Tripositronium generation in electron-nucleus collisions

Electro-production of tripositronium (bound states of two electrons and a positron) on nuclei is investigated. Intensity of the tripositronium production at heavy-current betatrons is estimated. A basis is presented for a possibility to detect such systems experimentally and to generate them at electron accelerators. It is proposed to use fast tripositronium to determine parameters of the wave function of relativistic three-particle systems