The Atomic Fingerprint: Neutron Activation Analysis by Bernard Keisch CONTENTS INTRODUCTION 4 WHAT IS NEUTRON ACTIVATION ANALYSIS? 5 THE SENSITIVITY OF NEUTRON ACTIVATION ANALYSIS 10 HOW AND WHERE TO USE IT 19 In a Physics Laboratory 19 In a Hospital 28 In a Plastics Plant 32 In a Museum 35 In a Criminology Laboratory 42 SUMMING UP: WHAT LIES AHEAD 46 APPENDIX 49 READING LIST 52 MOTION PICTURES 54 U. S. Energy Research and Development Administration Office of Public Affairs Washington, D.C. 20545 Library of Congress Catalog Card Number: 79-182556 1972 [Illustration: Photograph, spiral galaxy] The U. S. Energy Research and Development Administration publishes a series of booklets for the general public. Please write to the following address for a title list or for information on a specific subject: USERDA—Technical Information Center P. O. Box 62 Oak Ridge, Tennessee 37830 [Illustration: Photograph: shelf with china] A 19th century photograph restored by neutron activation. This picture, which is in the collection of the Smithsonian Institution, was exposed to neutrons in a nuclear reactor and then placed in contact with modern photographic film. The original, which had been taken by William Henry Fox Talbot who began his career in 1834, is badly faded. INTRODUCTION You are a physicist investigating the properties of semiconductors, which are materials used to make transistors. The electrical properties of one specimen are not quite like the others that you’ve studied. What makes this specimen different? OR You are a physician treating a patient who, because of a severe calcium deficiency, has been suffering from osteoporosis (a softening of the bones). Are you on the right track with your treatment? OR You are an analytical chemist working for a plastics manufacturer. You have been asked by the plant superintendent to determine why some of the plastic coming from the plant has been discolored.