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Purpose The purpose is to verify experimentally whether application of magnetic fields longitudinal and perpendicular to a proton beam alters the biological effectiveness of the radiation. Methods and Materials Proton beams with linear energy transfer of 1.1 and 3.3 keV/μm irradiated human cancer and normal cells under a longitudinal (perpendicular) magnetic field of BL (BP) = 0, 0.3, or 0.6 T. Cell survival curves were constructed to evaluate the effects of the magnetic fields on the biological effectiveness. The ratio of dose that would result in a survival fraction of 10% without the magnetic field Dwo to the dose with the magnetic field Dw, R10 = Dwo/Dw, was determined for each cell line and magnetic field. Results For cancer cells exposed to the 1.1- (3.3-) keV/μm proton beams, R10s were increased to 1.10 ± 0.07 (1.11 ± 0.07) and 1.11 ± 0.07 (1.12 ± 0.07) by the longitudinal magnetic fields of BL = 0.3 and 0.6 T, respectively. For normal cells, R10s were increased to 1.13 ± 0.06 (1.17 ± 0.06) and 1.17 ± 0.06 (1.30 ± 0.06) by the BLs. In contrast, R10s were not changed significantly from 1 by the perpendicular magnetic fields of BP = 0.3 and 0.6 T for both cancer and normal cells exposed to 1.1- and 3.3-keV/μm proton beams. Conclusions The biological effectiveness of proton beams was significantly enhanced by longitudinal magnetic fields of BL = 0.3 and 0.6 T, whereas the biological effectiveness was not altered by perpendicular magnetic fields of the same strengths. This enhancement effect should be taken into account in magnetic resonance imaging guided proton therapy with a longitudinal magnetic field.

A study of multiple-ion therapy with charged heavy-ion beams was performed to improve outcomes of refractory cancer treatments. We proposed the accelerator operation method for applying the multiple-ion therapy, to quickly switch the ion species and energies of the output beams. In this method, the irradiation ion species can be changed only by switching the selected ion source and the injector parameters, and the output beam energies can be varied without changing the magnetic operation patterns of the synchrotron. We verified the effectiveness of our approach by conducting experiments at the Heavy Ion Medical Accelerator in Chiba (HIMAC) and confirmed that the approach can provide the fast switching of both the ion species and the beam energies. The experimental results also demonstrated that our approach will greatly reduce the commissioning time and the routine adjustments for multiple-ion beams.

Purpose: Our previous study revealed that the application of a magnetic field longitudinal to a carbon-ion beam of 0.1 ≤ B//≤ 0.6 T enhances the biological effectiveness of the radiation. T...

Several research and developments have been performed at a compact ECR ion source (Kei3) with a fixed magnetic field at HIMAC. The Kei3 is a testing machine for application of Kei series developed for high-energy carbon-ion radiotherapy. It is difficult for Kei3 to produce ions that are heavier than carbon ion because it uses the same magnetic field distribution as the Kei series. In order to improve the beam current of multiply charged ions such as neon and argon, the two-microwave-frequency heating method was tested in the Kei3. Microwaves are introduced into the plasma chamber with a WR-90 rectangular waveguide. A traveling wave tube (TWT) amplifier made by the NEC (LD79X75A1) is used as the microwave source. The frequency band is 9.75-10.25 GHz and the maximum output power is 750 W. The WR-75 waveguide is also introduced from the upper part of the upstream vacuum chamber and installed on top of the existing the WR-90 waveguide. A TWT amplifier manufactured by the Xicom (XTRD-300IJ) was used as a microwave source for the two-microwave-frequency heating. The frequency band is 10-18 GHz and the maximum output power is 300 W. A beam test with oxygen, neon, and argon was performed in order to confirm the effect of two microwave frequency heating. In this test, we focused on O6+, Ne7+, and Ar9+ ions. We measured the dependence of the XTRD-300IJ microwave frequency and the microwave power of the LD79X75A1 on a charge state distributions.

The multi-ion radiotherapy with dose distribution and Liner Energy Transfer optimization is being studied at QST. Helium, carbon, oxygen and neon ions are considered as ion species for multi-ion therapy. A basic experiment using these ion beams has been carried out at the HIMAC. For heavy-ion radiotherapy facility, it is desirable to operate with only one ECR ion source with permanent magnets from the viewpoint of cost and maintenance. We considered the operating method with only one ion source for multi-ion radiotherapy. Ionization gases were helium, methane, oxygen, and neon to produce He2+, C4+, O6+ and Ne7+ ions. Requirement values of beam current were 940 μA correspond to He2+, 290 μA to C4+, 330 μA to O6+, and 245 μA to Ne7+, respectively. This value was obtained from the number of particles required for the cancer treatment and the transmission efficiency of the accelerator in the HIMAC. We performed some beam tests for design of a new compact ion source with the existing 18 GHz ECR ion source (NIRS-HEC). From the results of the beam tests, we estimate the mirror magnetic field of NIRS-HEC by using POISSON/SUPERFISH code. Then, the structure of the permanent magnets for new ECR ion source is determined so that they reproduce the values of the upstream mirror peak (Binj), B minimum (Bmin) and the downstream mirror peak (Bext) at the NIRS-HEC. The magnetic field of Binj, Bmin and Bext at NIRS-HEC were 1.14 T, 0.475 T and 0.9 T, respectively.

