Film Thickness Of The Alpha Energy Loss Measurement And Detection Efficiency γ Spectrum Of MCNP Simulation Method Described

Analysis of the film thickness in material science, semiconductor technology, optical devices and biomaterials has always been attracting people's attention, With development of membrane technology and requirement of application, the increasing need for more accurate and more sensitivity measurement technology of film thickness. Commonly, the optical film thickness measurement method is only used for linear transparent material thickness measurement, and can also not directly measure the thickness of material's quality. Due to the direction of motion of the heavy charged particles passing the material almost being not shift and the particle energy being continuously variation with the crossing paths' charge, it can be sensitive to detect the thickness of film quality by measuring energy loss of particles through film. This method needs for knowing single-energy heavy charged particles, but it's very expensive and inconvenient for accelerations to produce this kind of particles. By radioactive nucleus releasing Alpha particles can meet the single-energy requirements and this kind of particles is very convenient to use. So we choose to study on the issues using Alpha particles to measure film thickness in order to provide a more accurate method for using the energy loss to measurement for film thickness.This paper analyzes analyses the source of factors impacting of film thickness measurement accuracy, the main reasons including: First, measurement error of energy loss of Alpha particles through the film, the Second, inaccurate prevention capability of Alpha particles in the material which are adopted to calculate thickness of film using the method of measuring energy loss.. A response to the first reason, in the energy spectrometer, the paper put forward to use high-energy resolution Au-Si surface barrier detector and stable magnification linear amplifier and exact stable the pulse generator to achieve energy scale for spectrograph and get very good energy linearity scale curve for precision pulse generator. A response to the second reason, this paper calculates the total thickness of thin films by delamination, as the film thickness constituted by a number of layers, each layer is very thin. Alpha particles as well as the level of energy loss rate for a constant, constant from the Alpha particles enter this level of energy decisions. The results showed that Layered calculated by the Mylar film thickness measurement results are usually not stratified than the calculated accuracy of the results can more than a 20％increase. Furthermore, in order to expand use of Alpha particles can damage film thickness measurement of the range, This paper analyzes the extra voltage detector size and vacuum measurement of the level of the measuring range, To broaden the film thickness measurement range to provide meaningful information..Soil samples of radioactivity of high purity germanium(HPGe)γspectrometer measurement is the most accurate understanding of the environment of radioactive standards, as well as a study of soil erosion in an effective manner. The types of measurement is known to the unknown sample and the standard sample activity compared to the measured, When the analyse in the sample loaded samples of the number and density of the samples and standards to produce inconsistent measurement error, Monte Carlo(M. C) simulation method can effectively reduce the error, The method has been used in the amendmentγspectrometer to measure soil samples radioactivity error has been widely used. Using the method normally required under the system detailed description, especially when the sample room shielding a complex, this description of the more cumbersome and prone to error description. This paper presents a simplified description of the method that is used in the calculation of HPGe detectors on soil samples detection efficiency, Samples can be simplified to shield part of the room description. Two methods described by contrast, proved that the proposed simplified description of the accuracy and convenience. The results for the use of simulation methods M.Cγemission spectrometer to sample theγ-ray detection efficiency provides a convenient system Description.