Search

We have considered the accessibility condition of electromagnetic and electrostatic waves propagating in an electron cyclotron resonance (ECR) ion source (ECRIS) plasma and then investigated experimentally their correspondence relationships with production of multicharged ions. It has been clarified that there exists an efficient configuration of ECR zones for producing multicharged ion beams and has been suggested that a new resonance, i.e., upper hybrid resonance (UHR), must have occurred. We have been trying to perform advanced experiments with 4–6 GHz X-mode microwaves to the 2.45 GHz ECRIS plasma, and we have succeeded in enhancing the production of multicharged ions by launching X-mode microwaves of these bands. Furthermore, at the same time, we have observed sharp increases in electron energy distribution functions in the ECRIS plasma by means of probe methods. It has been concluded that the UHRs must have occurred when applying multiplex microwaves with their frequencies away from those frequencies for ECR in the ECRIS. In this paper, we will describe in brief the theoretical background and the results of these new experiments.We have considered the accessibility condition of electromagnetic and electrostatic waves propagating in an electron cyclotron resonance (ECR) ion source (ECRIS) plasma and then investigated experimentally their correspondence relationships with production of multicharged ions. It has been clarified that there exists an efficient configuration of ECR zones for producing multicharged ion beams and has been suggested that a new resonance, i.e., upper hybrid resonance (UHR), must have occurred. We have been trying to perform advanced experiments with 4–6 GHz X-mode microwaves to the 2.45 GHz ECRIS plasma, and we have succeeded in enhancing the production of multicharged ions by launching X-mode microwaves of these bands. Furthermore, at the same time, we have observed sharp increases in electron energy distribution functions in the ECRIS plasma by means of probe methods. It has been concluded that the UHRs must have occurred when applying multiplex microwaves with their frequencies away from those frequencie...

Penetration conditions of electromagnetic and electrostatic waves propagating in electron cyclotron resonance (ECR) ion source (ECRIS) plasma in Osaka Univ. have been examined in detail, and its relationship with the production of multicharged ions have been investigated experimentally. It has been clarified that there exists efficient configurations of ECR zones for producing multicharged ion beams, and it has been suggested that new resonances, i.e. upper hybrid resonances, must have occurred. We have been conducting new advanced experiments inducing actively these additional effects to enhance multicharged ion beams by launching extra-ordinary (x) mode waves. We have been trying to apply 4-6GHz x-mode microwaves to the 2.45GHz ECRIS, and in this paper we will describe the preliminary experimental results.Penetration conditions of electromagnetic and electrostatic waves propagating in electron cyclotron resonance (ECR) ion source (ECRIS) plasma in Osaka Univ. have been examined in detail, and its relationship with the production of multicharged ions have been investigated experimentally. It has been clarified that there exists efficient configurations of ECR zones for producing multicharged ion beams, and it has been suggested that new resonances, i.e. upper hybrid resonances, must have occurred. We have been conducting new advanced experiments inducing actively these additional effects to enhance multicharged ion beams by launching extra-ordinary (x) mode waves. We have been trying to apply 4-6GHz x-mode microwaves to the 2.45GHz ECRIS, and in this paper we will describe the preliminary experimental results.

Fundamental studies have been made to elucidate the basis of various physical processes and physical phenomena in electron cyclotron resonance (ECR) plasma. In order to obtain guiding principle for further improvement of the state of art technology on ECR ion sources (ECRIS), it is the object to develop moreover efficiencies of them in new fields together still existing applications in various field. In this paper, spatial variations of electron energy distribution function (EEDF) have been experimentally measured and reported with relationship extracted ion beam currents and other parameters.

Our goal is producing and extracting multicharged ion beams ranged wide mass/charge numbers in the single device. We are constructing the extractor which can be optimized for various ion species. The extractor in an electron cyclotron resonance ion source (ECRIS) consists of three electrodes. We improve the width of gap length between plasma electrode and mid-electrode of the extractor. The width of gap length can be enlarged in 10-65mm. We investigate the behaviors of ion beam currents and the beam losses under different gap and operating pressures. We succeed in extracting ion beams of different plasma parameters efficiently and in suppressing the beam losses by changing the gap length and by applying mid-electrode potential. In addition, we can understand the characteristics of the extractor by using a simple theoretical calculation on the compact modelling for ion beam formation.

It has been performing to elucidate the basis of various physical processes, phenomena in an electron cyclotron resonance (ECR) plasma, and its various empirical methods. In order to obtain guiding principle for further improvement of the state of art technology on ECR ion source (ECRIS) will be used in various fields, the object is to develop moreover new fields together still existing applications. In this paper, spatial distribution of multicharged ions has been experimentally measured from space potential measurements with probe and beam methods, and relationship between extracted ion beam currents and other parameters has been investigated.

A new tandem type source has been constructed on the basis of electron cyclotron resonance plasma for producing synthesized ion beams in Osaka University. Magnetic field in the first stage consists of all permanent magnets, i.e., cylindrically comb shaped one, and that of the second stage consists of a pair of mirror coil, a supplemental coil and the octupole magnets. Both stage plasmas can be individually operated, and produced ions in which is energy controlled by large bore extractor also can be transported from the first to the second stage. We investigate the basic operation and effects of the tandem type electron cyclotron resonance ion source (ECRIS). Analysis of ion beams and investigation of plasma parameters are conducted on produced plasmas in dual plasmas operation as well as each single operation. We describe construction and initial experimental results of the new tandem type ion source based on ECRIS with wide operation window for aiming at producing synthesized ion beams as this new source can be a universal source in future.

