Mc Method With ¦Ã Measuring The Radioactivity Of Environmental Samples And Measuring The Density Of New Materials With ¦Â

As every radiation has characters of nucleus and its energy and intensity will change when passing through any material, we can know the material's characters by testing radiations' energies and intensities. For example, we can make sure the kinds of radionuclides,the radio activity and materials' mass thickness,etc. When radiation passing through materials,the change of radiation's energy and intensity will be influenced by many factors. Some factors make error to the test results.It's often a trouble work to make sure the degree of error by using method of experiment,and sometimes it's even more a very difficult work. However, by using monte carlo(M.C.) method it becomes a very easy work. In this paper,we first bring forward two problems,one is about the radio activities of gamma radiations and the other is about testing mass thickness with beta radiations. Using M.C. method we simulate and compute the two problems and get some significative results.In order to protect people's healthy and know the lost of water and soil, It is important to test the environmental soil's radio activity. Testing with HPGe gamma spectrometer can make the least error which is made by the apparatus itself. So, the differentce between the pending test samples and the standard samples becomes the main source of making test error. For instance, compared with standard samples,there is different water content in pending test samples as the drying methods are not same. Water content of the soil samples which we test will make more gamma radiation's absorbing or scattering so that gamma ditecting efficiencies of pending test samples is less than standard samples'. However, we often omit this difference. In this paper, using M.C. method, we simulate and compute the detecting efficiencies with HPGe gamma spectrometer of testing gamma radiations of different energies (i.e, they are the character radiations of natural radionuclide of ²³⁸U, ²³²Th, ²²⁶Ra, ⁴⁰K and their daughters,which are most cared by people.)when soil samples have different water content . By the relations between detecting efficiencies and different water content, We can get the influence on accuracy of test results by different water content. This result have practical significance in preparing samples and improve the accuracy of testing environmental samples' radio activities. Evenmore, in writing input programs,by using skill we have saved much programming time and pledged correctness of input programs in effect.For explore new material preparing technics and right theories computing,it is important to test new materials'(for instance,ICF target materials) mass thickness and distributing of mass thickness using radiations. In testing mass thickness , using beta radiations to do it are very important. While,the method of beta testing mass thickness must at first know the mass attenuation coefficient of standard materials. However, to test new materials,the standard materials whose element forms are the same as pending test materials are often lack. So we bring forward that light element materials can replace with print paper or aluminum foil. But in this way, the replace will influence the veracities on test results because their atomic number are not same. In order to make clear the degree of this influence, aiming at the beta radiations'energy range of ⁹⁰Sr, using M.C. method we simulate and compute the relations between the beta radiations'transmission rate of different energies and mass thickness in different materials. As results of the relations, we get the degree of errors in testing different mass thicknesses when using different standard materials. This result prove that in method of beta test mass thickness choosing materials whose elements are close as standard materials are viable and we offer the method correcting error which comes from the replace. Its significance is very obvious to test new materials' mass thickness using beta radiations.