An electroluminescence emission detector to search for positron double-beta decays of Xe-124 and of Kr-78

An emission detector, self-triggered with scintillation, is proposed to search for positron double-beta decays of Xe-124 and of Kr-78. Ionisation clusters are extracted from liquid phase and measured with matrix of photodetectors as electroluminescent flashes of the gas phase. in case of 2 beta(+) decay, a useful event will contain 5 ionisation clusters, cross-laying in the same plane. In case of K beta(+) decay, a useful event will contain 3 clusters, laying in the same line. Proposed detector with 0.4 m(3) working volume will be able to check the theoretical prediction for T-1/2 of 2 beta(+)2v and K beta(+)2V decays of Xe-124 isotope in over-ground experiment and of 2 beta(-)0v, 2 beta(-)2v decays of Xe-134, Xe-136 isotopes in underground experiment with natural mixture of Xe isotopes. Seeking for 2 beta(+)0v, 2 beta(+)2v, K beta(+)0V and K beta(+)2V decays of Kr-78 in over-ground experiment with natural mixture of isotopes is also possible with additional NaI(Tl) triggering system surrounding the emission detector. High pressure Xe gas-filled model of the emission detector with working volume of 40 cm diameter and 4 cm depth is built and tested with multi-clusters events generated by absorbing gamma-radiation.