A new tandem type source of electron cyclotron resonance (ECR) plasmas has been constructing for producing synthesized ion beams in Osaka University. Magnetic mirror field configuration with octupole magnets can be controlled to various shape of ECR zones, namely, in the 2nd stage plasma to be available by a pair mirror and a supplemental coil. Noteworthy correlations between these magnetic configurations and production of multicharged ions are investigated in detail, as well as their optimum conditions. We have been considering accessibility condition of electromagnetic and electrostatic waves propagating in ECR ion source plasma, and then investigated their correspondence relationships with production of multicharged ions. It has been clarified that there exits efficient configuration of ECR zones for producing multicharged ion beams experimentally, and then has been suggested from detail accessibility conditions on the ECR plasma that new resonance, i.e., upper hybrid resonance, must have occurred.

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.

With the miniaturization of semiconductors, the technology of shallow junctions becomes important. As shallow junctions advance, ion implantation by using ion beams at low energy with good control is needed. An electron cyclotron resonance ion source (ECRIS) can efficiently generate a high-density plasma at low pressure and a high intensity ion beam. In our ECRIS, the wide operation of various ion beam is available from deeper implantation of multi-charged ions at high energy to shallow junction at very low energy. However, a potential and a sheath near the wall are formed with an ECR plasma, because ECRIS is a volume source. Therefore, the potential affects the control of the ion beam at very low energy. In this study, we measure the potential by using the ion beam extracted from the ECRIS. In addition, we confirm that the potential by using the ion beam method correlates with electron temperature when microwave power and pressure change in ECRIS.

A tandem-type electron cyclotron resonance (ECR) ion source (ECRIS) has been constructed for synthesizing, extracting, and analyzing ions. The feasibility and realization of the device which has rangy operation window in a single device are investigated to produce many kinds of ion beams like universal source based on ECRIS. The ECR plasmas are considered to be necessary to be available to coexist and to be operated individually with different plasma parameters. Both of analysis of ion beams and investigation of plasma parameters will be conducted on produced plasmas. In this article the experimental study concentrates on improvement of producing and extracting multicharged ion beams from the second stage of the tandem-type ECRIS under lower magnetic mirror field with octupole magnets. The assembly of the extractor is modified and their positions, gap, and potentials are investigated against each ion spices. We succeeded in producing, extracting multicharged ion currents and improving ion extraction, while the magnetic field is about 60% of the previous magnetic field strength. We will present obtained evidences experimentally in detail.

A new concept on magnetic field of plasma production and confinement has been proposed to enhance efficiency of an electron cyclotron resonance (ECR) plasma for broad and dense ion beam source under the low pressure. We make this source a part of new tandem type ion source for the first stage. We are also constructing the large bore second stage for synthesizing, extracting and analyzing ions. Both ECR plasmas are necessary to be available to coexist and to be operated individually with different plasma parameters. In the first stage, we optimize the ion beam current and ion saturation current by a mobile plate tuner. They change by the position of the plate tuner for single and multi-frequencies microwaves. The peak positions of them are close to the position where the microwave mode forms standing wave between the plate tuner and the extractor. We show a new guiding principle, which the number of efficiently azimuthal microwave mode should be selected to fit to that of multipole of comb-shaped magnets. We obtained the excitation of selective modes using new mobile plate tuner to enhance ECR efficiency. Furthermore we first obtained charge state distributions of ion beams extracted from the first stage after constructing the second stage and its beam line.

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.

Efficient production of multicharged ions has been investigated on the tandem-type ECRIS in Osaka University. According to the consideration of the accessibility conditions of microwaves to resonance and cutoff regions, it was suggested that the upper hybrid resonance (UHR) heating contributed to enhancement of ion beam intensity. In order to enhance multicharged ion beams efficiently, injecting higher frequency microwave with extraordinary (X-mode) toward UHR region has been tried. In this study, 2.45 GHz frequency microwaves are used for conventional ECR discharge, and 9.9 GHz frequency microwaves with X-mode are superimposed for UHR heating. The effects of additive microwave injection are investigated experimentally in terms of plasma parameters and electron energy distribution function (EEDF) measured by Langmuir probe and ion beam current. As the results show, it is confirmed that the electrons in the high energy region are affected by 9.9 GHz X-mode microwave injection from the detailed analysis of EEDF.

A new tandem type source has been constructed on the basis of electron cyclotron resonance (ECR) plasma for producing synthesized ion beams. We investigate feasibility and hope to realize the device which has wide range operation window in a single device to produce many kinds of ion beams based on ECR ion source (ECRIS). It is considered that ECR plasmas are necessary to be available to individual operations with different plasma parameters. Both of analysis of ion beams and investigation of plasma parameters are conducted on produced plasmas. We describe construction of the new tandem type ion source based on ECRIS with wide operation window for aiming at producing synthesized ion beams as this new source can be a universal source.