Approximate criteria for a Z pinch spark of an axial detonation in DT plasma are derived. On the basis of these, 2-D simulations are perfomed that suggest correct combinations of parameters for Z pinch sparks. The Iz currentrequired for ignition is of the order of 10 MA and the radii of the sparksless than 10 μm. Such μZ pinches may be produced by a fastimplosion of a cylindrical liner.