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ARS Home » Plains Area » Houston, Texas » Children's Nutrition Research Center » Research » Publications at this Location » Publication #328148

Title: Stability evaluation and correction of a pulsed neutron generator prompt gamma activation analysis system

Author
item SHYPAILO, ROMAN - Children'S Nutrition Research Center (CNRC)

Submitted to: Journal of Radioanalytical and Nuclear Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/1/2015
Publication Date: 3/1/2016
Citation: Shypailo, R.J. 2016. Stability evaluation and correction of a pulsed neutron generator prompt gamma activation analysis system. Journal of Radioanalytical and Nuclear Chemistry. 307(3):1781-1786.

Interpretive Summary: Prompt gamma neutron activation is a technique used to measure the amounts of certain elements in the human body. One such element is nitrogen. Nitrogen is present at fairly low levels in the human body – only about 2.5% of body weight. So the equipment and electronics used to measure nitrogen must be stable to be accurate. We evaluated the stability of the neutron generator used in our prompt gamma system. We reviewed the patterns of data acquired over time by measuring a series of standards. We found that the instability of the neutron generator affected measurement precision. The generator must be monitored and checked for consistency. We need to make adjustments to measurement results to correct for the generator output.

Technical Abstract: Source output stability is important for accurate measurement in prompt gamma neutron activation. This is especially true when measuring low-concentration elements such as in vivo nitrogen (~2.5% of body weight). We evaluated the stability of the compact DT neutron generator within an in vivo nitrogen measurement system. Review of gamma event/time patterns and data from an auxiliary detector showed significant variations among repeated phantom runs. Neutron generator instability had a significant effect on measurement precision. The neutron generator used in our system must be monitored for output consistency. Adjustments must be made to measurement results to correct for generator instability.