Search

Coherent double neutral-pion photoproduction on the deuteron, γ d → π 0 π 0 d , has been experimentally studied at incident photon energies ranging from 0.75 to 1.15 GeV. The total cross section as a function of the γd center-of-mass energy shows resonance-like behavior, which peaks at approximately 2.47 and 2.63 GeV. The measured angular distribution of deuteron emission is rather flat, which cannot be reproduced by the kinematics of quasi-free π 0 π 0 production with deuteron coalescence. In π 0 d invariant-mass distributions, a clear peak is observed at 2.14 ± 0.01 GeV / c 2 with a width of 0.09 ± 0.01 GeV / c 2 . The spin-parity of this state is restricted to 1 + , 2 + or 3 − from the angular distributions of the two π 0 s. The present work shows strong evidence for the existence of an isovector dibaryon resonance with a mass of 2.14 GeV / c 2 . The 2 + assignment is consistent with the theoretically predicted D 12 state, and also with the energy dependence of the πd partial-wave amplitude P 2 3 for the π ± d → π ± d and π + d → p p reactions.

The non-strange \(B=2\) system (dibaryon) has been studied using coherent neutral-meson photoproduction from the deuteron, \(\gamma d\rightarrow \pi ^0\pi ^0d\) and \(\gamma d\rightarrow \pi ^0\eta d\), measured with the FOREST detector at the ELPH facility. A rather flat angular distribution of deuteron emission and a peak in the \(\pi ^0d\) invariant-mass distribution give evidence for the 2.15-GeV isovector dibaryon. The excitation function of the total cross section as a function of the \(\gamma d\) center-of-mass energy for the former reaction shows the evidence for the existence of 2.47- and 2.63-GeV isoscalar dibaryons.

An electromagnetic calorimeter, BGOegg, composed of 1320 BGO crystals, has been constructed at the Research Center for Electron Photon Science, Tohoku University to study the structure of hadrons in detail using photo-induced reactions. The design of the new electromagnetic calorimeter and the basic characteristics of the manufactured BGO crystals are described. A performance test has been conducted for the prototype, which consists of 25 crystals arranged in a 5×5 matrix, using positron beams at energies ranging from 100 to 800 MeV. The obtained energy resolution is ( σ E / E ) 2 = ( 0.63 % ) 2 + ( 1.15 % ± 0.04 % ) 2 / ( E / GeV ) + ( 0.42 % ± 0.03 % ) 2 / ( E / GeV ) 2 at room temperature. The energy resolution corresponds to 1.38 % ± 0.05 % for 1-GeV positrons. The position resolution is found to be σ r / mm = ( 3.07 ± 0.03 ) ( E / GeV ) − 0.202 ± 0.008 which corresponds to an angular resolution of approximately 1 ° for 1-GeV positrons.

An electromagnetic calorimeter complex, FOREST, has been constructed for meson photoproduction experiments at the Research Center for Electron Photon Science, Tohoku University. It consists of three types of calorimeters, which are made of pure cesium-iodide crystals, lead scintillating-fiber modules, and lead glass Cherenkov counters. Each calorimeter is equipped with a plastic scintillator hodoscope to identify charged particles. The design and performance of FOREST are described. The energy responses of test calorimeters have been investigated by using 100–800 MeV positron beams. The energy resolutions of the three calorimeters are found to be approximately 3%, 7%, and 5% for 1-GeV photons, respectively. A cryogenic hydrogen/deuterium target system fitted to the FOREST experiments and a newly developed data acquisition system are also presented.

We investigated the use of a simplified soilless tomato culture system fertilized with controlled-release fertilizers (CRF) in northern Japan. The utility of this system was assessed by measuring plant growth, fruit yield, yield components, light interception by plant canopy and nutrient use during August–January. Five levels of fertilizer (5–15 g N per plant) were applied using CRF in a closed system and these were compared with plants given liquid fertilizer (LF) with an electrical conductivity (EC) control in an open system. The CRF was supplied in a water recirculation tank. Total N supply in the LF system (19.7 g N per plant) was higher than in the CRF treatments. In the latter, fresh fruit yield increased with higher fertilizer levels up to 12.5 g N. The fruit yields at 12.5 and 15.0 g N were similar to those with the LF system. The high fresh fruit yield was caused by high dry matter yield regardless of the CRF treatments, which showed similar dry matter distribution to fruit. A high correlation was noted between cumulative light interception and total dry matter production. Although both were high, dry matter distribution to fruit was lower in the LF system than in the CRF treatments. Overall, however, these effects resulted in similar dry and fresh fruit yields between CRF and LF treatments, with excessive vegetative growth in the LF system. We conclude that the closed CRF application system reduced 37% of nutrient use but still gave a fruit yield equivalent to that obtained by culturing with the open LF system and EC-based management.

