BCS

During many years in Scientific Research Institutes of Nuclear Physics and Introscopy at Tomsk Polytechnical University (TPU) researches into induction electron accelerators and their uses for non-destructive radiation quality control of materials and articles have been conducted. Control sensitivity and efficiency detection experimental researches have been conducted with the high-current stereo-betatron modifications [1], and KBC-25 M and BC-50 high-current betatrons [2,3] in range of 11 MeV and 25-50 MeV radiation energy. 

As for BC-50 betatron it is possible to fulfill radiographic control of steel with thickness of 360 mm for the same time tmd energy at focal distance of 3.0m 450 mm steel at F=1.5m, and 480mm steel at F=3.0m with the help of PT-1 film type. 

At 45 MeV mode BC-50 betatron allows to x-ray steel barrier with 500mm thickness using PT-1 film type at F=3m in less than seven minutes. During one hour exposure and at the same focal distance betatron allows to x-ray 500mm thickness steel on PT-5 film type. And 700mm thickness steel on PT-1 film type. 

Assume that an aqueous solute adsorbs at the mercury-water interface according to the Langmuir equation x/xm = bc/( + be), where Xm is the maximum possible amount and x/x = 0.5 at C = 0.3Af. Neglecting activity coefficient effects, estimate the value of the mercury-solution interfacial tension when C is Q.IM. The limiting molecular area of the solute is 20 A per molecule. The temperature is 25°C. 

Figure Al.6.26. Stereoscopic view of ground- and excited-state potential energy surfaces for a model collinear ABC system with the masses of HHD. The ground-state surface has a minimum, corresponding to the stable ABC molecule. This minimum is separated by saddle points from two distmct exit chaimels, one leading to AB + C the other to A + BC. The object is to use optical excitation and stimulated emission between the two surfaces to steer the wavepacket selectively out of one of the exit chaimels (reprinted from [54]).

Figure A3.7.1. Two-dimensional contour plot for direct collinear reaction A + BC —> AB + C. Transition state is indicated by J.

Consider the collision of an atom (denoted A) with a diatomic molecule (denoted BC), with motion of the atoms constrained to occur along a line. In this case there are two important degrees of freedom, the distance R between the atom and the centre of mass of the diatomic, and the diatomic intemuclear distance r. The Flamiltonian in tenns of these coordinates is given by ... 

Let us continue with the atom-diatom collinear collision model, this time allowing for the possibility of the reaction A -r BC —> AB -i- C. We first introduce mass-scaled coordinates, as these are especially convenient to describe rearrangements, using... 

Although the Sclirodinger equation associated witii the A + BC reactive collision has the same fonn as for the nonreactive scattering problem that we considered previously, it cannot he. solved by the coupled-channel expansion used then, as the reagent vibrational basis functions caimot directly describe the product region (for an expansion in a finite number of tenns). So instead we need to use alternative schemes of which there are many. 

Eqnation (B3.4.1) is general and applies to both scattering and bonnd state spectroscopy. Scattering will be considered first. For shnplicity, the discnssion rises the collinear model for the A -l- BC AB -l- C reaction (i.e. assuming all particles lie on a line). This model is easy to visualize and embodies most elements of tlnee-dimensional (3D) scattering of larger molecules. 

The eollinear model does not inelude bifiiroation, i.e. the possibility oiseveral produet ehaimels whieh the system ean aeeess. A model potential surfaee for an A -1- BC— AB -1- C, AC -i-B reaetion is shown in figure B3.4.2. Both of these examples will be used in the diseussion below. 

Alternatively, one can use close-coupling methods. These methods are easiest to understand for single arrangement problems (i.e. when both the AB + C and AC + B product arrangements are very high in energy so that only the A + BC reactant arrangement can be accessed). Then one writes... 

For example, for the collinear reaction A+BC this would be the probability that if initially the diatom BC is in a vibrational state then after the reaction a diatom AB is fonned (in any product vibrational state). In... 

Figure B3.4.14. The infmite-order-sudden approximation for A+ BC AB + C. In this approximation, the BC molecule does not rotate until reaction occurs.

The conceptually simplest approach towards controlling systems by laser field is by teaching the field [188. 191. 192 and 193]. Typically, tire field is experimentally prepared as, for example, a sum of Gaussian pulses with variable height and positions. Each experiment gives an outcome which can be quantified. Consider, for example, an A + BC reaction where the possible products are AB + C and AC + B if the AB + C product is preferred one would seek to optimize the branching ratio... 

A + BC -> AC + chemical reactions with excited atom or B molecule... 

Multichannel time-resolved spectral data are best analysed in a global fashion using nonlinear least squares algoritlims, e.g., a simplex search, to fit multiple first order processes to all wavelengtli data simultaneously. The goal in tliis case is to find tire time-dependent spectral contributions of all reactant, intennediate and final product species present. In matrix fonn tliis is A(X, t) = BC, where A is tire data matrix, rows indexed by wavelengtli and columns by time, B contains spectra as columns and C contains time-dependent concentrations of all species arranged in rows. 

BC CA Physically allowed combinations lie inside the circle, with the conical... 

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