Takuya Nebiki

Production of a microbeam of slow highly charged ions with a tapered glass capillary

The authors have developed a method to produce a microbeam of slow highly charged ions based on a self-organized charge-up inside a tapered glass capillary. A transmission of 8keV Ar8+ beam through the capillary 5cm long with 800∕24μm inlet/outlet inner diameters was observed stably for more than 1200s. The transmitted beam had the same size as the outlet with a beam density enhancement of approximately 10 and a divergence of ±5mrad. The initial beam was guided through a capillary tilted by as large as ±100mrad, and it still kept the incident charge.

Ion irradiation in liquid of μm3 region for cell surgery

We present here a cell surgery scheme involving selective inactivation or disruption of cellular structures. Energetic ions are injected into a cell through a tapered glass capillary like a microinjection method. A slight but essential difference from microinjection is that a thin window is prepared at the outlet so that no liquid material can flow in or back through the outlet while still allowing energetic ions to penetrate into the cell. An ∼MeV He ion beam from such a capillary having 10μm outlet diameter inactivated a selected volume (∼μm3) of fluorescent molecules located in a HeLa cell nucleus.

Production of a nm sized slow HCI beam with a guiding effect

We have developed a method to produce a nm sized slow highly-charged ion beam based on a self-organized charge up inside a single tapered-glass capillary. In order to investigate the characteristics of the obtained beams, the transmission of 8 keV Ar8+ beam through the capillary of 5-cm long with 800/24 μm inlet/outlet inner diameter was examined. The transmitted beam had the same size as the outlet with the beam-density enhancement of approximately 10. The initial beam was guided through a capillary tilted by as large as ±100 mrad and it still kept the incident charge. A focused ion beam of Ga+ was employed to manufacture the capillary outlet as small as several hundreds nm in diameter and fabricate a thin glass window at the capillary outlet for biological applications.

Growth and characterizations of electrochemically deposited ZnO thin films

In this study,Wepresent ZnO thin films using electrochemical deposition method. ZnO thin films are deposited onto metal(Cu) and semiconductor (n-type Si) substrates. The electrolyte consists of a 0.1M Zn(NO3)2 solution, and we applied various potentials at different bath temperatures. XRD shows preferential orientation to (002) that increases with the applied cathodic potential and the bath temperature. Similar tendency is shown on both Cu and n-type Si substrates. SEM micrographs show ZnO surface morphology is greatly affected by the applied cathodic potentials. The RBS analysis reflects the rough morphology of ZnO thin film. The composition ratio Zn:O on n-type Si substrate is determined to be 1.0:1.3 ± 0.3 at the cathodic potential of -1.0[V] and the cell temperature of 70.

NITROGEN LATTICE LOCATION IN MOVPE GROWN Ga1-xInxNyAs1-y FILMS USING ION BEAM CHANNELING

We have investigated the nitrogen lattice location in MOVPE grown Ga1-xInxNyAs1-y with x = 0.07 and y = 0.025 by means of ion beam channeling technique. In this system, the lattice constant of the Ga1-xInxNyAs1-y film is equal to GaAs lattice. Therefore, we can grow apparently no strain, high quality and very thick GaInNAs film on GaAs substrate. The quality of the films as well as the lattice location of In and N were characterized by channeling Rutherford backscattering spectrometry and nuclear reaction analysis using 3.95 MeV He2+ beam. The fraction of substitutional nitrogen in the film was measured using the 14N(α,p)17O endothermic nuclear reaction. Our results indicate that more than 90% of In and N atoms are located the substitutional site, however, N atoms are slightly displaced by ~0.2 A from the lattice site. We suggest that the GaInNAs film has a local strain or point defects around the N atoms.