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Particulate matter (PM) collected hourly by an automated sampling unit of the Atmospheric Environmental Regional Observation System (AEROS) was characterized by external micro-particle-induced X-ray emission (PIXE) analysis and imaging. Micro-PIXE analysis revealed the overall elemental composition and differences in the elemental composition ratios of PM2.5 and PM2.5-10 collected as individual spots on Teflon tape filters from the unit, and the blank Teflon tape showed a clean background. Moreover, micro-PIXE imaging visualized regions with different elemental compositions in PM2.5 and PM2.5-10. Accumulation of PM2.5 particles was found frequently on tape filters which accounted approximately for 70% of particular elemental composition including heavy metals like iron, compared to that from whole area. The results suggest that PIXE effectively reveals elemental composition of hourly-collected PM by AEROS system for futuristic application for source apportionment of those over Japan.

Lithium distribution in the composite electrode of an all-solid-state lithium battery was analyzed by microbeam- particle-induced X-ray emission and gamma-ray emission techniques. Two kinds of pellet-type cells, incorporating LiCoO2 as the cathode-active material and the superionic conductor Li10GeP2S12 as the solid electrolyte, were prepared: one in the as-prepared state and the other in the charged state. Changes in the lithium distribution near the interface of the composite cathode and separator were visualized by normalizing lithium/cobalt and lithium/ germanium intensity. Lithium extraction from LiCoO2 due to charging was confirmed by the decrease in normalized intensity at the cathode composite region. The evaluation of the lithium concentration variation in the composite electrode for the all-solid-state battery during the electrochemical reactions could provide essential information for construction of a favorable composite electrode to enable preparing high-performance all-solid-state lithium batteries.

Lithium distribution in the composite electrode of an all-solid-state lithium battery was analyzed by microbeamparticle-induced X-ray emission and gamma-ray emission techniques. Two kinds of pellet-type cells, incorporating LiCoO2 as the cathode-active material and the superionic conductor Li10GeP2S12 as the solid electrolyte, were prepared: one in the as-prepared state and the other in the charged state. Changes in the lithium distribution near the interface of the composite cathode and separator were visualized by normalizing lithium/cobalt and lithium/ germanium intensity. Lithium extraction from LiCoO2 due to charging was confirmed by the decrease in normalized intensity at the cathode composite region. The evaluation of the lithium concentration variation in the composite electrode for the all-solid-state battery during the electrochemical reactions could provide essential information for construction of a favorable composite electrode to enable preparing high-performance all-solid-state lithium batteries.

全固体リチウムイオン電池の高性能化には、充電状態の変化に伴うリチウム分布の変化の可視化が必須である。しかし、従来技術ではその可視化が困難であった。今回、3MeVのプロトンビームが通過できる薄いポリイミド膜を用いた測定用の全固体リチウムイオン電池セルを開発し、その可視化を試みた。実際に全固体リチウムイオン電池セルの充電電圧を3.6V〜4.2Vに変化させ、3MeVプロトンマイクロビームをプローブとするマイクロPIXE/PIGEで元素分布を分析したところ、正極と固体電解質の界面において充電電圧の上昇に伴うリチウム濃度低下が可視化された。リチウム濃度の低下は全固体リチウムイオン電池の欠点である界面抵抗の原因と考えられており、今後、開発した電池セルを用いたマイクロPIXE/PIGEを活用することにより、全固体リチウムイオン電池の性能向上に資するデータが得られると期待される。, Materials Research Meeting 2021

Two different types of SiAlON phosphors, namely, α-SiAlON:Eu and β-SiAlON:Eu, that have been developed as scintillators are evaluated for their luminescent properties by ion-beam-induced luminescence (IBIL) analysis under 2–3-MeV H+-microbeam irradiation. The IBIL spectra show that both α-SiAlON:Eu and β-SiAlON:Eu have bright luminescence similar to that of ZnS:Ag scintillators. The α-SiAlON:Eu and β-SiAlON:Eu IBIL spectra have peaks at wavelengths of 605 and 540 nm, respectively, which lie in the preferred range of general optical sensors. As the irradiation progresses, the IBIL intensity of conventional ZnS:Ag scintillators decreases sharply, whereas that of the two SiAlONs remains largely unchanged. Moreover, the thermal resistivity of β-SiAlON:Eu is measured by IBIL under temperature control. The IBIL intensity retains half of its original value at the highest temperature of 773 K. The present experimental results reveal the two different types of SiAlON to be potential candidates for a scintillation monitoring tool for harsh environments in which intense beam irradiation at high temperature can be expected.

