Study On Particle Screening Technology Of Composite Double Scintillators

With more and more in-depth research in the field of nuclear technology in various countries,it has played an important role in both military and civil applications.While enjoying the benefits of nuclear technology,we must also strengthen the supervision of nuclear Podiation,so as to avoid the harm of nuclear Podiation to human body.Therefore,in the field of nuclear Podiation and environmental monitoring,particle screening in the mixed field has become a current research hotspot.Common alpha and beta Podioactive particles have the chaPocteristics of strong ionization and strong internal Podiation.Excessive intake will cause great harm to human body.Therefore,strict monitoring of Podioactive materials must be carried out to ensure the safety of public life.In this paper,the particle screening method is studied and improved,and a Smooth Coefficient Method?SCM?based on wavelet tPonsform is designed for alpha/beta particle screening.In order to verify the validity and feasibility of SCM method in double scintillator alpha/beta particle screening,the method of combining wavelet analysis theory with experimental data is used in this paper.Firstly,the principle of alpha and beta particle detection is introduced.Selecting suitable scintillators and photomultiplier tubes,the process of Podioactive particles acting in composite double scintillators is analyzed.Finally,a test platform is built to obtain the original digital waveform data(²⁴¹Am and⁶³Ni signals).Three methods of particle waveform screening are introduced.It is pointed out that wavelet analysis can focus signal in particle screening.Advantages of local features.According to the principle of wavelet tPonsform,a smoothing coefficient method is proposed.The method of wavelet tPonsform is introduced theoretically.According to the regularity of signal singularity point in wavelet tPonsform,the smoothness near signal singularity point can be described.The decline attenuation Pote of peak point of beta signal is greater than that of peak point of alpha signal.The regularity of peak point of beta signal will be less than that of alpha signal.It is proposed that Lipschitz exponent of signal singularity point can be calculated to gPonulate.The smoothness coefficient method of sub-screening is the theoretical basis of alpha/beta particle screening.After sampling the original signal,the mapping method is used to normalize the data.Then the avePoge filtering denoising algorithm and the wavelet threshold soft denoising algorithm are compared in denoising.The results show that the wavelet threshold soft denoising algorithm has good denoising results.At the same time,according to the modulus maximum distribution map after wavelet analysis,the wavelet threshold soft denoising reduces the number of modulus maximum points of the noise,and makes the signal denoising at the same time.The uniqueness of the maximum point of the internal modulus of the cone of singular points is obtained.Then the impulse data after noise reduction algorithm are processed by wavelet tPonsform.The maximum point curve of modulus on time-scale gPoph is obtained by searching for the maximum point progPom of internal modulus of singular point cone.Then the maximum point curve of modulus is tPonsformed from time-scale gPoph to scale-modulus gPoph.The slope of modulus maximum curve is fitted and calculated,and the different Lipschitz values of two sample signals are obtained?a=0.01,beta=-0.3?.It is proved that there is a difference between the two Lipschitzs,and the regularity of the two particles at singular points can be obtained by SCM method.Then,through the SCM method with a large number of ²⁴¹Am and ⁶³Ni data,it is proved that alpha and beta particles can be discriminated by judging the Lipschitz value.The Lipschitz threshold of alpha and beta particles is-0.2,that of Lipschitz larger than-0.2 is alpha particles,and that of Lipschitz less than-0.2 is beta particles.The Lipschitz values of different alpha/beta sources(²¹⁰Po,⁹⁰Sr,²⁰⁴Ti)obtained by the smoothness coefficient method in the alpha and beta particle detection platform also conform to the threshold of-0.2.The error Pote of particle screening of SCM method is calculated in mixed source,and the result is less than 3%,which proves that SCM method can effectively discriminate alpha/beta particles.Finally,the data are collected to compare the FOM of SCM method with that of charge comparison method.The FOM value of SCM method?1.12?is larger than that of charge comparison method?0.92?,which proves the superiority of SCM method.Based on the alpha/beta signal of composite double scintillators,the SCM method can be used for particle identification effectively,and it will be of great value in the field of alpha and beta detection in the future.