  The deuteron spectrum in n+p -> 2 H(pi pi) at k_n = 1.88 GeV/c and theta_d =
0^o is explained by considering a Delta Delta excitation as the dominant
reaction mechanism for the 2 pi production. We present a new theoretical
approach based on a coupled channel formalism which allows to include the
residual interaction within the intermediate Delta Delta and Delta N systems.
The corresponding interaction potentials V_{DeltaDelta} and V_{DeltaN} are
adopted from a meson exchange model with pi, rho, omega, and sigma exchange
taken into account. The influence of the residual interaction on the deuteron
spectrum is studied. We also predict the angular distribution of the two pions.
It is shown that this distribution is closely connected to the spin structure
of the DeltaDelta excitation.