Direct observation of the lithiation and de-lithiation in lithium batteries on the component and microstructural scale is still difficult. This work presents recent advances in MeV ion-beam analysis, enabling quantitative contact-free analysis of the spatially-resolved lithium content and state-of-charge (SoC) in all-solid-state lithium batteries via 3 MeV proton-based characteristic x-ray and gamma-ray emission analysis. The analysis is demonstrated on cross-sections of ceramic and polymer all-solid-state cells with LLZO and MEEP/LIBOB solid electrolytes. Different SoC are measured ex-situ and one polymer-based operando cell is charged at 333 K during analysis. The data unambiguously show the migration of lithium upon charging. Quantitative lithium concentrations are obtained by taking the physical and material aspects of the mixed cathodes into account. This quantitative lithium determination as a function of SoC gives insight into irreversible degradation phenomena of all-solid-state batteries during the first cycles and locations of immobile lithium. The determined SoC matches the electrochemical characterization within uncertainties. The presented analysis method thus opens up a completely new access to the state-of-charge of battery cells not depending on electrochemical measurements. Automated beam scanning and data-analysis algorithms enable a 2D quantitative Li and SoC mapping on the µm-scale, not accessible with other methods.

This study investigated the interaction of inorganic aqueous Eu(III), Pb(II), and U(VI) with Paramecium sp., a representative single-celled protozoan that lives in freshwater. Living and prekilled Paramecium cells were tested. The prekilled cells were killed with a fixative. After 24 h exposure of the cells to inorganic aqueous solutions containing Eu(III) or U(VI), analyses by microparticle-induced X-ray emission with a focused beam (1 μm) did not detect Eu and U in the living cells, whereas Eu and U were detected in the prekilled cells. Size exclusion chromatography coupled with on-line ultraviolet-visible detection and elemental detection by inductively coupled plasma mass spectrometry of the aqueous phases collected after the living cell experiments revealed that a fraction of the Eu, Pb, and U in the aqueous phase bound to a large (ca. 250 kDa) Paramecium biomolecule and formed a metal-organic complex. The characteristics of the biomolecule were consistent with those of the soluble glycoproteins covering the surfaces of Paramecium cells. These results show that Paramecium cells transform inorganic aqueous Eu, Pb, and U to organic complexes. This paper discusses the relation between this novel complexation and the sorption of these heavy elements on Paramecium cells.

A high-speed wavelength-dispersive ion beam induced luminescence (IBIL) detector was demonstrated using a newly developed photon-counting mode spectrometer based on a 32-channel photomultiplier tube (PMT) array combined with a high-efficiency optical grating. An integrated electrical circuit based on a field-programmable gate array was prepared to process 32 individual IBIL signals from different PMT channels. These signal were further processed conventionally by a micro-PIXE analysis system. Individual pulses corresponding to each IBIL photon incident from the PMT array were multiplexed into a single analog chain with different amplitudes corresponding to the channel number of the array. The signal had a pulse width of 2 μs in the amplitude range 0–10 V. The results suggest that the demonstrated IBIL detector can be used to detect differences in IBIL images at multiple wavelengths.

A compact ion microbeam system, which comprises a three-stage acceleration lens and a duoplasmatron-type ion source and produces beam of several hundred kiloelectron-volts, has been developed to form a beam that has a diameter of several micrometers. Previous studies have indicated that a small divergence angle of an incident beam is required to improve the demagnification of the three-stage acceleration lens. A simulation of an ion beam extraction demonstrated that the optimum distance between the anode and the extraction electrode in the ion source could lead to an ion beam being generated with the smallest possible divergence angle. As a result, a hydrogen beam with a 2.6 μm diameter was experimentally produced at 120 keV.

Continuous measurement of ion beam induced luminescence (IBIL) spectra was demonstrated with organic targets of nicotinamide adenine dinucleotide (NADH), tryptophan, riboflavin, and a polycyclic aromatic hydrocarbon (PAH), which are typically used as markers of biological contaminants in airborne particles. A 3 MeV external proton microbeam from a single-ended accelerator at QST/Takasaki was used to probe for changes in the IBIL spectrum using micro-optics sharing a focal point with the microprobe. We find that the decay of IBIL spectra from NADH and riboflavin varied by target organic species. Moreover, new peaks in the IBIL spectrum were recorded by continuous IBIL spectroscopy from the PAH target after destruction of a peak originally obtained in the initial measurement. These results suggest that IBIL monitoring can detect changes in the chemical composition of organics under focused beam irradiation.

