Evaporative evolution of stellar clusters is shown to be relaxation limited when the number of stars satisfies N > > N _ { c } , where N _ { c } \simeq 1600 .
For a Maxwell velocity distribution that extends beyond the escape velocity , this process is bright in that the Kelvin-Helmholtz time scale , f _ { H } ^ { -1 } t _ { relax } , is shorter than the Ambartsumian-Spitzer time scale , f _ { N } ^ { -1 } t _ { relax } , where f _ { H } > f _ { N } denote the fractional changes in total energy and number of stars per relaxation time , t _ { relax } .
The resulting evaporative lifetime t _ { ev } \simeq 20.5 t _ { relax } for isolated clusters is consistent with Fokker-Planck and N-body simulations , where t _ { relax } is expressed in terms of the half-mass radius .
We calculate the grey body factor by averaging over the anisotropic perturbation of the potential barrier across the tidal sphere , and derive the tidal sensitivity { d \ln t _ { ev } } / { dy } \simeq - 1.9 to -0.7 as a function of the ratio y of the virial-to-tidal radius .
Relaxation limited evaporation applies to the majority of globular clusters of the Milky Way with N = 10 ^ { 4 } -10 ^ { 6 } that are in a pre-collapse phase .
It drives streams of stars into the tidal field with a mean kinetic energy of 0.71 relative to temperature of the cluster .
Their S shape morphology leads in sub-orbital and a trails in super-orbital streams separated by 3.4 \sigma / \Omega in the radial direction of the orbit , where \Omega denotes the orbital angular velocity and \sigma the stellar velocity dispersion in the cluster .
These correlations may be tested by advanced wide field photometry and spectroscopy .