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Observation of cosmic ray flux deficit in the direction of the sun using a charged particle traking telescope
, Article Astroparticle Physics ; Volume 86 , 2017 , Pages 27-31 ; 09276505 (ISSN) ; Sharif University of Technology
Elsevier B.V
2017
Abstract
A cosmic ray tracking telescope has been made for the measurement of the secondary cosmic ray flux at ground level. The observations have been made both looking in the direction of the sun and away from the sun. Our observations by the telescope shows a deficiency in the detected number of cosmic rays entering the telescope when its axis was pointing to the sun compared to that entering the telescope with no sun in its field of view. The statistical significance of this deficit with the Li and Ma method stands near 1.3σ for all of our observations. © 2016 Elsevier B.V
Determining the muon charge ratio using an experimental measurements and the CORSIKA simulation code
, Article Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment ; Volume 945 , 2019 ; 01689002 (ISSN) ; Sharif University of Technology
Elsevier B.V
2019
Abstract
The muon charge ratio contains important information about the flux of atmospheric neutrinos and the hadronic interactions. Using a cosmic ray telescope, the atmospheric muon charge ratio has been studied. The result of this experiment is compared with simulation results using the CORSIKA code. © 2019 Elsevier B.V
A method for determining the angular distribution of atmospheric muons using a cosmic ray telescope
, Article Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment ; Volume 916 , 2019 , Pages 1-7 ; 01689002 (ISSN) ; Sharif University of Technology
Elsevier B.V
2019
Abstract
A cosmic ray telescope consisting of two scintillators (each one with a surface area of 0.14 m2, spaced 283 cm top of each other) was constructed to study the angular distribution of atmospheric muons. Using the CORSIKA code, the muons energy spectrum is parameterized in different energy regions at Tehran's altitude (1200 m above sea level ≡897 gcm−2), and by using a Monte Carlo program, the minimum energy recorded by the telescope is calculated. Due to the geomagnetic field, in the azimuth angle distribution of atmospheric muons, an anisotropy is observed in the East–West direction. The zenith angle distribution of the atmospheric muons follows the function cosnθ. Due to the relatively...
Muon charge ratio using the corsika simulation code
, Article Physical Review D ; Volume 100, Issue 8 , 2019 ; 24700010 (ISSN) ; Fazlalizadeh, M ; Sharif University of Technology
American Physical Society
2019
Abstract
Using the corsika code, in 21 energy states between 7 and 900 GeV, in each state, 2×104 extensive air showers were simulated separately with 88% protons and 12% alpha as primary particles. The zenith and azimuth angles of the primary particles were between 0° to 60° and 0° to 360°, respectively. These simulations are carried out at Tehran's level (35°43′N, 51°20′E; 1200 m a.s.l=897 g cm-2) and with two models GHEISHA and UrQMD for hadronic interactions at low energy and the QGSJET-II model for high-energy interactions. Using the positive and negative muons produced from these air showers, the muon charge ratios are obtained at various angles and energies. An east-west anisotropy is also...
Determining the angular resolution of an air shower array including five scintillation detectors using two methods: Shadow of the moon and the CORSIKA simulation
, Article Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment ; Volume 932 , 2019 , Pages 62-68 ; 01689002 (ISSN) ; Heydarizad, M ; Sharif University of Technology
Elsevier B.V
2019
Abstract
An array including five scintillation detectors at Sharif University of Technology in Tehran (35°43′N, 51°20′E, 1200m a.s.l= 897 gcm−2), over a year from October 2016 to October 2017, collected more than 5.6×105 extensive air shower (EAS) events in the energy range between 0.03PeV and 3PeV. Data from the array were used to examine the cosmic ray shadow of the Moon in the energy range mentioned. The observation of a deficit of cosmic rays in the direction of the moon can be an estimate of the accuracy of the measurement of the primary particles of the air showers. The deficit of cosmic rays from the direction of the moon, in fact, is due to the presence of the moon in the early direction of...
