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A kinky and clumpy ringlet shares orbit with the moon Pan in the center ofthe 320-km wide Encke gap in Saturn's rings (Porco et al., 2005). The ringletis mainly composed of micron-sized particles (Showalter, 1991, Hedman et al.,2011), implying that these particles may be significantly perturbed bynon-gravitational forces, which can limit their lifetimes. We establish akinetic model considering the birth, evolution, and death of dust in the Enckecentral ringlet allowing to evaluate the ringlet optical depth. First, weinvestigate the generation of dust by micrometeorite impacts (the`impact-ejecta' process) on putative, yet undetected embedded moonlets. Takinginto account the orbital evolution under the influence of the relevantperturbation forces, the dominant loss mechanisms are collisions with ringparticles in the gap edges, the putative moonlets in the gap, or erosion bysputtering in Saturn's plasma environment. However, our results show that thisimpact-ejecta process alone can only sustain a ringlet of optical depth 3-4orders of magnitude smaller than the observed values. Consequently, otherprocesses must be taken into account. For example, mutual collisions amongputative moonlets should produce dust at about the same rate, while furtherdisruption of ejecta, as proposed by Dikarev (1999), should increase the totalamount of particles. Furthermore, observations show an azimuthal asymmetry ofthe material in the Encke gap ringlets (Ferrari and Brahic 1997, M.Srem\v{c}evi\'c, private communication). We investigate the scenario proposedby Hedman et al. (2013) that for the Encke central ringlet, the observedasymmetry is mainly due to the combined action of plasma drag and Pan's gravitycausing a focusing of dust in the region leading Pan's orbit (Hedman et al.2013).

Particle dynamics in the central ringlet of Saturn's Encke gap