Cascade Applied Sciences Inc.

High Energy-Density Physics Simulations

Radiation Hydrodynamics Simulation Codes

Research into the physics of high energy-density matter requires the use of very high power energy sources such as intensely bright lasers. The interaction of the laser radiation with material is quite complex, and results in the rapid heating of a portion of the material. This heating and concomitant energy transport results in extreme states of matter being achieved and characterized by high pressure, high density and high temperature. As a result the material is usually vaporized. Characteristic times for this behavior are in the range of less than one picosecond to several tens of nanoseconds.

Laboratory experiments on high energy-density matter require the assistance of theoretical physics models in the form of computer-based simulation codes. The physics is characterized by a large set of coupled differential equations that can be solved only by numerical methods. These computer codes help design the experiment and provide a powerful means to analyze and interpret the experimental data.

Two such codes are HYADES and h2d. HYADES is a one-dimensional, three temperature code, and h2d is a two-dimensional, three temperature code. Both of these solve the equations of conservation of momentum and energy taking into account the realistic properties of the materials under extreme conditions.

These radiation hydrodynamics codes are used by more than sixty laboratories world wide. The majority of the users are research groups at academic institutions, and the several major national research laboratories both in the United States and in Europe and Asia.

Hyades in Mythology

In Greek mythology, the Hyades were daughters of Pleione and Atlas. The Hyades had several sisters, including the Pleiades and the Hesperides as well as a brother Hyas. The sisters were very close to Hyas, but one day as he was hunting, he was killed by a lion, and the Hyades were so overcome with grief they committed suicide.

Upon their death, Zeus raised them to the heavens and arranged them as a cluster of stars in the constellation Taurus the Bull. Zeus was grateful to them because they nursed his son, the god Dionysus. Aldebaran, the brightest star in Taurus, represents the Bull's eye, but it in itself is not a part of the cluster. The Hyades are in a V-shape, forming the horns and nose of the bull. The star cluster is quite close and is important in astrophysics since the distance can be measured by geometrical methods. The distance is 46.34 pc (150 light years) to the cluster's center.

The Hyades appear in the heavens during rainy seasons, autumn to spring. The Greeks believed them to be messangers of spring showers and autumn storms, and the rain represented the sister's tears of grief for their brother Hyas. Indeed, hyades in Greek means "to rain."

About Cascade Applied Sciences, Inc.

Cascade Applied Sciences, Inc. (CAS) was founded in early 1990 in Boulder, Colorado. CAS currently develops and markets two radiation hydrodynamics simulation codes (HYADES and h2d) for the high energy-density physics and astrophysics research communities.

The President and Senior Scientist at CAS is Jon T. Larsen. Dr. Larsen earned his Ph.D. in physics at Iowa State University. He then became a staff member at the Lawrence Livermore National Laboratory and worked on the first significant laser fusion experiments, primarily designing targets for those experiments. In the 1980s, Dr. Larsen joined the technical staff at KMS Fusion, Inc., in Ann Arbor, MI, where he headed the theoretical department, and later became the Vice President for Fusion Programs. He left KMSF in 1988 to found CAS.

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