The deformed relativistic Hartree theory(DRH)is solved both in coordinate space(DRH-c)and in harmonic oscillator basis(DRH-o).Results obtained from these two methods are compared in details.The DRH-c and DRH-o calcula...The deformed relativistic Hartree theory(DRH)is solved both in coordinate space(DRH-c)and in harmonic oscillator basis(DRH-o).Results obtained from these two methods are compared in details.The DRH-c and DRH-o calculations give similar total binding energies,deformation,level structures and radii for nitrogen iso topes,while their descriptions on the density distributions for drip-line nuclei are very different.The large spatiai istributions of nucleon densities,which is crucial to understand a weakly bound system,can only be obtained by DRH-c calculations.This implies that the DRH theory should be solved in coordinate space in order to describe uclei close to the drip line.展开更多
The d-t and d-d fusion catalyzed by muons without the need of high-temperature plasmas has been the subject of increasing experimental and theor-etical interest in these years.It has been established experimentally th...The d-t and d-d fusion catalyzed by muons without the need of high-temperature plasmas has been the subject of increasing experimental and theor-etical interest in these years.It has been established experimentally that a singlemuon can catalyze d-t fusion about 150 times on the average during its lifetimein a dense mixture of deuterium and tritium under certain conditions.Inthe pure deuterium without tritium less efficlent muon-catalyzed d-d fusionoccurs.展开更多
The high-spin states of ^(143)Nd have been studied in the ^(130)Te(^(18)O, 5n)^(143)Nd reaction at a beam energy of 80 MeV using techniques of in-beam γ-ray spectroscopy. Measurements of γ - γ - t coincidences, γ-...The high-spin states of ^(143)Nd have been studied in the ^(130)Te(^(18)O, 5n)^(143)Nd reaction at a beam energy of 80 MeV using techniques of in-beam γ-ray spectroscopy. Measurements of γ - γ - t coincidences, γ-ray angular distributions, and γ-ray linearpolarizations were performed. A level scheme of 143Nd with spin and parity assignments up to 53/2^(+) is proposed. While a weak coupling model can explain the level structure up to the J^(π)=39/2^(-)state,this model can not reproduce the higher-lying states. Additionally, a new low-lying non-yrast level sequence in ^(143)Nd was observed in the present work, which can be well described by the weak coupling of an i_(13/2) neutron to the ^(142)Nd core nucleus.展开更多
Background and Aims: Mesocentrotus nudus is commercially harvested from shallow rocky bottoms in northern Japan. The gonads are targeted as an edible product. The objective of this study was to identify odor-active vo...Background and Aims: Mesocentrotus nudus is commercially harvested from shallow rocky bottoms in northern Japan. The gonads are targeted as an edible product. The objective of this study was to identify odor-active volatile organic compounds (VOCs) from the gonads of adult M. nudus collected at a fishing ground in Miyagi Prefecture, Tohoku, Japan. Methods and Results: Gas chromatography-mass spectrometry analysis and gas chromatography-sniffing techniques identified 42 compounds categorized as alcohols, aldehydes, aromatic hydrocarbons, esters, halomethanes, hydrocarbons, ketones, sulfur-containing compounds, and nitrogen-containing compounds. GC-sniffing analysis characterized four compounds with preferable odors of sea urchin gonads;limonene, propyl acetate, acetone, dibromochloromethane. On the other hand, the analysis characterized three compounds with unpreferable odors;methyl mercaptane, dimethyl sulfide, and s-methyl thioacetate. Several VOCs from the gonads were derived from seaweeds, terrestrial plants, and fish flesh as food because M. nudus is omnivorous. Conclusion: This is the first study to identify VOCs from edible sea urchin gonads in the wild in Japan. These VOC data comprise a typical standard in order to evaluate a higher quality of sea urchin gonads.展开更多
Superconducting magnet system for a 28GHz ECR ion source has been designed.The maximum axial magnetic fields are 4T at the rf injection side and 2T at the beam extraction side,respectively.The hexapole magnetic field ...Superconducting magnet system for a 28GHz ECR ion source has been designed.The maximum axial magnetic fields are 4T at the rf injection side and 2T at the beam extraction side,respectively.The hexapole magnetic field is about 2T on the inner surface of the plasma chamber.The superconducting coils consist of six solenoids and six racetrack windings for a hexapole field.Two kinds of coil arrangements were investigated:one is an arrangement in which the hexpole coil is located in the bore of the solenoids,and another is the reverse of it.The coils use NbTi-Copper conductor and are bath-cooled in liquid helium.The six solenoids are excited with individual power supplies to search for the optimal axial field distribution.The current leads use high Tc material and the cryogenic system is operated in LHe re-condensation mode using small refrigerators.The thermal insulated supports of the cold mass have also been designed based on the calculated results of the magnetic force.The heat loads to 70K and LHe stages were estimated from the design of the supports,the current leads and so on.展开更多
