A description is given of a neutron time‐of‐flight spectrometer used for energies up to 140 Mev. A 20‐m&mgr;sec neutron pulse is obtained by electrostatic deflection of the internal proton beam of the cyclotron onto a thick aluminum target. By timing the neutrons over a 26‐meter flight path an energy spread of 4.2% at 15 Mev is obtained rising to 14% at 140 Mev. The advantages of the technique and possible improvements are discussed.