FIBER OPTIC MEASUREMENT OF SHOCK FRONT VELOCITY

A DESIGN FOR A HIGHLY ACCURATE, SMALL, MODULAR, RUGGEDIZED FIBER OPTIC LASER SYSTEM TO CONTINUOUSLY MEASURE DETONATION SHOCK FRONT VELOCITY IN EXPLOSIVES IS DESCRIBED. A UNIQUE APPROACH BASED ON A VISAR VELOCITY INTERFEROMETER IS PROPOSED. IN THIS APPROACH, THE SENSOR FIBER MAY BE EMBEDDED IN THE EXPLOSIVE OR ATTACHED EXTERNALLY WITH A SUITABLE ADHESIVE AND TAMPER MATERIAL. A UNIQUE FEATURE OF THE DESIGN MAKES IT RELATIVELY IMMUNE TO THE EFFECTS OF SHOCK INDUCES SELF LUMINOSITY WITHIN THE SENSOR FIBER OR INTENSE LIGHT SOURCES ANYWHERE IN THE OPTIC TRAIN. A PURELY OPTICAL APPROACH TO THE SENSOR HEAD AND DATA TRANSMISSION CABLE DESIGNS MAKES THEM IMMUNE TO THE EFFECTS OF ELECTROMAGNETIC NOISE. FURTHERMORE, THE MODULAR NATURE OF THE DESIGN AND ARBITRARY OPTICAL DATA TRANSMISSION CABLE LENGTH ALLOWS THE OPTICAL SIGNAL PROCESSOR AND SUPPORTING ELECTRONICS MODULE TO BE PLACED IN A LOCATION SAFE FROM THE TEST ENVIRONMENT.