Tetsuji Shimizu

Electron temperature control by varying size of slits made in a grid

Electron temperature is controlled by varying the length of slits made in a grid immersed in a weakly ionized discharge plasma. The grid, which is kept at floating potential, has six slits in this experiment. With a decrease in the slit length from 6 to 0 cm, the electron temperature decreases from 2.1 to 0.09 eV, being accompanied by an electron-density increase from 0.32×109 to 1.53×109 cm−3 at argon gas pressure of 1.5 mTorr. This method of electron–temperature control is applicable to reactive plasmas in which grids are often covered by insulators.

High quality diamond formation by electron temperature control in methane-hydrogen plasma

We report a new method for the nucleation and growth of diamonds by employing an electron-temperature control technique in CH4/H2 radio frequency glow discharge plasma under a low gas pressure of 100 mTorr. The electron temperature in the plasma is controlled under constant gas pressure in a range from 0.5 to 2.5 eV continuously by changing the open area of the slits situated around a grid that is kept at the floating potential. It is observed that the film quality is changed in accordance with the variation of electron temperature, and we can produce high quality diamond in a low electron temperature plasma, even though usually only graphite film is deposited, unless the electron temperature is controlled.

Electron temperature and ion energy control in modified magnetron-typed RF discharge

The basic properties of the control of electron temperature and ion energy in modified magnetron-typed (MMT) radio-frequency (RF) plasma are investigated by using the grid and double-plasma methods, respectively. By changing the open area of the slots situated on a cylindrical grid, the electron temperature in the center region is controlled continuously in the range from 0.5 to 2.4 eV. On the other hand, by changing the plasma potential of an ion-beam source, we control the ion energy from 0 to 30 eV.

Plasmabehandlung von Ulzera

Das Wissen uber die Pathogenese von Ulzera ist innerhalb des letzten Jahrhunderts stetig gewachsen. Dennoch stellt uns die effektive Therapie von Ulzera trotz mannigfaltiger Behandlungsmethoden im klinischen Alltag vor grose Probleme. Atmospharische Niedertemperaturplasmen haben groses Potenzial, die effektive Therapie von Ulzera kunftig voran zu treiben. Zum einen konnen die atmospharischen Niedertemperaturplasmen die klassischen Wundtherapien durch ihre breiten antimikrobiellen Charakteristika sinnvoll unterstutzen. Pathogene Bakterien, insbesondere resistente Formen, spielen eine bedeutende Rolle unter den Faktoren, die zu Wundheilungsstorungen fuhren. Zum anderen besitzen die Plasmen Eigenschaften, die das Wundmilieu innerhalb der verschiedenen Wundphasen positiv beeinflussen konnen. Erste klinische Studien an Patienten mit unterschiedlichen Ulzera geben Hoffnung, dass die hohen Erwartungen an die atmospharischen Niedertemperaturplasmen als kunftige therapeutische Moglichkeit berechtigt sein konnen.