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1.
C. Yonezawa P. P. Ruska H. Matsue M. Magara T. Adachi 《Journal of Radioanalytical and Nuclear Chemistry》1999,239(3):571-575
Determination of ppm levels of B in 21 igneous and sedimentary rocks of the Japanese geochemical reference samples prepared
by the Geological Survey of Japan (GSJ) has been performed by neutron-induced prompt γ-ray analysis (PGA) using cold and thermal
guided neutron beams of the JRR-3M. Owing to the Doppler broadened γ-ray line of B 478 keV, many elements such as Na, Ni,
Cl and so on showed spectral interference in the determination of B. The interference was corrected by computer fitting and
a reference peak method. The analytical results obtained by the present method almost agreed with the GSJ values recommended
in 1994 within the standard deviation of the recommended values. Sodium contents determined by the PGA in the reference rock
samples are also reported. 相似文献
2.
S. Ohde K. Tanaka A. Snidvongs H. Matsue 《Journal of Radioanalytical and Nuclear Chemistry》2011,289(2):401-406
A systematic and non-destructive technique is proposed for the determination of boron in coral samples by neutron-induced
prompt γ-ray analysis (PGA) using a thermal neutron guide beam of the JRR-3M reactor. About 50–150 mg samples in sealed FEP
film were irradiated and measured for 5000 s in the PGA system at a neutron flux of 2.4 × 107 n cm−2 s−1. In order to determine B content in coral skeletons, the Doppler-broadened γ-ray peak of 478 keV (10B) was used together with the correction of interference from the Na-peak of 472 keV. The analytical precision was ~3% for
the JCp-1 coral standard. The data (n = 56) obtained by the present method showed a range of B content from 40.7 to 76.9 ppm which is similar to reported values.
Boron in corals showed the highest levels in Rukan-sho (Okinawa) with an average B content of 62.5 ppm, whereas corals collected
from Mizugama (Okinawa), Cebu (the Philippines) and Khang Khao (Thailand) exhibited B contents of 56.5, 53.0 and 45.7 ppm,
respectively. The uptake of boron by living corals may be influenced by seawater pH related to higher seawater B(OH)4−. In this paper we discuss factors controlling the B levels in corals. 相似文献
3.
T. Sano T. Fukuoka T. Hasenaka C. Yonezawa H. Matsue H. Sawahata 《Journal of Radioanalytical and Nuclear Chemistry》1999,239(3):613-617
An accurate and efficient analytical method using neutron-induced prompt γ-ray was developed for the determination of boron
contents in volcanic rocks. We corrected the effect of sample geometry and flux fluctuation by using silicon as an internal
standard. However, we found that the slopes of the calibration line vary among volcanic samples with different matrix. Because
the increase of boron activity correlates positively with γ-ray count rate of hydrogen (water), we call this as the hydrogen
effect. The hydrogen effect was confirmed by our experiment in which the boron activities showed systematic increase with
the amount of added hydrogen (water). Most volcanic rocks, however, contain little water (<2 wt.%) to show this effect. We
determined boron contents in various volcanic rocks in order to confirm the validity of the procedure that we established.
The analyzed boron contents agreed well with the previous reported values. For efficient PGA of boron in volcanic rocks, we
recommend JB-2 (GSJ standard rock) as a single geochemical standard, because of its high boron content (31.2 ppm). 相似文献
4.
R. A. Nadkarni G. H. Morrison 《Journal of Radioanalytical and Nuclear Chemistry》1977,38(1-2):435-449
A rapid and comprehensive method has been developed for the determination of ppm to sub-ppb amounts of Ru, Pd, Ag, Os, Ir,
Pt and Au, based on thermal neutron irradiation, dissolution of samples, selective absorption on Srafion NMRR ion exchange
resin and high resolution γ-ray spectrometry. Two noble metals “specific” resins were tested for their absorption behaviour.
The method has been used for analysis of standard rocks, ores, minerals, lunar samples, coal, coal fly ash, and several biological
materials. 相似文献
5.