Proceedings of the 27th International Conference on Diamond and Carbon Materials (DCM), Montpellier, FRANCE, SEPT 04-08, 2016; International audience; Single crystal diamond is a suitable material for the next generation particle detectors because of the superior electrical properties and the high radiation tolerance. In order to investigate charge transport properties of diamond particle detectors, transient currents generated in diamonds by single swift heavy ions (26 MeV O$^{5+}$ and 45 MeV Si$^{7+}$) were investigated. Two dimensional maps of transient currents by single ion hits are also measured. In the case of 50 $\mu$m-thick diamond, both the signal height and the collected charge are reduced by the subsequent ion hits and the charge collection time is extended. These results are thought to be attributable to the polarization effect in diamond and it appears only when the transient current is dominated by hole current. In the case of 6 $\mu$m-thick diamond membrane, an "island" structure is found in the 2D map of transient currents. Signals in the islands showed different applied bias dependence from signals in otherregions, indicating different crystal quality. The instability of signals resulting from the polarization effect was also observed in the 6 $\mu$m-thick diamond membrane. Simulation study of transient currents based on the Shockley-Ramo theorem clarifies that the polarization appears only in the irradiated region and both the electric field and the hole lifetime are reduced by the polarization effect

For confirming the feasibility of micrometer scale analysis of lithium distribution in the all-solid-state lithium battery using a sulfide-based solid electrolyte, the cross-section of pellet type battery was analyzed by microbeam particle-induced X-ray emission (PIXE) and particle-induced gamma-ray emission (PIGE) measurements. A three-layered pellet-type battery (cathode: LiNbO3-coated [Formula: see text]/solid electrolyte: [Formula: see text]/anode: [Formula: see text]) was prepared for the measurements. Via elemental mapping of the cross-section of the prepared battery, the difference in the yields of gamma rays from the [Formula: see text] inelastic scattering (i.e., the lithium concentrations) between the composite electrodes and the solid electrolyte layer was clarified. The difference in the number of lithium ions at the composite anode/solid electrolyte interface of ([Formula: see text] mol) in the battery can be clearly detected by the microbeam PIGE technique. Therefore, lithium distribution analysis with a micrometer-scale spatial resolution is demonstrated. Further analysis of the cathode/anode composite electrodes with the different states of charge could provide important information to design a composite for high-performance all-solid-state lithium batteries.

The Compton camera can simultaneously acquire images of multiple isotopes injected in a body; therefore, it has the potential to introduce a new subfield in the field of biomedical imaging applications. The objective of this study is to assess the ability of a prototype semiconductor-based silicon/cadmium telluride (Si/CdTe) Compton camera to simultaneously image the distributions of technetium (

“Clickable” nanowires with well-defined and uniform structures made of conjugated polyfluorene polymers were successfully fabricated by single particle nanofabrication technique (SPNT). Poly[(9,9-dihex-5-yn-1-ylfluorenyl-2,7-diyl)-co-(9,9′-di-n-octylfluorenyl-2,7-diyl)] (F6E8) and poly[(9,9-dihex-5-yn-1-ylfluorenyl-2,7-diyl)-co-(2,2′-bithiophene)] (F6E2T) underwent an efficient cross-linking reaction upon irradiation, resulting in formation of one-dimensional nanostructures with high and desired aspect ratio reaching up to 200. Alkyne groups on the surface of nanowires were functionalized effectively by click reaction with fluorescent 5-TAMRA-PEG3-azide, which was confirmed by confocal microscopy. Substrates functionalized with the nanowires provide dramatic expansion of “clickable” surface area immobilized directly with TAMRA, and the fluorescence resonance energy transfer (FRET) processes between TAMRA and nanowire backbones are demonstrated as biological sensing platforms.

To investigate electrically-active deep levels in high-resistivity single-crystalline diamond, particle-induced charge transient spectroscopy (QTS) techniques were performed using 5.5 MeV alpha particles and 9 MeV carbon focused microprobes. For unintentionally-doped (UID) chemical vapor deposition (CVD) diamond, deep levels with activation energies of 0.35 eV and 0.43 eV were detected which correspond to the activation energy of boron acceptors in diamond. The results suggested that alpha particle and heavy ion induced QTS techniques are the promising candidate for in-situ investigation of deep levels in high-resistivity semiconductors.

