Mary Ann Sweeney (born 1945) [1] is an American physicist at Sandia National Laboratories. Although her doctoral research concerned astronomy, her work at Sandia has largely concerned inertial confinement fusion and pulsed power. [2]
Sweeney is originally from Mercersburg, Pennsylvania; her parents moved to Baltimore when she was a teenager to improve their children's educational prospects. She majored in physics at Mount Holyoke College, [2] graduating in 1967 [3] with a bachelor's thesis concerning white dwarf stars. She went to Columbia University for doctoral study but, unable to find a faculty member at Columbia who would take a female student for the topics that interested her, finished her doctorate at Columbia with an outside advisor from Princeton University. [2]
She married a fellow Columbia astronomy student and followed him to Albuquerque, where he had been assigned for his service in the United States Air Force. Seeking a science job nearby, Sweeney applied to work at Sandia National Laboratories, in "anything but secretarial work", and started her career in pulsed power physics there in 1974. [2]
Sweeney chaired the IEEE Plasma Science and Applications Committee from 1989 to 1990, [4] as its first female chair. [2] She also chaired the Committee on Women in Plasma Physics of the American Physical Society from 2010 to 2012. [5]
In 1992, Sweeney was named a Fellow of the IEEE "for contributions to the understanding of plasma opening switches and beam interactions with matter in particle beam accelerators". [6] In 2007, Mount Holyoke College gave her their Alumnae Achievement Award. [3]
Sweeney won the 2013 National Nuclear Security Administration (NNSA) Defense Programs Award of Excellence for her work as editor-in-chief of the NNSA Stockpile Stewardship and Management Plan. [7] She is one of four coauthors of the book Impactful Times: Memories of 60 Years of Shock Wave Research at Sandia National Laboratories (2017). [8] [9]
The National Ignition Facility (NIF) is a laser-based inertial confinement fusion (ICF) research device, located at Lawrence Livermore National Laboratory in Livermore, California, United States. NIF's mission is to achieve fusion ignition with high energy gain. It achieved the first instance of scientific breakeven controlled fusion in an experiment on December 5, 2022, with an energy gain factor of 1.5. It supports nuclear weapon maintenance and design by studying the behavior of matter under the conditions found within nuclear explosions.
In fusion power research, the Z-pinch is a type of plasma confinement system that uses an electric current in the plasma to generate a magnetic field that compresses it. These systems were originally referred to simply as pinch or Bennett pinch, but the introduction of the θ-pinch concept led to the need for clearer, more precise terminology.
The Z Pulsed Power Facility, informally known as the Z machine or Z, is the largest high frequency electromagnetic wave generator in the world and is designed to test materials in conditions of extreme temperature and pressure. It was originally called the PBFA-II and was created in 1985. Since its refurbishment in October 1996 it has been used primarily as an inertial confinement fusion (ICF) research facility. Operated by Sandia National Laboratories in Albuquerque, New Mexico, it gathers data to aid in computer modeling of nuclear weapons and eventual fusion pulsed power plants.
Plasma acceleration is a technique for accelerating charged particles, such as electrons or ions, using the electric field associated with electron plasma wave or other high-gradient plasma structures. These plasma acceleration structures are created using either ultra-short laser pulses or energetic particle beams that are matched to the plasma parameters. The technique offers a way to build affordable and compact particle accelerators.
A dense plasma focus (DPF) is a type of plasma generating system originally developed as a fusion power device starting in the early 1960s. The system demonstrated scaling laws that suggested it would not be useful in the commercial power role, and since the 1980s it has been used primarily as a fusion teaching system, and as a source of neutrons and X-rays.
A pinch is the compression of an electrically conducting filament by magnetic forces, or a device that does such. The conductor is usually a plasma, but could also be a solid or liquid metal. Pinches were the first type of device used for experiments in controlled nuclear fusion power.
