New generation of double beta decay experiments: are there any limitations?
New generation of experiments to search for neutrinoless double beta decay with sensitivity to effective Majorana neutrino mass on the level of {approx}3-5 meV is discussed. Possible restrictions in achievement of this sensitivity such as: possibility to produce large amount of enriched isotopes, possibility to reach of a very low level of background, energy resolution and possible cost of experiments are considered. It is shown that for realization of so ambitious project 10 tons (or more) of enriched isotope is required. Background index should be on the level {<=}10{sup -5}-10{sup -6} c/kg{center_dot}keV{center_dot}y. In addition, the energy resolution of the detector should be no worse than 1-2%. It is shown that {sup 130}TeO{sub 2} low temperature bolometer could be the most realistic candidate for such an experiment. Under certain conditions experiments with {sup 76}Ge, {sup 100}Mo and {sup 136}Xe can be realized too.