Monte Carlo Simulation of Transmission Experiement

Monte Carlo Simulation of Transmission Experiement Liquid Densitometer Design dependent on Transmission and Scattering Gamma Ray Method utilizing Monte Carlo Approach R.Wirawan, M. Djamal, A.Waris, G. Handayani, H.J. Kim Theoretical. Non-damaging testing is one technique in the material testing that was applied and created for some reasons in the mechanical field. Gamma spectrometer is a one strategy that can be applied for the liquid densitometer. It was examined the capability of the utilization of transmission and dissipating gamma beam estimations so as to assess the liquid thickness utilizing GEANT4 Monte Carlo reproduction toolbox. Watchwords: Non-damaging testing, dispersing gamma, Monte Carlo, GEANT4. PACS: 29.40.- n Presentation Gamma-beam range estimation is one of promising creating technique in the non-damaging test application particularly for an online estimation. It’s relevant for some modern applications, for example, in clinical, mining and oil industry, country security. The nature of the material can be separating from another dependent on its thickness. In the use of gamma spectrometry, it’s impact the gamma beam energies range identification result. Ball et al. (1998) have researched the reaction of gamma backscatter to the spatial thickness in mass example [1]. In the liquid item investigation particularly for the oil item thickness estimation, it’s a promising strategy for a densitometer. Hussein (2011) has created examination of the liquid stream in the funnel utilizing gamma spectrometry [2]. Khorsandi and Feghhi have examined the transmission mode in densitometer application for the oil based commodities checking applications [3]. The blend of transmission and dispersing estimation modes are acceptable drawing nearer for a superior examination strategy in the indicator reaction estimation because of the liquid thickness inside the funnel. For this reason, reenactment utilizing Monte Carlo strategy can be directed. Monte Carlo strategies have abilities in the usage of the few of material science models and give the anticipating bring about the radiation material science application [4, 5]. In the current examination we explored the capability of the blend of these estimations utilizing the Monte Carlo radiation transport from GEANT4 recreation toolbox. Hypothesis Gamma beam vitality range trademark that recognized from its collaboration with the material have data to distinguish the material qualities included. In the gamma beam range estimation, there are two sorts of estimation type for example transmission and dispersing. In the transmission, the gamma beam shafts have a constricted force due to vitality assimilation by material. The mass constriction coefficient à ¯Ã¢ Ã¢ ­ of photon is a component of photon vitality. The lessened force was depicted by the Beerâ€Lambert recipe: (1) where I0 episode gamma beams powers, x is material assimilation thickness, is mass retention coeficient and its corresponding to the all out cross-segment as follows , NA is the Avogadro’s number (6.021023 molecule/mole) and An is nuclear mass number of material[8]. For the dissipating estimation, the distinguished photon bar is the consequence of diverting with an electrons material. Dissipating collaborations that may happen is the single dispersing or different scattering.The photon pillar force has lessening in the way before the dissipating point cooperation and in the way to the indicator after the dispersing point communication. Figure 1 shows the single dissipating cooperation of photon with a component volume dV. Figure 1 Schematic graph of photon single dispersing association with a component volume in the material (embraced from Devlin and Taylor) [9]. As per the Compton dissipating association, the photon with a vitality E㠯⠁â § will be diverted with dispersing edges à ¯Ã¢ Ã¢ ± to the root heading after impact with a nuclear electron. The dissipated photon vitality (EScatt) is communicated by the recipe: (2) The power of identified gamma photon are impact of weakening along essential photon, number of electron in component volume, differential cross-segment, lessening of dispersed photon way and the strong edge subtended by locator at the component volume. For the single dissipating association, the power of recognized photon as delineated in the equation: (3) where S is the source movement (photon s-1), dV is component volume cooperation, n is the electron thickness of the material, r1 and r2 are the length way of the essential photon before communication and subsequent to dispersing individually. The thickness à ¯Ã¢ Ã¢ ² of the material is identified with the electron thickness by (4) where NA is the Avogadro number, Z is the nuclear number and M is the nuclear mass. For the Compton connection probabilities of the photon shaft when it communicate with an electron of the material was depict in differential structure by Klein-Nishina recipe, (5) where r0 is clasical electron range (2,82 fm) and P