Donald “Bruce” Montgomery SM ’57, a remarkably influential engineer and longtime MIT researcher whose job was focused on the advancement of large-scale electromagnets, died on July 1. He was 89.
Montgomery’s contributions have been pivotal for numerous major amenities in fusion strength, in the structure of magnets for particle accelerators for physics and professional medical applications, for magnetically levitated transportation, and in a lot of other disciplines. He was a acknowledged global chief in magnet design and style and fusion engineering, a member of the National Academy of Engineering, and receiver of many awards which includes the Dawson Award for Excellence in Plasma Physics Investigation (1983) and the Fusion Electric power Associates Distinguished Vocation Award (1998).
Montgomery graduated with a BA from Williams College and an MS from MIT in the Department of Electrical Engineering in 1957. In 1967 he received an ScD from the University of Lausanne.
Next his graduation from MIT he joined the employees of MIT Lincoln Laboratory, and soon just after commenced work on large-industry magnets underneath Francis Bitter, renowned magnet designer and founder of the Countrywide Magnet Laboratory at MIT. Montgomery rose to come to be the affiliate director of what was later renamed the Francis Bitter Countrywide Magnet Laboratory. Throughout this period he authored the guide “Solenoid Magnet Layout: The Magnetic and Mechanical Factors of Resistive and Superconducting Magnets,” which continues to be a regular reference.
A turn towards fusion
Montgomery’s abilities was upcoming harnessed to a increasing program in fusion energy. Subsequent the measurement of plasma temperatures exceeding 10 million levels in the Soviet T3 tokamak, a race was on to develop at any time extra capable magnetic confinement experiments. Functioning with Bruno Coppi of MIT’s physics department and Ron Parker from electrical engineering, Montgomery led a team that created and manufactured two tokamak devices able of running with magnetic fields up to and exceeding 12 Tesla, still today an unprecedentedly significant magnetic field for fusion exploration. The initial gadget, recognised as Alcator A, established a planet document for the critical plasma confinement metric. The stick to-on gadget, Alcator C, extended this document in the 1980s and gave self-confidence that plasma disorders enough for a fusion energy plant could certainly be realized.
The file-placing overall performance by equally devices was produced probable by the use of breakthrough magnet engineering formulated with Montgomery’s insight and management. A single can draw a straight line between these early breakthroughs in magnet know-how and the resultant scientific progress that they enabled to the further more evolution of magnet technologies currently being applied in SPARC, a demonstration fusion system led by MIT and startup business Commonwealth Fusion Techniques that is built to develop much more vitality than it consumes.
Montgomery also had a very well-identified skill to deal with quite significant tasks and to guide varied teams of researchers, engineers, technicians, and college students. As a consequence he was appointed main engineer on quite a few countrywide fusion system design projects and experienced a management function in the early times of the intercontinental fusion task identified as ITER. In the 1990’s he led just one of the a few nationwide consortia groups vying to build maglev technology beneath the U.S. Office of Transportation Maglev Initiative.
Generating a innovative cable
When at the Countrywide Magnet Lab, Montgomery, Henry Kolm, and Mitch Hoenig invented the concept for the cable-in-conduit-conductor (CICC). In all those early days of massive-scale superconducting magnet exploration, significant-bore, high-field superconducting magnets ended up constructed in a kind of brute-power system. These older types have been unstable and unsuitable to the have to have for at any time bigger magnetic fields, and much larger dimensions maximize the functionality of magnetic confinement fusion machines. This technological know-how was impeding improvement, primarily for the tokamak’s poloidal discipline magnets which ended up demanded to produce swiftly shifting fields.
Montgomery, Kolm, and Hoenig solved these complications by combining numerous superconducting wires into a cable, employing conventional industrial machines, and then putting the cable within a metal or other higher energy steel alloy tube (conduit). The magnet was cooled down and managed at 4K by flowing supercritical helium in just the conduit. Due to the fact each individual conductor could be insulated against superior voltages, large-bore, significant-area, significant-saved magnetic electricity magnets could be securely secured from quench. The potent metal alloy conduit provided significant mechanical toughness dispersed most optimally throughout the winding cross-part. And the flowing helium offered superb warmth transfer from all the superconducting wires in the cable, resulting in pretty higher electrothermal security, in particular for rapid ramped magnets.
Even though the CICC principle was considered heretical within the worldwide applied superconductivity group and dismissed as impractical, below Montgomery’s leadership the MIT group promptly created and proved the idea. Now, every single doing work fusion product in the environment that takes advantage of superconducting magnets employs this conductor, together with tokamaks (e.g., EAST, KSTAR, JT60-SA), helical devices (LHD), and stellarators (Wendelstein 7-X). It is the baseline conductor layout for ITER and has located application in particle accelerators and magnetic levitation.
Discovering magnetic levitation and propulsion
In the 1970’s, Montgomery and Kolm from the Francis Bitter Magnet Laboratory collaborated with Richard Thornton from the MIT Division of Electrical Engineering in formulating the “magplane” strategy of magnetic levitation and propulsion. An early demonstration of a design scale system was designed and tested on MIT’s athletic fields. Montgomery and Henry Kolm later on established Magplane Technology, Inc. (MTI) a small company focused on producing sophisticated applications of magnetic levitation and propulsion. A doing the job version of this technological know-how was designed in China, where it was made use of to supply coal from coal mines, avoiding the excessive coal dust and squander resulting from open trucking vehicles. In the 1980’s, Montgomery labored with Peter Marston and Mitch Hoenig, foremost an MIT crew acquiring really significant-scale superconducting magnets for magnetohydrodynamic electric electricity technology.
Engineers and experts know that failure can be the very best teacher. Montgomery took that lesson to coronary heart, diagnosing failure mechanisms in substantial magnet units and authoring various meta-studies which analyzed and tabulated the underlying brings about. This get the job done allowed engineers to concentration on the most significant features of their layouts and contributed to the rising reliability of investigation magnets. Following his retirement from MIT in 1996, Montgomery was the founder and president of MTECHNOLOGY Inc., an engineering consultancy which specializes in threat and reliability.
An engineer’s engineer
Joe Minervini, 1 of Montgomery’s proteges, notes: “Bruce was regarded by me and most persons who realized him to be an ‘engineer’s engineer.’ Whilst he always possessed a deep scientific knowing of the technology issue he was attacking, he often seemed to formulate a amazing but realistic engineering remedy. Above his extended occupation at MIT, he shown this time and all over again on a lot of of the most innovative and challenging new technologies created close to regular and superconducting magnets.”
Outside of the breadth of his technical contributions and committed mentorship, Bruce Montgomery will be remembered for his heat individuality and his quiet, regular demeanor, which was of inestimable benefit when things obtained difficult — a typical occurrence when pushing the envelope in investigate. He had a exceptional ability to take management of contentious technical and administration conversations and to gently pull or drive everybody to an successful consensus and into motion. He will be sorely missed by his close friends, relatives and colleagues.
Montgomery is predeceased by his spouse of 52 years, Nancy Ford Fenn, who passed away in 2006, and by Elizabeth Bartlett Sturges, with whom he spent numerous delighted several years until eventually her passing in 2021. He is survived by his son Timothy Montgomery and his wife Susan of Scituate, Massachusetts daughter Melissa Sweeny and her husband Tom of Groton, Massachusetts as very well as his grandchildren, Jenna Sweeny, Christopher Sweeny, and Benjamin Sweeny.