To identify markers closely linked to the everbearing gene in the octoploid cultivated strawberry Fragaria × ananassa, we conducted linkage analysis based on simple sequence repeat (SSR) polymorphisms. We analyzed F1 populations from three crosses: ‘Sagahonoka’ × ‘Summer-berry’ (94 individuals), ‘Sagahonoka’ × ‘Ever-berry’ (137 individuals), and ‘Hecker’ × ‘Sagahonoka’ (177 individuals). ‘Sagahonoka’ is a June-bearing cultivar; ‘Summer-berry’ and ‘Ever-berry’ are everbearing cultivars classified as older everbearers with a long-day flowering response; ‘Hecker’ is a day-neutral cultivar having F. virginiana ssp. glauca in its ancestry. In these populations, the closest marker, FxaACA02I08C, was mapped at 1.1 cM (‘Summer-berry’ and ‘Hecker’) or 1.5 cM (‘Ever-berry’) from the everbearing gene. We detected correspondence between SSR allele segregation and the flowering habit: one allele was linked to the everbearing trait and the other one to the June-bearing trait. The concordance between the phenotype and marker genotype was more than 98 % in all three populations. These results indicate that the everbearing trait is regulated by a single dominant gene. We also conclude that the locus regulating the everbearing or June-bearing flowering habit is the same in long-day and day-neutral types. The identified markers will be useful for the selection of progeny of various everbearing cultivars.

A micro-pattern gaseous detector based on gas electron multiplier technology (GEM detector) was developed as a new transmission beam monitor for charged-particle therapy to obtain real-time information about the parameters of a therapeutic beam. Feasibility tests for the GEM detector were performed using an 80-MeV proton beam to evaluate the lateral intensity distributions of a pencil beam and the dose delivered to a target. The beam intensity distributions measured with the GEM detector were in good agreement with those measured with an imaging plate while the charge output from the GEM detector was in proportion to that of a reference dose monitor of an ionization chamber design. These experimental results showed that the GEM detector can be used not only as a beam monitor for the position and two-dimensional intensity distribution but also as a dose monitor. Thus, it is possible to simultaneously measure these beam parameters for beam control in charged-particle therapy using a single GEM-based transmission monitor.

Photo-production of hadrons is experimentally studied using 0.8 – 1.2 GeV photon beams at the Research Center for Electron Photon Science, Tohoku University, Japan. Photons areproduced at the bremsstrahlung process by inserting a carbon fiber into the circulating electrons in the 1.3 GeV electron synchrotron. The energy of each photon is determined from the trajectory of the corresponding recoil electron. The energy resolution and time resolution of the current photontagging system is not enough high for the next-generation physics program. We have developed a new system called TaggerIIs. The angular resolution should be higher than 5° to reject the background particles coming from other points than the carbon fiber. The time resolution is required to be less than 200 ps to identify the bunch corresponding to a produced photon. We have adopted a combined system of a multi wire drift chamber and plastic-scintillator hodoscope for the new system. The wire chamber has a frame with length of 1000 mm along pole shape of a bending magnet and consists of 3 sense wire planes (X, X’, X) of wire length of 116 mm. A shape of the cell is hexagonal andthe spacing of the sense wires is 6 mm. The hodoscope consists of 60 plastic scintillators (EJ212) of 30 mm height and 5mm thickness. The width of each scintillator is designed from 5 mm to 30 mm. A performance of the new system has been tested using positron beams. As a result, weachieved that the detection efficiency of the wire chamber was 99%, the angler resolution was 0.60\ensuremath{\unicode{0x25E6 \textbf{and the timing resolution of the hodoscope was 165.8 ps.

We develop an event mixing technique with a missing mass consistency (MMC) cut and a pion energy (PE) cut for the measurement of two-pion Bose-Einstein correlations (BEC) in reactions with only two identical pions produced in the final state. A multi mixing mode that allows one event to be mixed with multiple other events is proposed for the purpose of improving the statistics of mixed samples, and compared with the single mixing mode which requires one original event can be mixed only once. Numerical tests using the {\gamma}p -> {\pi}^0 {\pi}^0 p events are used to testify its ability to measure two-pion correlations. To improve the mixing speed, the optimal MMC cut window is also explored via simulations., Comment: Progress of Theoretical and Experimental Physics, 2017

In the frame of a systematic study of activation cross sections of deuteron induced nuclear reactions on rare earths, the reactions on neodymium for production of therapeutic radionuclides were measured for the first time. The excitation functions of the Nd-nat(d,x) Pm-151.150,Pm-149,Pm-148m,Pm-148g,Pm-146,Pm-144,Pm-143, Nd-149.147,Nd-139m, Pr-142 and Ce-139g nuclear reactions were assessed by using the stacked foil activation technique and high resolution gamma-spectrometry. The experimental excitation functions were compared to the theoretical predictions calculated with the modified model codes ALICE-IPPE-D and EMPIRE-II-D and with the data in the TENDL-2012 library based on latest version of the TALYS code. The application of the data in the field of medical isotope production and nuclear reaction theory is discussed. (C) 2014 Elsevier B.V. All rights reserved.

