Gas cluster ion Beam

Bourelle, E., Suzuki, A., Sato, A., Seki, T., and J. Matsuo. 2005. Sidewall polishing with a gas cluster ion beam for photonic device applications. Nuclear Instruments and Methods in Physics Research B 241 622-625. 

Insepov, Z., Hassanein, A., Norem, J., and D. R. Swenson. 2007. Advanced surface polishing using gas cluster ion beams. Nuclear Instruments and Methods in Physics Research B 261 664—668. 

Moritani, K., Mukai, G., Hashinokuchi, M., Mochiji, K. (2009) Energy-dependent fragmentation of polystyrene molecule using size-selected Ar gas cluster ion beam projectile. Appl. Phys. Express, 2,046001. 

PHI TRIFT IV ToF-SIMS (Physical Electronics, USA) employs three electrostatic analyzers in the ion path to filter the background and metastable secondary ions. Using liquid metal cluster ion guns (such as Aut ion beam for sputtering of sample surface) increased sensitivity compared to a Ga+ primary ion beam are obtained (www.phi.com). The application of dual primary ion guns is useful for an effective dual beam depth profiling on multi-layered samples. 

Ionization ionization using primary ions Ar+, Cs+, , 0, Ga+, cluster ions post-ionization of neutrals plasma, e-beam, laser (resonant, non-resonant)... 

The result of intensity alternation for the boron nitride cluster ions is in accordance with the generation of high cluster ion beams MnXn, for several systems (e.g. NaCl, CuBr or Csl26 49) by other methods of cluster formation such as by quenching condensation in a cold rare gas or by ion bombardment of hahdes. 

Toyoda, N., Yamada, I. (2009) Size effects of gas cluster ions on beam transport, amorphous layer formation and sputtering. Hud Instrum. Methods Phys. Res., B267, 1415-1419. 

In the last decade, cluster ion sources have been frequently reported to be better than atomic ion sources for mass spectral analysis and imaging of organic and polymeric materials. A representative example of the secondary ion yield enhancement induced by the use of a cluster ion beam for the characterization of polymeric materials is presented in Figure 42.8 for the case of low MW PS, PS-2000 [137]. The results obtained for PS-2000 are representative of those obtained from the other studied polymers poly(ethylene terephthalate) (PET) and poly(tetrafluoroethylene) (FIFE). With respect to the more traditional Ga" projectiles, the mass spectra obtained with Ceo show a large increase in secondary ion yield. In comparison, the MWD was not even detectable in the mass spectra acquired with the 10 keV Ga" source. 

The fonnation of clusters in the gas phase involves condensation of the vapour of the constituents, with the exception of the electrospray source [6], where ion-solvent clusters are produced directly from a liquid solution. For rare gas or molecular clusters, supersonic beams are used to initiate cluster fonnation. For nonvolatile materials, the vapours can be produced in one of several ways including laser vaporization, thennal evaporation and sputtering. 

Pulse electron-beam mass spectrometry was applied by Kebarle, Hiraoka, and co-workers766,772 to study the existence and structure of CH5+(CH4) cluster ions in the gas phase. These CH5+(CH4) clusters were previously observed by mass spectrometry by Field and Beggs.773 The enthalpy and free energy changes measured are compatible with the Cs symmetrical structure. Electron ionization mass spectrometry has been recently used by Jung and co-workers774 to explore ion-molecule reactions within ionized methane clusters. The most abundant CH5+(CH4) cluster is supposed to be the product of the intracluster ion-molecule reaction depicted in Eq. (3.120) involving the methane dimer ion 424. 

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