کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1682539 | 1518736 | 2012 | 5 صفحه PDF | دانلود رایگان |
We have extended our previous experimental and Monte–Carlo work on the detection of Gd by in vivo prompt gamma neutron activation analysis to include X ray emission. In this paper we incorporate the characteristic K X ray emission that occurs due to internal conversion from the de-excitation of the 155Gd(n,γ)156Gd∗ and 157Gd(n,γ)158Gd∗ reactions. The experimental Gd K X ray intensities are compared with the Monte–Carlo model and demonstrate excellent agreement. The experiment was consistently higher than simulation by 5%. For the detection system used, the Gd Kα X rays are about 1.5 times as intense as the most dominant prompt gamma ray from the 157Gd(n,γ) reaction. The partial elemental cross section for Kα X ray emission is ∼1.35 times larger than that of the most dominant prompt gamma ray from neutron capture of 157Gd alone. The use of the K X rays was found to improve the sensitivity of the proposed system to measure Gd retention after exposure to a Gd-based MRI contrast agent. The detection limit in phantoms was ∼30% better when the X ray signal was incorporated into the analysis method, reducing the detection limit from 0.89 to 0.64 ppm Gd.
Journal: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms - Volume 281, 15 June 2012, Pages 21–25