ENGINEERING PHYSICS

NUCLEAR REACTOR GOING STRONG AFTER 40 YEARS

The pool of the college's nuclear reactor (20K JPG)

When the college's nuclear reactor achieved initial criticality at 10 kilowatts in 1961, only five or so such university teaching-and-research facilities existed in the United States. Since then, that number grew and then fell as tight budgets and funding cuts forced universities to pull the plug.

As UW-Madison's reactor turns 40, however, staff have applied for a 20-year license renewal from the Nuclear Regulatory Commission and the department is gearing up for more students, drawn by renewed nationwide interest in nuclear energy.

Now running at 1 megawatt, the reactor is one of seven like it in the country. It features upgraded controls, and though some aspects are computerized, students and staff still operate it via traditional individual channels integrated into an overall control system — the "teaching" in its mission. And on the research side, reactor staff have helped scientists study just about everything, including cow manure, moon rocks, soil, fish samples — even rhinoceros sperm.

GOOD VIBRATIONS

Professor Daniel Kammer recently presented Marshall Space Flight Center, Huntsville, Alabama, with a software "toolbox" that will standardize one aspect of its testing process and may help its space vehicles — including the International Space Station — fly more safely.

The vehicles undergo a battery of tests, including one that measures their vibrations to predict whether the structures will survive stresses they're subjected to during a flight. Engineers must corroborate the data with complex mathematical models (sets of differential equations in the form of finite-element models), and Kammer's software enables them to develop accurate models more easily and efficiently.

SHOCKING WAVES

Professor Riccardo Bonazza might say he grows "mushrooms" in his 10-meter-tall shock tube. Actually, the mushrooms are wave shapes that result at the interface of two gasses when Bonazza applies a shock wave to them. The mushroom shapes experimentally verify a part of computer codes that simulate fusion reactions.

His process and ingredients are simple: Add a couple of gasses of different densities to the tube, separate them with a unique, sinusoidally shaped retracting copper plate, launch a shock at Mach 3 (three times the speed of sound) and observe how the gasses behave. The experiment replicates, on larger spatial and temporal scales and at lower energies, the fluid mechanics of a typical inertial confinement fusion implosion experiment without the plasma and radiation events.

The shock tube can issue shocks as strong as Mach 5, and Bonazza hopes future experiments will even more closely simulate higher-energy fusion research.

LITTLE BATTERIES PACK BIG POWER

Combining nuclear- and electrical-engineering technologies, a trio of engineers hopes to make independently powered microelectromechanical systems (MEMS) about the size of a grain of sand.

Until now, researchers looking for such devices were limited by the comparatively large batteries needed to power them. But Engineering Physics Associate Professors James Blanchard and Douglass Henderson and Electrical and Computer Engineering Assistant Professor Amit Lal have developed "nanobatteries" from minute amounts of coated radioactive material, similar to that in smoke detectors and pacemakers.

The batteries work by harnessing the material's natural radioactive decay, and could last for hundreds of years. The research is funded by a three-year, $970,000 Defense Advanced Research Projects Agency grant.