Formation of multi-charged ion beams by focusing effect of mid-electrode on electron cyclotron resonance ion source.

We are constructing a tandem type electron cyclotron resonance ion source (ECRIS) and a beam line for extracting ion beams. The ion beam is extracted from the second stage by an accel-decel extraction system with a single-hole and the ion beam current on each electrode is measured. The total ion beam current is measured by a faraday cup downstream the extraction electrodes.

New tandem type ion source based on electron cyclotron resonance for universal source of synthesized ion beams.

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.

Enhanced production of electron cyclotron resonance plasma by exciting selective microwave mode on a large-bore electron cyclotron resonance ion source with permanent magnet.

We are constructing a tandem type ECRIS. The first stage is large-bore with cylindrically comb-shaped magnet. We optimize the ion beam current and ion saturation current by a mobile plate tuner.

Controlling precise magnetic field configuration around electron cyclotron resonance zone for enhancing plasma parameters and beam current.

Multi-charged ion source which has wide operating conditions is required in various application fields. We have constructed tandem type ECR ion source (ECRIS); one of the features of its main stage is an additional coil for controlling magnetic field distribution around the mirror bottom precisely. Here the effect of magnetic field variation caused by the additional coil is experimentally considered in terms of plasma parameters and beam current as the first investigation of the main stage plasma.

Electron energy distribution function by using probe method in electron cyclotron resonance multicharged ion source.

We are constructing a tandem type electron cyclotron resonance (ECR) ion source (ECRIS). High-energy electrons in ECRIS plasma affect electron energy distribution and generate multicharged ion. In this study, we measure electron energy distribution function (EEDF) of low energy region (≦100 eV) in ECRIS plasma at extremely low pressures (10(-3)-10(-5) Pa) by using cylindrical Langmuir probe.

Electron cyclotron resonance plasma production by using pulse mode microwaves and dependences of ion beam current and plasma parameters on the pulse condition.

We measure the ion beam current and the plasma parameters by using the pulse mode microwave operation in the first stage of a tandem type ECRIS. The time averaged extracted ion beam current in the pulse mode operation is larger than that of the cw mode operation with the same averaged microwave power. The electron density n(e) in the pulse mode is higher and the electron temperature T(e) is lower than those of the cw mode operation.

Profiles of ion beams and plasma parameters on a multi-frequencies microwaves large bore electron cyclotron resonance ion source with permanent magnets.

In order to contribute to various applications of plasma and beams based on an electron cyclotron resonance, a new concept on magnetic field with all magnets on plasma production and confinement has been proposed with enhanced efficiency for broad and dense ion beam. The magnetic field configuration consists of a pair of comb-shaped magnet surrounding plasma chamber cylindrically. Resonance zones corresponding for 2.

Dependence of ion beam current on position of mobile plate tuner in multi-frequencies microwaves electron cyclotron resonance ion source.

We are constructing a tandem-type electron cyclotron resonance ion source (ECRIS). The first stage of this can supply 2.45 GHz and 11-13 GHz microwaves to plasma chamber individually and simultaneously.

Development of thermal neutron-sensitive glass dosemeter containing lithium.

New radiophotoluminescence (RPL) phosphate glass containing (6)Li was successfully made from the powder of NaPO(3), Al(PO(3))(3), LiOH, HPO(3) and AgCl. The ternary diagram of NaPO(3)-Al(PO(3))(3)-LiPO(3) has clarified the region where satisfactory RPL characteristics of the glass are kept up. The synthesised phosphate glass indicated good RPL characteristics on the condition that the content of LiPO(3) was below 10 wt%.

Development of confocal laser microscope system for examination of microscopic characteristics of radiophotoluminescence glass dosemeters.

A confocal laser microscope system was developed for the measurement of radiophotoluminescence (RPL) photons emitted from a minute alpha-ray-irradiated area in an RPL glass dosemeter. The system was composed mainly of an inverted-type microscope, an ultraviolet laser, an XY movable stage and photon-counting circuits. The photon-counting circuits were effective in the reduction of the background noise level in the measurement of RPL photons.

Pulse modulated microwave operation on large bore electron cyclotron resonance ion source with cylindrically comb-shaped magnetic fields configuration.

In order to enhance efficiency of an electron cyclotron resonance (ECR) plasma for broad and dense ion beam source under the low pressure, the magnetic field configuration is constructed by a pair of comb-shaped magnet which has opposite polarity each other, and which cylindrically surrounds the plasma chamber. By using the pulse microwave mode operation, we aim at generation of plasma with parameters that cannot be achieved at the continuous microwave (cw) mode. The maximum beam current is obtained in the experimental condition of the pulse width 100-200 micros at the duty ratio 40%-50%.

Induction heating pure vapor source of high temperature melting point materials on electron cyclotron resonance ion source.

Multicharged ions that are needed are produced from solid pure material with high melting point in an electron cyclotron resonance ion source. We develop an evaporator by using induction heating (IH) with multilayer induction coil, which is made from bare molybdenum or tungsten wire without water cooling and surrounding the pure vaporized material. We optimize the shapes of induction coil and vaporized materials and operation of rf power supply.

Production of electron cyclotron resonance plasma by using multifrequencies microwaves and active beam profile control on a large bore electron cyclotron resonance ion source with permanent magnets.

A new concept on magnetic field with all magnets on 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. The magnetic field configuration is constructed by a pair of magnets assembly, i.e.

Microchamber arrays for the identification of individual cells exposed to an X-ray microbeam.

To identify individual cells exposed to a X-ray microbeam in a cell population, we developed a biocompatible microchamber-array chip using UV lithography of photopolymer SU-8. The center-to-center distance between microchambers is 50 mum including a wall of 15 mum height. Using the microchamber-array chip, we performed tracking of individual exposed cells.

Effects of fundamental and second harmonic electron cyclotron resonances on ECRIS.

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. The magnetic field configuration is constructed by a pair of comb-shaped magnet which has opposite polarity to each other, and which cylindrically surrounds the plasma chamber. This magnetic configuration suppresses the loss due to E x B drift, and then plasma confinement is enhanced.

Multicharged iron ions produced by using induction heating vapor source.

Multiply charged Fe ions are produced from solid pure material in an electron cyclotron resonance (ECR) ion source. We develop an evaporator by using induction heating with an induction coil which is made of bare molybdenum wire partially covered by ceramic beads in vacuum and surrounding and heating directly the pure Fe rod. Heated material has no contact with insulators, so that outgas is minimized.

Hydrated thymine cluster in the supersonic gas jet.

Fragmentation of hydrated thymine clusters in the gas phase induced by UV laser pulse at 266 nm was studied by means of time-of-flight (TOF) mass spectrometry. Hydrated thymine clusters were produced by supersonic expansion in the gas jet in a high vacuum region. The range of laser intensity for ionisation of the gaseous targets was from 10(6) to 10(9) W cm(-2).

Synthesis of phenylnitroxides bridged by an sp(3)-linkage.

Silicon- and carbon-bridged phenylnitroxides were synthesized. They exhibited similar ESR profiles independent of the nature of the sp(3) bridge and the substitution mode of the phenylene units. The spectra revealed a quintet signal at room temperature, which became a broad triplet by lowering the temperature.