Direct observation of lithium concentration distribution in lithium-ion battery composite electrodes has been performed for the first time. Lithium-ion battery model cells for particle induced X-ray emission (PIXE) and particle induced gamma ray emission (PIGE) measurements were designed and fabricated. Two dimensional images of lithium concentration in LiFePO4 composite electrodes were obtained with PIXE and PIGE by scanning the proton microbeam for various charged states of the electrodes. Lithium concentration in LiFePO4 composite electrodes was decreased from the contact interface between LiFePO4 electrode and liquid electrolyte during the charge reaction.

We studied feasibility of detection of a gap which is located across a beam track by measuring low-energy (63–68 keV) photons generated by beam irradiation. An experiment was performed with the Heavy Ion Medical Accelerator in Chiba (HIMAC). A 12C beam having 290 MeV/u was injected on a target consisting of two acrylic blocks. These two blocks were placed with a 10 mm gap along the beam axis. A detection system consisting of a semiconductor detector, a lead collimator having a slit, and borated polyethylene blocks was placed on a movable stage to detect low-energy photons emitted perpendicularly to the beam axis. The position of the detection system was moved at 2 mm intervals along the beam axis. It was found that the yield of 63–68 keV photons was clearly correlated with the position of the detection system. The position at which the yield curve had the lowest value agreed with the gap position. We also confirmed that the experimental result was well reproduced by a Monte Carlo simulation that includes generation of secondary electron bremsstrahlung.

The nanoparticles, which releases anticancer drug with response to radiation, were developed. Also, two categories were tested: (i) their ability to release anticancer drug in vitro; and (ii) their kinetics in the body, when they were injected through tail vein of BALB/c mice in vivo. To prepare the particles, hyaluronic acid and protamine were mixed into carboplatin solution, and reacted for 30 min in room temperature. Those particles were exposed to a single dose of 10 Gy of 140 KeV X-ray. Their ability to release carboplatin with response to radiation was expressed as the percentage of ruptured particles, basing on images of particles, using micro PIXE camera. The amount of released carboplatin was measured by quantitative PIXE method. The kinetics of particles in body was assessed by counting the number of particles, which were trapped in lungs, using micro PIXE camera. The mean diameter of particles was 743 ± 34 nm. By irradiation, 59.3 ± 7.23% of particles ruptured, and 95.9 ± 2.3% carboplatin was released from particles. The trapped particles in lungs were significantly reduced, when compared with previous alginate-hyaluronic particles.

We have been developing a medical imaging technique using a Compton camera. This study evaluates the feasibility of clear imaging with

Microstructure patterning in single-crystal chemical vapor deposition (SC-CVD) diamond films was investigated to establish a direct patterning procedure by using proton beam writing with a focused microbeam of protons. Test microstructural patterns on SC-CVD diamond with different total fluences from 0.5 to 10 pC/μm2 were formed with a probe diameter of approximately 1 μm, a maximum scanning area of 800 × 800 μm, and a beam current of up to 100 pA. The most intensively irradiated pattern with beam fluence of 10 pC/μm2 was visualized with both transmission and reflection optical microscopy. The other patterns created with lower beam fluences were characterized by the changes in reflective index and were visible only in the transmission microscopy images. The depth of patterns was precisely controlled by changing proton energies in range of 0.75–3 MeV. The structures in depth from 5 to 45 μm were successfully observed in optical microscope images.

Herein, we review the last half decade of progress in ion-microbeam technology and applications at the Takasaki Ion Accelerators for Advanced Radiation Applications facility. Materials were microanalysed with the light-ion-microbeam system by combining micro-particle-induced X-ray and γ-ray emission, nuclear-reaction analysis and micro-ion-beam-induced luminescence to analyse elements, including light elements such as lithium, boron or fluoride, and also their chemical states. For microfabrication, we used particle-beam writing and techniques of maskless patterning to processes materials without etching. The goal was to develop optical, magnetic or other new types of microdevices with both light-ion and the heavy-ion microbeam systems. In addition, techniques were developed to monitor in real time every individual ion injection by using an efficient scintillator or a thin diamond particle detector in both heavy-ion and high-energy heavy-ion microbeam systems.

