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tokens: results in Tables 3 , A.1 , A.2 ). The addition of this component also significantly improves all the fits. We consider “rdb-rfxconv-pl”, which includes the hard power-law component, rfxconv, as a reflection component smeared by the rbdblur component, to be our best fit model (see Table 3 ). The fit of the XMM-Newton spectra with the same model gave values of the parameters that agree overall with those obtained fitting the NuSTAR spectra. In this case, we found values of the ionization parameter log() ranging between 2.58 and 2.71 (slightly higher, i.e., approx. 3, for the XMM-Newton spectra) and reflection amplitudes between 0.2 and 0.3, indicating a relatively low superposition between the source of the primary Comptonization continuum and the disk (a value of 0.3 would be compatible with a spherical geometry of a compact corona inside an outer accretion disk). For the smearing parameters of the reflection component, we find values of the emissivity index of the disk ranging from 2.8 to 2.48, an inner radius of the disk from 10.6 to , and an inclination angle of the system with respect to the line of sight of . In our results, the inclination angle is higher than that found by ( Miller et al. 2013 ; who report an inclination angle less than ), but is very similar to that estimated from Chandra spectra (, see Chiang et al. 2016a ). Moreover, the inner disk radius we find is not compatible with the ISCO. Assuming a for the neutron star, the inner radius of the disk is located at km from the neutron star center. Note that this value is compatible to the estimated radius of the emission region of the soft blackbody component, which is in the range km. We interpret this component as the intrinsic emission from the inner disk since this is the coldest part of the system and because the temperature of the blackbody component appears to be too low to represent a boundary layer. 5. Conclusions The main aim of this paper is to test the robustness of disk parameters inferred from the reflection component in the case of neutron star LMXBs. To this aim, we used broad-band, moderately-high-resolution spectra of Serpens X-1, a neutron star LMXB of the atoll type with a very clear reflection spectrum that has been studied with several instruments. In particular, we carried out a broad-band spectral analysis of this source using data collected by NuSTAR and XMM-Newton satellites, which have the best sensitivity at the iron-line energy. These data have already been analyzed in literature. In particular, Miller et al. (2013) have analyzed the NuSTAR spectra and obtained a low inclination angle of approximately 8, an inner disk radius compatible with the ISCO, an ionization parameter between 2.3 and 2.6, along with an iron abundance of approximately 3. We performed the fitting using slightly different continuum and reflection models with respect to those used by other authors to fit the X-ray spectrum of this source. Our best fit of the NuSTAR spectrum of Ser