Certain problems of PDISPL implementation can be solved in pulsed mode, including :

— Photo-electric transformation of PDISPL radiation;

— Specification of the products generated at PDISPL operation;

To solve these problems a laboratory bench was developed and fabricated featuring the following characteristics:

— duration of the pumping pulse 1.510-3 sec;

— spectral distribution of the energy as in black body spectrum with luminescent temperature 3500 — 5000 K;

— intensity corresponding to ~3105 solar constants (~4-104W/cm2).

A crystal of GaSb made in the Institute of Physics and Technology by Ioffe (FTI) was used as the conversing element. Duration of laser pulse was 650 ^sec and the energy, after release, was 1.1 mJ or 2.2 mJ. These values were chosen jointly with FTI for obtaining the optimal conversion ratios of laser energy into the electrical one.

Selection of the operating composition for iodine laser pumped by solar light is one of the fundamental problems. All the experience of experimental studies of iodine photo-dissociation lasers offers the conclusion — the only class of compositions suitable for implementation as the operational substances are the saturated fluorine organic compositions with one iodine atom, the so-called perfluoroalkyliodides (PFAI), having the common formulation RFI, where RF are fluorine substituted radicals of different construction (linear, branched, cyclic, with ether groups, etc.) The literature [4-6] cites the data on the following compositions: linear: CF3I — C6 F13I

isomeres: iso-C3F7I, 2- C4 F5I, t-C4F9I, 2 — C6 F13I ethers: C3F7OI, h30-C3F7OI

The available spectral-kinetic data on these compositions are presented in tables 3,4.

The following conclusions can be done on selection of the operational compositions for PDISPL based on the data presented in the tables.

Presently the best choice for PDISPL is t-C4F9I. Firstly, this composition possesses relatively wider absorption band with the maximum shifted to the "red” region as compared to the majority of optional compositions. Secondly, t-C4F9I possesses the unique kinetic characteristics. The constant of recombination velocity into the original state for this composition is twice as higher as for KR+R, withdrawal of radicals in reaction 2R-o — R2. This fact can be possibly explained by the necessity of overcoming

the conformational energy barrier at formation of (CF3)3 — (CF3)3 as opposed to reaction I+(CF3)3 -o — (CF3)3I, following the normal radical, that is without activation energy mechanism. The drawbacks of t-C4F9I include its aggregate state: within the range of normal temperatures and pressures this composition does not have the liquid state.

Conclusions

The resulting PDISPL model will be implemented in follow-up applied research activities. One of those implies further research aimed at optimization of the effectiveness of laser energy conversion into the electrical one at 1.315 pm wavelength. Above all, the technologies and methods developed will be implemented for creation of more powerful simulators of solar radiation.

The scientific results obtained on different spheres of interest cannot be named final. The authors have highlighted the ways for upgrading the effectiveness of PDISPL model together with updating the methods pre-developed.