  The 56 tonne high resolution liquid scintillation calorimeter KARMEN at the
beam stop neutrino source ISIS has been used to search for neutrino
oscillations in the disappearance channel nu_e->x. The nu_e emitted in mu+
decay at rest are detected with spectroscopic quality via the exclusive charged
current reaction 12-C(nu_e,e-)12-N_g.s. almost free of background. Analysis of
the spectral shape of e- from the nu_e induced reaction as well as a
measurement of the absolute nu_e flux allow to investigate oscillations of the
type nu_e->nu_tau and nu_e->nu_mu . The flux independent ratio R(CC/NC) of
charged current events 12-C(nu_e,e-)12-N_g.s. to neutral current events
12-C(nu,nu')12-C* provides additional information in the oscillation channel
nu_e->x . All three analysis methods show no evidence for oscillations. For the
nu_e->nu_tau channel 90%CL limits of sin^2(2t)<0.338 for dm^2>100eV^2 and
dm^2<0.77eV^2 for maximal mixing in a simple 2 flavor oscillation formalism are
derived. A complete 3 flavor analysis of the experimental data from five years
of measurement with respect to nu_e<->nu_tau and nu_e<->nu_mu mixing is
presented.