Exploration and modification of data for k
0-PGAA (prompt γ-ray activation analysis) values used as standards for k
0 standardization are needed. An integrated system has been installed and calibrated in Hot Laboratories Center for PGAA, using
252Cf isotopic neutron source with neutron flux of 6.16E8 n/cm2 s. The prompt k
0-factors of about 12 elements were determined versus the 1951.1 keV γ-ray of the 35Cl, as well as analyzing crude oil and oil product samples. The concentrations of the elements in crude oil H, B, Mg, Al,
Na, Si, P, S, Cl, V and Cd were 1.18E5, 0.084, 5.48E2, 8.45E2 4.88E2, 1.62E2, 3.72E2, 8.2, 144.3, 393 and 209.2 ppm while
in oil product samples were 1.32E5, 5.87, 4.56E2, 4.22E2, 7.16E3, 699, 157, 8.74, 492.3, 61 and 198.2 ppm. Validation of the
k
0-PGAA was applied in analyzing standard IAEA reference material (soil-7) which give good agreement with the literature data.
The 252Cf neutron beam in radiation position was characterized by the cadmium-ratio method, and found that the cadmium ratio (f), was 160. 相似文献
6.
Xinfeng You Shengdong Zhang Zhihong Yang Youqian Ding Anzhi Cui 《Journal of Radioanalytical and Nuclear Chemistry》2011,287(1):267-272
101Tc is a very important nuclide as fuel burn up monitor, and its half-life value has been measured many times, however, they
were so different from each other. In this work, 101Tc liquid samples were prepared by irradiating analytical pure (NH4)6Mo7O24·4H2O solution in Miniature Neutron Source Reactor (MNSR) of China. A rapid procedure which takes only 5 min was developed to
separate 101Tc samples. The final samples were analyzed by γ-ray spectrum using high purity Germanium (HPGe) multi-channel analysis system.
The results showed that there were no peaks of other nuclides except 101Tc. The half-life of 101Tc was accurately measured with HPGe γ-detector following 306.8 keV γ-ray for about 140 min, and three methods R-value method,
iterative method and translation method were adopted to process the data. Finally, a more precise and accurate value 14.02 ± 0.01 min
was given and compared with former measured data. 相似文献
7.
Sz. Vass B. Vorsatz E. Szabó E. Kelen B. Keszei S. Cseh S. Saly 《Journal of Radioanalytical and Nuclear Chemistry》1971,8(2):325-334
A non-destructive simultaneous method has been developed for the rapid determination of Al, Si and K in WO3 powders and W metal powders. The samples were activated by 14 MeV neutrons and the radioactive isotopes identified by their
γ-ray spectra with a 3″×3″ NaI(Tl) detector. Quantitative analysis was carried out by measuring the full energy peak areas.
The determined concentrations of Al, Si and K were above 100, 100 and 500 ppm, the sensitivities being about 20, 10 and 100
ppm, respectively. 相似文献
8.
Abdulrahman Abdul-Hadi Wedad Al-Qadhi Enayat El-Zeen 《Journal of Radioanalytical and Nuclear Chemistry》2011,290(2):261-266
Uranium, thorium and potassium contents in 16 different rock samples from various sites in Republic of Yemen were determined
using three different techniques of analysis: γ-spectrometry, Instrumental neutron activation analyses (INAA) and X-ray fluorescence
(XRF). The concentration range for thorium, uranium and potassium were found to be from 9,810 ± 272 to 3.6 ± 1.3 ppm, 1,072 ± 40
to 1.2 ± 0.7 ppm and 11 ± 1 to 0.26 ± 0.05%, respectively. 相似文献
9.
R. Acharya 《Journal of Radioanalytical and Nuclear Chemistry》2009,281(2):291-294
Prompt gamma ray neutron activation analysis methodologies were standardized using a reflected neutron beam and Compton suppressed
γ-ray spectrometer to quantify boron from trace to major concentrations. Neutron self-shielding correction factors for higher
boron contents (0.2–10 mg) in samples were obtained from the sensitivity of chlorine by irradiating KCl with and without boron.
This method was validated by determining boron concentrations in six boron compounds and applied to three borosilicate glass
samples with boron contents in the range of 1–10 mg. Low concentrations of boron (10–58 mg kg−1) were also determined in two samples and five reference materials from NIST and IAEA. 相似文献
10.
