Investigation of the same isomeric pair, produced from different nuclear reactions

The isomeric ratio (IR) of isomeric pair 109m,gPd, produced in 110Pd(γ, n)109m,gCd reaction and 108Pd(n, γ)109m,gPd neutron capture reactions, induced by thermal, epithermal and mixed thermal-epithermal neutrons have been determined. The off-line activation technique using a spectroscopic system consisting of a HPGe semiconductor detector with high energy resolution and a PC based 8192 channel analyzer (CANBERRA) was applied. The investigated samples were prepared from the 99.99 % purity PdO and irradiated at the electron accelerator Microtron MT-25 of the Joint Institute for Nuclear Research Dubna, Russia. The data analysis and necessary corrections were made to upgrade the precision of the experimental method. The obtained results were discussed, compared and combined with those from other authors to point out the role of the reaction channels in nuclear reactions.

Kajian Erosi Tanah menggunakan Isotop 137Cs dan 210Pb Excess di Sub DAS Ciesek, DAS Ciliwung Hulu, Bogor

Metode jatuhan radioisotop (Fallout Radio Nuclides) telah lama dimanfaatkan dan dikembangkan untuk mempelajari dan mengukur erosi tanah. Penelitian ini bertujuan menduga erosi/deposisi tanah di Sub DAS Ciesek, DAS Ciliwung Hulu menggunakan jatuhan radioisotop 137Cs dan 210Pb excess di alam. Pengambilan sampel tanah dilakukan menggunakan soil core pada empat transek penggunaan lahan yang berbeda. Sampel tanah dianalisis menggunakan Multi Channel Analyzer (MCA) untuk mendapatkan nilai inventori kedua radioisotop tersebut. Hasil penelitian menunjukkan perbedaan pola distribusi erosi/deposisi antara isotop 137Cs dan 210Pb excess. Penggunaan isotop 137Cs menunjukkan proses erosi tanah terjadi pada lahan kebun campuran dan tegalan, tapi proses deposisi terjadi di lahan terbuka. Penggunaan 210Pb excess menunjukkan erosi tanah terjadi di lahan terbuka, namun deposisi terjadi di lahan kebun campuran dan tegalan. Penggunaan 210Pb excess pada penelitian ini lebih dapat diandalkan dibandingkan dengan 137Cs, dalam hal pendugaan erosi tanah

Factors affecting the minimum detected activity of the GAMMAVISION software report protocol

The article presents the results of a gamma- spectrometer study with a low- capacity scintillation (NaI(Tl)) detection unit, with software GammaVision v.8, adopted to solve certification problems, including for measuring activities close to zero. The list of factors influencing the presentation of the minimum detected activity (MDA) in the report protocol is analyzed software GammaVision v.8. To perform the measurements, the company´s ORTEC gamma-spectrometer with a low-capacity detection unit a type digiBASE-RH, in which a high-voltage power supply unit, amplifier, digital multi-channel analyzer with USB-connection to a computer with the installed driver are installed, was used. The peak search in the library was performed using a compressed version of the library, which contains two nuclides 137Cs and 40K. Methods of calculating MDA are based on the intensity of accounts. Nuclide activity is calculation for all peaks in the library, the energy of which is in the selected energy ranges for analysis. Measurements and calculations MDA under the given conditions of research for five methods depending on time of measurement and geometry of measurements are carried out. It is shown that the level of MDA can be reduced by choosing the optimal conditions, time of measurement and geometry of measurements. Recommendations are given for the use of capacity for counting sample, which will reduce the amount of substance required for analysis and optimize the time spent on measuring the counting sample. In a prospect it is expedient to undertake a study of dependence of MDA from the physical properties and radionuclide composition of the substance for the counting sample and the dependence from the uncertainty in the equation MDA.

The magnetic field effect of K X-ray fluorescence parameters of elements in the range 39 ≤ Z ≤ 48

In this work, the fluorescence parameters (the fluorescence cross section (σ), the fluorescence yield (ω), and vacancy transfer probability (η)) of the fifth period elements, which have great potential to be developed as a technology, are investigated by taking advantage of interactions between atoms and radiation. For this process, the samples were excited via 241Am source without magnetic field and in the external magnetic field. The radiation emitted from targets was collected by an Si(Li) detector and energy channels were located on a computer program by means of a multi-channel analyzer. The data on the computer program were analyzed for calculations. The discrepancies have been observed between the experimental results and the theoretical results calculated without magnetic field. It was determined that results changed with the magnetic field (B = 0.4 and 0.8 T) and the variation of the X-ray fluorescence (XRF) parameters with the magnetic field for diamagnetic Ag and Cd is lower than for paramagnetic elements.

Study and construction of a successive approximation ADC8K for multichannel analyzer system

Multi-channel Analyzer (MCA) is one of very essential equipment in nuclear physics and nuclear engineering for the measurement of ionization radiation. Generally, an MCA system consists of radiation detector, amplifier system, ADC circuit, and MCD connected with computer for data processing. Among them, ADC is a functional electronic block, which plays an important role for converting analog to digital signals. Corresponding to the domestic needs in development of nuclear instruments, this work presents a design and construction of an ADC8K module with successive approximation method. Some experimental results are as follows: Differential non-linearity (DNL%) = 1.42, Integral non-linearity (INL% = 0.58), and χ2 = 8.109 proved that mentioned system can be used with considerable reliability in practical nuclear engineering.