Recent thermal transport and NMR experiments have indicated that adding a small amount (1%) of Ni impurities to the famous S=1/2 quantum spin chain compound SrCuO2 opens up a gap in the spin excitation spectrum. This is highly surprising, since magnetic impurities in quantum spin chains usually enhance the density of states at low energies, rather than deplete it. Thermodynamic measurements are unable to shed light on this phenomenon due to a very large in-chain exchange constant. From our own initial neutron scattering time-of-flight measurements (at MAPS/ISIS) we find a clear energy gap of approximately 7 meV. However, the lacks of neutron flux in this energy range at the MAPS spectrometer we could not perform a systematic and detailed study, including temperature dependence, of this sample. Here we propose to make good use of the much higher intensity/resolution of ILL/IN8 in order to perform such a detailed study of our SrCuO2-1%Ni sample.