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Fusion Science and Technology
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Remembering ANS member Gil Brown
Brown
The nuclear community is mourning the loss of Gilbert Brown, who passed away on July 11 at the age of 77 following a battle with cancer.
Brown, an American Nuclear Society Fellow and an ANS member for nearly 50 years, joined the faculty at Lowell Technological Institute—now the University of Massachusetts–Lowell—in 1973 and remained there for the rest of his career. He eventually became director of the UMass Lowell nuclear engineering program. After his retirement, he remained an emeritus professor at the university.
Sukesh Aghara, chair of the Nuclear Engineering Department Heads Organization, noted in an email to NEDHO members and others that “Gil was a relentless advocate for nuclear energy and a deeply respected member of our professional community. He was also a kind and generous friend—and one of the reasons I ended up at UMass Lowell. He served the university with great dedication. . . . Within NEDHO, Gil was a steady presence and served for many years as our treasurer. His contributions to nuclear engineering education and to this community will be dearly missed.”
J. E. Rice, E. S. Marmar, P. T. Bonoli, R. S. Granetz, M. J. Greenwald, A. E. Hubbard, J. W. Hughes, I. H. Hutchinson, J. H. Irby, B. LaBombard, W. D. Lee, Y. Lin, D. Mossessian, J. A. Snipes, S. M. Wolfe, S. J. Wukitch
Fusion Science and Technology | Volume 51 | Number 3 | April 2007 | Pages 288-302
Technical Paper | Alcator C-Mod Tokamak | doi.org/10.13182/FST07-A1423
Articles are hosted by Taylor and Francis Online.
Spontaneous toroidal rotation of impurity ions has been observed in the core of Alcator C-Mod plasmas with no external momentum input. The magnitude of the rotation ranges from -60 km/s (countercurrent) in limiter L-mode discharges to +140 km/s (cocurrent) in ion cyclotron range of frequencies-heated H-mode plasmas. The core rotation in L-mode plasmas is generally countercurrent and is found to depend strongly on the magnetic topology; in near double null discharges, the core rotation changes by 25 km/s with a variation of a few millimeters in the distance between the primary and secondary separatrices. In H-mode plasmas, the rotation increments in the cocurrent direction with the toroidal rotation velocity increase proportional to the corresponding stored energy increase, normalized to the plasma current. These discharges exhibit a positive Er in the core. Immediately following the transition from L-mode into enhanced D (EDA) H-mode, the cocurrent rotation appears near the plasma edge and propagates to the center on a time scale similar to the energy confinement time but much less than the neoclassical momentum diffusion time, indicating both the role of the plasma boundary in the dynamics of the H-mode transition and the anomalous nature of momentum transport. Rotation velocity profiles are flat in EDA H-mode plasmas and centrally peaked for edge-localized mode-free H-modes, demonstrating the effects of an inward momentum pinch. In EDA H-mode discharges that develop internal transport barriers, the core toroidal rotation inside the barrier foot is observed to drop on a time scale similar to the core pressure profile peaking (hundreds of milliseconds), indicating a negative Er well in the core region.
