Argon emission lines

When ammonia gas was introduced into an argon plasma jet at a flow rate of 60 seem, all argon emission lines disappeared, and a very short but brilliant light-blue flame was formed. A very strong NH emission band was observed. In the ammonia radio frequency plasma, some very weak N2 emission bands due to N2 second positive appeared, but in the ammonia flame formed in an argon plasma jet no emission related to N2 species was observed. 

Figure 10.3. Same as Figure 10.3, but the instrument automatically recalibrated the shift axis against argon emission lines, compensating for the mode hop. Results obtained on a Chromex Sentinel spectrometer. Both spectra and their difference use the same intensity scale. 

When ammonia gas was introduced into an argon plasma jet at a flow rate of 60 seem, all argon emission lines disappeared, and a very short but brilliant light blue flame was formed. A very strong NH emission... 

Figure 6 shows a block diagram of the optics used in the prototype apparatus. The beam of an argon ion laser operated in multiline mode (in which several argon emission lines are simul-... 

C07-0125. The argon-ion laser has two major emission lines, at 488 and 514 nm. Each of these emissions... 

Since chlorinated PVC is totally transparent in the near-UV and visible range, it will not absorb at 488 nm, the emission line of the argon ion laser that we intended to use to perform the carbonization. Therefore C-PVC films were first exposed to the UV radiation of a medium pressure mercury lamp in order to produce the strongly absorbing polyenes. This irradiation was carried out at room temperature in the absence of oxygen, thus preventing the formation of undesirable oxidation products. 

Obviously, the clusters NaAry (c), NaAry (c), NaAr4 (c), NaAry (d), and NaAre (c), which correspond to the simple van der Waals long distance addition of a excited sodium atom to an argon cluster, are characterized by 3p states and 3s states only weakly shifted with respect to the isolated atom limit. Their emission lines are therefore very close to the atomic line. 

Most elements are almost completely singly ionized in the argon ICP (a fact which also makes it an ideal ion source for mass spectrometry), hence the majority of the most sensitive emission lines result from atomic transition of ionised species, so-called ion lines, with fewer sensitive atom lines. Ion lines are usually quoted as, e.g., Mn II 257.610 nm and atom lines as, e.g., Cu 1324.754 nm, with the roman numerals II and I denoting ionic and atomic species, respectively. 

We have developed a novel ultrasensitive detection method, thermal lens microscopy (TLM), for nonfluorescent species [13]. TLM is photothermal spectroscopy under an optical microscope. Our thermal lens microscope (TLM) has a dual-beam configuration excitation and probe beams [13]. The wavelength of the excitation beam is selected to coincide with an absorption band of the target molecule and that of the probe beam is chosen to be where the sample solution (both solvent and solute) has no absorption. For example, in determination of methyl red dye in water, cyclohexane, and n-octanol, a 514-nm emission line of an argon-ion laser and a 633-nm emission line of a helium-neon laser were used as excitation and probe beams, respectively [21], Figure 4 shows the configuration and principle of TLM [13]. The excitation beam was modulated at 1 kHz by an optical chopper. After the beam diameters were expanded, the excitation and probe beams were made coaxial by a dichroic mirror just before they were introduced into an objective lens whose magnification and numerical aper-... 

Table I. Coincidences between transitions in the B liy-X Tg Systems of Na2 and Li2 and argon laser lines. Dimer laser emission has been observed from all the underlined transitions. The accuracy is 5 x lO" A for all resolved lines. A is the difference in A between measured vacuum wavelength and the calculated wavelength from the constants of References 6 and 7.

Before the invention of lasers in 1960 (Maiman), radiation emitted by the mercury arc, especially at 435.8 and 404.7 nm, has been u.sed for exciting Raman spectra (Brandmiiller and Moser, 1962). Today, most types of lasers ( continuous wave (cw) and pulsed, gas, solid state, semiconductor, etc.), with emission lines from the UV to the NIR region, are used as radiation sources for the excitation of Raman spectra. Especially argon ion lasers with lines at 488 and 515 nm are presently employed. NIR Raman spectra are excited mainly with a neodymium doped yttrium-aluminum garnet laser (Nd YAG), emitting at 1064 nm. 

Table 16.1 Most Intense Emission Lines Observed in Argon and Helium Plasma Jets...

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