Investigation of the pinch-time dependence to the gas pressure, in Filippov type plasma focus devices Mohammad Amirhamzeh Tafreshi انرژی اتمی ایران author Dariush Rostamifard انرژی اتمی ایران author Ali Nasiri انرژی اتمی ایران author text article 2019 per Abstract: This paper has been prepared by using experimental and simulated data due to a large and a small Filippov type plasma focus devices. In the first part of the paper, the plasma-focusing phenomenon is introduced and the parameters of the devices are presented. Then the results of empirical studies of the pinch-time dependence to the gas pressure are provided. In the next part, the theoretical basis of the ML-model is reviewed and the results of applying this model to simulate the two devices are presented. Both simulated and experimental results showed that in the larger device, the pinch time is clearly more sensitive to the pressure variations. The study also showed that the model predictions for larger device are more accurate than the predictions for the smaller device. Iranian Journal of Physics Research Isfahan University of Technology, The Physics Society of Iran 1682-6957 17 v. 4 no. 2019 507 512 https://ijpr.iut.ac.ir/article_1286_426589afdb82b6f2a08b0b9e7093d622.pdf dx.doi.org/10.29252/ijpr.17.4.507 Determination of the penetration hardness and analysis of stainless steel alloys by means of Laser Induced Breakdown Spectroscopy (LIBS) mohamad Vahid Dastjerdi اصفهان -دانشگاه اصفهان - گروه فیزیک author Seyyed Jabbar Mousavi اصفهان -دانشگاه اصفهان - گروه فیزیک author Mahmood Soltanolkotabi دانشگاه اصفهان author text article 2019 per A significant feature of alloys is the surfaces hardness that is always accompanied by challenges when it’s measured by common mechanical techniques. In this investigation, we used Laser Induced Breakdown Spectroscopy (LIBS) as a replacement method for common mechanical techniques to measure the surfaces hardness of different alloys. After recording the spectrum of alloy samples in order to identify the surface hardness of analyzed sample, K-Nearest Neighbors method (KNN) was used and obtained results showed that the LIBS-KNN method can separate and identify the surfaces hardness of samples with precision of 93.3%. In addition, in order to identify the percentage of constituent elements of alloys and their hardness, calibration approach was investigated that showed there is an appropriate linear relation between recorded emission lines from the LIB spectra of sample alloys and the percentage of their constituent elements and also their Vickers hardness numbers. Therefore, According to exclusive advantages of LIBS technique i.e. high speed analysis, non-destructive analysis and being portable, some of available difficulties in conventional mechanical techniques can be removed. Iranian Journal of Physics Research Isfahan University of Technology, The Physics Society of Iran 1682-6957 17 v. 4 no. 2019 513 522 https://ijpr.iut.ac.ir/article_1287_09c63415a8aab03565e3b1af6aa60252.pdf dx.doi.org/10.29252/ijpr.17.4.513 Designing and manufacturing of solar imaging and tracking system Mehrdad Hosseini دانشگاه اصفهان author Ahmad Kiasatpour دانشگاه اصفهان author text article 2019 per Abstract – in this study, designing and manufacturing of solar imaging and tracking system in order to research and spectroscopy applications are investigated. The device has the ability to be used as a Telescope, spectroscope, spectrophotometer and spectrohelioscope. The results obtained from this device are used in the various field of research such as absorption spectra of the surface of the sun, transit of planets in front of the sun, Doppler effects, evaluation of the Fraunhofer lines, plot of intensity versus wavelength and studying of Solar Flares. In this research, design and manufacture of the device, along with some of the results, are reported. Iranian Journal of Physics Research Isfahan University of Technology, The Physics Society of Iran 1682-6957 17 v. 4 no. 2019 523 530 https://ijpr.iut.ac.ir/article_1288_9dc5b8f0631353a42f67414a2d63dcba.pdf dx.doi.org/10.29252/ijpr.17.4.523 Study of hematite-iron phase transformation during iron-carbon core-shell nanoparticles synthesis and investigation of their magnetic and microwave properties Omid Khani دانشگاه شهید چمران اهواز author Morteza Zargar Shoushtari دانشگاه شهید چمران اهواز author Mohammad Jazirehpour دانشگاه صنعتی مالک اشتر author Mansoor Farbod دانشگاه شهید چمران اهواز author text article 