Laser ion beam

Fig. 2 Portion of the collinear laser-ion beam apparatus. QDl, QD2, electrostatic quadrupole deflectors CEM, channel electron multiplier DP, deflection plates PD, positive ion detector FC, Faraday cup ND, neutral particle detector CG, conducting glass plate AP, aperture MP, metal plate A, any element. The distance between QDl and QD2 is approximately 0.5 m.

A further important property of the two instruments concerns the nature of any ion sources used with them. Magnetic-sector instruments work best with a continuous ion beam produced with an electron ionization or chemical ionization source. Sources that produce pulses of ions, such as with laser desorption or radioactive (Californium) sources, are not compatible with the need for a continuous beam. However, these pulsed sources are ideal for the TOF analyzer because, in such a system, ions of all m/z values must begin their flight to the ion detector at the same instant in... 

Although the above has considered only the use of a continuous main ion beam, which is then pulsed, it is not necessary for the initial beam to be continuous it too can be pulsed. For example, laser desorption uses pulses of laser light to effect ionization, and the main ion beam already... 

Most schemes that have been proposed to propel starships involve plasmas. Schemes differ both in the selection of matter for propulsion and the way it is energi2ed for ejection. Some proposals involve onboard storage of mass to be ejected, as in modem rockets, and others consider acquisition of matter from space or the picking up of pellets, and their momentum, which are accelerated from within the solar system (184,185). Energy acquisition from earth-based lasers also has been considered, but most interstellar propulsion ideas involve nuclear fusion energy both magnetic, ie, mirror and toroidal, and inertial, ie, laser and ion-beam, fusion schemes have been considered (186—190). 

In Surface Analysis by Laser Ionization (SALI), a probe beam such as an ion beam, electron beam, or laser is directed onto a surfiice to remove a sample of material. An untuned, high-intensity laser beam passes parallel and close to but above the sur-fiice. The laser has sufficient intensity to induce a high degree of nonresonant, and hence nonselective, photoionization of the vaporized sample of material within the laser beam. The nonselectively ionized sample is then subjected to mass spectral analysis to determine the nature of the unknown species. SALI spectra accurately reflect the surface composition, and the use of time-of-flight mass spectrometers provides fast, efficient and extremely sensitive analysis. 

In Surface Analysis by Laser Ionization (SAU) ionized and neutral atoms are sputtered from the sample surface, typically using an ion beam (like SIMS) or a... 

In other articles in this section, a method of analysis is described called Secondary Ion Mass Spectrometry (SIMS), in which material is sputtered from a surface using an ion beam and the minor components that are ejected as positive or negative ions are analyzed by a mass spectrometer. Over the past few years, methods that post-ion-ize the major neutral components ejected from surfaces under ion-beam or laser bombardment have been introduced because of the improved quantitative aspects obtainable by analyzing the major ejected channel. These techniques include SALI, Sputter-Initiated Resonance Ionization Spectroscopy (SIRIS), and Sputtered Neutral Mass Spectrometry (SNMS) or electron-gas post-ionization. Post-ionization techniques for surface analysis have received widespread interest because of their increased sensitivity, compared to more traditional surface analysis techniques, such as X-Ray Photoelectron Spectroscopy (XPS) and Auger Electron Spectroscopy (AES), and their more reliable quantitation, compared to SIMS. 

For cmlian puiposes the inertial concept is to compress and heat a small sphere of D-T fuel with an external driver such as laser light, x-rays produced by lasers, or high energy ion beams. The resulting hot and extremely dense plasma burns the D-T mixture rapid-... 

DEC coating was first prepared by Aisenberg and Chabot using ion beam deposition in 1971 [2]. At present, PVD, such as ion beam deposition, sputtering deposition, cathodic vacuum arc deposition, pulsed laser deposition, and CVD, like plasma enhanced chemical vapor deposition are the most popular methods to be selected to fabricate DEC coatings. 

Up to the present, a number of conventional film preparation methods like PVD, CVD, electro-chemical deposition, etc., have been reported to be used in synthesis of CNx films. Muhl et al. [57] reviewed the works performed worldwide, before the year 1998, on the methods and results of preparing carbon nitride hlms. They divided the preparation techniques into several sections including atmospheric-pressure chemical processes, ion-beam deposition, laser techniques, chemical vapor deposition, and reactive sputtering [57]. The methods used in succeeding research work basically did not... 

Some physical techniques can be classified into flame treatments, corona treatments, cold plasma treatments, ultraviolet (UV) treatment, laser treatments, x-ray treatments, electron-beam treatments, ion-beam treatments, and metallization and sputtering, in which corona, plasma, and laser treatments are the most commonly used methods to modify silicone polymers. In the presence of oxygen, high-energy-photon treatment induces the formation of radical sites at surfaces these sites then react with atmospheric oxygen forming oxygenated functions. 

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