INTERESTED IN ATOMIC RADIATIONS?

S C I N T I L L A T I O N C O U N T E R

The Scintillation Counter is an extremely useful tool in the detection and quantitative measure­ment of the radiation particles from radioactive nuclei. Scintillation Grade Anthracene, which makes this instrument possible, is an aromatic hydrocarbon which crystallizes into crystals which are sensitive to α-, β-, p-particles and y-rays. Therefore, the crystals, in conjunction with suit­able electronic circuits, make a good instrument for measuring the number of radiation particles.

Interested in atomic radiations?—and how to mea­sure them? If so, you'll want to investigate an im­proved detector known as the Scintillation Counter which has recently been developed. In it, fluores­cent light is picked up by a photo-electric cell and is amplified for recording.

The phosphor material used in the Scintillation Counter is the heart of the instrument. This phos­phor must be in the form of an optically clear, single, large crystal. Anthracene, a coal tar hydro­carbon, possesses most of the necessary properties including excellent reaction speed. The difficulty involved in the development of the Scintillation Counter lay in the fact that the purest anthracene available either would not give sufficiently large crystals, or else had a high optical density because of impurities.

Reilly research and development technicians were asked by the Physics Department of the University of Rochester to produce an anthra­cene so pure that it could be used as the phos­

phor of a Scintillation Counter. Typical of the research and development that has characterized Reilly for over half a century was the almost im­mediate production of Reil ly Scintillation Grade Anthracene.

With this high purity product, physicists of the University of Rochester soon were able to report to other radiation scientists that they were suc­cessful in producing crystals 4 inches long and 21 /2 inches in diameter. What was more, the crystals when cut to a thickness of about 5 mm. appeared nearly colorless.

The new Scintillation Counters made possible by Reilly Scintillation Grade Anthracene are now used in most of the radiation laboratories in the U. S. Not only atomic energy research, but industry as well, is benefited by this Reilly contribution to coal tar chemistry. Perhaps you have a product or process that might be bettered by a Reilly-developed coal tar chemical. It will pay you to get in touch with our Research Department today.

REILLY TAR & CHEMICAL CORPORATION M E R C H A N T S B A N K B U I L D I N G , I N D I A N A P O L I S 4 , I N D I A N A

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