A. Hussein 《Journal of Radioanalytical and Nuclear Chemistry》1994,188(4):255-265
Uranium (U) and thorium (Th) isotopes and their several radioactive descendants found in soil, rock, water, plants, air, etc., contribute to the natural radiation exposure of the population. Phosphate rocks are really rich natural sources of uranium and thorium among the other minerals forming the earth's crust. U and Th concentrations in some Egyptian phosphate samples were determined using a nuclear track registration methodology and -ray spectroscopy. The resulting latent tracks from all -decaying isotopes in both U and Th series were recorded in plastic detectors. A uniquely sensitive polycarbonate CR-39 nuclear detector was used. Results showed that the U and Th concentration in the samples studied range from about 4.0 up to 35.0 ppm and from 11.0 to 124.0 ppm, respectively. Results are discussed within the frame work of track formation methodology in plastic and -ray spectroscopic analysis. 相似文献
11.
J. Kuncíř J. Benada Z. Řanda M. Vobecký 《Journal of Radioanalytical and Nuclear Chemistry》1970,5(2):369-378
The use of high-resolution Ge(Li) detectors in non-destructive instrumental neutron activation analysis (INAA) of mineral
materials makes possible the simultaneous determination of a number of trace elements. In routine applications of INAA the
use of a multi-element standard (MES) has proved to have advantages over a set of standards for each determined element. An
MES has been prepared containing 8 trace elements mixed in a suitable proportion and giving, after neutron activation, long-lived
γ-emitters, the γ-ray lines of which regularly occur in the γ-ray spectra of silicate mineral materials. This method has been
used in the determination of Sc, Cr, Co, Rb. Cs, Eu, Hf and Th in samples of standard rocks and moldavites. 相似文献
12.
A comprehensive compilation of X- and γ-ray emitting isotopes produced by the (n, γ) reaction is reported in this paper for
application to instrumental neutron activation analysis (INAA). The X- and γ-ray sensitivities are computed theoretically
by a computer code. Interfering photons from isotopes of neighbouring elements are identified by the code and the percentage
interference is computed. Additionally an advantage factor (X-ray: γ-ray sensitivity) is computed, which is a figure of merit
for X-ray spectroscopy in INAA. Further, mathematical representation of background continua for typical matrices encountered
in INAA allow the calculation of elemental detection limits for the X-ray and γ-ray photons. 相似文献
13.
Monte Carlo calculations were carried out to study the dependence of γ-ray yield on the bulk density and moisture content
of a sample in a thermal-neutron capture-based prompt gamma neutron activation analysis (PGNAA) setup. The results of the
study showed a strong dependence of the γ-ray yield upon the sample bulk density. An order of magnitude increase in yield
of 1.94 and 6.42 MeV prompt γ-rays from calcium in a Portland cement sample was observed for a corresponding order of magnitude
increase in the sample bulk density. On the contrary the γ-ray yield has a weak dependence on sample moisture content and
an increase of only 20% in yield of 1.94 and 6.42 MeV prompt γ-rays from calcium in the Portland cement sample was observed
for an order of magnitude increase in the moisture content of the Portland cement sample. A similar effect of moisture content
has been observed on the yield of 1.167 MeV prompt γ-rays from chlorine contaminants in Portland cement samples. For an order
of magnitude increase in the moisture content of the sample, a 7 to 12% increase in the yield of the 1.167 MeV chlorine γ-ray
was observed for the Portland cement samples containing 1 to 5 wt.% chlorine contaminants. This study has shown that effects
of sample moisture content on prompt γ-ray yield from constituents of a Portland cement sample are insignificant in a thermal-neutrons
capture-based PGNAA setup. 相似文献
14.
A sensitive procedure for the simultaneous determination of trace levels of osmium and ruthenium in platinum, by thermal neutron
activation analysis utilizing γ-ray spectrometry, was developed. The radiochemical separation method utilized perchloric acid
for a selective oxidation of osmium and ruthenium to the volatile tetroxides. The distillation of the tetroxides greatly reduced
the radiation hazard presented by the bulk of the activities in the matrix. Activities of 15-day191Os and 40-day104Ru were measured by accumulation of pulses from a 3″ diameter NaI(Tl) crystal detector. Analyses of γ-ray spectra were achieved
using digital computer techniques. The procedure provided analyses for a high purity platinum stock of 0.032±0.007 ppm Os
and 0.044±0.005 ppm Ru.
Work was performed at the Ames Laboratory of the U. S. Atomic Energy Commission, Contribution No. 3073. 相似文献
15.
