Detection sensitivities of the chemical elements following thermal-neutron activation have been compiled from the available experimental cross sections and nuclear properties and presented in a concise and usable form. The report also includes the equations and nuclear parameters used in the calculations

Wahlgren, M. A.

Wing, J.

English

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December 1967	 Brief 67-10641 
toy C
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AEC-NASA Tech Briefs describe innovations resulting from the research and development program 
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application. Tech Briefs are published by NASA and may be purchased, at 15 cents each, from 
the Clearinghouse for Federal Scientific and Technical Information, Springfield, Virginia 22151. 
Compilation of Detection Sensitivities in Thermal-Neutron Activation 
The detection sensitivities of the chemical elements 
following thermal-neutron activation have been com-
piled from the available experimental cross sections 
and nuclear properties and presented in a concise 
and usable form. Calculating the sensitivities for each 
situation is time-consuming and tedious, and alternate 
counting methods must often be used and possible 
interfering activities must be considered. 
The detection sensitivities of neutron-activated 
elements were calculated and tabulated using 4R beta, 
single-gamma, gamma—gamma, alpha—gamma, and 
beta—gamma coincidence, beta—gamma—gamma triple 
coincidence, plus triple gamma coincidence counting 
techniques. The material presented permits a rapid, 
qualitative estimation of the detection limits and best 
detection methods for these elements. 
The information and tables presented would be 
useful for the following: 
1. Identification, prediction, and estimation of the 
amount of induced radioactivities and interfer-
ences. 
2. Comparison of the relative detection sensitivities 
of the chemical elements. 
3. Feasibility of nondestructive or radiochemical 
analysis. 
4. Selection of counting techniques. 
5. Selection of irradiation and cooling times. 
6. Choice of target matrix. 
As further aids to these applications, some of 
the calculated sensitivities are plotted as a function 
of time of irradiation. Most of the results plotted are 
the maximum sensitivities for the target element (or 
isotope). The decay half-lives versus coincidence-
gamma energies and the decay half-lives versus the 
sum of the coincidence-gamma energies are also 
plotted for the nuclides covered in the report.
The detection sensitivities were calculated for 
irradiation times of 0.5, 5, 50, 500, and 5000 minutes 
at a flux of 10 14 thermal neutrons/sec-cm 2 . The 
calculated sensitivities can be alternately read as 
sensitivities for one-gram samples at a flux of 108 
thermal neutrons/sec-cm2. 
Several of the nuclides are formed from pairs of 
isomeric product nuclides. The sensitivities for these 
nuclides were calculated from the two paths of forma-
tion, one from the metastable state and the other from 
the ground state of the product nuclide. 
For single-gamma counting, the source was 3 cm 
and 9.3 cm from the face of a 3-in, by 3-in. Nal 
(TI) crystal. For coincidence counting, the source 
was 3 cm from two opposed 3-in, by 3-in. Nal (TI) 
crystals. The single-gamma counting results have 
been compared with existing experimental data for 
accuracy. 
Notes: 
I. All calculations were performed by an IBM 1620 II 
computer. 
The report also includes the equations and nuclear 
parameters used in the calculations. 
This information would be of interest to persons 
concerned with activation analysis. 
Complete details are contained in Detection Sensi-
tivities in Thermal-Neutron Activation, by J. Wing 
and M. A. Wahlgren, ANL-6953, December 1965, 
Argonne National Laboratory, Argonne, Illinois. 
This report is available from the Clearinghouse for 
Federal Scientific and Technical Information, 
Springfield, Va. 22151. Price $3.00 each (micro-
fiche, $0.65).
(continued overleaf) 
This document was prepared under the sponsorship of the Atomic 
Energy Commission and/or the National Aeronautics and Space 
Administration. Neither the United States Government nor any per-
son acting on behalf of the United States Government assumes any
liability resulting from the use of the information contained in this 
document, or warrants that the use of any information, apparatus, 
method, or process disclosed in this document may not infringe pri-
vately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19670000640 2020-03-11T21:33:35+00:00Z
Inquiries concerning this innovation may be di-
rected to:
Office of Industrial Cooperation 
Argonne National Laboratory 
9700 South Cass Avenue 
Argonne, Illinois 60439 
Reference: B67-10641 
Source: J. Wing and M. A. Wahigren 
Chemistry Division 
(A RG- 10068)
Patent status: 
Inquiries about obtaining rights for commercial 
use of this innovation may be made to: 
Mr. George H. Lee, Chief 
Chicago Patent Group 
U.S. Atomic Energy Commission 
Chicago Operations Office 
9800 South Cass Avenue 
Argonne, Illinois 60439
O 
Brief 67-10641	 Category 03


Compilation of detection sensitivities in thermal-neutron activation

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