The National Institute of Radiological Sciences has investigated multiple-ion therapy using energetic beams of helium, carbon, oxygen, and neon ions, to improve treatment outcomes of refractory cancer. For this therapy, it is necessary to ensure the helium-ion beam purity to avoid irradiation by unwanted ions. Here, we develop a measurement method for monitoring beam purity. This method can measure the charge number of the ions in a high-purity beam using an ionization chamber and Faraday cup. In addition, it can be used to detect the contamination of the clinical helium-ion beam. We perform beam experiments to evaluate our beam-purity monitoring method and predict that our method is capable of detecting contamination below 1%.

Radiotherapy using high-energy carbon beams from the Heavy Ion Medical Accelerator in Chiba has been carried out at the National Institute of Radiological Sciences (NIRS) since June 1994, and more than 10 000 patients have been treated to date. With the prospective clinical results for the first ten years, we designed a compact accelerator facility for carbon-ion radiotherapy (CIRT), and performed related Research and Development (RD two of them have both horizontal and vertical fixed-irradiation-ports, and the other is a rotating-gantry port. For all ports, fast three-dimensional raster-scanning irradiation technology is employed. The rotating gantry equips ten combined-function superconducting magnets, and can deliver carbon ions having the energy of between E = 430 and 50 MeV/ u to an isocenter with irradiation angles of over ±180°. Construction as well as installation of the superconducting gantry was completed by the end of September 2015, and treatments using the gantry began since May 2015. Presently, we are further designing a next-generation compact facility as a future project; superconducting and laser technologies are to be used for accelerator design. In this paper, we report development of carbon-ion accelerator facilities as well as the future project.

An electron cyclotron resonance (ECR) ion source (ECRIS) can generate an available amount of multicharged ions, thus it is not limited for use in the field of accelerator science, but also in medical/biological fields, such as for heavy ion beam cancer treatment and ion engines. The processes of generating multicharged ions are mainly sequential collisions of a direct ionization process by electrons, and have good ion confinement characteristics. By utilizing this confinement property, we have synthesized iron-encapsulated fullerenes, which are supramolecular and can be expected to have various high functions. Fullerenes and iron ions are vaporized from pure solid materials and introduced into the ECRIS together with the support gas. We investigated conditions under which fullerene ions do not dissociate and iron ions are generated so that both can coexist. Generated ions are extracted from the ECRIS and separated by mass/charge with a dipole magnet, and detected with a Faraday cup. This measurement system is characterized by a wide dynamic range. The charge-state distribution (CSD) of ion currents was measured to investigate the optimum conditions for supramolecular synthesis. As a result, a significant spectrum suggesting the possibility of iron-encapsulated fullerenes was obtained. This paper describes the details of these experimental results.

We here report the production of highly spherical protein nanoparticles based on the domain-swapping oligomerization of a circularly permuted trimeric protein, major histocompatibility complex (MHC) class II associated chaperonin. The size distribution of the nanoparticles can be adjusted to between 40 and 100 nm in diameter, and thus, these particles are suitable as drug carriers following purification under basic conditions. Our approach involves no harsh treatments and could provide an alternative approach for protein nanoparticle formation.

A new compact electron-beam ion source (EBIS) with a low-energy hollow electron beam has been designed to produce ions for use in heavy-ion therapy. Numerical analyses of the electron beam using the three-dimensional particle-in-cell method determine the appropriate shape of the inner electrodes to realize a compact size and a sufficient number of confined ions for heavy-ion therapy. The analyses also show that the undesirable instability of the hollow electron beam is mitigated by the reflection mode with an electron repeller. Experimental tests were performed on the assembled EBIS to assess the validity of its design. The results of an electron-beam test show that the electrodes have been designed appropriately. Additionally, the results of an ion-beam test show that ions can be produced and confined in the newly developed compact EBIS and the number of extracted ions is just shy of the target value, showing the prospects of modifications aimed at realizing a compact EBIS specialized for the production of ions used in heavy-ion therapy.

Electron Cyclotron Resonance Ion Sources (ECRISs) are widely used for many practical purposes. We are aiming at synthesizing iron-endohedral fullerene by collision reaction in vapor phase on an ECRIS. We have already succeeded in producing multiply charged fullerene ions by using fullerene evaporator in the ECRIS. In the collision reaction method for fullerene ions and iron ions, other impurities ions must be reduced. In this paper we describe the experimental results that the impurities in ion beams were decreased by using the gettering effect of Ti evaporation. We also investigated the dependence of fullerene ion beam currents on He, Ar, and Xe gas pressures. We are planning to conduct experiments to synthesize iron-endohedral fullerene with these gasses using in the ECR plasma.

