Double internal Bremmstrahlung in the L-electron capture decay of Ar

Double internal bremsstrahlung (DIB) has been observed in the electron capture decay of /sup 37/ Ar. The energy distribution and angular correlation of photons emitted in this process have been measured and theoretical predictions were compared with experimental data. For higher energy rays the agreement between the theoretical predictions and experimental data was found. For photons below 100 keV this process was not investigated. In our experiment the energy distribution of the two photons has been investigated, at an angle of 900 between two photons propagation vectors. Photons were recorded in 1/2'' X 2'' and 2'' X 2'' Nal (TI) detectors in the energy intervals of 12 - 168 keV and 23 - 815 keV, respectively