2019 per The structural properties and microwave absorption capability of the iron nanoparticles and iron-carbon core-shell nanoparticles have been studied, in the present paper. The investigated nanoparticles were synthesized by hydrothermal route and by reduction of hematite nanoparticles during annealing in argon-hydrogen atmosphere. Hematite-iron phase transformation during the reduction process has been studied by X-ray diffraction (XRD). XRD patterns showed that in iron nanoparticles, hematite-iron phase transformation was completed after 30 min annealing whereas about iron-carbon nanoparticles, the phase transformation completion occurred after 65 min, and before 65 min annealing, wustite (FeO) phase was still present in XRD patterns. M-H loops and relative complex permittivity (ε) and permeability (µ) of the iron nanoparticles and iron-carbon nanocapsules were investigated too. According to the ε and µ spectra in 1-18 GHz, the carbon shell can affect microwave properties of the iron nanoparticles. Carbon shell can reduce microwave permeability and permittivity of the composites containing iron nanoparticles.  Iranian Journal of Physics Research Isfahan University of Technology, The Physics Society of Iran 1682-6957 17 v. 4 no. 2019 531 540 https://ijpr.iut.ac.ir/article_1289_d23d4d09e6dbf411b8ffff2ed26038ab.pdf dx.doi.org/10.29252/ijpr.17.4.531 The Application of Bayesian Spectral Analysis in Photometric Time Series saeideh latif موسسه آموزش عالی عبدالرحمن صوفی رازی، زنجان author Hossein Safari دانشگاه زنجان author Asadollah Safaei دانشگاه کاشان author text article 2019 per The present paper introduces the Bayesian spectral analysis as a powerful and efficient method for spectral analysis of photometric time series. For this purpose, Bayesian spectral analysis has programmed in Matlab software for XZ Dra photometric time series which is non-uniform with large gaps and the power spectrum of this analysis has compared with the power spectrum which obtained from the Period04 software, which designed for statistical analysis of astronomical time series and used of artificial data for unify the time series. Although in the power spectrum of this software, the main spectral peak which represent the main frequency of XZ Dra variable star oscillations in the f = 2.09864 (day -1) is well known but false spectral peaks are also seen. Also, in this software it’s not clear how to generate the synthetic data. These false peaks have been removed in the power spectrum which obtained from the Bayesian analysis; also this spectral peak which is around the desired frequency has a shorter width and is more accurate. It should be noted that in Bayesian spectral analysis, it’s not require to unify the time series for obtaining a desired power spectrum. Moreover, the researcher also becomes aware of the exact calculation process. Iranian Journal of Physics Research Isfahan University of Technology, The Physics Society of Iran 1682-6957 17 v. 4 no. 2019 541 551 https://ijpr.iut.ac.ir/article_1290_7c5fa53feb37252087307a2cbe0b9525.pdf dx.doi.org/10.29252/ijpr.17.4.541 Rectification of a Casimir Nanomachine with a Triangular Wave Signal ali moradian دانشگاه کردستان author mohammmadreza setare دانشگاه کردستان author Asrin Seyedzahedi دانشگاه کردستان author text article 2019 per In this paper, we investigate the Casimir nano system composed of two quadrisected dielectric disks separated by a thin gap. Initially the two disks have the same surface dielectric distributions. We use scatting approach in the weak coupling limit and show that the top plate experiences a torque  if it rotates about its axes by an angle. Consequently, we will be able to calculate. Quite interesting, such a nanomachine may be used to examine the dielectric dependence of the Casimir torque. Our small system can be used to measure small torques. We assume that the top disk is mounted on an axle and part of the rotational friction in the system comes from the axial friction and an external load is mounted on it. For such a system with specified parameters, we can estimate inertia and axial friction. Therefor we can neglect the inertia term and use the over damped regime to describe the dynamics of our system. We show that our small system can rectify a periodic square-wave angular velocity and we obtain the average angular velocity of the top plate. Iranian Journal of Physics Research Isfahan University of Technology, The Physics Society of Iran 1682-6957 17 v. 4 no. 2019 553 560 https://ijpr.iut.ac.ir/article_1291_7893b34fd66058bdc105d03734fd3e17.pdf dx.doi.org/10.29252/ijpr.17.4.553 Improving gas sensor properties of encapsulated ZnO nanorods for ethanol detection using ZnO:Cr layer as an encapsulated layer S. Safa دانشگاه صنعتی مالک اشتر author M. Asghari دانشگاه صنعتی مالک اشتر author S. Mokhtari دانشگاه صنعتی مالک اشتر author R. Azimirad دانشگاه صنعتی مالک اشتر author text article 2019 per In this study, encapsulated ZnO nanorods with different amount of chromium (Cr) dopant (0-4.5 at.