An ion source on the basis of electron cyclotron resonance (ECR) plasma has been constructed for producing wide-range mass/charge (m/q) ion beams in Osaka Univ. It is considered to be suitable for synthesizing new molecules using a wide operating range. We have already produced and extracted multicharged fullerenes and their compound ion beams with gaseous material, i.e. nitrogen and argon from the second stage using pure C 60 vapor source. We are planning to produce endohedral fullerenes in the ECR ion source (ECRIS) plasma. We describe initial experimental results on producing and optimizing for coexistence of iron and fullerene ions in the ECRIS in order to produce metal endohedral fullerenes, e.g. iron endohedral fullerenes.

The National Institutes for Quantum and Radiological Science and Technology (QST) manages various types of ion sources for research and development in the fields of life sciences, medical and industrial applications, and fusion energy science. The QST is currently developing on electron cyclotron resonance ion sources, negative ion sources (ion sources for fusion and for tandem accelerators), ion sources for radioactive beams, laser ion sources, and miscellaneous ion sources. Its intra- and inter-institutional collaborations make QST a promising platform for future ion source technologies.

Endohedral Fullerene is expected to be utilized for such application as quantum computing or magnetic resonance imaging contrast agent, because it has various material characteristics. It is confirmed that multiply charged fullerene ion beams have been produced on the electron cyclotron resonance ion source (ECRIS) at Osaka Univ. However, it is difficult to identify multiply charged fullerene ions because their spectrums overlap single charged dissociated-fullerene ions. Therefore, production of multiply charged fullerene ions can be confirmed by identifying non-overlapped fullerene ions spectrums. The aim of this paper is to product and identify multiply charged fullerene ions in the ECRIS. As a result, multiply charged fullerene ions have been clearly isolated from dissociated ones and then identified them. Furthermore, we report the result of identifying nitrogen-fullerene compounds produced in the ECRIS.

A prototype compact electron cyclotron resonance ion source with all permanent magnets named Kei3 and based on Kei2, has been developed to produce various ions. Kei3 has an outer diameter of 280 mm and a length of 1120 mm. The magnetic field is formed by the same permanent magnet as Kei2. We investigated the basic performance of the Kei3 source at a previous experiment. The maximum beam current of C4+, N5+, O6+ and Ne7+ were 565 µA, 185 µA, 99 µA and 50.5 µA, respectively. In order to increase the beam current of heavy ions, such as argon, we modified the microwave injection. The rf shield in the plasma chamber was used as a tuner of microwaves. The rf shield was installed at the position of a mirror peak of the injection side, and it can be moved 30 mm to an upstream side from there. As a result, we found optimal position of the rf shield for the production of Ar ions.

A compact accelerator for high energy carbon-ion radiotherapy (C-ion RT) has been studied at Heavy Ion Medical Accelerator in Chiba (HIMAC) of National Institute of Radiological Sciences (NIRS) since 2004. Compact accelerators have already been used for treatments at several C-ion RT facilities. The Electron Cyclotron Resonance Ion Source (ECRIS) with all permanent magnets (Kei series) [1] is used at these facilities. The Kei series has a magnetic field structure optimized for the production of C4+ ions. The operating cost can be further reduced by using an ion source optimized for C5+ production. Therefore, we have designed a new compact ECRIS with all permanent magnets to produce C5+ ions. At first, we aimed to determine the optimum mirror magnetic field for the production of a sufficient number of C5+ ions by using the NIRS-HEC [2] ion source. Experiments were performed to measure the beam currents of C5+ ions with various mirror magnetic fields, microwave power and frequency. As a result, we confirmed that the beam currents of C5+ ions could be achieved to more than 0.3mA with the coil currents of the electromagnets being optimized. Based on the parameters obtained from the test results this time, we will design a new ion source.A compact accelerator for high energy carbon-ion radiotherapy (C-ion RT) has been studied at Heavy Ion Medical Accelerator in Chiba (HIMAC) of National Institute of Radiological Sciences (NIRS) since 2004. Compact accelerators have already been used for treatments at several C-ion RT facilities. The Electron Cyclotron Resonance Ion Source (ECRIS) with all permanent magnets (Kei series) [1] is used at these facilities. The Kei series has a magnetic field structure optimized for the production of C4+ ions. The operating cost can be further reduced by using an ion source optimized for C5+ production. Therefore, we have designed a new compact ECRIS with all permanent magnets to produce C5+ ions. At first, we aimed to determine the optimum mirror magnetic field for the production of a sufficient number of C5+ ions by using the NIRS-HEC [2] ion source. Experiments were performed to measure the beam currents of C5+ ions with various mirror magnetic fields, microwave power and frequency. As a result, we confirmed...

