Simon Foner, an experimental physicist in magnetism and superconductivity and their applications, died on 2 October 2007 in Cambridge, Massachusetts. He was active in his laboratory and involved in journal editorial activities until very near the end of his life.

Born on 13 August 1925 in Pittsburgh, Pennsylvania, Si remained in the area for his higher education at what is now Carnegie Mellon University; he received his BS in 1947, MS in 1948, and doctorate in 1952 under the direction of Emerson Pugh. From 1944 to 1946, Si served in the US Navy, troubleshooting sonar equipment aboard vessels in the Pacific theater. He took a position in 1953 as a staff physicist at the MIT Lincoln Laboratory, where he served until 1961. It was at the Lincoln Lab that he developed the idea for and eventually patented the vibrating sample magnetometer. His name will forever be associated with that versatile and widely used method for magnetism measurements.

In 1961 Si became one of the founding staff members of the MIT high-field laboratory, principally founded by Ben Lax the year before; the lab was named the Francis Bitter National Magnet Laboratory in 1967. Si was a project leader for the FBNML until 1977, when he became its chief scientist; he served for two years (1988–89) as associate director of the lab. After 1982 Si also was affiliated with the MIT physics department as a research scientist. He retired from MIT in 1995.

While at the FBNML, Si assumed several positions of influence and authority in the greater condensed-matter physics community. He was chair of the condensed-matter physics division of the American Physical Society (APS) from 1978 to 1981 and was the division’s councillor from 1982 to 1986. He served as an advisory editor from 1975 to 1989 for the Journal of Magnetism and Magnetic Materials . As a consulting editor of the Review of Scientific Instruments from 1979 until a few years before his death, Si was responsible for expanding the scope and increasing the number of the journal’s review articles.

A prolific experimentalist, Si published more than 400 refereed papers. He edited four books on the topics of superconductivity and magnetism and their applications. He worked tirelessly on committees, boards, panels, advisory groups, and workshops and was active in many conferences on those subjects. He hosted at least four well-attended Advanced Study Institutes in Europe for the North Atlantic Treaty Organization between 1970 and 1980. In the 1980s Si took an interest in developing high-quality superconducting wire for high-field applications and was responsible for the measurement and understanding of many materials in superconductivity and magnetism. He was chair of the International Cryogenic Materials Conference from 1983 to 1985.

Si and his colleagues at the FBNML were pioneers in pulsed high-field magnet technology; his advances underpin much of the current technology in that area. In the mid-1980s Si used a high-strength, metal-matrix copper-niobium microcomposite conductor to wind magnets that generated millisecond-length fields in the 60–70 T range; those magnets were regularly and successfully operated at the FBNML. Even after the lab’s DC high-field facility stopped running in 1995, Si continued to use the magnets for experiments with collaborators such as Yaacov Shapira and one of us (Guertin).

His invention of the vibrating sample magnetometer won Si APS’s Joseph F. Keithley Award in 1999. He was chosen as a distinguished lecturer for the IEEE Magnetics Society in 1995–97 and was a recipient of the IEEE Millennium Medal in 2000.

A familiar figure at the APS March meetings, Si will be remembered for buttonholing participants at all hours of the day and night, challenging their contentions (and pretensions), and keeping them honest, yet doing it all without rancor.

Si was a tireless tinkerer with experimental apparatus, a restless gadfly, and an uncontrollable and incorrigible punster who will be greatly missed by his many friends in the physics and engineering communities. Si’s professional life was dedicated to honest scientific advancement, and he gave every indication that he thoroughly enjoyed the ride.