
                         Roanoke Times
                 Copyright (c) 1995, Landmark Communications, Inc.

DATE: FRIDAY, February 1, 1991                   TAG: 9102010264
SECTION: EXTRA                    PAGE: E-2   EDITION: METRO 
SOURCE: The Washington Post
DATELINE:                                 LENGTH: Short

INVENTION HAS A BRIGHT FUTURE

The brightest new idea in lighting needs no electricity, works without a bulb or tube and looks like "a glowing sugar cube," according to its creators at Sandia National Laboratories in Albuquerque, which developed the new lights for use in remote areas, deep-space vehicles and emergencies.

Illumination generally is produced by exciting an atom so that its electrons jump to higher energy orbits; when they fall back to normal levels, they release their excess energy in photons, or light units. In the familiar incandescent bulb, this is done by forcing electrical current through a metal filament. But it also can be achieved by bombarding certain glow-prone chemicals, called phosphors, with atomic particles from radioactive material such as tritium gas, an isotope of hydrogen.

The earliest "radioluminescent" lights were made by trapping tritium in a phosphor-coated glass tube. But Sandia scientists have found ways to suspend both gas and phosphor in a clear block of styrene plastic or a super-lightweight silicon foam, called an aerogel, making unbreakable "light cubes" 10 times brighter than tube-type lights. Surround those cubes with photovoltaic cells, which convert the light to electricity, and the result is "possibly a power source that'll go for 20-plus years," said one Sandia researcher. No word yet on implications for night baseball.

by CNB