We report an elemental analysis of murine solid tumors treated with cisplatin-incorporated polymeric micelles (NC-6004) to evaluate the concentration of the drug in the tumor tissue using conventional particle-induced X-ray emission (PIXE) analysis, as well as the spatial distribution in the tumor section using sub-millimeter PIXE analysis. The results reveal that the platinum concentration in the tumor treated with NC-6004 was higher than in that treated with cisplatin, whereas no significant difference was found in platinum concentration between NC-6004 and cisplatin samples in the normal tissue. This suggests that NC-6004 can both provide therapeutic efficacy and reduce the side effects caused by conventional treatment using cisplatin. These results show that PIXE analysis is a powerful tool for research into drug delivery systems.

We present an updated assessment of soil contamination due to the nuclear accident at the Fukushima No. 1 nuclear power plant on 11 March 2011. A safe limit for the spatial dose rate (micro-Sv/h) of gamma rays from 134,137 Cs has been established in this work. Based on this value, the highly contaminated region within Fukushima Prefecture that must be decontaminated could be defined. Moreover, a conceptual model for the chemical speciation that occurred during the accident has been delineated. The compound model Cs 2 CO 3 was found to be meaningful and practical (non-radioactive) to simulate contamination in our decontamination experiments. Finally, we explain the mechanism of action of our soil remediation technique, which effectively reduces the total volume of contaminated soil by isolating the highly Cs-adsorptive clay fraction. The adsorption of non-radioactive Cs atoms on clay particles with diameters

The strangeness photoproduction processes near the threshold have been intensively studied by measuring K + in reactions such as γ + p → K + + Λ ( Σ 0 ) . There has been no reliable data on the neutron and as a consequence theoretical investigation suffered seriously from the lack of the data. We have an effort to measure the γ + d → K 0 ( Λ ) + X reaction in the π + π − ( p π − ) decay channel of K S 0 (Λ) using a liquid D2 target and internally-tagged photon beams ( E γ = 0.80 – 1.08 GeV ) at Research Center for Electron Photon Science (ELPH), Tohoku University. We have renewed the spectrometer (NKS2) and took data with a liquid D2 target in 2005–2007. More recently, we took data in 2010 after a detector upgrade in the vertex region to substantially increase the acceptance. The results of Λ single measurements on a deuterium target were obtained for differential cross-section as a function of momentum, as a function of angle, and integrated cross-section as a function of beam energy. The results are compared with recent theoretical studies: Isobar models (Kaon-MAID and Saclay-Lyon A) and a Regge-plus-Resonance model.

We report on a simple, compact-size and cost-effective multi-channel charge-sensitive preamplifier system using the commercial IC operational amplifiers. An energy resolution of 5.6% at 511 keV is achieved with a large size (10×10×1 mm 3 ) planar CdTe detector. The system is well suited for use with the compound semiconductor detectors in the applications in which the rather high power consumption of the system (320 mW per channel) can be tolerated.

Baryon spectroscopy is important to understand Quantum Chromodynamics at low energies. In this purpose, a series of π 0 and η photoproduction experiments was carried out with an electro-magnetic calorimeter FOREST at Research Center for Electron Photon Science, Tohoku University. The incident tagged bremsstrahlung photon energy ranges from 550 to 1,150 MeV. The differential and total cross sections obtained for π 0 and η photoproduction processes on the proton are consistent with the SAID and MAID calculations. The analysis of π 0 and η photoproduction on the neutron is underway.

In the frame of a systematic study of charged particle production routes of medically relevant radionuclei, the excitation function for indirect production of $^{178m}$Ta through $^{nat}$Hf($\alpha$,xn)$^{178-178m}$Ta nuclear reaction was measured for the first time up to 40 MeV. In parallel, the side reactions $^{nat}$Hf($\alpha$,x)$^{179,177,176,175}$W, $^{183,182,178g,177,176,175}$Ta, $^{179m,177m,175}$Hf were also assessed. Stacked foil irradiation technique and $\gamma$-ray spectrometry were used. New experimental cross section data for the $^{nat}$Ta(d,xn)$^{178}$W reaction are also reported up to 40 MeV. The measured excitation functions are compared with the results of the ALICE-IPPE, and EMPIRE nuclear reaction model codes and with the TALYS 1.4 based data in the TENDL-2013 library. The thick target yields were deduced and compared with yields of other charged particle ((p,4n), (d,5n) and ($^3$He,x)) production routes for $^{178}$W.