Because environmental stress can reduce crop growth and yield, the identification of genes that enhance agronomic traits is increasingly important. Previous screening of full-length cDNA overexpressing (FOX) rice lines revealed that OsTIFY11b, one of 20 TIFY proteins in rice, affects plant size, grain weight, and grain size. Therefore, we analyzed the effect of OsTIFY11b and nine other TIFY genes on the growth and yield of corresponding TIFY-FOX lines. Regardless of temperature, grain weight and culm length were enhanced in lines overexpressing TIFY11 subfamily genes, except OsTIFY11e. The TIFY-FOX plants exhibited increased floret number and reduced days to flowering, as well as reduced spikelet fertility, and OsTIFY10b, in particular, enhanced grain yield by minimizing decreases in fertility. We suggest that the enhanced growth of TIFY-transgenic rice is related to regulation of the jasmonate signaling pathway, as in Arabidopsis. Moreover, we discuss the potential application of TIFY overexpression for improving crop yield.

Previously reported studies have revealed that the application of a magnetic field longitudinal to a carbon-ion beam enhances its biological effectiveness. Here we investigated how timing of the magnetic field application with respect to beam irradiation influenced this effect. Human cancer cells were exposed to carbon-ion beams with linear energy transfer (LET) of 12 and 50 keV/µm. The longitudinal magnetic field of 0.3 T was applied to the cells just before, during or immediately after the beam irradiation. The effects of the timing on the biological effectiveness were evaluated by cell survival. The biological effectiveness increased only if the magnetic field was applied during beam irradiation for both LETs.

In order to synthesize the Fe@C60 complex, iron ion beam irradiated to C60 thin films. The energy of the irradiated iron ions was controlled from 50 eV to 250 eV. The dose of that was controlled from 6.67 × 1012 to 6.67 × 1014 ions/cm2. By the analysis of the surface of the iron ion irradiated C60 thin films using laser desorption/ionization time-of-flight mass spectrometry, we could confirm the peak with mass/charge of 776. The mass/charge of 776 corresponds to Fe + C60. We obtained the maximum intensity of the peak with mass/charge of 776 under the irradiation iron ion energy and the dose were 50 eV and 3.30 × 1013 ions/cm2, respectively. Then, the separation of the material with mass of 776 was performed by using high performance liquid chromatography. We could separate the Fe + C60 from the iron ion irradiated C60 thin film. As a result, we could synthesize the Fe + C60 complex as a new material.

Multicharged metal ion beams are applied in various fields. We are planning synthesis of iron-endohedral fullerene by collision reaction in vapor phase in an electron cyclotron resonance (ECR) plasma. We have already succeeded in producing multicharged fullerene ions by using fullerene evaporator in ECR ion source (ECRIS). In a vapor phase synthesis, pure iron vapor is required. However, it is difficult to produce and introduce pure iron vapor into the ECRIS, therefore it is key technology for synthesizing iron-endohedral fullerene. We developed pure iron evaporators by ohmic heating method, and produced iron ion beam in the first stage of the tandem-type ECRIS. The aim of this paper is to investigate properties of new evaporators and to compare with previous researches. As a result, we have succeeded in producing large vapor flux and iron ion beam than the previous researches. We are planning synthesizing iron-endohedral fullerene on the tandem-type ECRIS by using these evaporators.

Multicharged metal ion beams are required to be applied in a wide range of fields. We aim at synthesizing iron-endohedral fullerene by transporting iron ion beams from the first stage into the fullerene plasma in the second stage of the tandem-type electron cyclotron resonance ion source (ECRIS). We developed new evaporators by using a direct ohmic heating method and a radiation heating method from solid state pure metal materials. We investigate their properties in the test chamber and produce iron ions on the first stage of the tandem-type ECRIS. As a result, we were successful in extracting Fe(+) ion beams from the first stage and introducing Fe(+) ion beams to the second stage. We will try synthesizing iron-endohedral fullerene on the tandem-type ECRIS by using these evaporators.

We have been constructing the tandem-type electron cyclotron resonance ion source (ECRIS). Two ion sources of the tandem-type ECRIS are possible to generate plasma individually, and they also confined individual ion species by each different plasma parameter. Hence, it is considered to be suitable for new materials production. As the first step, we try to produce and extract multicharged C60 ions by supplying pure C60 vapor in the second stage plasma because our main target is producing the endohedral fullerenes. We developed a new evaporator to supply fullerene vapor, and we succeeded in observation about multicharged C60 ion beam in tandem-type ECRIS for the first time.

We report on the modification of fullerenes with iron and chlorine using two individually controllable plasmas in the Bio-Nano electron cyclotron resonance ion source (ECRIS). One of the plasmas is composed of fullerene and the other one is composed of iron and chlorine. The online ion beam analysis allows one to investigate the rate of the vapor-phase collisional modification process in the ECRIS, while the offline analyses (e.g., liquid chromatography-mass spectrometry) of the materials deposited on the plasma chamber can give information on the surface-type process. Both analytical methods show the presence of modified fullerenes such as fullerene-chlorine, fullerene-iron, and fullerene-chlorine-iron.

