Experiments TGV I (double-beta decay of Ca-48) and TGV II (double-beta decay of Cd-106 and Ca-48)

Present status of experiments TGV I and TGV II is given. The TGV I collabor ation has studied the double-beta decay of Ca-48 with a low-background and high sensitivity Ge multi-detector spectrometer TGV (Telescope Germanium Ve rtical). The preliminary results of T-1/2(2 nu beta beta) = (4.2(-1.3)(+3.3 )) x 10(19) yars and T-1/2(0 nu beta beta) >1.5 x 10(21) years (90% CL) for double- beta decay of Ca-48 has been found after the processing of experim ental data obtained after 8700 hours of measuring time using approximately 1 gramme of Ca-48. The aim of the experiment TGV II is the development of t he experimental methods, construction of spectrometers and measurement of t he beta beta decay (beta(+)beta(+), beta(+)/EC, EC/EC) of Cd-106 particular ly the 2 nu EC/EC mode. The theoretical description and performance of the TGV II spectrometer are also given.