Design of a 3-m-long electromagnetic launcher

A 3-m-long 30-mm square bore launcher has been constructed for electromagnetic launch application at the Institute of Electrical Engineering, Chinese Academy of Sciences. The main purpose of the launcher is to conduct the basic and applied research in electromagnetic launch. An optimum structure of the insulators was adopted through the stress analysis using the software ANSYS. In order to know about the variation of the gap under a certain stress, an air pressure piston (maximum air pressure of 5 MPa) and a position sensitive detector were adopted. The measuring results have shown that the rail gap decreases gradually from breech to muzzle; this kind of design can abate the erosion of the rails caused by arc discharge effectively. A total of 85 tests has been performed, including 17 tests of single-module discharging and 68 tests of nine-module sequential discharging, and a highest muzzle velocity of 1.9 km/s with a 45-g mass was achieved, operating at a current of 410 kA and 2-ms pulse duration. This launcher is now used for the fundamental research on armature structure, performance of the pulsed power supply, and the diagnostic system. A novel launcher based on the previous experimental results is under development.