%) were prepared with hydrothermal method, and their sensitivities as gas sensors against ethanol vapor were investigated. Morphologies of samples were explored by field emission scanning electron microscope (FESEM) which showed that encapsulation process increased the diameter of ZnO nanorods. Existence of Cr in ZnO nanorods structures was confirmed by Energy-dispersive X-ray spectroscopy (EDX). Based on X-ray diffraction (XRD) analysis, the ZnO:Cr nanorods had wurtzite crystal structure, and adding Cr did not alter the crystal structure of ZnO. Electrical measurements revealed that current levels of samples were decreased by adding Cr, while the current level of the sample with 4.5 at.% was increased. This reduction could be attributed to the presence of Cr3+ ions, which led to decrease of charge carriers. Besides, due to the catalytic properties of Cr and its lower ionization energy than Zn, it was observed that Cr dopant improved the detection sensitivity of samples, and decreased the optimum operating temperature of samples. Among all samples, the most sensitivity (14) was obtained based on the sample with 1.5 at.% of Cr for 500 ppm ethanol vapor at the optimum temperature (250 ). In fact, by encapsulating the samples, they became rougher, so the appropriate places to absorb and decompose of gas molecules are increased. Iranian Journal of Physics Research Isfahan University of Technology, The Physics Society of Iran 1682-6957 17 v. 4 no. 2019 561 571 https://ijpr.iut.ac.ir/article_1292_ee74f708dfc18a5b954075cf6237cfbc.pdf dx.doi.org/10.29252/ijpr.17.4.561 Band structure and thermal emission of two dimentional silicon photonic crystal meysam daneshvar پژوهشکده الکتروسرام، دانشگاه صنعتی مالک اشتر، شاهین شهر، اصفهان author Ali Rostamnejadi پژوهشکده الکتروسرام، دانشگاه صنعتی مالک اشتر، شاهین شهر، اصفهان author text article 2019 per In this research, we have studied the photonic band structure, optical properties and thermal emission spectrum of 2D Silicon photonic crystal with hexagonal structure. The band structure, band gap map and the gap size versus radius have been calculated by plane wave expansion method. The maximum band gap size of TE (TM) polarization and the complete gap size are 51% (20%) and 17% at air hole radius r=0.43a (0.50a) and r=0.48a, respectively. The optical properies have been calculated by FDTD methd in the range of 1 to 10 . The thermal emission spectrum has been obtained from absorption by Kirchhoff’s law. The obtaine results show that by engineering the band structure, the thermal emission spectrum of 2D Silicon photonic crystal can be controlled in a manner that can be used in thermophotovoltaic systems. Iranian Journal of Physics Research Isfahan University of Technology, The Physics Society of Iran 1682-6957 17 v. 4 no. 2019 573 583 https://ijpr.iut.ac.ir/article_1293_6e7df407811b8e660105505f5f624f5d.pdf dx.doi.org/10.29252/ijpr.17.4.573 Effect of Dzyaloshinskii-Moriya on Magnetic orders of J_1-J_2 Antiferromagnetic Heisenberg model Fariba Masoudi دانشگاه شهرکرد author Hamid Mosadeq دانشگاه شهرکرد author text article 2019 per Motivated by recent experiments that detects Dzyaloshinskii-Moriya (DM) interaction in , we study the effects of DM interaction on magnetic orders of J1-J2 antiferromagnetic Heisenberg model. First, we find the classical phase diagram of the model using Luttinger-Tisza approximation. In this approximation, the classical phase diagram has two phases. For , the model has canted Neel and DM interaction cants the spins of one on the subluttices. The ground state of model is classically degenerate for , including infinit numbers of vorticity vectors that are able to minimize the model. This phase is important because of the probability of the existence of quantum spin liquid in this region. To investigate the effect of quantum fluctuation on the stability of the classical phase diagram, linear spin wave theory of  Holstein-Primakoff is used. The results