Research Of All Fiber M-Z Interferometer Used In The Plasma Density Measurement

Gas-puff Z-pinch plasma is one of the possible ways to make the controlled nuclear fusion come true. Z-pinch plasma device can be used as a high energy drive source bombarding deuterium and tritium target source for inertial confinement fusion for the fuel ignition. In order to understand the radiation behavior of the device, pulsed plasma density diagnosis has been the focus of research in this field. Compared with other technologies, laser interferometer has some excellent performance, such as high dynamic response range, high accuracy, and it can be achieved on the plasma density of the noncontact measurement with excellent quality. So it is high-profile. The traditional laser interferometer is composed of optical discrete components and space path. It is difficult to adjust the optical path. And the harsh external environment also limit its application in the plasma density measurement.With the quick development of fiber technology, the optical fiber passive components with high performance can replace optical discrete components to build the optical system. This new system structure is simple. Except the optical path of laser probe is outside, other beam of light is all in the fiber. It can adapt to the complex application environment. This thesis analysis the working principle of Mach-Zehnder interferometer and the principle of key components deeply and parameters are analyzed and calculated in detail.The electromagnetic probe plasma diagnosis, microwave diagnostic techniques, spectral diagnosis technology, and laser diagnostic techniques are analyzed and compared in this thesis. The Michelson interferometer and Mach-Zehnder interference system are studied, so as to select the more suitable for pulsed plasma diagnosis Mach-Zehnder interference scheme. On this basis, the design has been developed to meet the all fiber pulse plasma density diagnosis was Mach-Zehnder laser interferometer. In the same time, the interferometer, fiber coupling, laser collimator calibration and alignment of the interferometer key adjusting method are discussed in detail. The interferometer has been utilised in situ measurements, and it obtained good results.Such interference laser wavelength was chosen for the 632.8nm. It can be a single point density diagnosis of plasma density in the range of 1013~1016cm-3, the time resolution of 1 μs, the relative error of less than 2%, the spatial resolution of 0.5mm.