Photosynthetic organisms have evolved various acclimatory responses to high-light (HL) conditions to maintain a balance between energy supply (light harvesting and electron transport) and consumption (cellular metabolism) and to protect the photosynthetic apparatus from photodamage. The molecular mechanism of HL acclimation has been extensively studied in the unicellular cyanobacterium Synechocystis sp. PCC 6803. Whole genome DNA microarray analyses have revealed that the change in gene expression profile under HL is closely correlated with subsequent acclimatory responses such as (1) acceleration in the rate of photosystem II turnover, (2) downregulation of light harvesting capacity, (3) development of a protection mechanism for the photosystems against excess light energy, (4) upregulation of general protection mechanism components, and (5) regulation of carbon and nitrogen assimilation. In this review article, we survey recent progress in the understanding of the molecular mechanisms of these acclimatory responses in Synechocystis sp. PCC 6803. We also briefly describe attempts to understand HL acclimation in various cyanobacterial species in their natural environments.

For systematic and genome-wide analyses of rice gene functions, we took advantage of the full-length cDNA overexpresser (FOX) gene-hunting system and generated >12 000 independent FOX-rice lines from >25 000 rice calli treated with the rice-FOX Agrobacterium library. We found two FOX-rice lines generating green calli on a callus-inducing medium containing 2,4-D, on which wild-type rice calli became ivory yellow. In both lines, OsGLK1 cDNA encoding a GARP transcription factor was ectopically overexpressed. Using rice expression-microarray and northern blot analyses, we found that a large number of nucleus-encoded genes involved in chloroplast functions were highly expressed and transcripts of plastid-encoded genes, psaA, psbA and rbcL, increased in the OsGLK1-FOX calli. Transmission electron microscopy showed the existence of differentiated chloroplasts with grana stacks in OsGLK1-FOX calli cells. However, in darkness, OsGLK1-FOX calli did not show a green color or develop grana stacks. Furthermore, we found developed chloroplasts in vascular bundle and bundle sheath cells of coleoptiles and leaves from OsGLK1-FOX seedlings. The OsGLK1-FOX calli exhibited high photosynthetic activity and were able to grow on sucrose-depleted media, indicating that developed chloroplasts in OsGLK1-FOX rice calli are functional and active. We also observed that the endogenous OsGLK1 mRNA level increased synchronously with the greening of wild-type calli after transfer to plantlet regeneration medium. These results strongly suggest that OsGLK1 regulates chloroplast development under the control of light and phytohormones, and that it is a key regulator of chloroplast development.

An electron cyclotron resonance ion source (ECRIS) has been developed for a synthesis of endohedral metallofullerenes. The ECRIS has a traditional minimum-B magnetic field and an 8-10 GHz traveling wave tube (TWT) amplifier as a microwave source. C60 plasmas have been generated at the first experiment. Many broken fullerenes C58 and C56 are observed in fullerene ion beams. We investigated the fullerene ion beams against pressures in the ion source. From the results, these fullerene ion currents increase as the decrease of the pressure and the maximum current is 0.81 μA of C602+.

A compact injector for a heavy-ion medical-accelerator complex was developed. It consists of an electron-cyclotron-resonance ion-source (ECRIS) and two linacs, which are a radio-frequency-quadrupole (RFQ) linac and an Interdigital H-mode drift-tube-linac (IH-DTL). Beam acceleration tests of the compact injector were performed, and the designed beam quality was verified by the measured results, as reported earlier. Because the method of alternating-phase-focusing (APF) was used for beam focusing of the IH-DTL, the motion of beam ions would be sensitive to gap-voltage errors, caused during tuning of the gap-voltage distribution and by automatic-frequency tuning in actual operation. To study the effects of voltage errors to beam quality, further measurements were performed during acceleration tests. In this report, the effects of voltage errors for the APF IH-DTL are discussed.

The plasma potential and its distribution play an important role in the highly-charged ion production and it is an important parameter of the electron cyclotron resonance (ECR) plasma. Emitting probes have been successfully used to determine plasma potential distributions in many plasma machines. In the framework of the ATOMKI–ECRIS plasma diagnostics research project, plasma-induced emitting probe was developed. It was proved that in certain conditions such probes could be reliably used without being damaged and without disturbing the plasma. Important observations were made related to the biased-disc effect. In favor of establishing the method of emitting probe usage in ECR plasma, dedicated experiments were performed at the NIRS–Kei2 all permanent compact ECR ion source. Based on the experiences gained after the NIRS experiments, the ATOMKI plasma-induced probe measurements could be interpreted. It was shown that biasing the Disc electrode negatively with respect to the source potential, the plasma potential measured on the resonant zone decreased, while the well-known ion beam current increase was obtained. This result proves the previous assumption [K.E. Stiebing, O. Hohn, S. Runkel, L. Schmidt, H. Schmidt-Bocking, V. Mironov, G. Shirkov, Phys. Rev. ST Accel. Beams 2 (1999) 123501], that the biased-disc changes the plasma potential distribution creating favorable conditions for ion beam extraction.