A macroporous silica-based supramolecular recognition absorbent (Calix[4] + Dodecanol)/SiO2–P, was prepared by successive impregnation and fixing the 1,3-[(2,4-diethylheptylethoxy)oxy]-2,4-crown-6-Calix[4]arene (Calix[4]arene-R14) and its molecule modifier 1-Dodecanol onto SiO2 silica-based polymer support. The characterization of (Calix[4] + Dodecanol)/SiO2–P was examined by thermal gravimetry and differential thermal analysis and electron probe microanalysis. Relatively large separation factors of Cs and other metal ions (α Cs/M + ) above 60 were obtained in the presence of 3 M HNO3. The adsorption data of Cs(I) fitted well with Langmuir isotherm and the maximum adsorption capacity was estimated to be 0.19 mmol g−1. The Cs(I) in 3 M HNO3 were also effectively adsorption on (Calix[4] + Dodecanol)/SiO2–P in the column operation, and the loaded Cs(I) was successfully eluted with an eluent of H2O. The column packed with (Calix[4] + Dodecanol)/SiO2–P had excellent reusability after three cycles.

A crown ether loaded resin was prepared by successive impregnation and fixing the 4′,4′(5″)-di(tert-butylcyclohexano)-18-crown-6 (DtBuCH18C6) and its molecule modifier, 1-dodecanol, onto the porous silica/polymer composite support (SiO2-P particles). The characterization of DtBuCH18C6 loaded resin was examined by thermal gravimetry and differential thermal analysis and electron probe microanalysis. The adsorption behavior of Sr(II), Cs(I), Ru(III), Pd(II), La(III), Nd(III), Sm(III), Gd(III), Zr(IV), and Mo(VI) was investigated by the batch method. Furthermore, the column test for Sr (II) was performed. The batch experiments were carried out by varying the shaking times, HNO3 concentration, and initial concentration of metal ions. A relatively large K d value above 182 cm3/g for Sr(II) was obtained in the presence of 3 M HNO3. In contrast, the K d values of Cs(I), Ru(III), Pd(II), La(III), Nd(III), Sm(III), Gd(III), Zr(IV), and Mo(VI) were considerably lower than 10 cm3/g. The adsorption of Sr(II) was foun...

From a viewpoint of direct separation of trivalent minor actinides (MA: Am, Cm etc.) from fission products (FP) including rare earths (RE) in high level radioactive liquid waste, the authors have developed a simplified separation process using a single column packed with novel extraction adsorbents. Attention was paid to a new type of nitrogen-donor ligand, R-BTP (2,6-bis(5,6-dialkyl-1,2,4-triazin-3-yl)pyridine, R: alkyl group) as an extractant because it has higher extraction selectivity for Am(III) than RE(III). Since the R-BTP ligands show different properties such as adsorbability and stability when they have different alkyl groups, several R-BTP extraction adsorbents were prepared by impregnating the R-BTP ligands with different alkyl groups (isohexyl-, isoheptyl- and cyheptyl-BTP) into a porous silica/polymer composite support (SiO2-P particles). This work investigated: (1) fundamental properties of the synthesized R-BTP/SiO2-P adsorbents, (2) adsorption and desorption properties of Am and FP in nit...

In order to develop a direct separation process for trivalent minor actinides from fission products in high level liquid waste (HLLW) by extraction chromatography, a novel macroporous silica-based 2,6-bis(5,6-diisohexyl)-1,2,4-triazin-3-yl)pyridine resin (isohexyl-BTP/SiO2-P resin) was prepared. The content of isohexyl-BTP extractant in the resin was as high as 33.3 wt%. The resin exhibited much higher adsorption affinity for Am(III) in 2–3 M (mol/L) HNO3 solution over U and FP which are contained in HLLW. The kinetic data were analyzed using pseudo-second-order equation. The results suggested that the Eu(III), Gd(III), and Dy(III) adsorption was well explained by the pseudo-second-order equation. Quantitative desorption for adsorbed elements was achieved by using H2O or thiourea as eluting agents. However, the kinetics of adsorption and desorption were rather slow and this drawback needs to be resolved. Stability of the resin against HNO3 was also examined. It was found that the resin was considerably stable against ≤4 M HNO3 solution for the reasons of an extremely small leakage of the extractant into the solution from the resin and the adsorption performance keeping for rare earths in 3 M HNO3 solution.

