Heterdyne Interferometer for Triggering Gas Puff PRSs

Large X-ray generators using gas fill loads are a key element in the DTRA simulator program. Consistent relative timing between the injection of the gas shell and the generator current pulse is crucial to producing consistent, high-yield x-ray pulses.To that end HY-Tech proposes replacing existing high voltage trigger pin technology, with a sensitive, all fiber-optic heterodyne interferometer based trigger generator. The innovative features include the implementation of an all fiber optic system inconjunction with a novel load cell to increase sensitivity and reduce noise susceptibility. In addition to acting as a trigger source, the interferometer will posses all the usual capabilities of a heterodyne system. It will provide an absolute timehistory of the gas puff which can then be manipulated to give an axial line density profile for each simulator shot. It will also provide a measure of the preionization level and well as the early electron density buildup during the generator pulse.This program should take the interferometer from the status of a research tool to a standard diagnostic device which can be easily and routinely installed and used on simulators throughout the DTRA community. The benefits anticipated for DTRA programs isto produce a more reliable and efficient simulator technology using gas puff loads. This will come about in two ways. The first is to provide a consistent trigger source. The second is to provide a data base on the shot-to-shot consistency of puffvalve technology and initial conditions for each shot. Commercially, the proposed technology may well posses the sensitivity and robustness for application in many venues requiring mass flow control. Specific areas include airliner fuel control andpetroleum pipelines.