3)Sn conductors and protection heater performance.