Commissioning and operating experience with the LISA superconducting accelerator

The commissioning of the LISA superconducting (SC) RF electron linac at INFN Frascati Laboratories has been concluded although, due to a change in program priorities, the full possibilities of the machine have not been exploited. In this report we illustrate the results achieved so far and the difficulties encountered in commissioning, with the hope that this material might be of some help to those who intend to start the enterprise of building a SC linac in a non-specialized environment. The part concerning the SC system is particularly stressed, but a relevant attention is also devoted to the traditional room temperature injector, the proper setting of which is fundamental to achieving the high beam quality that such a machine allows. (orig.)