show that in the classical degeneracy regime, the quantum fluctuations for  cause spiral order in this region. The ground state of model remains disorder for, and this region is a good place for finding quantum spin liquid Iranian Journal of Physics Research Isfahan University of Technology, The Physics Society of Iran 1682-6957 17 v. 4 no. 2019 585 594 https://ijpr.iut.ac.ir/article_1294_01ebfa1c66762749440bbb7a9928ebe0.pdf dx.doi.org/10.29252/ijpr.17.4.585 On the possibility of magnetic field detection of a source star at caustic crossing Ahmad Mehrabi دانشگاه بوعلی سینا author Habib Khosroshahi پژوشگاه دانش های بنیادی author Hadi Rahmani دانشگاه مارسلی author text article 2019 per In a microlensing event, at caustic crossing, flux of a spot can be magnified several times with respect of the source star. This magnification contrast provide a unique opportunity to measure the magnetic field over a source star. In this work we investigate possibility of magnetic field detection through the Zeeman effect when a source crosses a caustic line. Using Fourier analysis, one can separate other broadening agents from actual Zeeman broadening. At next stage we use microlensing formalism to measure the magnification contrast of spot and source and finally using two reliable strategy, we find the delectability of magnetic field as a function of maximum magnification for spots with different sizes. The resolution and the signal to noise in each strategy determine which magnetic fields are detectable.   Iranian Journal of Physics Research Isfahan University of Technology, The Physics Society of Iran 1682-6957 17 v. 4 no. 2019 595 601 https://ijpr.iut.ac.ir/article_1295_cdd6b78da64d785de29826cda04fe6fb.pdf dx.doi.org/10.29252/ijpr.17.4.595 Exclusive pipi production in proton-proton collisions at 7 TeV Mohsen Khakzad پزوهشگاه دانشهای بنیادی author text article 2019 per The exclusive production of charged pions, are reported in the proton-proton collisions, where the π+π- pair is emitted at the central rapidity, y, and the scattered protons stay intact (p) without detection. This measurement is performed with the CMS detector at the LHC, using a data sample corresponding to an integrated luminosity of 450 μb-1 collected at a center-of-mass energy of  7 TeV. The dipion cross section, measured for single-pion transverse momentum pT > 0.2 GeV/c and rapidity |y| < 2, is 20.5 ± 0.3 (stat) ± 3.1 (syst) ± 0.8 (lumi) μb. The differential cross sections as a function of π+π- invariant mass, is compared to phenomenological predictions.  Iranian Journal of Physics Research Isfahan University of Technology, The Physics Society of Iran 1682-6957 17 v. 4 no. 2019 603 607 https://ijpr.iut.ac.ir/article_1296_1edb44f919d1e472162952a5ffa5d274.pdf dx.doi.org/10.29252/ijpr.17.4.603 Study of Nilsson Potential at different nuclear deformations Azam Kardan دانشگاه دامغان author text article 2019 per p { margin-bottom: 0.1in; direction: ltr; color: rgb(0, 0, 0); line-height: 120%; }p.western { }p.ctl { } We have studied the Nilsson potential energies at different deformation parameters using a code based on the perturbative treatment. Special attention is given to the projection of a proton state at different deformations on the asymptotic basis functions. Our calculations show that the spin-orbit and the orbital angular momentum terms couple different asymptotic eigenstates, Nilsson Hamiltonian being hence not diagonal in these basis functions. Therefore, at least at deformations 0.4, the asymptotic quantum numbers are not good quantum numbers. Iranian Journal of Physics Research Isfahan University of Technology, The Physics Society of Iran 1682-6957 17 v. 4 no. 2019 609 613 https://ijpr.iut.ac.ir/article_1297_0b88eda1237b8c9753efb8b7bd62f5d5.pdf dx.doi.org/10.29252/ijpr.17.4.609 Solution of DGLAP evolution equation for gluon fragmentation in LO and NLO G R Boroun دانشگاه رازی author S Zarrin دانشگاه رازی author text article 2019 per In this work, we calculate DGLAP evolution equation at LO and NLO by Laplace method for fragmentation function of gluon to meson or baryon. To prove the validity of this method, we evolve the fragmentation functions of  andby using this method. In this method, it is not necessary to calculate these functions in Laplace space. This method is just used for simplifing the equations Iranian Journal of Physics Research Isfahan University of Technology, The Physics Society of Iran 1682-6957 17 v. 4 no. 2019 615 620 