The detection efficiency of the submilli-PIXE camera was improved by installing a new X-ray detector with a smaller distance from specimens. The distortion of elemental images caused by position dependent detection efficiency was corrected by estimating the detection efficiency based on the geometrical configuration of the detection system. The detection efficiency of characteristic X-rays from heavy elements such as iron and bromine became from 11 to 23 times higher than the previous system. The signal to noise ratios was improved from 1.8 to 2.5 times higher and detection limit was also decreased from 1/8 to 1/6 compared to the previous system. The in-air submilli-PIXE camera with improved detection system can be useful to biological applications.

The space radiation dose rates at several points in Miyagi prefecture and their time dependencies were measured. Radiation exposure was mainly caused by 131 I at the earlier stage of Fukushima first nuclear power accidents and then by 134 Cs and 137 Cs . We inspected radioactive contamination for food produced in Miyagi prefecture and Fukushima city. As the result, almost all food were safe.

NABESHIMA-DANTSU is the name of the first Japanese-made carpets which have been produced in the Nabeshima domain (Saga Prefecture) since the later Edo period. The NABESHIMA-DANTSU carpets have been woven from one kind of cotton, and have been dyed with various dyes and color fixatives. We analyzed pieces of the NABESHIMA-DANTSU carpets stored in the Saga Prefectural Museum and the Saga Prefectural Art Museum, by using PIXE method in order to detect dyeing methods used in them. We also analyzed dyes, color fixatives and cotton used in the traditional Japanese dyeing method. From the NABESHIMA-DANTSU carpets, small amounts of dyed and non-dyed samples were picked up and were analyzed by in-air PIXE system at Tohoku University. It was found that Fe and Cu are related to the parts dyed orange, and Al is related to the parts dyed green. The analysis of cotton dyed by the traditional Japanese method shows the similar results. It means that both colors in the NABESHIMA-DANTSU carpets were dyed by the traditional Japanese method which uses natural dyes. From literature documentation, it is considered that synthetic dyes were mainly used during the Taisho era. The present result shows that natural dyes might have been used in the Taisho era. In this research the PIXE method has proved to be very effective for the analysis of dyeing methods.

Naturally shed deciduous teeth are potentially useful as a biomarker of environmental exposure. To assess the prenatal environment of child, we tried to present the neonatal line on the elemental maps and investigate the trace elements in pre- and post-natally formed tooth enamel using micro-PIXE. Generally, the neonatal line is observed more clearly in the tooth from child who has some difficulties at birth. In this study, five deciduous teeth from five children with developmental disorders were used for analysis. Seven trace elements ( Na , Mg , Si , Cl , Fe , Zn , and Sr ) were detected in enamel of all five teeth. The line, it was thought neonatal line, was observed on the elemental map of Ca and P in the tooth from the child with serious birth complications. In order to compare the elemental concentration between pre- and post-natal enamel, concentration variation of elements were projected along the line perpendicular to the neonatal line. Lower Ca concentration in prenatal enamel was observed. By tracing the location of neonatal line on the other elemental maps, the concentrations of detected trace elements were compared in the same way. The differences of concentration of these trace elements between pre- and post-natal enamel were not clear because of much statistic variation. We could determine the trace elemental profiles and concentrations around the neonatal line in the enamel from the child with serious birth complications.

The great East Japan earthquake consisted of three catastrophes. The first one was the earthquake, the second one was the tsunami and the third one was nuclear power plant accidents. The magnitude 9 was recorded. After the earth quake, huge tsunami waves of above 16m height hit the east coast of Northeastern Japan. Many people died and many things were lost. The tsunami caused the accident of Fukushima first nuclear power plant which resulted in a serious radioactive pollution.

We have been developing microcapsules that release anticancer drug with response to radiation. We attempted to decrease the diameter of capsules. Then, two categories were tested in VIVO in C3He mice: (1) the antitumor effect in combination with radiation and subcutaneously injected nanocapsules, (2) the kidnetics of nanocapsules when they were injected intravenously. Microcapsules were produced by spraying a mixture of 3.0 % hyaluronic acid, 2.0 % alginate, 3.0 % H2O2, and 0.3 mmol carboplatin (Pt containing anticancer drug) onto a mixture of vibrated 0.3 mol FeCl 2 and 0.15 mol CaCl 2. The antitumor effect was measured by measuring tumor diameter every day. The kinetics of microcapsules were expressed as the numbers of capsules in 5 views (25 × 25 μm) of micro PIXE camera and Pt concentration of quantiative PIXE. The generated microcapsules 752 ± 64 nm, which were significantly downsized relative to previous capsules. The accumulations of capsules in lungs, liver, and kidneys were decreased by downsizing, whereas those of tumors were increased. By adjusting Pt concentration in tumor, there were no significant differences in antitumor effect between not downsized and downsized microcapsules with combination with radiation. Decreased trapping of downsized microcapsules to lungs, liver, and kidneys, also increased trapping in tumors will lead to new targeted chemoradiotherapy via intravenous injection of microcapsules.

