We would like to add a note concerning some of the historical information published in our article “Superconducting Magnets Above 20 Tesla” (Physics Today, August 2002, page 37). During the 1960s, the RCA Laboratories in Harrison, New Jersey, also made significant contributions to the early development of niobium tin conductors and magnets, based on the chemical vapor deposition process. In particular, by 1968, RCA had developed a 14-T magnet using their Nb 3Sn tape conductor. The company discontinued development of superconducting magnet technology in 1970. We thank J. J. Hanak for bringing to our attention the details of RCA’s activities.
Our article was not intended as a rigorous review, and the history was intentionally kept short to highlight the progress in the early days of development. Rather, our aim was to give some perspective for later large-magnet development at extreme magnetic fields, development that includes the use of the new high-temperature superconductors.