A focused 750 keV proton microbeam was used to fabricate an embedded Mach–Zehnder (MZ) optical waveguide in a polydimethylsiloxane (PDMS) film for interferometer application. The sample position was precisely controlled by a mechanical stage together with scanning microbeam to form an embedded MZ waveguide structure within an area of 0.3 mm × 40 mm. The MZ waveguides with core size of 8 μm was successfully embedded in PDMS film at a depth of 18 μm by 750 keV proton microbeam with fluences from 10 to 100 nC/mm2. The MZ waveguides were coupled with an IR fiber-laser with a center wavelength of 1550 nm and evaluated by using the transmitted intensity images from an IR vidicon camera. The results indicate that the embedded MZ waveguide structure in PDMS achieved single spot light propagation, which is necessary for building optical switching circuits based on polymer MZ waveguides.

In order to study defects that create deep energy levels in semiconductors which act as carrier traps, Charge Transient Spectroscopy using heavy ion microbeams (HIQTS) was developed at JAEA Takasaki. The HIQTS system was connected with the heavy ion microbeam line of the 3 MV Tandem accelerator. Using the HIQTS system, deep levels in 4H-SiC Schottky barrier diodes irradiated with 3 MeV-protons were studied. As a result, a HIQTS peak with an activation energy of 0.73 eV was observed. In addition, local damage in 6H-SiC pn diodes partially irradiated with 12 MeV-O ion microbeams was studied using HIQTS. With increasing 12 MeV-O ion fluence, charge collection efficiency in locally damaged areas decreased and HIQTS signals increased.

A several hundred-keV compact ion microbeam system with a three-stage acceleration lens has been developed to form an ion beam of several micrometers in diameter. In a previous study of the Ohkubo et al. (2013) and Ishii et al. (2014), a hydrogen beam of 143 keV having 17 μm diameter was experimentally formed using such a microbeam system. It was demonstrated that a three-stage acceleration lens functioned as a focusing lens and indicated that the beam diameter (hereinafter referred to as the “beam size”) depended on the extraction voltage to generate the ion beam and the vacuum pressure in the extraction space in a plasma-type ion source. In this study, the hydrogen beam sizes were experimentally measured at 130 keV as functions of the extraction voltage and vacuum pressure to form the beam size with several micrometers in diameter. These two relationships showed that beam sizes were reduced in the extraction voltage range of 400–500 V and when the vacuum pressure was lowered to a minimum value of 5.33 × 10 −5 Pa. In addition, the result showed that the beam size was dominantly influenced by the vacuum pressure. Consequently, a hydrogen beam 5.8 μm in diameter was formed experimentally—the smallest beam yet obtained.

We aimed to image and treat the lung metastases of MM48 breast cancer cells in C3He/N mice by using microcapsules that release liposome-protamine-hyaluronic acid nanoparticles (LPH-NP) in response to two radiation sessions. In session one, computed tomography (CT)-detectable microcapsules containing P-selectin and 5% iopamiron were mixed with a 1 mL solution of 4% alginate, 3% hyaluronate, 1 mg ascorbate, and 1 μg/mL P-selectin. This was sprayed into 0.5 mmol/L FeCl2 containing 1 μg/mL VEGFR-1/2 antibodies (Abs). The mice were intravenously injected with microcapsules, which released the P-selectin, and then a CT study was performed to detect lung metastases. After the CT evaluation, the mice received 10 or 20 Gy (140 keV) of X-ray radiation to the lungs. In session two, carboplatin-LPH-NP was released into the tumor, which was treated with another dose of radiation. To do this, carboplatin LPH-NP was mixed with the cocktail used in session one and sprayed into 0.5 mmol/L FeCl2 containing 1 μg/mL anti-P-selectin Abs. Microcapsules (1 × 1010) were injected intravenously and then interacted with the P-selectin. The released carboplatin LPH-NP attacked lung metastases synergistically with radiation, which resulted in further reduction of the lung metastases.

Ion microbeam technology and its applications at the TIARA facility of JAEA Takasaki were summarized. In 1990, R&D of microbeam technology for TIARA was initiated in order to use an ion beam for analysis, radiation effect studies, or fabrication by the micro or nanometer scale. Three different types of ion microbeam systems with high-spatial resolutions were constructed and techniques of micro-PIXE, single ion hit and particle beam writing (PBW) were developed and applied widely in science and technology. Superior performance of these microbeams, on the other hand, was based on the highest quality of beams from the accelerators, the cyclotron in particular, which were also an important part of the R&D at TIARA.

