company scientists at Yallecitos -were interested primarily in proving thai* the MVàtein would work, they did not design for optimum capture of heat; there-fore, they do not know exactly how cHrWient their system is. That is why they re?port efficiency as V ( of the heat captnrcnl by the converter. For use in space, Naymark says „ GE would use isotopes with longer lives than gold-198and 199-cerium-14-4. for example. By designing the wholt? system lor optimum use of heat anc3 improving the thermionic converter itself, GE hopes to bring the efficiency *ip to the 1 0 ' , level. This will take Λ few years. U p to now, GE ha.s been using company money for this devclopiment.
RESEARCH
Cancer Studies Continue Tobacco Industry Research Committee studies pos-sible role of tobacco in disease General Electric engineers Mark Lyons and Sherman Naymark show relation of components of nuclear thermionic converter to a scale model of a satellite. Satellite model shows radio transmitter ( inside ) and radiator used to dissi p a t e excess heat ( o u t s i d e ) . I n Naymark s hand, are converter and gold strips
Gold Gets Role in Outer Space G e n e r a l Electric uses h e a t f r o m r a d i o i s o t o p e s t o fuel its t h e r m i o n i c c o n v e r t e r RADIOACTIVE isotopes as a source of electric power in space vehicles have been pushed forward again. General Electric engineers at the Yallecitos lab oratory have suecessfuHy obtained power from a thermionic converter us ing a radioactive isotope as a source of heat (C&EX, F e b . 2, page 1 9 ) . Just a few weeks ago. President Eisenhower unveiled a similar device made by Mar tin Co., which uses thermocouples and isotopes. These miniature power plants have two advantages which make them use ful in space vehicles—they have a high ratio of power to weight, and they have a long life. G E now has proved that its system will work at high tempera tures ( u p to 1700° F . at the hot side. OVW
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and under gamma irradiation—conditions to be met in outer space. Efficiencies obtained so far are rela52
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tively low. GE engineer Sherman Naymark estimates that the thermionic wafer used at Yallecitos converted about A'.'f of the heat it received to electricity. In a few years, he feels, efficiency can be upped to about 10'
