If they are in Libya, its likely that the purpose is that it makes perfect place to test the weapon. Imagine the chaos if we detect a test in the midst of the Libyan desert only after it has been tested. Hard to blame the Iranians for the test, impossible to act against the Libyans given the cover the Euros have given him to get supplied with oil. Ghadaffi would certainly take credit as it bolsters his case and the actual practitioners would be safe in their bunks in Tehran before the first detections were seen.
Again, this might be a case where Ghadaffi has no idea that this is going on, even if it is happening in his own backyard. Libya is a huge desert, and the vast majority of it is completely devoid of life or any sort of human involvement.