A new technique for evaluating the phase bunching performance in the central region of a cyclotron was developed. A newly-developed radial probe with a 6-mm-wide, 5-mm-height plastic scintillator was applied to analysis of the correlation between the internal beam phase distribution and the initial beam phase, defined by adjusting the relative RF phase of the beam buncher. The phase distribution measurement system, comprising the radial probe equipped with a plastic scintillator and the signal-processing modules, had a sufficiently good time resolution of 45 ps full-width at half-maximum for the phase bunching evaluation. The correlations between the buncher phase and the measured phase distribution for the acceleration harmonic number h =1 and 2 were consistent with the calculation result of the geometric trajectory analysis. For h =1 case of a 107 MeV 4 He 2+ beam, the internal beam phase region spread over 71 RF degrees full-width at quarter-maximum (FWQM) for the acceptable buncher phase region of 48 RF degrees, and no evidence of the phase bunching effect was observed. For h =2 case of a 260 MeV 20 Ne 7+ beam, the internal beam phase region for the acceptable buncher phase region of 59 RF degrees was compressed into 21 RF degrees FWQM. The phase bunching effect was sharply evident for h =2, and contributed to increase of the acceptable beam phase region and the beam intensity per phase width.

Hydrogen ion microbeams were experimentally formed at beam energies below 150 keV using a 300-keV compact microbeam system that was constructed at the Japan Atomic Energy Agency. This paper is a preliminary report on the performance of the three-stage acceleration lens used in the compact microbeam system. This system consists of a three-stage acceleration lens and a plasma-type ion source. Since the three-stage acceleration lens was designed to simultaneously accelerate and focus the ion beam, the compact microbeam system is only about 1-m high and can be placed in a small experimental room. To evaluate the effectiveness of the three-stage acceleration lens, experimentally measured beam sizes are compared with theoretically calculated ones. The calculated and measured beam sizes were consistent within 10%. This shows that the three-stage acceleration lens is effective as a focusing lens for forming microbeams.

Simultaneous microscopic imaging and spectroscopy of individual aerosol particles were performed with an external microbeam. Visible luminescence induced by the external microbeam was successfully used as a probe to detect organic contaminants in the targets. Combined ion luminescence (IL)/particle-induced X-ray emission (PIXE) analysis of the aerosol targets revealed microscopic chemical and elemental composition distributions under ambient atmospheric conditions. The simple confocal micro-optics for the IL spectroscopy and microscopic imaging were sufficiently sensitive for detecting these molecules at sub-parts per million concentrations and at a wavelength resolution of less than 5 nm. The IL spectra were monitored to prevent severe damage to the samples. Furthermore, our IL system has the advantage that it is simple to add to a conventional micro-PIXE system.

Continuous irradiation effects on a thin-film diamond detector were investigated for the utilization of these films as a detector for heavy ion microbeams. Temporal signal degradation in the energy spectrum was frequently observed during the focused heavy ion microbeam irradiation. To measure the temporal response to the each ion incidents, focused heavy ion microbeam with different beam fluence rates were irradiated to a single crystal (SC)-CVD diamond film detector with thickness of 50 μm. The responses to each ion were continuously observed and characterized by ion beam-induced charge (IBIC) measurement system. Heavy ions with short penetration path in diamond generate the large difference in mean path of electrons and holes, which is inverted by changing bias polarity. Signal degradation condition was relied on the bias polarity under the irradiation of heavy ions with short penetration length in the diamond. The continuous observation of IBIC signals revealed that temporal degradation in pulse height of signals, so called polarization effects, seems to be mainly caused by the hole trapping in this diamond crystal.

The Fukushima Daiichi nuclear power plant accident caused radioactive pollution by 131I, 134Cs and 137Cs. The surface of the ground was contaminated at a volume of 3 × 107 m3. The government has mandated that the top 5 cm of the contaminated soil be removed and stored, in this way, it is desirable to reduce its volume. Soil samples were collected from a mountain, a rice field and a vegetable field in northern Japan, and the silt was extracted from the muddy water by washing the soil. Next, the silt was sprayed with a solution of cesium carbonate (Cs2CO3). We determined the amounts of Al, Si, K and Cs in the silt particles using micro-particle-induced X-ray emission (micro-PIXE) analysis. The silt particles from a vegetable field, a rice field and a mountain were mainly formed from smectite or vermiculite, which absorbs Cs atoms. The measurements at multiple detection angles confirmed that Cs atoms were uniformly absorbed within silt particles less than [Formula: see text] in diameter. This resulted that the radioactive Cs atoms were adsorbed in silt particles within [Formula: see text] of the surface.

