Big European Bubble Chamber (BEBC) coil

One of the coils of the superconducting magnet of the 3.7 m European bubble chamber, BEBC, during its assembly in 1970. The coil had twenty pancakes, stacked vertically one above the other, each with 87 turns of superconductor — altogether one of the largest superconducting magnets ever built. Faults on a coil connection necessitated a major dismantling of the bubble chamber which was out of action until early 1971.