The structure of 1,2-dipalmitoyl-sn-glycero-3-phosphoserine was analyzed by positive ion fast atom bombardment mass spectrometry and collisional activation mass-analyzed ion kinetic energy spectroscopy. The molecular weight, the polar-head group, and the fatty acid composition of this species were identified by the appearance of protonated and solvated protonated species ions, diglyceride and m...

The influence of ion bombardment on the structure of the silicon lattice has been the subject of numerous investigations. The various effects induced by low energy ion bombardment in the outer layers of a solid lattice damage, ion implantation, surface roughness, sputtering and surface state changes are reflected in changes of the complex dielectric constant Z, which can be measured by means of...

Scanning tunnelling microscopy has been used to study the effect of ion bombardment at different angles of incidence on a graphite surface. The 246 MeV energy of Kr+ ions was selected in the medium energy range, where the electronic and nuclear stopping is nearly balanced. The low dose (1 x 10(12)/cm2) of ions allows the characterization of single features caused by bombardment in perpendicular...

The erosion of frozen SO 2 due to bombardment by both light and heavy ions (He and F) was measured for bombarding energies of 0.08 to 1.3 MeV/amu. The number of SOp molecules ejected from the target per incident ion (i.e.• the sputtering yield) was 50 for 1.5 MeV He ions and ?300 for 6 MeV F ions. Ion bombardment followed by heating produced an oxygen/sulfur residue which was much more stable a...

A new plasma ion source for in situ keV He ion bombardment of solid state samples or thin films was designed and built for ion fluences between 1 × 10(12) and 1 × 10(17) ions/cm(2). The system was designed to be mounted to different diffraction chambers for soft x-ray resonant magnetic scattering. Without breaking the vacuum due to He-ion bombardment, structural and magnetic modifications of th...

The effects of fluorine ion bombardment on the channel transport properties of AlGaN /GaN heterostructures have been investigated. Ion bombardment of the heterostructure was carried out within a CF4 plasma in a reactive ion etching system at various self-bias voltages. Hall mobility and sheet electron concentration for the two-dimensional electron gas showed strong dependence on bombardment dur...

The sputtering yield of liquid tin due to heavy-ion bombardment has been found to have significantly reduced dependence on the sample temperature than that of light-ion bombardment. These results, combined with previous light-ion data, show that the mechanisms that increase the sputtering yield of materials under ion irradiation are diminished or surpassed by the effects of heavy-ion bombardmen...

Interstitial N diffusion under low energy (approximately 700 eV) Ar+ bombardment at 673 K in ion beam nitrided austenitic stainless steel is investigated. Ar+ ion bombardment increases the N mobility in depths far beyond the ion penetration depth, resulting in an increased broadening of the N depth profile as a function of Ar+ flux. This effect cannot be explained by any established mechanism o...

The synthesis of vertically aligned single-walled carbon nanotubes (VA-SWNTs) by plasma-enhanced chemical vapor deposition (PECVD) was achieved at 500-600 °C, using ethylene as the carbon source and 1 nm Fe film as the catalyst. For growth of high-quality VA-SWNTs in a plasma sheath, it is crucial to alleviate the undesirable ion bombardment etching effects by the optimization of plasma input p...

Ion bombardment of plant and bacterial cellular material has recently been used as a tool for the transfer of exogenous DNA macromolecules into the cell interior region. The precise mechanism that leads to the transfer of macromolecules through the cell envelope is not yet clear, however it has been observed that the ion bombardment is accompanied by the formation of “microcraters” on the cell ...