Confocal optics for ion luminescence (IL) was developed for the precise analysis of the chemical composition of microscopic targets with an external proton microbeam probe. Anti-reflection-coated confocal micro-lens optics with an effective focus area of approximately 800 × 800 μm was installed on the microbeam line of a single-ended accelerator. Chromatic aberrations of the confocal optics were examined at wavelengths of 300–900 nm. An electrically-cooled back-thinned charge coupled device spectrometer with a wavelength resolution of 0.5 nm was used for the microscopic spectroscopy and IL imaging of microscopic mineral targets. Simultaneous microscopic IL and micro-PIXE analysis were performed using an external 3 MeV H + microbeam with a current of less than 100 pA. A spectral resolution of 3 nm was achieved for a single IL peak which corresponded to Cr 3+ impurities in a single-crystal of aluminum oxide. The use of IL spectroscopy and imaging for aerosol targets revealed microscopic distributions of the chemical and elemental composition in the atmosphere.

We used micro-PIXE to investigate the distribution of Cs and Rb in rice grains. We succeeded, for the first time, in measuring the elemental distributions in entire rice grains (with dimensions of 6.25 mm [Formula: see text] 6.25 mm) at micrometer spatial resolution. We found that Cs and Rb accumulated in the bran and germ of the rice. The distributions of P, K, Rb and Cs were similar within the rice grain. The concentrations of Cs and Rb in the rice were proportional to those in the soil, as well as to the exposure time. The uptake of Rb was significantly larger than that of Cs. Furthermore, the behavior of Rb was similar to that of Cs in the micrometer-scale regions in plants. It follows that the distribution of Rb can be used to investigate the behavior of radioactive Cs in plants.

In this study, two types of microcapsules were designed: (1) computed tomography (CT)-detectable anti-αvβ3 (E[c(RGDfK)]2) microcapsules, containing P-selectin and P-selectin glycoprotein ligand-1 (PSGL-1), for the observation of metastases through αvβ3-antigen–antibody accumulation; and (2) metastasis-targeting microcapsules that upon irradiation release anticancer drugs with high affinity for P-selectin. These microcapsules were tested on C3He/N mice with MM48 tumors undergoing two radiotherapy sessions. The injected anti-αvβ3 microcapsules accumulated in the vascular endothelium of metastatic tissues and could be detected by CT. These microcapsules released P-selectin in response to the first irradiation, which was also induced in the endothelium of vessels in the case of metastasis. The microcapsules used for radiosensitizing metastases were injected 6 h after the first radiotherapy session. Their accumulation reached a maximum at 3 h after injection. After the second radiotherapy session, the microcapsules released carboplatin, which reduced the number of metastases; however, this reduction was not significant.

In this paper, we used microcapsules releasing liposome-protamine-hyaluronic acid nanoparticles (LPH-NP) with/without carboplatin in response to radiation to image and treat MM48 breast cancer in C3He/N mice in two radiation sessions. The micro-particle-induced X-ray emission (PIXE) camera and quantitative PIXE were used to image and measure the release of nanoparticles from the microcapsules. In session one, iopamiron and computed tomography (CT)-detectable microcapsules containing P-selectin and LPH-NP were mixed with a solution of alginate, hyaluronate, ascorbate, and P-selectin. This solution was sprayed into an FeCl2 solution containing VEGFR-1/2 antibodies (Abs). The microcapsules obtained were injected intravenously into mice, and after 9 h, the mice were exposed to 10 or 20 Gy (140 keV) of X-ray radiation. Anti-VEGFR-1/VEGFR-2 microcapsules accumulated around tumors and released P-selectin and the iopamiron-labeled LPH-NP in response to the first radiation. The iopamiron-containing nanoparticles were detected by CT, allowing detection of MM48 tumors by CT. In the second session, the microcapsules released LPH-NH that delivered carboplatin into the tumor cells. This treatment had a significant antitumor effect [Formula: see text]. The micro-PIXE camera and quantitative PIXE successfully imaged and measured the release of contents from microcapsules. Our results indicate that targeted nanoparticles allow for accurate detection and treatment of tumors.