parameter as capacity of episode photon vitality and dispersing points à ¯Ã¢ Ã¢ ± as the recipe (6) where steady [1,8]. Utilizing the condition (4) and (5) to substitute parameter n and in the condition (3), we have the connection of force with the material thickness: (7) Arrangement of the condition (7) can be communicated in the basic structure: (8) where An and B are steady. Technique The reenactment arrangement was created dependent on the transmission design which led tentatively done by Khorsandi [3]. Four identifiers are set in two kind positions where two finders in a similar side with source and two others in the contrary site as appeared in Figure 2. The spatial separation between two identifier d10 and d30 from the collimated source pivot are about hub 27.5cm. For identifier d20 is set 20 cm far away from locator d10. Polyethylene pipe have an internal sweep 5cm and thickness it’s about 2mm. Liquids under scrutiny inside the channel (for example gas, gasoil and water) are thought to be of uniform density㠯⠁â ². A circle gamma beam source model is utilized for Cs-137 source is collimated by the chamber protecting lead with 5cm thickness. The 3in. x 3in. NaI(Tl) locator model recreation in the reenactment is embraced from references [6, 7]. Reenactment dependent on GEANT4 Penelope Monte Carlo utilizing 5.0 x 107 of the gamma source beamon. Figure 2 Schematic perception of GEANT4 reenactment for the transmission and dispersing estimations arrangement. Result and Discussion To inspect the reaction capacity of transmission and dissipating estimation, right off the bat we have to consider the arrangement intended for the finder development as per the c gamma source vitality range. The Cesium 137 source was set before the Pb collimated NaI(Tl) 3 in. x 3 in. glimmer locator. Figure 3 shows the indicator reaction work range of GEANT4 reproduction result contrasting with the estimation aftereffect of the 15uCi gamma source. There are a decent understanding for photopeak vitality between the recreation result and the examination result. Figure 3 Response capacity of Cs137 15uCi gamma hotspot for 3 in. x 3 in NaI(Tl) identifier. In light of finder development arrangement, at that point we breaks down the indicator reaction capacity of transmission and dispersing estimation. Figure 4 shows the reaction work consequence of identifier that set in the four unique situations for three distinctive kind of thickness liquid for example gas, gasoil and water. Figure 4 Response capacity of identifier NaI(Tl) 3in. x 3in. from GEANT4 reenactment of four distinctive indicator positions for fuel, gasoil and water liquids in pipe. In the all vitality range appropriation above, thickness of liquid issue give an impact to the gamma energies range. The fuel has a lower thickness number, however it shows a higher power (number of occasions) of gamma beam vitality identified contrast with the gasoil and water. The expanded thickness of liquid will expanded the quantity of electrons at the dissipating point communication, lessening of essential and dispersed photons. Along these lines, it’s give an impact to the diminishing force or pinnacle vitality range that distinguished by the identifier. For transmission mode as appeared at d0 indicator position, the primary pinnacle of Cesium 137 gamma source is in the 0.662 MeV. The standardize top power shows that the GEANT4 reenactments result have a decent consent to the Khorsandi (2011) test result as appeared in Figure 5. This outcome shows that the model can be utilized for anticipating the liquid densitometer try. Figure 5 Normalize force bend of transmission mode (d0 identifier position) from reenactment and examination results. Here in the Figure 6(a), we have similar patterns that the diminishing of the photopeak stature because of the liquids thickness increment. Figure 6 Gaussian stature bends of photopeak at four distinctive identifier positions. In light of the power as thickness work condition (8), the proposed steady An and B for the bend fit in the Figure 6(a) are portrayed in Table 1. Table 1. Bend fitting consistent In light of the B consistent of the four standardize tally rates bends, d20 indicator position have a higher diminishing incline than the others. In opposite side, the quantity of section photon to the indicator d20 position is excessively little, so for this design its need the higher action source. Ends In this investigation, a Monte Carlo reproduction of transmission and dissipating estimations of gamma beam for the liquid densitometer was completed utilizing GEANT4. Because of an expansion in the liquid thickness in the channel, the pinnacle statures of identified gamma beam force have diminished. The reenactments for the gamma beam transmission examination were led by the test arrangement give the best fit bend result. Affirmations The creator recognizes the monetary help of Directorate General of Indonesian Higher Education through the Sandwich-Like (PKPI) Program 2013. Refference [1] A.J. Ball, C.J. Solomon, J.C. Z