Over the past two years, INFN-LNS has undertaken to improve the source reliability for high-power proton accelerators. A full set of magnetic field measurements has been carried out to define a different design of the TRIPS magnetic system, based on permanent magnets, in order to increase the reliability of the source devoted to the ADS. The OPERA-3D package was used to design the new magnetic system as a combination of three rings of NdFeB magnets and soft iron in between. The description of the magnetic measurements and the comparison with the simulations are presented, along with the design of a new version of the source, called PM-TRIPS. Finally the new low-energy beam transfer line (LEBT) will be described, with particular regard to the improvement of accelerator availability, which can be obtained with the installation of two PM-TRIPS sources or more on a switching magnet.