We studied the structure of radioactive cesium distribution in soil and found the exponential dependence. This behavior could be explained theoretically. We developed a useful method to decontaminate the soil contaminated with radioactive cesium atoms. We applied our method to the contaminated school yards of elementary schools of Marumori town and decontaminated total area of about 7000 m2.

The K-mean clustering algorithm was employed for processing signal waveforms from TlBr detectors. The signal waveforms were classified based on its shape reflecting the charge collection process in the detector. The classified signal waveforms were processed individually to suppress the pulse height variation of signals due to the charge collection loss. The obtained energy resolution of a 137 Cs spectrum measured with a 0.5 mm thick TlBr detector was 1.3% FWHM by employing 500 clusters.

In the frame of a systematic study of the activation cross-sections of deuteron induced nuclear reactions, excitation functions of the 103 Rh(d,x) 100,101,103 Pd, 100g,101m,101g,102m,102g Rh and 103g Ru reactions were determined up to 40 MeV. Cross-sections were measured with the activation method using a stacked foil irradiation technique. Excitation functions of the contributing reactions were calculated using the ALICE-IPPE, EMPIRE-II and TALYS codes. From the measured cross-section data integral production yields were calculated and compared with experimental integral yield data reported in the literature. From the measured cross-sections and previous data, activation curves were deduced to support thin layer activation (TLA) on rhodium and Rh containing alloys.

In the frame of a systematic study on activation cross-sections of deuteron induced reactions experimental excitation functions on 55 Mn were measured with the activation method using the stacked foil irradiation technique up to 40 MeV. By using high resolution γ-ray spectrometry, cross-section data for the production of 56,54,52 Mn and 51 Cr were determined. Comparison with the earlier published data and with the results predicted by the ALICE-IPPE and EMPIRE-II theoretical codes – improved for more reliable calculations for d-induced reactions – and with data in the TENDL 2010 libraries are also included. Thick target yields were calculated from a fit to our experimental excitation curves and implications for practical applications in industrial (Thin Layer Activation) accelerator technology are discussed.

Planar detectors, strip detectors and double-sided strip detectors were fabricated from TlBr crystals grown by the traveling molten zone method using zone-purified material. The detector performance including the leakage current, energy resolutions and timing performance were evaluated in order to assess the capability of the detectors for PET and SPECT applications. The TlBr detectors exhibited excellent spectroscopic performance at room temperature. An energy resolution of 3.4% FWHM at 511 keV was obtained from a TlBr planar detector 1 mm thick. A TlBr strip detector 1 mm thick with four anode strip electrodes exhibited almost uniform detector performance over the strips with the average energy resolution of 4.4% FWHM at 511 keV. A TlBr double-sided strip detector exhibited an energy resolution of 6.3% FWHM for 122 keV gamma-rays. Coincidence timing spectra between a TlBr planar detector and a BaF 2 scintillation detector were recorded at room temperature. Timing resolutions of 14 ns and 24 ns were obtained from TlBr detectors 0.5 mm and 1 mm thick, respectively. By cooling the detector to 0 oC, an improved timing resolution of 12 ns was obtained from a TlBr detector 1 mm thick.

Cross-sections of deuteron induced nuclear reactions on gold were measured up to 40 MeV by using the standard stacked foil irradiation technique and high resolution gamma-ray spectroscopy. Experimental cross-sections and derived integral yields are reported for the 197 Au(d,xn) 197m,197g,195m,195g Hg and 197 Au(d,x) 198g,196m,196g,195,194 Au nuclear reactions. The experimental data are analyzed and compared to literature and predictions of the ALICE-IPPE, EMPIRE and TALYS theoretical model codes. The application of the new cross-sections for accelerator technology, medical radioisotope production, thin layer activation and dose calculation is discussed.

Digital pulse processing and electronic noise analysis are proposed for improving energy resolution in planar thallium bromide (TlBr) detectors. An energy resolution of 5.8% FWHM at 662 keV was obtained from a 0.5 mm thick planar TlBr detector at room temperature using a digitizer with a sampling rate of 100 MS/s and 8 bit resolution. The electronic noise in the detector–preamplifier system was measured as a function of pulse shaping time in order to investigate the optimum shaping time for the detector. The depth of interaction (DOI) in TlBr detectors for incident gamma-rays was determined by taking the ratio of pulse heights for fast-shaped to slow-shaped signals. FWHM energy resolution of the detector was improved from 5.8% to 4.2% by implementing depth correction and by using the obtained optimum shaping time.

