Experimental investigation on wax-filled superconducting solenoids

The test results of about fifty wax-filled superconducting solenoids are summarized. These experiments have proved that high current density wax-filled solenoids can reach or approach short-sample performance. After many room temperature-liquid nitrogen temperature thermal cycles the performance of magnet is stable. Different technology of wax filling has been investigated. The largest tested magnet has a bore of 400mm, energy about 0.4 MJ. Its maximal field is about 5.2 T, current density of NbTi superconductor is 9 × 10⁴a/cm²and overall current density is about 2.2 × 10⁴a/cm².