Word: cesium
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Last week the National Bureau of Standards laboratories at Boulder, Colo, announced that it has settled on a system of time measurement that presumably will not change at all in thousands or millions of years. It is based on the convenient fact that atoms of cesium vibrate at an absolutely constant rate: about 9,200 million times per second. A cesium "clock" has neither a face nor hands. Instead, cesium atoms are shot down a vacuum tube, and radio waves are directed across the cesium beam. When the radio waves are at precisely the frequency at which cesium vibrates, they...
Time measured by the rotation of the earth will continue to be used, in spite of its inconstancy, for catching trains or getting to the church on time. But the cesium clock will be the arbiter for super accuracy. It will have no cumulative drift and can be read with an error of less than three parts in 100 billion (one second in a thousand years...
Even more exciting is the possibility of using the MHD system with a nuclear reactor. In this case the gas will probably be argon or helium, laced with cesium to make it more conductive. It will circulate through the reactor, then through the generator and back to the reactor again. This system will have to wait for the development of high-temperature reactor cores, but Project Rover, the Atomic Energy Commission's nuclear-rocket program, has shown that the prospects of this are promising...
Almost daily, ways are found to give bigger radiation doses more safely to hard-to-reach parts of the body. Examples: cobalt-60 "bombs," a new cesium-137 unit at M. D. Anderson Hospital, higher-powered X-ray machines and linear-particle accelerators, ingeniously refined ways of implanting radioisotopes such as iridium 192 and yttrium 90 in tumors...
After twelve hours, the device had to be shut down because the uranium fission produces gas as a byproduct that dilutes the plasma and dangerously raises the pressure inside the can. In future plasma thermocouples, this can be solved by bleeding off the gas. But the cesium plasma proved to have a thermoelectric efficiency much higher than any combination of solid metals...