Andrea "Annie" Kritcher is an American nuclear engineer and physicist who works at the

Lawrence Livermore National Laboratory Lawrence Livermore National Laboratory (LLNL) is a federal research facility in Livermore, California, United States. The lab was originally established as the University of California Radiation Laboratory, Livermore Branch in 1952 in response ...

. She was responsible for the development of Hybrid-E, a capsule that enables

inertial confinement fusion Inertial confinement fusion (ICF) is a fusion energy process that initiates nuclear fusion reactions by compressing and heating targets filled with thermonuclear fuel. In modern machines, the targets are small spherical pellets about the size of ...

. She was elected Fellow of the

American Physical Society The American Physical Society (APS) is a not-for-profit membership organization of professionals in physics and related disciplines, comprising nearly fifty divisions, sections, and other units. Its mission is the advancement and diffusion of k ...

in 2022.

Early life and education

Kritcher is a native of

Traverse City, Michigan Traverse City ( ) is a city in the U.S. state of Michigan. It is the county seat of Grand Traverse County, although a small portion extends into Leelanau County. It is the largest city in the 21-county Northern Michigan region. The population was ...

, and attended both

Traverse City Central High School Traverse City Central High School (also known as Central High School or TCC) is a public high school in Traverse City, Michigan. It is one of two comprehensive high schools in the Traverse City Area Public Schools district. History The first pu ...

and

Northwestern Michigan College Northwestern Michigan College (NMC) is a public community college in Traverse City, Michigan. Founded in 1951, it enrolls nearly 4,000 students. NMC offers associate degrees and professional certificates, bachelor's degrees through the Great La ...

before studying nuclear engineering at the

University of Michigan , mottoeng = "Arts, Knowledge, Truth" , former_names = Catholepistemiad, or University of Michigania (1817–1821) , budget = $10.3 billion (2021) , endowment = $17 billion (2021)As o ...

. She moved to the

University of California, Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California) is a public land-grant research university in Berkeley, California. Established in 1868 as the University of California, it is the state's first land-grant u ...

for graduate studies, where she earned a master's degree and doctorate in nuclear engineering. She spent summer 2004 at the

on an internship. Her first project involved analyzing data for the

electron beam ion trap Electron beam ion trap (EBIT) is an electromagnetic bottle that produces and confines highly charged ions. An EBIT uses an electron beam focused with a powerful magnetic field to ionize atoms to high charge states by successive electron impact. ...

. Her doctoral research considered

Thomson scattering Thomson scattering is the elastic scattering of electromagnetic radiation by a free charged particle, as described by classical electromagnetism. It is the low-energy limit of Compton scattering: the particle's kinetic energy and photon frequency ...

from shocked compressed matter. She became a postdoctoral researcher at the Lawrence Livermore National Laboratory in 2009. Her postdoctoral research explored using X-rays to measure the properties of warm and hot dense matter (plasma), and measuring how nuclei interact with dense plasma. She made use of the LLNL Jupiter laser and the

OMEGA laser The Laboratory for Laser Energetics (LLE) is a scientific research facility which is part of the University of Rochester's south campus, located in Brighton, New York. The lab was established in 1970 and its operations since then have been fund ...

at the

University of Rochester The University of Rochester (U of R, UR, or U of Rochester) is a private research university in Rochester, New York. The university grants undergraduate and graduate degrees, including doctoral and professional degrees. The University of Roc ...

Research and career

Kritcher was made a permanent member of staff in the Weapons and Complex Integration's Design Physics Division of the Lawrence Livermore National Laboratory in 2009. Kritcher works in nuclear engineering, with a particular focus on

, which looks to emulate the nuclear processes that take place in the sun by compressing and heating capsules full of thermonuclear fuel. High energy beams (photons or electrons) bombard the outer layer of the capsule, which explodes outward and generates a reaction force that accelerates the remainder of the capsule toward the center. The explosion creates a shockwave that travels through the fuel target, resulting in sufficient heat and compression for the fusion to begin. These capsules contain heavy isotopes of hydrogen (typically deuterium and tritium). Kritcher designed Hybrid-E, a target capsule that includes a high density carbon capsule and a deuterium-tritium fill tube. The capsule is encased in a

hohlraum In radiation thermodynamics, a hohlraum (a non-specific German word for a "hollow space" or "cavity") is a cavity whose walls are in radiative equilibrium with the radiant energy within the cavity. This idealized cavity can be approximated in pra ...

that converts the incident laser light into x-rays. Kritcher said that it was challenging to design the hohlraum such that it generated a symmetric implosion of the capsule. This involved confining the size of the entrance holes to enhance the energy that is coupled into the system, and a structure that can systematically adjust the wavelength of each beam to balance the X-ray energy required to drive the capsule to implode. The Hybrid-E capsule enabled inertial confinement fusion able to produce more than a megajoule of fusion energy. Hybrid-E represents the first time that it was possible to generate a burning plasma state that emits more energy than the energy required to initiate the fusion. In 2022, Kritcher was elected Fellow of the

. Her citation read, “for leadership in integrated hohlraum design physics leading to the creation of the first laboratory burning and igniting fusion plasma.” Kritcher went on to study the behavior of ions in inertial confinement fusion, showing that the energy of neutrons produced from a deuterium–tritium plasma recorded experimentally was higher than could be predicted from the hydrodynamics-informed algorithms that simulate inertial confinement implosions. Kritcher was the designer of the December 5, 2022 experiment that achieved fusion

breakeven Break-even (or break even), often abbreviated as B/E in finance, (sometimes called point of equilibrium) is the point of balance making neither a profit nor a loss. Any number below the break-even point constitutes a loss while any number above i ...

at the

National Ignition Facility 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 wit ...

Awards and honors

* 2021 Finalist for Physics Breakthrough of the Year * 2022

Outstanding Alumni * 2022

Falling Walls The Falling Walls Conference is an annual science event in Berlin, Germany, that coincides with the anniversary of the Fall of the Berlin Wall (9 November 1989). The one-day scientific conference showcases the research work of international scient ...

Winner in Physical Sciences * 2022 Elected Fellow of the

Selected publications

* * *

References

{{DEFAULTSORT:Kritcher, Andrea Lynn Living people Year of birth missing (living people) American nuclear engineers University of Michigan alumni University of California, Berkeley alumni Lawrence Livermore National Laboratory staff Fellows of the American Physical Society American women engineers 21st-century American engineers 21st-century women engineers Northwestern Michigan College People from Traverse City, Michigan Engineers from Michigan