The U.S. Department of Energy has awarded the 2004 E.
O. Lawrence Award in Physics to Claire Max, a professor of astronomy
and astrophysics at the University of California, Santa Cruz. Max,
who is deputy director of the Center for Adaptive Optics at UCSC and
holds a joint appointment at the Lawrence Livermore National
Laboratory, received the award for her contributions to the theory of
laser guide star adaptive optics and its application in ground-based
astronomy. Adaptive optics sharpens the vision of telescopes by
correcting for the blurring effects of the atmosphere.
The E. O. Lawrence Award is given in seven categories to honor
scientists and engineers for exceptional contributions in the field
of atomic energy, broadly defined. The awards were established in
1959 in memory of the pioneering physicist Ernest Orlando Lawrence,
inventor of the cyclotron. Three of the seven winners this year are
UC faculty and five are affiliated with the national laboratories
managed by UC.
The awards will be presented in a ceremony in Washington, D.C., on
November 8. Each recipient receives a gold medal, a citation, and
$50,000.
“We are all enriched by the contributions these researchers have
made, ranging from engines with no moving parts to better ways to see
the stars,” said Secretary of Energy Spencer Abraham.
Max has made important contributions to the separate fields of plasma
physics and astrophysics, and she is a central figure in the field of
adaptive optics for ground-based telescopes. Her work on laser guide
stars for adaptive optics has led to an ongoing revolution in
ground-based astronomy.
Adaptive optics (AO) enables astronomers to counteract the blurring
effects of turbulence in Earth’s atmosphere, which seriously degrades
images seen by ground-based telescopes. An AO system precisely
measures the blurring of a telescope’s image caused by the
atmosphere, then corrects the image using a special deformable
mirror. These measurements and corrections are made hundreds of times
per second.
The instantaneous measurement of atmospheric blurring along the line
of sight of the telescope requires a bright point-source of light in
the field of view. The first AO systems relied on bright stars, but
this limited the use of AO to areas of the sky where there are
natural guide stars. Max is one of the inventors of the sodium laser
guide star as a source of the bright reference light, and she is a
leader in implementing these new artificial guide stars at
astronomical observatories. Today, ground-based telescopes using AO
systems with laser guide stars are delivering high-resolution
infrared images that rival, or in some cases even exceed, the
sharpness of the infrared cameras on the Hubble Space Telescope.
Max joined the Lawrence Livermore National Laboratory (LLNL) in 1974
as part of a new group formed to understand the plasma physics
aspects of laser fusion. She made important contributions to
laser-plasma interactions and to the understanding of astrophysical
plasmas. In 1984, she became the founding director of the Livermore
branch of UC’s Institute of Geophysics and Planetary Physics, and in
this role she helped guide much of Livermore’s astrophysical and
geophysical research.
Also in the early 1980s, Max became the first female member of the
elite JASON group of scientific advisers to the Department of
Defense. In 1983, she carried out some of the first detailed
theoretical work on adaptive optics for its possible application to
strategic defense when she and three fellow JASONs conceived the idea
of the sodium laser guide star for ground-based telescopes.
The laser creates an artificial “star” by exciting sodium atoms in a
tenuous layer in the upper atmosphere at an altitude of about 100
kilometers (60 miles). Since the high-altitude sodium layer covers
the whole sky, a laser guide star is created wherever the laser beam
intercepts the sodium layer. Aiming the laser to follow the telescope
ensures that a guide star is always close to the astronomical object
of interest.
Max and her team of LLNL scientists demonstrated the concept by
making a star high in the sky above the Livermore site. Work on this
topic had been highly classified until the early 1990s, but was
declassified in time for the LLNL laser experiment. Max then led a
group that built the AO system and sodium laser guide star for UC’s
Lick Observatory on Mt. Hamilton. This laser guide star AO system was
the first to be installed at an astronomical observatory and is
currently the only one in the world used by astronomers on a regular
basis.
Max’s group also designed the laser beacon and AO system for the W.
M. Keck Observatory in Hawaii in collaboration with Keck Observatory
staff. The AO systems at Keck’s two 10-meter telescopes (the largest
in the world) produce infrared images that rival or exceed those of
the Hubble Space telescope at the same wavelengths. They have already
borne important fruit, including infrared images and spectra of
storms on Neptune, hydrocarbon oceans and ice continents on Saturn’s
moon Titan, and black holes in the core of our own Milky Way galaxy
and in the centers of other galaxies nearby. The newly operational
laser beacon at the Keck II Telescope is producing spectacular
results.
Although laser guide star adaptive optics on ground-based telescopes
is still in its infancy, the expanded science that can be done with
such modified telescopes is extraordinary. Adaptive optics enhances
the clarity of ground-based observations by a factor of 50 or more so
that it becomes comparable with that of space telescopes. The larger
ground-based telescopes already have the advantage of greater
light-gathering capacity than space telescopes.
Perhaps one of the most important future uses of adaptive optics will
be the direct detection of extrasolar planets (planets outside our
solar system). Much of the basis for using AO to search for
extrasolar planets has been developed by scientists in Max’s team.
Max earned her A.B. degree in astronomy from Harvard University
(Radcliffe College) in 1968 and her Ph.D. in astrophysical sciences
and plasma physics from Princeton University in 1972. Her many honors
include election to the American Academy of Arts and Sciences in
2002. Max joined the Center for Adaptive Optics as an associate
director when it was established by the National Science Foundation
in 1999, and she has been a member of the UCSC faculty since 2001.
The other recipients of this year’s E. O. Lawrence awards are
Nathaniel Fisch of Princeton University (nuclear technology); Bette
Korber (life sciences), Fred Mortensen (national security), and
Gregory Swift (environmental science and technology) of Los Alamos
National Laboratory; Richard Saykally of UC Berkeley and Lawrence
Berkeley National Laboratory (chemistry); and Ivan Schuller of UC San
Diego (materials research).