Simulation of the time structure of Extensive Air Showers with CORSIKA initiated by various primary particles at Alborz-I observatory level
, Article New Astronomy ; Volume 61 , 2018 , Pages 5-13 ; 13841076 (ISSN) ; Moghaddam, S. M ; Sharif University of Technology
Elsevier B.V
2018
Abstract
A detailed simulation of showers with various zenith angles in atmosphere produced by different primary particles including gamma, proton, carbon, and iron at Alborz-I observatory level (35∘43′N, 51∘20′E, 1200 m a.s.l= 890 gcm−2), in the energy range 3 × 1013 eV–3 × 1015 eV, has been performed by means of the CORSIKA Monte Carlo code. The aim of this study is to examine the time structure of secondary particles in Extensive Air Showers (EAS) produced by the different primary particles. For each primary particle, the distribution of the mean values of the time delays of secondary particles relative to the first particle hitting the ground level in each EAS, <τi>=, and the distribution...
System Identification and Control of Space Explorer Robot Arm Using Neural Network
, M.Sc. Thesis Sharif University of Technology ; Asadian, Nima (Supervisor)
Abstract
In this study, two conventional methods for controlling flexible two-link robots based on artificial neural networks is improved. The first method is implemented by combining fuzzy logic and reinforcement learning in the form of a neural network. This method is modified in two steps. In the first step, the system feedback is changed and in the second step, the system Jacobin is used. This Jacobin can be the result of system identification. In the second method, an optimal controller is proposed for the system, which is also implemented in the form of a neural network. The performance of the neural-optimal controller is further improved by redefining the Bellman's principle of optimality....
Investigation of the Characteristics of High Energy Cosmic Rays Using the Corsika Code
, M.Sc. Thesis Sharif University of Technology ; Bahmanabadi, Mahmoud (Supervisor)
Abstract
This thesis discusses cosmic particles. Cosmic particles are originated by stars and black holes that could live in the Milky Way or other galaxies. These energetic particles can be protons, carbon, iron, gamma, electrons and positrons, and so on. After reaching the earth, these particles collide with atmospheric atoms to make the first interaction, which leads to the production of secondary particles. The number of secondary particles produced also increases steadily due to successive collisions with atmospheric atoms. The set of secondary particles that originate from the cosmic primary particle is called the extensive air shower. The aim of this paper is to investigate the properties of...
Experimental Investigation of the Effects of Asymmetrical Grooves on Thermosyphon Heatpipes
, M.Sc. Thesis Sharif University of Technology ; Behshad Shafiei, Mohammad (Supervisor)
Abstract
technologies for cooling of electronic devices, have high efficiency due to the heat transfer in two-phase state. In this project, experimental effects of asymmetric triangle groove has been studied on the boiling fluid and effect of the motion on the boiling and heat pipe. Therefore, the experiment has been done by 3 heat pipes and each with 3 plates. The plates consist of a smooth plate, a plate with triangle groove and a plate with rectangle groove. Each heat pipe was filled by methanol in volumetric percentage from 10 to 60. The results show that 20 percent methanol is the optimum for all kind of heat pipe, which has been used. In addition, it is shown that heat pipe with triangle groove...
Investigating the features of a pentagon array for studying Extensive Air Showers
, Article Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment ; Volume 962 , 2020 ; Rastegarzadeh, G ; Mortazavi Moghaddam, S ; Sharif University of Technology
Elsevier B.V
2020
Abstract
We used a method to evaluate angular accuracy for air showers direction recorded by a pentagon array of scintillation detectors. This is achieved by using the coincidences between the air showers recorded by the two sub-arrays. Also, using the CORSIKA code the angular precision of this array and the effect of inherent error on it is obtained at different energies of the primary particles and at different zenith angles. © 2020 Elsevier B.V
Experimental examination of utilizing novel radially grooved surfaces in the evaporator of a thermosyphon heat pipe
, Article Applied Thermal Engineering ; Volume 169 , 2020 ; Faegh, M ; Shafii, M. B ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
The application of heat pipes with flat evaporators in cooling electronic devices has attracted a lot of attention in recent years. Increasing the rate of heat transfer in their evaporator by utilizing structured surfaces is considered as a prominent method for reducing the thermal resistance of the heat pipes. In this study, the performance of a thermosyphon heat pipe with novel radially rectangular-grooved and radially inclined triangular-grooved evaporator surfaces was evaluated experimentally. It is hypothesized that the radial grooves may enhance the performance by inducing rotational motions and increasing the heat transfer coefficients. Based on the results, the optimum filling ratio...