https://ijpr.iut.ac.ir/article_1298_c33c6dcfd946fdcb671c08bb7c06729f.pdf dx.doi.org/10.29252/ijpr.17.4.615 Investigation of uniformity SiO2 thin film deposited by electron beam and thermal evaporation method R shakouri گروه فیزیک، دانشکده علوم، دانشگاه بین المللی امام خمینی (ره) author H Haydari مرکز ملی علوم و فنون لیزر ایران author text article 2019 per In this paper, SiO2 thin film is produced by two methods: at the first method, SiO2 is evaporated by the electron gun and oxygen gas is injected to compensate for oxygen loss due to dissociation. At the second method, silicon monoxide is evaporated by thermal evaporation and during the evaporation time, substrate is bombarded by the ion oxygen that produced by an ion source. The refraction index, the extinction coefficient and the thickness layer are calculated by numerical method of the transmittance and reflectance equations. By the shift in the spectral transmittance, amount of non uniformity is calculated.  Results show that if the quantity of the current and the ion energy are selected properly, SiO2 film will not have absorption. Moreover, SiO2 film produced by the second method is more uniform than that of by the first method Iranian Journal of Physics Research Isfahan University of Technology, The Physics Society of Iran 1682-6957 17 v. 4 no. 2019 621 628 https://ijpr.iut.ac.ir/article_1299_b25657d368dfd8dc3ee41641a91abd2e.pdf dx.doi.org/10.29252/ijpr.17.4.621 Improving the Upper Bound on the Scaling Dimension in 2 Dimensional CFT Maryam Ashrafi دانشگاه صنعتی اصفهان author text article 2019 per Modular invarinat, constraints the spectrum of the theory. Using the medum temprature expansion, for first and third order of derivative, a universal upper bound on the lowest primary field has been obtained in recent researches.  In this paper, we will improve the upper bound on the scaling dimension of the lowest primary field. We use by the medium temprature expansion for an arbitrary orders of derivative. We show that the upper bound depends on the order of derivative. In this research, we obtain the optimal values of the order of derivatives which leads to the best upper bound. Iranian Journal of Physics Research Isfahan University of Technology, The Physics Society of Iran 1682-6957 17 v. 4 no. 2019 629 629 https://ijpr.iut.ac.ir/article_1300_c5c2790716ce891ea7f534cecd3f7fcd.pdf dx.doi.org/10.29252/ijpr.17.4.629 Effect of impurities on the optical properties of KTP single crystals grown from flux Hamideh Zaliani گروه فیزیک، دانشگاه سمنان، سمنان author M J Tafreshi گروه فیزیک، دانشگاه سمنان، سمنان author Dariush Souri گروه فیزیک، دانشگاه ملایر، ملایر author text article 2019 per In the present work, KTP crystals have been grown by spontaneous nucleation technique in flux medium using K6P < sub>4O13 flux. 0.4-1 °C/h cooling rates were applied in the spontaneous nucleation process. The presence and amount of impurities has been determined by using XRF. The optical transmission spectra of impure KTP crystals in the UV–visible region are discussed. The transmission cut-off is clearly shown at the optical absorption edge, as well as the rapidly reduced absorption with increasing wavelength. It is shown that the presence of impurity shifts the absorption edge of KTP towards lower energy region. The wavelength dependence of absorption coefficient is determined in the UV–visible range, and the characteristics of the optical absorption edge are discussed. Results reveal that the absorption edge and the type of optical charge carrier transition can be attributed to indirect transition for these crystals. It is shown that presence of impurity decreases the indirect band gap (Eg) of KTP crystals, causing the indirect transition absorption edge to move towards lower energy. Iranian Journal of Physics Research Isfahan University of Technology, The Physics Society of Iran 1682-6957 17 v. 4 no. 2019 630 630 https://ijpr.iut.ac.ir/article_1301_83f9021b2fbd593715e1ac240ca26cd1.pdf dx.doi.org/10.29252/ijpr.17.4.630 A Novel Method Describing the Space Charge Limited Region in a Planar Diode Mitra Ghergherehchi دانشکده مهندسی انرژی و فیزیک، دانشگاه صنعتی امیرکبیر، تهران 3. دانشکده مهندسی برق و الکترونیک، دانشگاه سونگ کیانکوان، سوان، کره جنوبی author Esfandiar Mehrshahi دانشکده مهندسی برق، دانشگاه شهید بهشتی، تهران author hesam ahmady دانشکده مهندسی برق، دانشگاه شهید بهشتی، تهران author text article 2019 per A novel and rather simple method is presented to describe the physics of space-charge region in