Platinum concentration in a murine solid tumor treated with proton therapy combined with the platinum-based chemotherapeutic agent cisplatin [cis-diamminedichloro-platinum(II) (CDDP)] was investigated with conventional and submilli-PIXE (particle-induced X-ray emission) analyses. An enhanced therapeutic effect on tumor growth was observed in NFSa fibrosarcoma tumors in mice when proton therapy with a single dose of 30 Gy and CDDP treatment (10 mg/kg) were combined. The conventional PIXE analysis based on an internal standard method showed that the platinum concentration was 2.6 ± 0.3 µg/g for the tumor samples excised from the mice 6 h after the CDDP administration. The submilli-PIXE analysis of the tumor sections showed that spatial distribution of CDDP may be more or less uniform in the tumor. Copyright © 2011 John Wiley & Sons, Ltd.

In machine workshops and laboratories, specific materials and chemicals are processed and toxic aerosols may be released into air. For protection of the health of employees working in that environment, it is therefore important to gather knowledge about aerosol composition related to specific working activity and to monitor the aerosol concentration levels. An extensive study of this kind was performed in the machine workshop of Jožef Stefan Institute using a combination of time-, particle size- and location-resolved sampling. The majority of samples were analyzed by particle induced X-ray emission (PIXE) and energy dispersive X-ray spectrometry (EDX) techniques and the main results have been described in a separate paper. Here, we concentrate on presenting the results of individual particle analysis of an aerosol emission that is related to a short, unexpected episode related to the restoration of old furniture. Although the activity was identified by a strong correlation of elemental concentrations in a series of samples taken with a 2-h time resolution, the single microparticle analysis of the cascade impactor samples taken over the longer time period offered an additional insight into the corresponding aerosol composition. The analysis of the aerosol size-selected samples revealed strong pair correlations among concentration levels of Ba, Zn, S, Pb and Cl in a number of individual microparticles. The result is explained by the emission of Ba- and Pb-rich aerosol particles in course of removal of the old white paint layers. The former particles appear to originate from white pigment called lithopone, which is a mixture of BaSO4 and ZnS, and the latter group seems to be related to Pattinson's white lead PbCl·OH. Although the individual particle analysis by itself is in principle capable of assigning the emission source, in this case, it was used as an excellent tool to enhance the quality of source characterization. Copyright © 2011 John Wiley & Sons, Ltd.

A new position-sensitive detection technique for semiconductor detector fabrication was developed for a high-spatial-resolution PET scanner with CdTe detectors. We constructed a two-dimensional sensitive CdTe detector with a size of 20×9.5×1.0 mm 3 , of which one side had 1 mm wide resistive strip anodes. Using our method, we succeeded in obtaining a linear presentation of a two-dimensional detection image from a distorted detection image. We showed that the detection positioning within a width of 1.2 mm for the x -axis was obtained with a confidence level of 0.98, and a spatial resolution of approximately 1 mm FWHM was obtained for the y -position. Our newly developed position-sensitive detector will enable the construction of a high-performance PET scanner due to the detector's high spatial resolution and good sensitivity; such a PET scanner is now under construction in our laboratory.

Particle-induced X-ray emission (PIXE) analysis of Lentinula edodes (Shiitake) mushrooms contaminated with radioactive cesium was performed to study relationships between concentrations of principal elements of shiitake mushrooms and their radioactive cesium levels. After the Fukushima nuclear disaster caused by the huge tsunami on March 11, 2011, we collected five shiitake samples in Marumori town, Miyagi Prefecture, on April 21, 2011. The mean radioactive level of the samples was 228 Bq/kg (the sum of 134 Cs and 137 Cs ). The preliminary result of PIXE analysis using an internal standard method has demonstrated that shiitake mushrooms significantly collect rubidium as well as potassium. It is suggested that radioactive cesium is accumulated in shiitake just like rubidium during the course of potassium uptake.