Investigation of EGRET gamma-ray sources by an extensive air shower experiment
, Article 29th International Cosmic Ray Conference, ICRC 2005, Pune, 3 August 2005 through 10 August 2005 ; Volume 6 , 2005 , Pages 29-32 ; Samimi, J ; Bahmanabadi, M ; Sharif University of Technology
Tata Institute of Fundamental Research
2005
Abstract
Ultra-high-energy ( E ≥ TeV) Extensive Air Showers (EASs) have been monitored for a period of five years (1997-2003 ), using a small array of scintillator detectors in Tehran, Iran. The data have been analyzed to take in to account of the dependence of source counts on zenith angle. During a calendar year different sources come in the field of view of the detector at varying zenith angles. Because of varying thickness of the overlaying atmosphere, the shower count rate is extremely dependent on zenith angle which have been carefully analyzed over time. High energy gamma-ray sources from the EGRET third catalogue where observed and the data were analyzed using an excess method. Upper limits...
Experimental studies of positive and negative atmospheric muons with a cosmic rays telescope
, Article Astroparticle Physics ; Volume 24, Issue 3 , 2005 , Pages 183-190 ; 09276505 (ISSN) ; Khakian Ghomi, M ; Sheidaei, F ; Sharif University of Technology
2005
Abstract
An experiment has been developed for the measurement of the muon charge ratio (ratio of positive to negative muons) in the cosmic ray flux in energy range 0.236-0.242 GeV. The muon charge ratio is found to be 1.35 ± 0.10 with a mean zenith angle of 32° ± 5°. Meanwhile, the distributions of muons in zenith (θ) and azimuth angles have been studied. A cosnθ distribution with n = 1.95 ± 0.13 has been obtained. An asymmetry has been observed in East-West directions because of geomagnetic field. © 2005 Elsevier B.V. All rights reserved
Galactic anisotropy of cosmic ray intensity observed by an air shower experiment
, Article Publications of the Astronomical Society of Australia ; Volume 23, Issue 3 , 2006 , Pages 129-134 ; 13233580 (ISSN) ; Khakian Ghomi, M ; Sheidaei, F ; Samimi, J ; Sharif University of Technology
2006
Abstract
We have monitored multi-TeV cosmic rays by a small air shower array in Tehran (35°43′ N, 51°20′ E, 1200 m ≤ 890 g cm -2). More than 1.1 × 106 extensive air shower events were recorded. These observations enabled us to analyse sidereal variation of the galactic cosmic ray intensity. The observed sidereal daily variation is compared to the expected variation which includes the Compton-Getting effect due to the motion of the earth in the Galaxy. In addition to the Compton-Getting effect, an anisotropy has been observed which is due to a unidirectional anisotropy of cosmic ray flow along the Galactic arms
The charge ratio of the atmospheric muons at low energy
, Article Physical Review D - Particles, Fields, Gravitation and Cosmology ; Volume 74, Issue 8 , 2006 ; 15507998 (ISSN) ; Sheidaei, F ; Khakian Ghomi, M ; Samimi, J ; Sharif University of Technology
2006
Abstract
From the nature of the muon production processes, it can be seen that the ratio of positive to negative cosmic muons has important information in both "the atmospheric neutrino problem," and "the hadronic interactions." We have carried out an experiment for the measurement of the muon charge ratio in the cosmic ray flux in momentum range 0.112-0.178GeV/c. The muon charge ratio is found to be 1.21±0.01 with a mean zenith angle of 32°±5°. From the measurements it has been obtained a zenithal angle distribution of muons as I(θ)=I(0)cos nθ with n=1.95±0.13. An asymmetry has been observed in East-West directions because of the geomagnetic field. Meanwhile, in about the same momentum range,...