Genes encoding subunits of photosystem I (PSI genes) in the cyanobacterium Synechocystis sp. strain PCC 6803 are actively transcribed under low-light conditions, whereas their transcription is coordinately and rapidly down-regulated upon the shift to high-light conditions. In order to identify the molecular mechanism of the coordinated high-light response, we searched for common light-responsive elements in the promoter region of PSI genes. First, the precise architecture of the psaD promoter was determined and compared with the previously identified structure of the psaAB promoter. One of two promoters of the psaAB genes (P1) and of the psaD gene (P2) possessed an AT-rich light-responsive element located just upstream of the basal promoter region. These sequences enhanced the basal promoter activity under low-light conditions, and their activity was transiently suppressed upon the shift to high-light conditions. Subsequent analysis of psaC , psaE , psaK1 , and psaLI promoters revealed that their light response was also achieved by AT-rich sequences located at the −70 to −46 region. These results clearly show that AT-rich upstream elements are responsible for the coordinated high-light response of PSI genes dispersed throughout Synechocystis genome.

A compact injector, designed for a heavy-ion medical accelerator complex, was constructed. It consists of an Electron-Cyclotron-Resonance Ion-Source (ECRIS) and two linacs, which are a Radio-Frequency-Quadrupole linac and an Interdigital H-mode Drift-Tube-Linac (IH-DTL) having the same operating frequency of 200 MHz. For beam focusing of the IH-DTL, the method of Alternating-Phase-Focusing (APF) was employed. The compact injector can accelerate heavy ions having a charge-to-mass ratio of q m = 1 3 up to 4.0 MeV / u . Use of the APF IH-DTL and operating frequency of 200 MHz allowed us to design compact linacs; the total length of the two linacs is less than 6 m. Beam-acceleration tests of the compact injector system were performed. The measured intensity of accelerated C 4 + 12 beams with the compact injector was 380 e μ A . Beam transmission of the APF IH-DTL was estimated to be as high as 96%, which is comparable to the value calculated by a simulation code. Transverse phase-space and energy distributions of accelerated beams were measured and compared with those calculated by the simulation code, and we found that they were agreed well with each other.

A compact Drift-Tube-Linac (DTL) using an Interdigital H-mode (IH) cavity was designed for an injector of medical accelerators. For beam focusing, the method of Alternating-Phase-Focusing (APF) was applied. The APF IH-DTL can accelerate heavy ions having a charge-to-mass ratio of q / m = 1 3 up to 4.0 MeV / u . Having optimized an array of synchronous phases for cells, namely arranging drift tubes and gaps appropriately, both longitudinal and transverse focusing strengths were produced just with the rf acceleration field, and therefore no focusing element or cooling equipments had to be installed in the cavity. This allowed us to employ a rather high operating frequency, and hence to design a compact and cost-effective cavity. A further advantage of the APF linac can be found in its operation. Since the parameters to be adjusted are just the level and phase of the input rf, beam tuning can be made with ease. Consequently, the APF linac is suitable for an injector for medical accelerators. Tuning methods of the gap voltages and cavity frequency as well as the design of the cavity for APF IH-DTL have been developed. After constructing the cavity, measurements of the electric field and tuning of the gap voltages were performed. Finally, the rf power was fed into the cavity. In this paper, the design and results of the measurements are described.

Since 1994, the clinical trial for cancer therapy with HIMAC has successfully progressed, and more than 2100 cancer patients have been treated with a carbon beam. Based on the development of the accelerator and irradiation technologies for 10 years, we have designed a new carbon-therapy facility for widespread use in Japan, and key technologies for the new facility have been developed. We describe the conceptual design of the new facility and the status of development for the key technologies.

In acclimation to changing light environments, photosynthetic organisms modulate the ratio of two photosynthetic reaction centers (photosystem I and photosystem II). Two mutants, which could not modulate photosystem stoichiometry upon the shift to high light, were isolated from mutants created by random transposon mutagenesis. Measurements of chlorophyll fluorescence and analysis of the reaction center subunits of photosystem I through Western blotting in these mutants revealed that the content of photosystem I could not be suppressed under high-light condition. In these mutants, transposon was inserted to sll1961, which is homologous to the gene of gluconate operon transcriptional repressor (GntR) in Bacillus anthracis A2012. DNA microarray analysis revealed that the expression of sll1773 was drastically induced in the sll1961 mutant upon exposure to high light for 3 h. Our results demonstrate that a novel transcriptional regulator, Sll1961, and its possible target protein, Sll1773, may be responsible for the regulation of photosystem stoichiometry in response to high light.

The shape of the magnetic field of an electron cyclotron resonance ion source (ECRIS) gives rise to different particle fluxes (losses) from the plasma to the end plates (mainly diffusion of electrons), and to the side walls (mainly ions). The electron fluxes to the injection end plate can be reduced by negatively biasing this plate (or so-called biased disk); this appeared to be successful to improve the output of highly charged ions (HCIs). In the present experiment it was demonstrated that by positively biasing the side walls, the HCI production can be improved as well. Electrons leaking from the ECRIS plasma to the side wall find their way easiest at the "pole" areas (of the hexapole magnet) because these are the areas where fieldlines pass the plasma chamber. A special construction was made to study the effect of biasing two different regions: (1) the areas between the six poles, and (2) the parts corresponding to the poles. Measurements show that method (2) gives better performance of the source. The relative improvement for the highest observed charge states is the best, and in absolute sense the application of the method is giving, e.g., a four times higher intensity for Ar11+ beams. (C) 2004 American Institute of Physics.