Microencapsulated anti-RLIP76 was tested in vivo using C 3 He / J mice to determine the increasing of antitumor effects by chemotherapeutic agent efflux inhibition during chemoradiotherapy. Microcapsules were produced by spraying a mixture of 3.0% hyaluronic acid, 2.0% alginate, 3.0% H 2 O 2, and 0.3 mmol carboplatin onto a mixture of 0.3 mol FeCl 2 and 0.15 mol CaCl 2. Microcapsules were subcutaneously injected into MM46 tumors previously inoculated into the left hind legs of C 3 He / J mice. Subsequent radiotherapy consisted of tumor irradiation with 10 Gy or 20 Gy 60 Co . The antitumor effects of microcapsules were tested by measuring tumor size and monitoring tumor growth. Three types of adverse effects were considered: fuzzy hair, loss of body weight, and mortality. Carboplatin levels were monitored using particle-induced X-ray emission (PIXE) and a micro-PIXE camera. Anti-RLIP76 inhibited the efflux of carboplatin from tumor tissue, which led to an increase in the concentration of carboplatin. Higher carboplatin concentration significantly increased the combined antitumor effect of radiation and chemotherapy. A significant decrease in adverse effects was also observed with microencapsulated anti-RLIP76.

スギ樹皮の鉢物花卉栽培への利用を目的として，シクラメンを材料にスギ樹皮培地の撥水性と生育阻害性の改善を検討した．供試したスギ樹皮は，重力水排出時の固相率12％，液相率55％，気相率32％から構成されていた．また，仮比重が0.15 g・mL−1，pHが6.13であった．スギ樹皮培地に非イオン系界面活性剤（アクアグロー2000L）を処理することにより，吸水性が向上した．直径15 cmのポットに定植した中輪系シクラメン‘F1Kミディコーラス’の点滴灌水栽培において，界面活性剤処理は生育に影響しなかった．一方，エブ・アンド・フローによる底面給水栽培では，界面活性剤処理により乾燥に伴う培地の水分張力の上昇程度が小さくなり，培地の撥水および植物の萎凋が抑えられ，生育が促進された．硫酸第一鉄0.3％溶液に浸漬処理したスギ樹皮培地で栽培すると，直径15 cmのポットに定植した中輪系シクラメン‘F1Kミディコーラス’の点滴灌水栽培，および，直径9 cmのポットに定植した小輪系シクラメン‘F1ミラクルディープローズ’の底面給水栽培のいずれにおいても，無処理の区と比較して生育が著しく促進された．植物の根の生育を阻害すると考えられるスギ樹皮中のタンニンが，硫酸第一鉄と結合して不活性化され，シクラメンの生育が改善されるものと推察された．

Wall thinning of piping made of carbon steel when exposed to high temperature water flow and va-por is a common problem in all types of these plants. Oxide layer formation and dissolution should be related to the mechanism of corrosion. In order to understand the mechanism of corrosion, characterization of oxide layer including elemental concentration in the localized area is indispensable. In this study, simultaneous μ-PIXE/RBS/SEM analysis system was developed to obtain elemental characterization on oxide layer in localized area as well as to obtaining surface condition. Carbon steel samples were oxidized dynamically for 1100 hours and analyzed by the system. The oxide layer is not uniform even in the localized area of 30 × 30 μm2. In the chromium content of 0.003 wt%, oxide layer thickness varied from 0.71 to 1.2 mg/cm2. While accumulation of chromium is seen in the map, accumulation is not related to the iron distribution. Chromium and iron ratio in the accumulated region is more than five times higher than that of the other area. The higher chromium and iron ratio indicates that chromium migrate from substrate to oxide layer. In the chromium content of 1.01 wt%, oxide layer thickness varies from 1.4 to 3.9 mg/cm2. Oxide layer is thicker than that in the chromium content of 1.01 wt%, which is opposite to the result in the static condition. Large variation of X-ray yield of iron indicates that dissolution of the oxide layer might occur during long exposure to the water flow. These results of this experiment obviously show the simultaneous μ-PIXE/RBS and SEM analysis system to be useful for better understanding of the corrosion mechanism.

In order to separate trivalent minor actinides (Am and Cm) from high-level liquid waste generated in a nuclear fuel reprocessing process, a silica-based macroporous TODGA (N,N,N′,N′-tetraoctyl-3-oxapentane-1,5-diamide) adsorbent (TODGA/SiO2-P) was prepared. In this study, the adsorption characteristics of some trivalent rare earths (Y, Nd, and Eu), whose separation behaviors were similar to those of the minor actinides from HNO3 solution with the TODGA/SiO2-P adsorbent, and the chemical stability of the adsorbent against the HNO3 solution were evaluated experimentally. It was found that the adsorbent exhibited a quite strong adsorption especially for Y(III). The standard enthalpy change for the Y(III) adsorption was determined to be −2.5kJ·mol−1 using the van't Hoff equation, which indicates that the adsorption was an exothermic reaction. The results of chemical stability experiments showed that the adsorbent had relatively excellent properties in long-time contact with the HNO3 solution.