R. S. Das P. S. Chakraborty S. N. Bhattacharyya 《Journal of Radioanalytical and Nuclear Chemistry》1976,34(2):249-259
Gold was determined in some selected rock samples by neutron activation analysis. The analysis was carried out both in destructive
and non-destructive ways followed by γ-ray spectrometry. The amounts of gold that were determined in the respective rock samples
varied in the range 10−4–10−6%. Besides gold, some other trace constituents such as As, Ag, Sb, W, Se, La, Sm, etc. were also detected and their approximate
order of occurrence was determined. 相似文献
16.
T. Belgya 《Journal of Radioanalytical and Nuclear Chemistry》2008,276(3):609-614
The 14N(n,γ)15N reaction is a primary γ-ray source for high energy calibration of detectors. The relative γ-ray-intensities of 15N and the relative γ-ray detection efficiency function have been simultaneously determined up to 10 MeV from γ-peak areas
alone. Absolute γ-ray-intensities were obtained with proper renormalization to known absolute intensity. The influence of
these new intensity values are assessed for use in PGAA. Any consistently used set of calibration intensities applied in the
creation of library values and for analysis do not influence the concentrations. Contrary to this, quantities based on sums
of γ-ray cross sections may provide different answers with the new 15N intensities and they give means to validate them. 相似文献
17.
D. L. Anderson M. P. Failey W. H. Zoller W. B. Walters G. E. Gordon R. M. Lindstrom 《Journal of Radioanalytical and Nuclear Chemistry》1981,63(1):97-119
A facility for neutron-capture γ-ray spectroscopy for analytical purposes has been developed and tested at the National Bureau
of Standards reactor. The system consists of an internal beam tube with collimators, an external beam tube and irradiation
station, a Compton-suppressed Ge(Li) γ-ray detection system, and a minicomputer-based data-collection and-analysis system.
Detection limits have been established for many elements and errors arising from neutron self shielding, γ-ray peak overlap,
neutron beam variations, and sample matrix evaluated. 相似文献
18.
The capabilities of reactor neutron and 12 MeV proton activation were evaluted on samples of orchard leaves, beef liver and
bovine liver. Based on γ-ray spectrometry, As, Ca, Cu, Fe, Mo, Pb, Sr, Ti, Zn and Zr at levels ranging from 2 to 20 900 ppm
were detected following proton activation of 1 hour. Al, Br, Ca, Cl, Cu, Mg, Mn, Rb and V (ranging from 0.4 to 20 900 ppm)
were measured by neutron activation (1 min irradiation). As, Ba, Br, Cr, Co, Fe, Hg, La, Na, Rb, Sb and Zn (ranging from 0.2
to 2400 ppm) were determined following a 14 h neutron irradiation. Although covering different elements, the two techniques
are comparable in their scope, i. e. detection limits that can be achieved and number of elements that can be detected simultaneously. 相似文献
19.
R. A. M. Rizk A. H. El-kateb A. M. Abdul-kader 《Journal of Radioanalytical and Nuclear Chemistry》1999,242(1):139-145
Developments and applications of on-line nuclear gauges in the coal industry are highly requested. In this work, a nuclear
ash gauge for coal, based on γ-ray transmission techniques is developed. Single and dual energy γ-ray beams are used to determine
the ash content of coal. The percentage ash content as a function of the γ-ray intensities transmitted through coal samples
is measured and sensitivity curves are obtained. An empirical formulation relating the ash content values to the γ-ray intensities
is derived. Preliminary results show that both single and dual energy γ-ray transmission techniques can be used to give a
rapid on-line estimation of the ash concentration values in coal with low cost and reasonable accuracy, but the dual one is
much preferable. 相似文献
20.
Estimation of very low amount up to pico-gram of Am and Pu in the liquid waste of U–Pu fuel cycle of the irradiated U fuel
from the nuclear reactor has been carried out using combined method of α- and γ-ray spectrometric techniques. 241Am was estimated by γ-ray spectrometry from a plancheted source. In spite of the same α energy of 5.49 MeV for 241Am and 238Pu, the amount 238Pu was estimated by α spectrometry from the same plancheted source after subtracting amount of the 241Am obtained from γ-ray spectrometry. The amount of Am and Pu obtained by this technique is found to be superior compared to
other techniques even in the presence of Th, U and fission products. 相似文献