The time structure of extracted beams has been improved in synchrotron rings with resonant slow-extraction including RF-knockout extraction. In order to control the global spill structure in the RF-knockout slow-extraction method, it is necessary to improve the amplitude modulation (AM) function of the transverse RF-field. For this purpose, a scheme with a simple model of the extraction process has been proposed. Using this simple model, an analysis was carried out for determining the parameter relevant to the diffusion process in the separatrix. With this parameter, the new AM function obtained by the analytical approach could provide a flat spill within ±23% in both a simulation and an experiment at the HIMAC synchrotron. Cooperating with the feedback system, the global spill structure was significantly suppressed to be less than ±5%.

A resonant slow-extraction method from synchrotron rings has been successfully developed in order to deliver a beam for a period of over several seconds. In the resonant slow-extraction method, an optimization of the parameters is necessary in order to keep the beam size and position constant during the extraction for sufficient use of the extracted beam. For this purpose, a simple method to measure the outgoing separatrix was proposed and verified at the HIMAC synchrotron. In this method, two tantalum rods each with diameter of 1 mm are used as internal probes located near the extraction channel. By observing the extracted beam under the rods inserted into the ring, the outgoing separatrix can be measured. This technique will significantly contribute to the operation of a synchrotron employing resonant slow-extraction.

An irradiation method for spot scanning has been developed in order to provide accurate irradiation even for an irregular target shape. In spot scanning irradiation, the beam is turned off while the beam position is shifted to the next spot for precise dose management. Recently, the fast beam cut-off method, which can achieve a cut-off time of around 50 μs, was proposed and verified at the Heavy Ion Medical Accelerator in Chiba synchrotron. In order to utilize such a speciality of the technique for spot scanning, the characteristics of fast beam switching were investigated while turning on/off both the transverse and longitudinal RF fields many times during a single flattop. As a result, it was verified that this technique provides more than 50 spots during a single flattop in the synchrotron operation pattern with a cut-off time of 50 μs. With an increase in a switching number, the momentum spread and the size of the extracted beam increase within the allowable range for practical usage.

We measured the charge fraction of 6.0 MeV/n heavy ions (C, Ne, Si, Ar, Fe and Cu) with a carbon foil at the NIRS-HIMAC injector. At this energy they are stripped with a carbon foil before being injected into two synchrotron rings with a maximum energy of 800 MeV/n. In order to find the foil thickness (DE) at which an equilibrium charge state distribution occurs, and to study the dependence of the DE-values on the projectile atomic number, we measured the exit charge fractions for foil thicknesses of between 10 and 350 μg/cm2. The results showed that the DE-values are 21.5, 62.0, 162, 346, 121, 143 μg/cm2 for C, Ne, Si, Ar, Fe, Cu, respectively. The fraction of Ar18+ ions was actually improved to 33% at 320 μg/cm2 from ∼15% at 100 μg/cm2. For Fe and Cu ions, the DE-values were found to be only 121 and 143 μg/cm2; there is a large gap between Ar and Fe, which is related to the differences in the ratio of the binding energy of the K-shell electrons to an electron energy (3.26 keV) corresponding to the velocity of a 6.0 MeV/n projectile. The well-known “two disjoint Gaussians (shell effect)” was also observed in the measured charge fractions of both Fe and Cu. The results of the charge fractions were also compared with other data and to calculations of Rozet et al. [2] , in which there was a good agreement for light ions (C); however, a significant difference was observed for ion species heavier than Ne.

Cyanobacteria, algae and plants reduce photosystem contents and modulate photosystem stoichiometry upon acclimation to high-light (HL) conditions to avoid the damage due to excess light energy. In order to elucidate the molecular mechanism of HL acclimation, mRNA levels of genes encoding subunits of photosystems were examined upon the change of photon flux density in the wild-type strain of Synechocystis sp. PCC 6803. Transcript levels and promoter activities of photosystem I (PSI) genes rapidly decreased upon the shift to HL to less than 10% of the initial level within 1 h, whereas responses of photosystem II (PSII) transcript levels were not coordinated. The prompt change of promoter activities of PSI genes, but not PSII genes, seems important for Synechocystis cells to regulate their photosystem contents in response to changes in photon flux density. mRNA stabilities of PSI genes also decreased during HL incubation. The down-regulation of PSI transcripts under HL did not depend on de novo protein synthesis, contrasting with the requirement of newly synthesized protein factor(s) for the accumulation of PSI transcripts under low light. When gene expression profiles were compared between wild-type cells and a pmgA-disrupted mutant that cannot modulate photosystem stoichiometry under HL, a large increase in the psaAB and psaA transcript levels was observed in the mutant under prolonged exposure to HL for 6 h. Repression of the promoter activity of the psaA gene by a pmgA-dependent mechanism was shown to be essential for the adjustment of photosystem stoichiometry under HL conditions., Copyright notice. c2003 Springer. All rights reserved. Publisher's version: http://www.springerlink.com/content/xuml42ertpu1945l/?p=7a361f357fc54d9aa1edc9acceef90f1&pi=10

Two advanced RF-knockout (RF-KO) slow-extraction methods have been developed at HIMAC in order to reduce the spill ripple for accurate heavy-ion cancer therapy: the dual frequency modulation (FM) method and the separated function method. As a result of simulations and experiments, it was verified that the spill ripple could be considerably reduced using these advanced methods, compared with the ordinary RF-KO method. The dual FM method and the separated function method bring about a low spill ripple within standard deviations of around 25% and of 15% during beam extraction within around 2 s, respectively, which are in good agreement with the simulation results.