We measured the main plasma parameters（density of electron,temperature of electron and ion confinement time）and beam intensity of various heavy ions as a function of B<sub>min</sub>.The B<sub>min&l...We measured the main plasma parameters（density of electron,temperature of electron and ion confinement time）and beam intensity of various heavy ions as a function of B<sub>min</sub>.The B<sub>min</sub> strongly affects the field gradient at the resonance zone,consequently the plasma parameters and beam intensity are changed. Based on these experimental results,we started to construct new 18GHz ECRIS and make a detailed design of the 28GHz SC-ECRIS for RIKEN RI beam factory project.展开更多
1 Results Nanometer-scale electrodes with a nano-junction allow us to investigate conduction properties of nano-materials. Because many nano-materials usually form grain boundaries or domain boundaries with high tunne...1 Results Nanometer-scale electrodes with a nano-junction allow us to investigate conduction properties of nano-materials. Because many nano-materials usually form grain boundaries or domain boundaries with high tunneling resistance, it is difficult to investigate the intrinsic properties through a series of tunneling resistance. To make direct contact with the single nano-material, such as a single polymer string, we developed nano-scale electrodes. By using these nano-electrodes as new tool, we invest...展开更多
At RIKEN,three ECR ion sources（10GHz ECRIS,18GHz ECRIS and liquid He-free SC-ECRIS） are operated as external ion sources of heavy ion accelerators.In the last year,multi-charged uranium ion beam was produced from 18...At RIKEN,three ECR ion sources（10GHz ECRIS,18GHz ECRIS and liquid He-free SC-ECRIS） are operated as external ion sources of heavy ion accelerators.In the last year,multi-charged uranium ion beam was produced from 18GHz ECRIS by using UF<sub>6</sub> and the <sup>238</sup>U ion was successfully accelerated by the accelerator complex which consists of the RFQ linear accelerator,RIKEN heavy ion linear accelerator（RILAC）and RIKEN ring cyclotron accelerator（RRC）.The typical beam intensity of<sup>238</sup>U<sup>14+</sup> was about 2pμA on faraday cup after analysing magnet.<sup>70</sup>Zn beam was still supplied for the new super-heavy element search experiment with insertion method.Intense beam of<sup>70</sup>Zn<sup>16+</sup> was produced for long term（～43 days）without vacuum break and remarkably low material consumption rate（～100μgr/h）.We already supplied Zn beam longer than 200 days for this experiment.<sup>48</sup>Ca ion was also produced by insertion method using<sup>48</sup>CaO rod for the nuclear physics experiment.In this contribution,we will present ion source parameter and techniques for production of each of the metal ions.展开更多
基金Supported in part by the Major State Basic Research Development Program Under Contract No.G2000077407National Natural Science Foundation of China under Grant Nos.19847002 and 19935030.
文摘The deformed relativistic Hartree theory(DRH)is solved both in coordinate space(DRH-c)and in harmonic oscillator basis(DRH-o).Results obtained from these two methods are compared in details.The DRH-c and DRH-o calculations give similar total binding energies,deformation,level structures and radii for nitrogen iso topes,while their descriptions on the density distributions for drip-line nuclei are very different.The large spatiai istributions of nucleon densities,which is crucial to understand a weakly bound system,can only be obtained by DRH-c calculations.This implies that the DRH theory should be solved in coordinate space in order to describe uclei close to the drip line.
文摘The d-t and d-d fusion catalyzed by muons without the need of high-temperature plasmas has been the subject of increasing experimental and theor-etical interest in these years.It has been established experimentally that a singlemuon can catalyze d-t fusion about 150 times on the average during its lifetimein a dense mixture of deuterium and tritium under certain conditions.Inthe pure deuterium without tritium less efficlent muon-catalyzed d-d fusionoccurs.
文摘The high-spin states of ^(143)Nd have been studied in the ^(130)Te(^(18)O, 5n)^(143)Nd reaction at a beam energy of 80 MeV using techniques of in-beam γ-ray spectroscopy. Measurements of γ - γ - t coincidences, γ-ray angular distributions, and γ-ray linearpolarizations were performed. A level scheme of 143Nd with spin and parity assignments up to 53/2^(+) is proposed. While a weak coupling model can explain the level structure up to the J^(π)=39/2^(-)state,this model can not reproduce the higher-lying states. Additionally, a new low-lying non-yrast level sequence in ^(143)Nd was observed in the present work, which can be well described by the weak coupling of an i_(13/2) neutron to the ^(142)Nd core nucleus.
