A: Results of the experimental study of electron emission from liquid xenon via electroluminescence of the gas phase are presented. We report on observation of a peculiar kind of delayed electroluminescent signal following initial electroluminescence caused by ionizing particles. We also present the results of a study of spontaneous single electron emission following cosmic muon signals. It was found that the rate of spontaneous single electron signals strongly depends on the time passed since the initial electroluminescence happened. The analysis of experimental data showed that both spontaneous single electron signals and delayed electroluminescent signals are associated with ionization electrons which are trapped by the potential barrier at the interface.

We propose to detect and to study neutrino neutral current coherent scattering off atomic nuclei with a two-phase emission detector using liquid xenon as a working medium. Expected signals and backgrounds are calculated for two possible experimental sites: Kalinin Nuclear Power Plant in the Russian Federation and Spallation Neutron Source at the Oak Ridge National Laboratory in the USA. Both sites have advantages as well as limitations. However the experiment looks feasible at either location. Preliminary design of the detector and supporting R&D program are discussed. ___________________________________

A technique for studying single electron noise in emission detectors that are intended for detec tion of rare processes with small energy releases is developed. Examples of possible applications are experi ments for search of dark matter in the Universe and detection of reactor antineutrinos via coherent neutrino scattering at heavy xenon nuclei. We present the first results of studying the nature of single electron noise in a liquid xenon emission detector and consider possible ways to suppress it.Note: µ 0 is the electron mobility in the zero field approximation; V 0 is the potential energy of the electron ground state; E c is the critical field in which electron heating is initiated; E 0 is the field corresponding to the emission threshold; and t e is the emission time.

The successful operation of a new optical readout system (THGEM + WLS + MGPDs (multichannel array of multipixel avalanche Geiger photodiodes) in a two-phase liquid xenon detector was demonstrated.

We present the results of the first experimental study of ionization yield of electron recoils with energies below 100 keV produced in liquid xenon by the isotopes: 37 Ar, 83m Kr, 241 Am, 129 Xe, 131 Xe. It is confirmed by a direct measurement with 37 Ar isotope (2.82 keV) that the ionization yield is growing up with the energy decrease in the energy range below ~ 10 keV accordingly to the NEST predictions. Decay time of scintillation at 2.82 keV is measured to be   25 ± 3 ns at the electric field of 3.75 kV/cm.