Coulomb cluster of dust particles in an RF helium plasma under cryogenic environment is observed experimentally. Background neutral temperature is controlled by cryogenic liquid such as liquid helium or liquid nitrogen. Dust dynamics in a sheath is studied. A dust injected into a sheath moves toward an equilibrium position where the sheath electric force balances with the gravitational force. D...

Inductively coupled plasma ~ICP! reactors are being developed for low gas pressure ~,10s mTorr! and high plasma density ~[e].10 cm! microelectronics fabrication. In these reactors, the plasma is generated by the inductively coupled electric field while an additional radio frequency ~rf! bias is applied to the substrate. One of the goals of these systems is to independently control the magnitude...

Rotating spokes commonly occur in partially magnetized plasma devices. This work explores the evolution from gradient drift instability into an m = 1 rotating spoke mode a magnetically enhanced hollow cathode discharge (with emissive cathode) by means of 2D radial-azimuthal particle-in-cell/Monte Carlo collision simulations. It is shown that formation potential hump region can be explained as r...

The onset and growth of a dust void are investigated in a radio-frequency (rf) sheath of a capacitively coupled argon plasma. A circularly symmetric void emerges and grows with increasing rf power and pressure in the central region of the dust cloud levitating in the sheath. Experimental measurements of the void diameter are compared with the predictions of a simple phenomenological theory, bas...

This work reviews formation processes of negative ions in low-pressure laboratory plasmas. There are many topics of discussion in the chemistry of negative ions. In most studies only volume production by dissociative electron attachment is considered. However, a typical problem is that experiments reveal higher negative ion densities than one would expect based on attachment rates to ground-sta...

Submitted for the DPP10 Meeting of The American Physical Society A Simple Method to Measure the Interaction Potential between Dielectric Grains in a Dusty Plasma ZHUANHAO ZHANG, KE QIAO, JIE KONG, LORIN MATTHEWS, TRUELL HYDE, CASPER Baylor University — A simple, minimally perturbative method is introduced to experimentally measure the interaction potential between two individual dust particles,...

The benefits of thermionic emission from negatively biased electrodes for perpendicular electric field control in a magnetized plasma are examined through its combined effects on the sheath and potential variation along magnetic lines. By increasing radial current flowing is confirmed to improve over at edge compared case cold electrode. Conversely, shown be responsible an increase drop lines q...

Sections of brain and spinal cord of mice and rats at 1, 3, 5, and 17 days after birth were examined with the electron microscope. In the early stages of myelinization only two to four lamellae surround the axon. These laminae are formed from the plasma membraces of glial processes, and in particular of oligodendroglial processes. In a later stage of myelinization a larger number of flattened g...

Laser ablation involves heating, evaporation of target material and ionization of vapor to form plasma plume surrounding the ablation spot. A self consistent model, that combines target heating, evaporation, ionization, shielding and expansion of plume, is employed to obtain ablation parameters. The results showed good agreement with experiments. For a given laser energy fluence and target mate...