[en] The collection efficiency of a filter for the determination of atmospheric volatile heavy metal compounds, i.e., arsenic trioxide, arsine, selenium dioxide and hydrogen selenide, was investigated by neutron activation analysis. The volatile compounds were collected by in-series filters placed after an emission source device and determined by neutron activation analysis. Collection efficiencies were obtained by comparison of the amount of these compounds on the first filter relative to the total collected. For this study, a quartz fiber filter, a glycerol impregnated filter, a polyethylenimine impregnated filter and activated carbon filter were used. As a result, the collection efficiency of the polyethylenimine impregnated filter was 100% for both arsenic compounds and selenium compounds. On the other hands, the efficiencies of the other filters obtained were less than 100%

[en] The size distribution of carbon and trace elements in suspended particulate matter (SPM) collected by a low pressure impactor has been investigated. Sampling was carried out at Setagaya, a typical residential area located southwest of Tokyo, Japan. The low pressure impactor has a cascade design with 12-stage collection plates, allowing the collection of size-fractionated SPM. It operates at a flow rate of 20 l/min. Elemental composition was determined by ion beam analysis, particle induced X-ray emission (PIXE) and Rutherford backscattering (RBS). PIXE provided data for elements from Al to U while RBS supplied information on elements lighter than Al such as C and O. The analysis is fast, non-destructive and requires no sample preparation. It is very suitable for determination of elements in SPM. In this paper we discuss size distribution and element concentrations in SPM together with their weekly and seasonal variations

[en] The PIXE facility at Tokyo Metropolitan Isotope Research Center is described. This system allows for one-man total operation including accelerator control. The ion beam is supplied by HVEE s 1.7MV Tandetorn Accelerator Model HV4117HC with a duoplasmatron ion source Model 358. The PIXE beam line has two variable slits and a beam profile monitor. The ion beam is arranged by these slits. The beam size on a target is from 1 mm square to 12 mm square. The PIXE chamber cylindrical main body made of stainless steel is 500 mm high and 450 mm in diameter. The sample holder for thin targets in the main body can be set a sample up to 100 mm square. It enables us to bombard at 36 points on any parts of the sample with proton. A Si(Li) semiconductor detector is used to collect the characteristic X-rays. This detector views the sample holder at 135. PIXE spectra are collected automatically by a computer which also controls the sample holder. We obtained the detection limits to be about 1 ng for KX-rays for the region 14< Z<26. The agreement between PIXE and ICP-MS or GFAAS for intercomparison analysis was satisfactory. (author)

[en] The PIXE facility at Tokyo Metropolitan Isotope Research Center is described. This system allows for one-man total operation including accelerator control. A sample up to 100 mm square can be set on the sample target which enable us to bombard arbitrary 36 points on the sample with proton. PIXE spectra are collected automatically using a computer which also controls the position of the sample holder. The facility is suitable for analysis of environmental samples and biological samples. (author)

[en] An HVEE 1.7MV Tandetron accelerator (Model HV4117HC) equipped with a negative sputter ion source (Model 860A) and a duoplasmatron ion source (Model 358) was employed for determination of hydrogen atom; particle elastic scattering analysis (PESA) and elastic recoil detection analysis (ERDA). An EG and G Ortec model TU-012-50-100 ion-implanted-silicon charge-particle detector with a resolution of 12keV at 5.486MeV alphas for ²⁴¹Am to collect scattering and recoil particles was set in ion beam analysis chamber. This detector faced the target at an angle of 30deg to the beam direction. For ERDA, typical incident beam energy and beam current were 4MeV He²⁺ and 3nA. For PESA, that energy and current were 3MeV proton 3nA. Polycarbonate filter sample gave detection limits in the 0.6% for ERDA and 0.2% for PESA. In the case of using for proton beam, PESA provided data for hydrogen while another technique, RBS and PIXE, supplied information on elements heavier than helium. Thus, the ion beam analysis provided data for carbon and elements from hydrogen to uranium. (author)

[en] Development of non-transmission type PIXE analysis technique (a PIXE analysis technique for thick specimen without transmission of beam) was conducted by using the Tandetron ion accelerator. A Faraday cup measurable for beam currents before irradiation and a secondary electron suppressor for measuring specimen current accurately were arranged for testing thick specimen. A detecting limit of trace elements in an aluminum alloy standard sample was investigated by using that of conductor for testing specimen. As a result, it was found that detecting limit in an aluminum alloy due to this method were 150 ppm for Cr, 70 ppm for Mn, 70 ppm for Fe, 80 ppm for Ni, 80 ppm for Cu, and 150 ppm for Zn. (G.K.)

[en] For diagnostic X-ray images, the quality of scattered radiation, which influences the image quality, is generally estimated in terms of the 'scatter fraction'. To improve the image quality, it is necessary to devise a way to decrease the influence of scattered radiation. For that purpose, one must have an understanding of the mechanism of influence on the images, together with the quantity that is expressed by scatter fractions. In the present study, by means of a Monte Carlo simulation, we calculated the energy spectra of the primary and scattered radiation, which was absorbed on the screen systems in radiography, and analyzed the influence of the scattered radiation. As a result, not only quantity, which is expressed by the scatter fractions, but also the spectrum make a difference to the influence of scattered radiation. Also, scatter fractions depend on exposure parameters and screen systems; however, mechanisms of dependence are different respectively. (author)

[en] An HVEE 1.7MV Tandetron accelerator (Model HV4117HC) equipped with a negative sputter ion source (Model 860A) was employed for a multipurpose thick-target PIXE system. Two Si (Li) semiconductor detectors were used to collect the characteristic X-rays. A beam extraction nozzle with an exit-foil was made of pure copper to reduce backgrounds. A carbon collimator, hole diameter 3 mm, length 5 mm, was set in the nozzle, resulting in a beam-spot diameter of 3 mm. An exit-foil consisting of 6-mm Al foil was used. The atmosphere of the PIXE chamber was replaced with He gas held at atmospheric pressure. Typical incident beam energy and beam current were 2 MeV and 5 nA, respectively. Aluminum alloy sample and glass sample gave detection limits around Z=30 of this system in the 100ppm (0. 01%) region. (author)

[en] Rice plant samples were grown in 14 cultivative pots by irrigation using the six conditions of artificial acid rain waters (pH: 6.5, 6.0, 4.5, 3.5, 3.0 and 2.5) and tap water (pH: 7.5). The rice grain yielded were separated into three parts, i.e., polished rice, bran and chaff, and they were reduced to powder one by one. Twenty six element contents in the three parts of grain (each 14 samples) were determined by a neutron activation analysis. The contents of Cr, Fe, Ni, Zn, Cu, Rb, Mo in the polished rice increased with decreasing of pH of the irrigation waters. The contents of Se and Br, on the contrary, decreased with decreasing of pH of the irrigation waters. Significant changes of the contents were not observed for the elements Na, Al, Cl, Sc, Mn, Co, V. The enrichment factor of trace elements to soils were calculated for the polished rice, bran and chaff. The high enrichments of Cl, Mo, Zn, Se, Cu and Ni were observed in the polished rice. The elements K, Rb, Mn, Mg and Cr were highly concentrated in the bran. (author)

[en] A high time-resolution system for dry deposition measurement was developed. This employed a modified beta-attenuation dust monitor and PIXE analysis in order to characterize the process of dry deposition. It was demonstrated that PIXE analysis can detect the presence of Al, Si, S and Fe in dry deposition samples for a one-hour sampling time. (author)