文摘Background and Aims: Mesocentrotus nudus is commercially harvested from shallow rocky bottoms in northern Japan. The gonads are targeted as an edible product. The objective of this study was to identify odor-active volatile organic compounds (VOCs) from the gonads of adult M. nudus collected at a fishing ground in Miyagi Prefecture, Tohoku, Japan. Methods and Results: Gas chromatography-mass spectrometry analysis and gas chromatography-sniffing techniques identified 42 compounds categorized as alcohols, aldehydes, aromatic hydrocarbons, esters, halomethanes, hydrocarbons, ketones, sulfur-containing compounds, and nitrogen-containing compounds. GC-sniffing analysis characterized four compounds with preferable odors of sea urchin gonads;limonene, propyl acetate, acetone, dibromochloromethane. On the other hand, the analysis characterized three compounds with unpreferable odors;methyl mercaptane, dimethyl sulfide, and s-methyl thioacetate. Several VOCs from the gonads were derived from seaweeds, terrestrial plants, and fish flesh as food because M. nudus is omnivorous. Conclusion: This is the first study to identify VOCs from edible sea urchin gonads in the wild in Japan. These VOC data comprise a typical standard in order to evaluate a higher quality of sea urchin gonads.
文摘Superconducting magnet system for a 28GHz ECR ion source has been designed.The maximum axial magnetic fields are 4T at the rf injection side and 2T at the beam extraction side,respectively.The hexapole magnetic field is about 2T on the inner surface of the plasma chamber.The superconducting coils consist of six solenoids and six racetrack windings for a hexapole field.Two kinds of coil arrangements were investigated:one is an arrangement in which the hexpole coil is located in the bore of the solenoids,and another is the reverse of it.The coils use NbTi-Copper conductor and are bath-cooled in liquid helium.The six solenoids are excited with individual power supplies to search for the optimal axial field distribution.The current leads use high Tc material and the cryogenic system is operated in LHe re-condensation mode using small refrigerators.The thermal insulated supports of the cold mass have also been designed based on the calculated results of the magnetic force.The heat loads to 70K and LHe stages were estimated from the design of the supports,the current leads and so on.
文摘We measured the main plasma parameters（density of electron,temperature of electron and ion confinement time）and beam intensity of various heavy ions as a function of B<sub>min</sub>.The B<sub>min</sub> strongly affects the field gradient at the resonance zone,consequently the plasma parameters and beam intensity are changed. Based on these experimental results,we started to construct new 18GHz ECRIS and make a detailed design of the 28GHz SC-ECRIS for RIKEN RI beam factory project.
文摘1 Results Nanometer-scale electrodes with a nano-junction allow us to investigate conduction properties of nano-materials. Because many nano-materials usually form grain boundaries or domain boundaries with high tunneling resistance, it is difficult to investigate the intrinsic properties through a series of tunneling resistance. To make direct contact with the single nano-material, such as a single polymer string, we developed nano-scale electrodes. By using these nano-electrodes as new tool, we invest...
文摘At RIKEN,three ECR ion sources（10GHz ECRIS,18GHz ECRIS and liquid He-free SC-ECRIS） are operated as external ion sources of heavy ion accelerators.In the last year,multi-charged uranium ion beam was produced from 18GHz ECRIS by using UF<sub>6</sub> and the <sup>238</sup>U ion was successfully accelerated by the accelerator complex which consists of the RFQ linear accelerator,RIKEN heavy ion linear accelerator（RILAC）and RIKEN ring cyclotron accelerator（RRC）.The typical beam intensity of<sup>238</sup>U<sup>14+</sup> was about 2pμA on faraday cup after analysing magnet.<sup>70</sup>Zn beam was still supplied for the new super-heavy element search experiment with insertion method.Intense beam of<sup>70</sup>Zn<sup>16+</sup> was produced for long term（～43 days）without vacuum break and remarkably low material consumption rate（～100μgr/h）.We already supplied Zn beam longer than 200 days for this experiment.<sup>48</sup>Ca ion was also produced by insertion method using<sup>48</sup>CaO rod for the nuclear physics experiment.In this contribution,we will present ion source parameter and techniques for production of each of the metal ions.
