RADIOACTIVATION ANALYSIS 



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Table 10-2. Neutron Sources and Available Flux 



Source 



Materials Testing Reactor 



Chalk River Pile 



Brookhaven National Laboratory Pile 



Argonne National Laboratory Heavy Water Pile (CP-3') 



Harwell Pile 



Oak Ridge National Laboratory Graphite Pile 



Van de Graaff generator 



Cyclotron 



Ra-Be (1 g) 



Sb-Be (1 c, 60-day half-life) 



Po-Be (1 c, 140-day half-life) 



Ra-Be (25 mg) 



It is clear that for high fluxes, and therefore high sensitivities, one must 

 depend upon accessible nuclear reactors or accelerators, which, of course, 

 are too expensive to be constructed and used primarily for analytical 

 purposes. It would be convenient to have a neutron source for the use of 

 the individual analytical laboratory, and the possibilities have been dis- 

 cussed by Meinke and Anderson (15). The 1-g radium-beryllium source 

 costs about $25,000 and is too expensive for this purpose. The 25-mg 

 radium-beryllium source costs about $600 and may be satisfactory for 

 certain elements of high cross section where sensitivity is not an important 

 consideration. This source was found useful for rapid assay of rhodium 

 and silver ores (15). The antimony-beryllium source costs about $150. 

 However, it has to be reactivated periodically on account of the relatively 

 short half-life (16). 



PROCEDURES 



The Oak Ridge National Laboratory is presently offering to perform 

 radioactivation analyses at a cost ranging from $30 to $50 per element per 

 sample (17). The cost figure is given only to indicate an order of magni- 

 tude and will vary with many factors, such as the bombardment time 

 required and the number of samples submitted. The individual desiring 

 this service should make known to the Laboratory the nature and history 

 of the sample, including data on boiling point, melting point, gross ele- 

 ments present, hygroscopic properties, explosive properties, etc., as well 

 as the element or elements to be analyzed for. The Laboratory will 

 indicate whether the analysis can be made and will provide appropriate 

 forms to be filled out. Upon receipt of authorization the samples should 



