In the lightest nuclei of 1p-shell the g-absorption cross section looks as a set of wide maximums with their own decay characteristics. It was predicted by theory and was observed experimentally. On the other hand the discrepancy of different experimental results and their disparity with theoretical ones should be noted.

It could be understood taking into account that only single charged particle was registered in experimental investigations of photodisintegration of nuclei, in particular lithium. At the same time the theory predicts that three particle?s desintegration is the most intensive decay channel. So the immediate experimental investigation of multiparticle disintegrations is essential for the theoretical treatment of the photodisintegration of these nuclei.

The method of nuclear emulsion was used for the experimental investigation of the photodisintegration of 1-p shell nuclei (⁶Li, ⁷Li and ¹²C) on three charged fragments. It is known that this method allows the registration of the interactions in full kinematics. The identification of the events under investigation was done using conservation laws for energy and momentum and difference method. The admixture of background events for every reaction investigated was about 10%.

At collected irradiation doze and energy of g-quantum ( < 46 MeV) the following reactions were observed and investigated.

              g + ⁶Li --> p + d + t - 21.28 МэВ.  (1)

              g + ⁷Li --> p + t + t - 22.28 МэВ,  (2)

              g+ ¹²C  --> a + a + a - 7.28 МэВ,    (3)

              g + ¹²C --> p + a + ⁷Li - 24.62 МэВ, (4)

Integral cross sections obtained - (6.6 + 0.7) mb^.MeV and (1.0 + 0.4) mb^.MeV don't confirm theoretical predictions 51 mb^.MeV [1] and 18 mb^.MeV [2] for reactions (1) and (2), correspondingly.

All features of the investigated reactions are in accordance with results determined only by Feynman diagram's mechanism. Features of the reaction (1) are in agreement with detailed theoretical calculations based on diagram technique too [3].

[1] I. V. Kurdyumov, S. H. El. Samarai, Yu. F. Smirnov and K. V. Shitikova,

Izv.Akad. Nauk SSSR, Ser. Fiz., 1966, V.30, P.292.

[2] S. H. El. Samarai, Yu. F. Smirnov, B. A. Yuryev, Izv.Akad. Nauk SSSR, Ser. Fiz.,

1968, V.32, P.1709.

[3] E. I. D. Dubovoy, G. I. Chitanava, Yad. Fiz., 1987, V. 45, P.677.