Mutual friction coefficients ﹩{{ \mathcal B }}_{{\rm{co}}}﹩ as a function of normalized cylindrical radius x/R_cc for PKDD with different L₀ and fixed 1.4 M_⊙ neutron star mass. The shaded region indicates the range of ﹩{{ \mathcal B }}_{{\rm{co}}}﹩ for ﹩{{ \mathcal M }}_{p}^{* }/{{ \mathcal M }}_{p}=0.5﹩–0.7, with the upper and lower boundaries corresponding to ﹩{{ \mathcal M }}_{p}^{* }/{{ \mathcal M }}_{p}=0.5﹩ and ﹩{{ \mathcal M }}_{p}^{* }/{{ \mathcal M }}_{p}=0.7﹩, respectively.