Theoretical And Technical Research Of X-ray Communication In Plasma Sheath

The problem of information transmission in the"blackout zone"has always been accompanied by the development of high-speed aircraft.It severely restricts the further development of the reentry control technology and poses a great threat to the aircraft’s own security.However,because of the lack of theoretical model and the difficulty in implementing reliable ground verification,the"blackout zone"communication problem has not yet been solved in a general sense.X-ray communication technology has the characteristics of high penetration,strong anti-interference,high orientation and confidentiality because of its short carrier wavelength and large single photon energy merits.X-ray communication is expected to communicate within the"blackout zone"plasma sheath.This project consists of plasma sheath modelling,X-ray and dynamic plasma interaction mechanism researching,"black barrier"X-ray communication demonstration and verification.It will fill the theory blank of X-ray and plasma interaction,as will as the verification of reliable communication in the"blackout zone".Facing the communication needs in the"blackout zone".The"blackout zone"X-ray communication demonstration and verification technology research has solved the theoretical gaps in X-ray and plasma interaction research.And realized the scheme verification of reliable communication in the"blackout zone".Unlike the interaction between electromagnetic waves and plasma,X-rays have strong particles and are not affected by Coulomb’s electric field,and the mechanism of interaction with plasma is complicated.The traditional wave model based on Maxwell’s equations can no longer accurately explain the interaction mechanism between X-ray and plasma.Based on the collision effects between X-ray photons and plasma,a model of interaction between X-rays and non-uniform,dynamic time-varying plasma based on particle collision effects is constructed.This theoretical model can well predict and explain experimental phenomena,filling the theoretical gap of the interaction between X-rays and even high-energy particles and plasma.At the same time,research on X-ray power transmission model and error probability model under the characteristics of"blackout zone"transmission channel was carried out.The relations between communication rate,communication distance,bit error rate,X-ray emission power and transmittance in plasma are given.Through the establishment of these three theoretical models,it is possible to completely describe and analyze the"black barrier"X-ray communication process.Secondly,the research of digital modulation technology based on grid-controlled X-ray pulse modulation transmission source was carried out,and the design and fabrication of PPM modulation,speech coding,and bit error rate detection circuit were realized.At the same time,it provides a powerful means for the modulation transmission and signal calibration of X-ray communication,and provides an experiment for"black barrier"X-ray communication Effective monitoring methods.Subsequently,for X-ray detection needs of 30ke V to 100ke V.The optimal scintillator thickness under different energies was studied,and a detection scheme for Na I（Tl）scintillator and photomultiplier tube PMT was proposed.Detector readout electronics including transimpedance amplifier circuits,constant ratio timing circuits,and digital time conversion circuits have been developed.And tested these circuit modules,the test results show that readout electronics can achieve 64ps time measurement accuracy.Finally,based on a grid-controlled X-ray modulation emission source,an X-ray detector and a dynamic plasma generating device,a demonstration and verification experimental study based on a glow discharge plasma generating device was carried out to realize a plasma with a high dynamic range and a long duration Ground experiments were carried out,and X-ray penetrating plasma experiments at different energies and flow rates were verified.Communication effects of X-ray communication in plasma environments were evaluated;and the dynamics of 10⁹～10¹⁴/cm³ electron density were achieved Under the plasma environment.It lays a certain theoretical and experimental basis for the engineering application of X-ray signal measurement and control technology in the"blackout zone".