Development of a new Si(Li)-detector array for the pair spectroscopy of the Hoyle-state

The 3α (triple-alpha) process leading to the formation of stable carbon in the Universe is one of the most important nuclear astrophysical processes. The radiative width of the so called Hoyle-state, involving the 7.654 MeV E0 and the 3.215 MeV E2 transitions, is known with 12.5% accuracy. We report on the development of a Si(Li)-detector array for a new magnetic pair spectrometer, which will be used for the measurement of the pair conversion of the E0 and E2 transitions from the Hoyle-state. The results of the final detector tests will be presented.