Beam sources discharge

Many of the metal cluster anions have been produced by cathode discharge in He doped with Ar and studied in a flow tube reactor. A few clusters have been prepared by laser vaporization using a supersonic cluster beam source and the reac-... 

Kaiser s studies employed a conventional spectrometer with A and B electric quadrupole fields, and by passing the HC1 gas through a microwave discharge situated prior to the molecular beam source, populations in the ratios 21 3 1 for the v = 0, I and 2 vibrational levels were obtained. An effusion source was operated at 170 K and line widths close to 1 kHz were obtained similar studies of DC1 were described, except that in this case the gas was preheated to 1440 K to produce increased vibrational excitation. Kaiser was able to observe spectra of H35C1 in J = 1, v = 0, 1,... 

An additional effusive beam source, operated with pure O2 as the precursor geis, is used for some studies. This source, shown schematically in Fig. 7, is a low pressure ( 100 mTorr) RF discharge tube, with a small hole (0.5 mm) in the end. The inductively coupled plasma is typically operated at a power of 50 W. The effluent (beam) from this source has been characterized by aligning the detector with the plasma source and placing... 

Fig. 2.13 Schematic of fluorine atom beam source by double-stage pulsed discharge method. Reprinted with permission from Ref. [28]. 2006, American Institute of Physics...

Ren ZF, Qiu MH, Che L et al (2006) A double-stage pulsed discharge fluorine atom beam source. Rev Sci Instrum 77 016102... 

It is curious that the most used Q source for an XeCl laser (either e-beam or discharge excited) is HQ and to first order neither of the above reaction schemes is relevant. The reaction e + HQ -> H + Q is 1(X) times too slow to allow for sufficient laser gain to be generated. Moreover, the harpoon mechanism fiom xenon metastables does not produce XeQ emission in high yield. The above considerations are not true for a based XeCl laser, but materials handling and background absorption make this a less desirable source of Q. 

Thus, electron impact can excite any dissociative state of a molecule and reduce it to fragments, and this is a key mechanism by which radicals and molecular fragments are produced in situations ranging from planetary atmospheres to molecular beam sources from experiments in molecular collisions. Another important process is electron-impact ionization, because this is the mechanism by which ions are created in any gas discharge system, and because it can produce any ionic state of the target. 

Thennal dissociation is not suitable for the generation of beams of oxygen atoms, and RF [18] and microwave [19] discharges have been employed in this case. The first excited electronic state, 0( D), has a different spin multiplicity than the ground 0( P) state and is electronically metastable. The collision dynamics of this very reactive state have also been studied in crossed-beam reactions with a RF discharge source which has been... 

Beams of metal atoms have been prepared by many researchers tlirough thennal vaporization from a heated cmcible. An example of such a source, employed for the generation of beams of alkaline earth atoms, is described by Irvin and Dagdigian [H]. By striking an electrical discharge within this source, beams... 

Gorry P A and Grice R 1979 Microwave discharge source for the production of supersonic atom and free radical beams J. Rhys. E Sc/. 12 857-60... 

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