Search Results

You are looking at 1 - 10 of 85 items :

  • "prompt-gamma" x
Clear All

Current Directions in Biomedical Engineering 2017; 3(2): 113–117 Paulo Magalhaes Martins*, Riccardo Dal Bello, Andreas Rinscheid, Katja Roemer, Theresa Werner, Wolfgang Enghardt, Guntram Pausch, and Joao Seco Prompt gamma spectroscopy for range control with CeBr3 Abstract: The ultimate goal of radiotherapy using external beams is to maximize the dose delivered to the tumor while minimizing the radiation given to surrounding healthy critical organs. Prompt Gamma Spectroscopy (PGS) has been proposed for range control of particle beams along with the

Radiochim. Acta 100, 687–698 (2012) / DOI 10.1524/ract.2012.1957 © by Oldenbourg Wissenschaftsverlag, München Application of the k0 method in neutron activation analysis and in prompt gamma activation analysis By Zs. Révay1,∗ and G. Kennedy2 1 Technische Universität München, Forschungsneutronenquelle Heinz Maier-Leibnitz (FRM II), 85747 Garching, Germany 2 Ecole Polytechnique, Montreal, Quebec, H3C 3A7, Canada (Received January 31, 2012; accepted in revised form February 17, 2012) (Published online June 25, 2012) k0 method / Standardization / Neutron activation

Radiochim. Acta 91, 361–369 (2003)  by Oldenbourg Wissenschaftsverlag, München Standardisation of the prompt gamma activation analysis method By Zs. Révay∗ and G. L. Molnár Institute of Isotope and Surface Chemistry, Chemical Research Centre of the Hungarian Academy of Sciences, H-1525 Budapest, Hungary (Received November 13, 2002; accepted in revised form December 20, 2002) PGAA / Thermal neutron capture / Gamma rays / Cold neutrons / Cross section / k0 method Summary. A complete series of measurements was per- formed at the Budapest prompt gamma neutron

References 1. Ghorbani, P., Sardari, D., Bayat, E., & Doostmohammadi, V. (2012). Neutron beam preparation with Am-Be source for analysis of biological samples with PGNAA method. J. Radioanal. Nucl . Chem ., 291 (1), 839–842. DOI: 10.1007/s10967-011-1359-5. 2. Naqvi, A. A., Kalakada, Z., Al-Anezi, M. S., & Raashid, M., Khateeb-ur-Rehman,, Maslehuddin, M., & Garwan, M. A. (2012). Low energy prompt gamma-ray tests of a large volume BGO detector. Appl. Radiat. Isot ., 70 (1), 222–226. DOI: 10.1016/j. apradiso.2011.06.019. 3. Ghassouna, J., & Mostacci, D. (2011

reaction / Prompt gamma activation analysis / HYPERGAM Summary. A Li ion from a 10B(n, αγ )7Li reaction induced by a thermal neutron undergoes a large degradation due to its high stopping power in a medium. This phenomenon influences the peak line shape of the 477.6 keV gamma line emitted from an excited 7Li nucleus recoiled by an energetic alpha particle and the peak line shape in a spectrum varies according to the slowing-down media. A numerical study for the analysis of the line shape has been conducted by perform- ing a parametric search and fitting the measured

Abstract

The aim of this study was to investigate the thermal neutron measurement capability of a CdZnTe detector irradiated in a mixed gamma-neutron radiation field. A CdZnTe detector was irradiated in one of the irradiation tubes of a 241Am-Be source unit to determine the sensitivity factors of the detector in terms of peak count rate (counts per second [cps]) per neutron flux (in square centimeters per second) [cps/neutron·cm−2·s−1]. The CdZnTe detector was covered in a 1-mm-thick cadmium (Cd) cylindrical box to completely absorb incoming thermal neutrons via 113Cd(n,γ) capture reactions. To achieve, this Cd-covered CdZnTe detector was placed in a well-thermalized neutron field (f-ratio = 50.9 ± 1.3) in the irradiation tube of the 241Am-Be neutron source. The gamma-ray spectra were acquired, and the most intense gamma-ray peak at 558 keV (0.74 γ/n) was evaluated to estimate the thermal neutron flux. The epithermal component was also estimated from the bare CdZnTe detector irradiation because the epithermal neutron cutoff energy is about 0.55 eV at the 1-mm-thick Cd filter. A high-density polyethylene moderating cylinder box can also be fitted into the Cd filter box to enhance thermal sensitivity because of moderation of the epithermal neutron component. Neutron detection sensitivity was determined from the measured count rates from the 558 keV photopeak, using the measured neutron fluxes at different irradiation positions. The results indicate that the CdZnTe detector can serve as a neutron detector in mixed gamma-neutron radiation fields, such as reactors, neutron generators, linear accelerators, and isotopic neutron sources. New thermal neutron filters, such as Gd and Tb foils, can be tested instead of the Cd filter due to its serious gamma-shielding effect.

/ Gamma rays / Cold neutrons / Cross section / k0 method / PGAA / NAA / Technetium 99 / Technetium 100 / Beta decay Summary. Accurate partial gamma-ray production cross sections were determined for the prompt and radioactive product decay gamma rays following cold neutron capture in 99Tc. They can be used for non-destructive assay of tech- netium by prompt gamma activation analysis (PGAA) and neutron activation analysis (NAA), offering orders of mag- nitude higher analytical sensitivities than passive gamma-ray counting. A lower limit of 21.21±0.17 b was also deduced

Research Center, Inorganic Analysis Laboratories, Sonoyama, Otsu, Shiga, 520-8567, Japan (Received December 3, 2009; accepted in revised form December 20, 2010) PGA / MPGA / Detection limits / Cold neutron / Coincident gamma rays Summary. A multiple prompt gamma-ray analysis (MPGA) system was constructed at a cold neutron beam line of JRR-3 at Japan Atomic Energy Agency (JAEA). The system consists of 8 clover Ge detectors and BGO Compton suppressors. The detection limits for 41 trace elements with this system were determined. The MPGA system has low detection limits to

isomer shifts (IS) for all identified subspectra were determined relatively to the α-Fe standard. Determination of Mn:Li and Mn:Ni ratios in Li, Mn, Ni oxides was performed by cold neutron prompt gamma-ray activation analysis (PGAA). The five analyzed samples were in the form of powders, weighing between 30 mg and 60 mg. All were derivatives of LiMn 2 O 4 , with a fraction of the Mn replaced by Ni. The samples were sealed in Teflon® Bags and analyzed using the NG7 cold neutron PGAA instrument located at the NIST Center for Neutron Research [ 57 – 59 ]. Irradiation

elements. So we sought a classification method for identifying the kinds of ores added to the consumer products from the correlation of the concentration ratios of the Th/U and the Gd/Sm in NORM and ores. The conventional γ -ray spectrometry by a Ge detector for analysis of Th and U and the prompt gamma-ray activation analysis for the determination of Sm and Gd were employed. It was found that the radiation sources of NORM in the consumer products in recent markets were mainly monazite. This classification method is found to be useful to identify the ores used for the