The yields of highly charged ions have been improved by using a gas-pulsing technique in the pulsed Penning-ionized-gauge ion source (PIGIS) in the heavy-ion medical accelerator in Chiba. So far, this pulsed PIGIS has been operated under a low-duty factor (10−2–10−3), in which the gas flow is not being pulsed. A solenoid-type gas valve, having a simple structure compared to the piezo-electric type, was attached to the outside of the PIGIS chamber in order to control the gas flow into the PIGIS chimney. Beam tests for Ne with gas pulsing showed that the pressure response time should actually be a few tens ms, and the intensity of Ne6+ was increased by ten times, from 20 to 200 eμA. The gas pulsing also improved the average vacuum in the low energy beam transport (LEBT) line by a factor of 4. When producing H2+, H3+, and He1+ by PIGIS with gas pulsing, the beam loss of highly charged ions from electron cyclotron resonance ion sources in the LEBT was reduced to be negligible; meanwhile, it was around 30% wit...

Screening of rice full-length cDNA overexpressing (FOX) lines allowed the identification of a TIFY gene, TIFY11b, as a growth-promoting gene whose overexpression increased plant height and seed size. The grains of TIFY11b-overexpressing plants exceeded those of non-transformants in length, width and thickness, resulting in 9-21% increases in grain weight. The increase was achieved by overexpressing the gene in the whole plant body, but not by seed-restricted expression, indicating that seed enlargement is attributable to overexpression in vegetative organs such as the leaf. The whole-body overexpressing plants developed longer leaves along with higher levels of starch and sucrose in the leaf sheath and culm at the heading stage than the non-transformants. Although overexpression of TIFY11b did not alter the photosynthetic rate per leaf area before and after heading, it caused an accumulation of higher levels of the carbohydrate assimilate, probably due to increased photosynthesis per plant, suggesting that the increase in grain size and weight is attained by enhanced accumulation and translocation of the carbohydrate in the culms and leaf sheaths of the transgenic plants. Thus, TIFY11b is a novel grain-size increasing gene.

The NIRS heavy-ion two-synchrotron medical facility, HIMAC, was approved in the 1987 fiscal year and clinical trials were started in late June 1994 as previously arranged. The operation experiences show that the entire HIMAC facility can work well with high stability and excellent reproducibility. For example, the intensity of beam extracted slowly from the rings can be reduced as low as 500 particles per pulse because stable and reproducible acceleration can be achieved in the rings in spite of no beam feedback. This performance enables direct counting of the beam and its fragments in the preparatory experiments toward clinical treatments and provides a promising basis for acceleration and storage of radioactive beams toward simultaneous treatment and diagnosis in future.

With about 1000-h of relativistic high-energy ion beams provided by Heavy Ion Medical Accelerator in Chiba, about 70 users are performing various biology experiments every year. A rich variety of ion species from hydrogen to xenon ions with a dose rate of several Gy/min is available. Carbon, iron, silicon, helium, neon, argon, hydrogen, and oxygen ions were utilized between 2012 and 2014. Presently, three electron cyclotron resonance ion sources (ECRISs) and one Penning ion source are available. Especially, the two frequency heating techniques have improved the performance of an 18 GHz ECRIS. The results have satisfied most requirements for life-science studies. In addition, this improved performance has realized a feasible solution for similar biology experiments with a hospital-specified accelerator complex.

There is a desire that a carbon-ion radiotherapy facility will produce various ion species for fundamental research. Although the present Kei2-type ion sources are dedicated for the carbon-ion production, a future ion source is expected that could provide: (1) carbon-ion production for medical use, (2) various ions with a charge-to-mass ratio of 1/3 for the existing Linac injector, and (3) low cost for modification. A prototype compact electron cyclotron resonance (ECR) ion source, named Kei3, based on the Kei series has been developed to correspond to the Kei2 type and to produce these various ions at the National Institute of Radiological Sciences (NIRS). The Kei3 has an outer diameter of 280 mm and a length of 1120 mm. The magnetic field is formed by the same permanent magnet as Kei2. The movable extraction electrode has been installed in order to optimize the beam extraction with various current densities. The gas-injection side of the vacuum chamber has enough space for an oven system. We measured dependence of microwave frequency, extraction voltage, and puller position. Charge state distributions of helium, carbon, nitrogen, oxygen, and neon were also measured.