The beam divergence of an indium LMIS at a distance of 50 μm as determined by plasma diagnostic measurements

► Experimental data of the beam divergence of an indium LMIS. ► Derived beam divergence close to needle tip from experimental data. ► Provision of initial conditions for ion trajectory simulations. ► Empiric formula for beam div. close to needle tip as function of emission current. ► Result is of special interest for applications without beam-limiting aperture.