The Trident Laser was a high power, sub-petawatt class, solid-state laser facility located at Los Alamos National Laboratory, in Los Alamos, New Mexico, originally built in the late 1980s for Inertial confinement fusion (ICF) research by KMS Fusion, founded by Kip Siegel, in Ann Arbor, Michigan, it was later moved to Los Alamos in the early 1990s to be used in ICF and materials research. The Trident Laser has been decommissioned, with final experiments in 2017, and is now in storage at the University of Texas at Austin.
Magnetized liner inertial fusion (MagLIF) is an emerging method of producing controlled nuclear fusion. It is part of the broad category of inertial fusion energy (IFE) systems, which drives the inward movement of fusion fuel, thereby compressing it to reach densities and temperatures where fusion reactions occur. Other IFE experiments use laser drivers to reach these conditions, whereas MagLIF uses a combination of lasers for heating and Z-pinch for compression. A variety of theoretical considerations suggest such a system will reach the required conditions for fusion with a machine of significantly less complexity than the pure-laser approach.
Direct energy conversion (DEC) or simply direct conversion converts a charged particle's kinetic energy into a voltage. It is a scheme for power extraction from nuclear fusion.
Chandrashekhar Janardan Joshi is an Indian–American experimental plasma physicist. He is known for his pioneering work in plasma-based particle acceleration techniques for which he won the 2006 James Clerk Maxwell Prize for Plasma Physics and the 2023 Hannes Alfvén Prize.
Leopoldo Soto Norambuena is a Chilean physicist. He works at the Comisión Chilena de Energía Nuclear where he founded the Plasma Physics and Nuclear Fusion Laboratory. His main contributions are in experimental physics.
Richard J. Temkin is a plasma physicist and researcher on plasma-heating gyrotrons and other electromagnetic devices involving high-powered microwaves or terahertz radiation.
Dmitri Dmitriyevich Ryutov is a Russian theoretical plasma physicist.
Jürgen Meyer-ter-Vehn is a German theoretical physicist who specializes in laser-plasma interactions at the Max Planck Institute for Quantum Optics. He published under the name Meyer until 1973.
Toshiki Tajima is a Japanese theoretical plasma physicist known for pioneering the laser wakefield acceleration technique with John M. Dawson in 1979. The technique is used to accelerate particles in a plasma and was experimentally realized in 1994, for which Tajima received several awards such as the Nishina Memorial Prize (2006), the Enrico Fermi Prize (2015), the Robert R. Wilson Prize (2019), the Hannes Alfvén Prize (2019) and the Charles Hard Townes Award (2020).
Victor Malka is a French plasma physicist and a pioneer in laser plasma acceleration. In 2004, Malka demonstrated that high energy monoenergetic electron beams could be generated using the technique of laser wakefield acceleration, and subsequently used them to develop compact X-ray and gamma radiation sources with applications in medicine, security technology and phase-contrast imaging. For these contributions to the field, he was awarded the IEEE Particle Accelerator Science and Technology Award in 2007, the Julius Springer Prize for Applied Physics in 2017, and the Hannes Alfvén Prize in 2019.
Thomas W. L. "Tom" Sanford is an American plasma physicist who developed a multi-wire array for use in a pulsed Z-pinch plasma system which resulted in a breakthrough for inertial confinement fusion (ICF) research. In 2005, he was awarded the Hannes Alfvén Prize with Malcolm Haines and Valentin Smirnov for his contributions to the field.
Richard Van Evera Lovelace is an American astrophysicist and plasma physicist. He is best known for the discovery of the period of the pulsar in the Crab Nebula, which helped to prove that pulsars are rotating neutron stars, for developing a magnetic model of astrophysical jets from galaxies, and for developing a model of Rossby waves in accretion disks. He organized a US-Russia collaboration in plasma astrophysics, which focused on modeling of plasma accretion and outflows from magnetized rotating stars.
David A. Hammer is the J. Carlton Ward, Jr. Professor of Nuclear Energy Engineering, in the Cornell University College of Engineering. In 2004, Hammer received the Institute of Electrical and Electronics Engineers Plasma Science and Applications Committee Award, as well as the Distinguished Career Award from Fusion Power Associates in 2018.