Field acceleration

Fig. 4. Schematic diagram of a TOF spectrometer where is the extraction field, E the acceleration field, and E tube length (1).

An Optical Bomb Study of the Combustion of Solid Propellants in High Acceleration Fields , Final Tech Rept, Contract N00014-67-C 0455, Atlantic Research Corp, Alexandria (1969) 9) R.W. Bryant R. Gledhill, Effect of Variations in Composition on Physical Properties of... 

To prevent withdrawal of the ions thus produced by penetration of the main accelerating field, either a small positive bias is applied to plate 6 or alternatively (31) the exit slit from the ionization chamber is covered by a transparent wire mesh. The ions are withdrawn from the ionization chamber by a voltage pulse of proper sign applied either to the repeller plate (plate 3) or to the ion withdrawal plate (plate 6). 

This chapter considers the first group of instabilities and introduces the analysis of processes implying an interaction with external flow-field perturbahons. This is exemplified by investigations of coupling between pressure waves and plane flames and also between an external acceleration field and flame fronts. The coupling between flow perturbations and flames giving rise to heat release unsteadiness and coupling with acoushc modes is considered in Chapter 5.2, which deals with the relationship between perturbed flame dynamics and radiated acoustic field, a fundamental process of thermo-acoustic instabilities. 

After detachment of the flame from the walls, the narrow ever-diminishing hot product zone behind the flame moves owing to the free convection in the centrifugal acceleration field toward the axis of rotation, with a speed scaling with circumferential velocity at the flame location, which reduces the observed flame speed to very low values, and in some cases negative ones. 

As a first example we consider a system bounded periodically in two coordinates and by thermal walls in the other coordinate. The two thermal walls are at rest and maintained at the same temperature, T. The system is subjected to an acceleration field which gives rise to a net flow in the direction of one of the periodic coordinates. For this system, the hydrodynamic equations yield solutions of quadratic form for the velocity and quartic for the temperature. 

HSCCC is attracting attention based on its high separation scale, 100% recovery of sample, and mild operating conditions. It is a chromatographic separation process based on the partition coefficients of different analytes in two immiscible solvent systems (mobile phase and stationary phase) subjected to a centrifugal acceleration field. 

G.C. Mattem, C.I. Nuessle, D.L. Green, W.M. Leimkuehler, J.D. Philpot, RJ. Ness, and K.S. Billesbach, Accelerated field residue analysis of tebuconazole using Soxtec extraction and HPLC/electrospray tandem mass spectrometry (HPLC/ESI-MS-MS), Presented at the Midwest Regional Meeting of the American Chemical Society, Osage Beach, MO, October 29, 1997. 

While reviewing the operation of measuring and transformation devices based on distributed potential structures utilizing the decelerating (reflective) and accelerating field areas (fig. 4), the problem of its operation... 

The electrons are bunched by the action of the RF accelerating field and therefore the emission occurs in sharp pulses, only tens of picoseconds in width, with frequency corresponding to the bunch spacing. For maximnm beam cnrrent many bnnches are used, giving a pulse frequency of typically 500 MHz. When only one bnnch is injected into the ring, the period drops to a few megahertz, while the pnlse width remains at a few picoseconds. This featnre has been used extensively for finorescence lifetime measnrements and may also be exploited in stroboscopic topography. 

Niioka, T, and Mitani, T, An Analytical Model of Solid Propellant Combustion in an Acceleration Field, Combustion and... 

Reimann (57), who mounted two U-shaped hairpin filaments of different radii, one inside the other, with their mid-points about 1 mm. apart (see Fig. 18b). Under these conditions, the emission produced by a small accelerating field was restricted to the tip of the filament, thus eliminating the need for the internal shielding used by Langmuir and Kingdon (93). In this apparatus the S.P. for the adsorption of O2 on W was —1.70 v., in agreement with the value recalculated from Kingdon s thermionic data (57). Later Reimann (94) obtained a C.P.D. of d-1.7 v. between clean and thoriated W filaments. 

The computational solution to a steady-state, two-dimensional, axisymmetric flow problem is illustrated in the Fig. 2.23. The solution itself is provided in spreadsheet form on a uniform mesh (CVD SolutionAlone. xls). Based on the given velocity fields, compute the acceleration field. Discuss in physical terms the behavior of the acceleration field, relating it, for example, to the flow patterns as illustrated by the streamlines. You may want to graph acceleration components, magnitudes, or directions along r or z cuts to make certain points. Excel s charting capabilities should assist this task. 

Phase separation in all solvent extraction systems, including CSSX, is greatly enhanced by the application of relatively high centrifugal forces that are generated in the separating zone of centrifugal solvent extraction contactors. Typical acceleration fields... 

The electron source of the PIMMS is an argon plasma. Inside the plasma chamber the gas is ionized by a 2.45 GHz microwave field, ignited by an electric spark. In the plasma chamber free electrons are created, that are accelerated by a static electric field for impact ionization of the sample gas atoms. The layout of the plasma chamber has to incorporate both the fluidic and the electrostatic requirements. On the one hand the gas apertures of the chamber must have the appropriate dimensions to assure that the gas flow out of the chamber is low. On the other hand the geometry must be such that most of the electrons are generated close to the outlet of the chamber and can be extracted through this small aperture. Electrons should be generated close to the acceleration field, which intrudes the chamber only to a small depth. 

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