Lamps argon

Nishi and coworkers (Shinohara et al. 1985, 1986) have reported the production of unprotonated water and ammonia cluster ions, as well as Ar X+ (X = H20 and NH3) cluster ions when argon/molecule mixed expansions were ionized using UV lines from an argon lamp. The quenching of the proton transfer reaction was attributed to the cooling of the heterocluster ions via... 

Photoionisation detector, PID component molecules in the detector are ionised by photons from a high energy ultraviolet source, selectivity can be achieved by using a different source, e.g. 10.2eV low energy krypton lamp for aromatics and alkenes, 11.7eV argon lamp for alkanes, halogenated compounds as well as aromatics. Sensitivity is similar to a FID, 10 to 10- 2gs-. ... 

The main uses for argon are in metallurgical appHcations and in electric lamps. Neon, krypton, and xenon, because of high costs, are limited to specialized uses in research, instmmentation, and electric lamps. There are no significant technical uses for radon. 

Aluminum is best detected quaUtatively by optical emission spectroscopy. SoHds can be vaporized direcdy in a d-c arc and solutions can be dried on a carbon electrode. Alternatively, aluminum can be detected by plasma emission spectroscopy using an inductively coupled argon plasma or a d-c plasma. Atomic absorption using an aluminum hoUow cathode lamp is also an unambiguous and sensitive quaUtative method for determining alurninum. 

In the continuous wave (CW) experimental setup a sample is constantly illuminated by a probe beam and the steady state change in the transmission is detected (see Fig. 7-1). An argon ion laser has been used to generate the pump beam and the probe beam was from an incandescent lamp (tungsten or others), producing a broad spectrum (0.5 to 5 pm) [6]. Both pump and probe beams are directed onto the sample film and the transmitted probe light is collected, filtered through a monochromator, and detected by a photodetector. Both the pump and the probe... 

Why is argon used in many electric light lamps ... 

As indicated in Fig. 21.3, for both atomic absorption spectroscopy and atomic fluorescence spectroscopy a resonance line source is required, and the most important of these is the hollow cathode lamp which is shown diagrammatically in Fig. 21.8. For any given determination the hollow cathode lamp used has an emitting cathode of the same element as that being studied in the flame. The cathode is in the form of a cylinder, and the electrodes are enclosed in a borosilicate or quartz envelope which contains an inert gas (neon or argon) at a pressure of approximately 5 torr. The application of a high potential across the electrodes causes a discharge which creates ions of the noble gas. These ions are accelerated to the cathode and, on collision, excite the cathode element to emission. Multi-element lamps are available in which the cathodes are made from alloys, but in these lamps the resonance line intensities of individual elements are somewhat reduced. 

To a solution of 2.31 g (10 mmol) or tert-butyl Ar-(tfr -buloxycarbonyl)glyeinate in 40 mL of dry CC14 is added 1.78 g (10 mmol) of A-bromosuccinimidc and the mixture is irradiated with a 500-W lamp at 20°C (water cooling) for 1 h. The succinimide is filtered off and the filtrate is concentrated to dryness in vacuo. The residual oil crystallizes on drying in vacuo to give the product in nearly analytical purity yield 3.0 g (97%) mp 55 X. The producl is stable when kept under argon in the refrigerator, and can be used in subsequent steps without further purification. 

B. 2-Phenylthio-5-heptanol. A photochemical reactor consisting of a tubular pyrex flask, a magnetic stirbar, a water-cooled high pressure mercury lamp, and an argon inlet tube (Note 9) is charged with... 

Our experimental techniques have been described extensively in earlier papers (2, 13). The gamma ray irradiations were carried out in a 50,000-curie source located at the bottom of a pool. The photoionization experiments were carried out by krypton and argon resonance lamps of high purity. The krypton resonance lamp was provided with a CaF2 window which transmits only the 1236 A. (10 e.v.) line while the radiation from the argon resonance lamp passed through a thin ( 0.3 mm.) LiF window. In the latter case, the resonance lines at 1067 and 1048 A. are transmitted. The intensity of 1048-A. line was about 75% of that of the 1067-A. line. The number of ions produced in both the radiolysis and photoionization experiments was determined by measuring the saturation current across two electrodes. In the radiolysis, the outer wall of a cylindrical stainless steel reaction vessel served as a cathode while a centrally located rod was used as anode. The photoionization apparatus was provided with two parallel plate nickel electrodes which were located at equal distances from the window of the resonance lamp. 

The apparatus is dried in an oven at 140° overnight and cooled under nitrogen or argon prior to the irradiation. A Vycor filter sleeve and a 450-watt medium-pressure mercury lamp are placed in the immersion well. The Vycor filter, the quartz immersion well (catlog No. 19434), the 450-watt mercury lamp (catalog No. 679A36), and the requisite transformer are all available from Hanovia Lamp Division, Canrad-Hanovia Inc., 100 Chestnut Street, Newark, New Jersey 07105. 

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. 

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