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An electron spectrometer consisting of an electron transport system with normal conducting solenoidal coils and a Si(Li)-detector as the energy dispersive element is described. It can be used for in beam spectroscopy of electrons in three different modes. The first one is the usual broad range mode with a low energy cut offofthe transmission performed by a tantalum disk between target and detector. The second one is the lens spectrometer mode. An envelope baffle system permits electron detection in a momentum band A pip = 0.12. To cover a large energy range the magnet current is sweeped. In the third mode-the recoil shadow method -a longitudinal semicylindrical baffle between target and Si(Li)-detector allows spectroscopy of delayed electrons emitted from recoil nuclei in flight. Special features of this method are high transmission, and strong suppression of the prompt 3-electron background. Lifetime measurements based on the detection of conversion electrons are possible by variation of the target position. This was tested with the 152Sm(160, x n) 168 -xyb compound nuclear reaction at a recoil velocity vr = 0.01 c, where half lives between 0.1 ns and 1 ns were determined.

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In 152Gd(~,Sn) and 136Ce(160,4n) reaction studies a 480 ns 10 + isomer in l~8Dy has been identified, and its decay has been characterized. All members of the ~h~i/2 level spectrum have been located, and the 10 v + 8 + B(E2) value gives the ~hi]/2 effective charge as 1.53 e. The 2 + and 3level energies in 148DY82 provide supporting evidence for a shell closure at Z=64.

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