a planar diode. The method deals with the issue in the time domain and as a consequence transient time behavior can be achieved. Potential distributions and currents obtained using this technique, supposing zero initial velocity for electrons, reveal absolute agreement with Child&#39;s results. Moreover, applying the method for non-zero uniform initial velocity for electrons, gives results which are in good agreement with previous works Iranian Journal of Physics Research Isfahan University of Technology, The Physics Society of Iran 1682-6957 17 v. 4 no. 2019 631 631 https://ijpr.iut.ac.ir/article_1302_6842152ef313ce3966d1981b48a63628.pdf dx.doi.org/10.29252/ijpr.17.4.631 Direct excitations of He+ and Li++ ions by collisions with protons or antiprotons Reda Tantawi 1. دانشکده ریاضی، گروه علوم، دانشگاه زاگازیگ، زاگازیگ، مصر author E I Nassar 2. دانشکده علوم پایه، موسسه تکنولوژی‌های پیشرفته، مصر author text article 2019 per The impact parameter formalism of the single-center close-coupling, first-, and second-order Born approximations have been applied to investigate direct excitations of Helium He+(2s) and Lithium Li++(2s) ions by colliding with protons or antiprotons. The total 3s, 3p, and 3d scaled excitation cross sections are calculated in the scaled impact energy region (2 to 1000 keV). The present work aims to explore the sensitivity of the cross sections to the different electronic transition mechanisms of the considered approaches as well as the charge of each of the projectile and the target nucleus. Also, the calculated cross sections are compared with those obtained by previous theoretical calculations. Iranian Journal of Physics Research Isfahan University of Technology, The Physics Society of Iran 1682-6957 17 v. 4 no. 2019 632 632 https://ijpr.iut.ac.ir/article_1303_b7392dfdba7191640503ee041aaa1ffd.pdf dx.doi.org/10.29252/ijpr.17.4.632 Light scattering by cubical particle in the WKB approximation redouane lamsoudi گروه فیزیک، دانشکده علوم، آزمایشگاه فیزیک مواد فشرده، دانشگاه شعیب دوکالی، مراکش author sallah eddine Elbahar گروه فیزیک، دانشکده علوم، آزمایشگاه فیزیک مواد فشرده، دانشگاه شعیب دوکالی، مراکش author text article 2019 per In this work, we determined the analytical expressions of the form factor of a cubical particle in the WKB approximation. We adapted some variables (size parameter, refractive index, the scattering angle) and found the form factor in the approximation of Rayleigh-Gans-Debye (RGD), Anomalous Diffraction (AD), and determined the efficiency factor of the extinction. Finally, to illustrate our formalism, we analyzed some numerical examples Iranian Journal of Physics Research Isfahan University of Technology, The Physics Society of Iran 1682-6957 17 v. 4 no. 2019 633 633 https://ijpr.iut.ac.ir/article_1304_2a4ae608b897d1a149e31ffc6f630afa.pdf dx.doi.org/10.29252/ijpr.17.4.633 Calibration curves for on-line leakage detection using radiotracer injection method Ayoub Khatooni 1. دانشکده مهندسی هسته‌ای، دانشگاه شهید بهشتی تهران، تهران author Faezeh Rahmani 2. دانشکده فیزیک، دانشگاه صنعتی خواجه نصیرالدین طوسی، تهران author Freydoun Abbasi Davani 1. دانشکده مهندسی هسته‌ای، دانشگاه شهید بهشتی تهران، تهران author text article 2019 per One of the most important requirements for industrial pipelines is the leakage detection. In this paper, detection of leak and determination of its amount using radioactive tracer injection method has been simulated by Monte Carlo MCNP code. The detector array included two NaI (Tl) detectors which were located before and after the considered position, measure emitted gamma from radioactive tracer. After calibration of radiation detectors, the amount of leakage can be calculated based on the count difference of detectors. Also, the effect of material and thickness and diameter of pipe, crystal dimension, types of fluid, activity of tracer and its type (24Na, 82Br, 131I, 99mTc, 113mIn) as well as have been investigated on the detectable amount of leakage. According to the results, for example, leakage more than 0.007% in volume of the inlet fluid for iron pipe with outer diameter 4 inch and thickness of 0.5 cm, Petrol as fluid inside pipe, 3 3 inch detector and 24Na with activity of 100 mCi can be detected by this presented method. Iranian Journal of Physics Research Isfahan University of Technology, The Physics Society of Iran 1682-6957 17 v. 4 no. 2019 634 634 https://ijpr.iut.ac.ir/article_1305_00106c5cc839140a634ea8a8c3279d83.pdf dx.doi.org/10.29252/ijpr.17.4.634