An investigation on anisotropy of cosmic rays with a small air shower array
, Article Experimental Astronomy ; Volume 15, Issue 1 , 2003 , Pages 13-27 ; 09226435 (ISSN) ; Ghomi, M. K ; Samimi, J ; Purmohammad, D ; Sharif University of Technology
2003
Abstract
We have studied anisotropy of cosmic rays with an Extensive AirShower(EAS) array in Tehran 1200 m above sea level. In analyzingthe data set, we have used appropriate techniques of analysis andconsidered environmental effects. An asymmetry has been observedin the azimuthal distribution of EAS of cosmic rays because ofmagnetic field of the Earth. © 2004 Kluwer Academic Publishers
Studies Related to Establishment of an Array Including 20 Scintillation Detectors
, Ph.D. Dissertation Sharif University of Technology ; Bahmanabadi, Mahmoud (Supervisor) ; Pourmohammd, Davoud ($item.subfieldsMap.e)
Abstract
Alborz-I array with 20 detectors will be established at Sharif University of Technology, to study Extensive Air Showers with energies around the knee of cosmic ray spectrum. In this thesis studies related to construction of this array is performed in two parts. First part is dedicated to evaluate detectors of Alborz-I array. Each detector consists of a plane plastic scintillator, 50×50×2 cm3 each, which is enclosed in a pyramidal light enclosure with a 5 cm photomultiplier tube at the vertex of the light enclosure. In order to optimize the height of the light enclosure, two parameters are considered: efficiency and uniformity of different parts of the detector. By building and comparing four...
Optimization of the size of scintillation detectors in order to use in an array of 20 detectors which is going to be placed in the Sharif University of Technology
, Article Proceedings of the 32nd International Cosmic Ray Conference, ICRC 2011, 11 August 2011 through 18 August 2011, Beijing ; Volume 3 , 2011 , Pages 40-43 ; Mortazavi Moghaddam, S ; Hedayati, H ; Bahmanabadi, M ; Khalaj, P ; Sharif University of Technology
Institute of High Energy Physics
2011
Abstract
As a primary step of establishment of an extensive air shower array consisting 20 scintillation detectors we optimized an individual detector. Square shaped scintillators are placed under a metal pyramid Light Enclosure with a photomultiplier tube (PMT) at the vertex of it. A set of experiments are performed to optimize the height of light enclosures by comparing 4 different heights 0.1, 0.2, 0.3 and 0.4 m. These experiments are supported by a Monte Carlo simulation of detection process. In this article, by considering experimental and simulation results we concluded that 20 cm is an optimum height for light enclosures
Optimization of dimensions and inner surface of water Cherenkov detector with one photomultiplier tube (PMT) for the Alborz observatory air shower array
, Article Astroparticle Physics ; Volume 35, Issue 12 , July , 2012 , Pages 792-796 ; 09276505 (ISSN) ; Khalaj, P ; Bahmanabadi, M ; Purmohammad, D ; Abdollahi, S ; Sharif University of Technology
2012
Abstract
In order to be more precise to find primary cosmic particles directions, nowadays detectors and data analysis for studying secondary particles in extensive air showers have an ongoing progress and water Cherenkov detector is considered as a secondary particles detector. Our aim in this paper is to optimize the size and the inner surface characteristic of a cylindrical water Cherenkov tank with one PMT in order to use at the Alborz observatory air shower array which consists of 20 plastic scintillation detectors and 10 water Cherenkov detectors. By comparing data gathered by tanks with diffusing and specular reflection inner surfaces, we show that the diffusing inner surface is more...
Probing the Local Bubble with Diffuse Interstellar Bands (DIBs)
, Ph.D. Dissertation Sharif University of Technology ; Khosroshahi, Habib (Supervisor) ; Bahmanabadi, Mahmoud (Supervisor)
Abstract
We present a new high signal to noise ratio spectroscopic survey of the Northern hemisphere to probe the Local Bubble and its surroundings using the 5780Å and 5797Å Diffuse Interstellar Bands (DIBs). We have observed 432 sightlines to a distance of 200 pc over a duration of 3 years. In this study, for both inside and outside the Local Bubble, we establish the 5780and 5797correlations with Na i, Ca iiand E(B-V). The correlations show that among all neutral and ionized atoms, the Na ihas more similarity with 5780and Ca iihas strong correlation with 5797, which suggest that the ionization level of 5797is more than 5780. We study the 5780correlation with 5797, which shows a tight correlation...