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Fragmentation of the 1,3-trans-Butadiene ion formed by two-photon resonant multiphoton ionization has been investigated utilizing two separate tuneble lasers. The butadien ion is formed by resonantly pumping the 0-0 transition of the 3s Rydberg state at 399.1 $\mu$m. This forms the parent ion predominantly in the vibrationless ground state which can be verified by the photoelectron spectrum. Fragmentation of the parent ion has been studied using a single laser as a function of laser power and the kinetic energy release of the fragments has been measured by varying the initial acceleration voltage. A second laser at 495.00 nm is used to photodissociate the parent ion. The resulting fragmentation can be explained on the basis of the breakdown $curves1$ and the photoelectron $spectrum.2$ A motastable peak is observed in the two laser mass spectrum at low dissociation laser power which decreases in intensity as the power is increased. By scanning the second laser the absorption spectrum of the ion can be taken. $\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}$J. Dannacher, J. Flamme, J. Stadelmann and J. Vogt, Chem. Phys. 51(1980)189. $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$K. Kimura, S, Katsumata, Y. Achiba, T. Yamazaki and S. Iwuta, Handbook of HeI Photoelectron Spectra of Fundamental Organic Molecules (Halsted Press, New York, 1981) p. 62.