Investigation In Lifetime Assessment Of Electron Multiplier Based On Double-stress Accelerated Degradation Test

The development of key field of national defense technology makes increasingly high demand for more precise frequency and time standard. As the key component of a cesium atomic frequency standard system, electron multiplier (EM) directly constraints the lifetime of the cesium atomic frequency standard system. How to assess the lifetime of EM have become an important problem in the research of extending lifetime of cesium atomic frequency standard system. This dissertation focuses on the problem of lifetime assessment of EM. The single-stress accelerated degradation test (ADT) data processing methods are extended to establish the double–stress ADT methods. Those methods are successfully applied in the lifetime assessment of EM and good effect is obtained. The main researches of this dissertation are summarized as follows:1. Operation and degradation mechanism of EM are studied. The double-stress ADT is presented as the lifetime assessment method of EM.2. On the basis of theory of single-stress ADT, modeling methods based on degradation date distribution and pseudo-failure lifetime for double-stress ADT data analysis are studied. The methods provide technical support for lifetime assessment of EM.3. An approach to search maxim stress level by pilot step-stress ADT is put forward. Based on prior information obtained by step-stress ADT, a double-stress ADT plan of EM is designed and applied to lifetime assessment of EM. The lifetime of EM is given by the presented two methods.4. The applicability of the two modeling methods is studied by specific model criteria. By contrasting the two assessment methods, the better method is picked out and reasonable conclusions are given.To sum up, the studying results are of engineering value for researches in lifetime extending of EM and of important significance for self-development of cesium atomic frequency standard system. At the same time it is helpful to improve the theory of accelerated degradation test.