The Compton camera can simultaneously acquire images of multiple isotopes injected in a body; therefore, it has the potential to introduce a new subfield in the field of biomedical imaging applications. The objective of this study is to assess the ability of a prototype semiconductor-based silicon/cadmium telluride (Si/CdTe) Compton camera to simultaneously image the distributions of technetium (99mTc)-dimercaptosuccinic acid (DMSA) (141 keV emission) and 18F-fluorodeoxyglucose (FDG) (511 keV emission) injected into a human volunteer. 99mTc-DMSA and 18F-FDG were injected intravenously into a 25-year-old male volunteer. The distributions of 99mTc-DMSA and 18F-FDG were simultaneously made visible by setting a specified energy window for each radioisotope. The images of these radiopharmaceuticals acquired using the prototype Compton camera were superimposed onto computed tomography images for reference. The reconstructed image showed that 99mTc-DMSA had accumulated in both kidneys, which is consistent with the well-known diagnostic distribution determined by clinical imaging via single-photon emission computed tomography. In the 18F-FDG image, there is broad distribution around the liver and kidneys, which was expected based on routine clinical positron emission tomography imaging. The current study demonstrated for the first time that the Si/CdTe Compton camera was capable of simultaneously imaging the distributions of two radiopharmaceuticals, 99mTc-DMSA and 18F-FDG, in a human body. These results suggest that the Si/CdTe Compton camera has the potential to become a novel modality for nuclear medical diagnoses enabling multi-probe simultaneous tracking.

We demonstrated a PMMA-based thermo-optic switch consisting of a Mach-Zehnder (MZ) type waveguide drawn by proton beam writing (PBW) and working at λ = 1.55 μm. The MZ waveguide was drawn by symmetrically coupling two Y junctions with a core width of 8 μm and a branching angle of 2°. A Ti thin-film heater and Al electrodes were formed on the surface of the MZ waveguide using conventional photolithography and wet-etching processes. An ON/OFF ratio of 9.0 dB and a switching power of 43.9 mW were obtained from the sample. The switching power is lower than for conventional commercial silica-based switches.

We investigated the ion irradiation induced ferromagnetic state of FeRh thin films with 10 MeV I ion beam by the measurements of a superconducting quantum interference device (SQUID) magnetometer as well as of soft X-ray Magnetic Circular Dichroism (XMCD). It was clearly shown in the magnetization loops by SQUID measurements that the ion irradiation induced the ferromagnetic state in the FeRh thin films even below room temperature. This was also confirmed by the Fe L2,3-edge XMCD measurements for the irradiated FeRh film samples. However, we found that the irradiation ion fluence dependence on the magnetization was totally different between two measurement techniques. We also revealed by XMCD sum rule analysis that the ferromagnetism in the ion irradiated FeRh thin films was mainly dominated by the spin moment.

Teflon surfaces were modified using a combination of 3 MeV proton microbeam scanning and subsequent 250 keV N 2 + ion beam irradiation. When a Teflon surface is irradiated using only an N 2 + ion beam, micro-protrusions are densely formed in the irradiated area. It has been previously confirmed that these protrusions aid the attachment of biological cells, which then spread on the surface. Therefore, modification of the Teflon surface patterning is necessary in order to enhance its functionality as cell culture substrata. In this study, flat areas and depressed structures were created among the dense micro-protrusions by bubbles that were generated inside the sample using proton beam scanning. This modification will contribute to the fabrication of cell culture dishes with the advantages of micro-protrusions.

Although numerous studies have confirmed the superb radiation hardness of diamond for high-energy (above 100 MeV) protons, almost no data have been reported in the MeV energy range. Because the interaction mechanism that dominates the displacement damage cross section is different for these two energy regimes, it could be misleading to simply extrapolate the results of previous papers down to low energies. Therefore, the radiation tolerance of a 50 μm thick single-crystal CVD diamond detector was tested by irradiating it with 4.5 MeV protons. The scanning microbeam allowed for the selective introduction of damage to a small area of the detector. The ion beam-induced current (IBIC) was used to monitor the charge collection efficiency (CCE) degradation due to the electrically active defects produced. The irradiation was stopped when a signal degradation of nearly 3% was observed. For comparison, the procedure was repeated on a 50 μm thick silicon surface barrier detector (SSBD), for which a significantly higher proton fluence was required to reach the same signal decrease as in the diamond detector. This result can be explained by the different recombination rates of the vacancies and interstitials created in the two materials. The transport properties of electrons and holes in the damaged and virgin areas of the diamond detector were also investigated by 500 keV protons and 6 MeV carbon ions as short-range IBIC probes. The mobility-lifetime products calculated for both charge carriers after fitting the single-carrier Hecht equation indicated that there was more pronounced electron trapping by the radiation-induced defects. The frequently reported effect of polarization in diamond was successfully avoided for 500 keV protons but still remained for 6 MeV carbon ions because an order of magnitude higher ionization rate.