Lepton Flavor violation searches with kaons at NA62

The ratio RK=Γ(K±→e±ν)/Γ(K±→μ±ν) between the two leptonic decay rates of charged kaons is precisely predicted within the Standard Model (SM). A recent theoretical work noticed that SUSY extensions of the SM can induce mu-electron universality violation in such a way to introduce a shift of the RK value up to few percent respect to SM prediction. Presently the experimental relative error of RK, that includes also the last two recent measurements from NA48 and KLOE, is around 1.5%. A new precise measurement of RK can be of extreme interest in order to have a more stringent test of the SM. During summer 2007 the NA62 collaboration performed a dedicated period of measurements at the CERN SPS in order to achieve both the statistical and systematic accuracy for a 0.5% relative error. A sample of about 110000K+→e+ν decays has been collected and special runs dedicated to the study of the main sources of systematic effects have been performed. The experimental set-up and the analysis strategy will be described.