M. M. Sherif

Cairo University | CU · department of physics-Faculty of Science- Cairo university

Two analytical methods based on the neutrons high penetrability, i.e. neutron diffraction (ND) and neutron computed tomography (NCT) were used to investigate the structure of the aragonitic skeleton of an exemplar/sample of Dipastraea pallida (Dana 1846), a modern hermatypic coral. ND was used to reconstruct the orientation distribution function (O...

Monte Carlo simulations are exploited to assess the annual radiation doses from some cosmetics due to the radioactive decay series of ²³⁸U and ²³²Th and to the radionuclide ⁴⁰K. The measured radioactivity concentrations are entered into simulation codes modeled and implemented by Monte Carlo n-particle software. The concentrations are found to be r...

A simulation model has been previously established to calculate the absorbed gamma dose rate inside a room by exploiting the MCNP5 simulation software. This study applies that model on rooms built from different types of building materials. The materials are collected from the North-Sinai Peninsula in Egypt and from the Gaza Strip in Palestine. The...

Five corals belonging to common scleractinian reef-building species, and collected from Gulf of Suez, Egypt were subjected to neutron activation analysis. The content of 26 elements: Na, Mg, Cl, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Zn, As, Br, Rb, Sr, Sb, I, Cs, Ba, La, Ce, Gd, Hf, Th, and U was experimentally determined. Ca and Sr have the highest conte...

concentrations for 238 U, 235 U, 226 Ra, 232 Th and 40 K are not that high. Annual absorbed amounts of heavy elements from daily applied kohl were calculated based on roughly assumption that about 50 % of the applied kohl is absorbed into the body. An appropriate simulation has been done for the eye using the MCNP code to estimate the dose rate of...

Within the experimental errors the interaction mean free paths of He-fragments produced by the collisions of 12C, 22Ne and 28Si nuclei at 4.5 A GeV/c in nuclear emulsion have been found to be independent of the He-multiplicity and the distance from the interaction point. Evidence for the multiplicity scaling of He-fragments is reported. The pseudo-...

The multiplicity and angular distributions of charged particles with velocities smaller than 0.7c produces in 6Li-Em collisions at 4.5 A GeV/c. The multiplicity distribution is independent of the energy of the projectile or its mass. The Ng multiplicity distributions are fitted with a parameter free model whose input information is the Ng multiplic...

Fifty three samples of building materials were collected from two governorates in Yemen (Taiz and Hodeidah); these materials are used mostly in Yemen. Samples were measured for gamma radiation using HPGe detector. The specific absorbed dose rates due to the three natural radionuclides 226 Ra, 232 Th and 40 K in the most used types of building mater...

We study the propagation of energetic muons produced by ultrahigh energy cosmic rays which could penetrate the cavern of a giant experiment called Compact Muon Solenoid (CMS) at CERN. The present work is based on our previous simulation model proposed in [1]. We have improved this model by (1) eliminating the ambiguity via adding Landau-Pomeranchuk...

Central collisions of 16O and 28Si nuclei with heavy (AgBr) nuclei in nuclear emulsion at 4.5 GeV/c per nucleon are selected and investigated under several selecting criteria. Central cross sections and average number of interacting protons from both projectile and target nuclei, multiplicity distributions of shower particles and dispersions are di...

This work presents results on charged state topology of relativistic fragmentation of 6Li and 7Li nuclei at 4.5A and 3.8A GeV/c, respectively, on photoemulsion nuclei. The results would make it possible to answer some topical questions concerning the cluster structure of lithium isotopes. The isotopic composition of fragments and the channels of 6,...

The CMS (Compact Muon Solenoid) tracing detector could be affected by atmospheric muons produced by ultra high energy cosmic rays. We study the propagation of such energetic muons by injecting air showers normally to the CMS location. Energetic showers produced be primary protons have been simulated using the QGSJET model depending on the Monte Car...

The isotopic composition of the emitted relativistic fragments in the interactions of 6Li, 7Li and 12C projectile nuclei with target nuclear emulsion nuclei at 4.5 AGeV/c is investigated. The relativistic isotopes (fragments) were separated (identified) by their charges and pβc measurements in the emulsion. Yields of [1H ( 3He)], [2H or 1H (4He)] a...

Experimental data are presented on the multiplicities of the charged secondaries of the various types in the interactions of 6Li and 7Li projectile isotopes with the target nuclei in nuclear emulsion at 4.5 A GeV/c and 3.7 A GeV/c, respectively. A systematic comparison using the corresponding values of 4He-Em interactions is made. The results are d...

This work presents a special type of interactions produced in emulsion targets exposed to different incident beams of light ions at a few GeV per nucleon. The events characterized by multi-fragment break-up of the projectile nucleus, which are produced via peripheral collisions or due to the effect of Coulomb field of the target nucleus, have been...

The results of investigations of inelastic interactions of 6 Li and 7 Li nuclei with photo-emulsion at 4.5 and 3.7 A GeV/c respectively are studied. The momenta and yields of hydrogen and helium isotopes and the fragmentation channels of incident projectile nuclei are obtained. The exotic nuclei 6 He produced from pion exchange of 6 Li reaction and...

Projectile multifragment breakup of 16O, 2C and 7Li at energies 3.0–4.5 A-GeV is studied by means of the Weizsäcker-Williams method. The fragmentation channels of the 16O projectile at 4.5 A-GeV are investigated and compared with that of 16O at 200 A-GeV. The events characterized by N h=0 and the events due to both Coulomb and diffraction dissociat...

Summary The charged-particle multiplicities produced in inelastic interactions of16O ions at 3.7 and 60A GeV with emulsion nuclei are investigated and compared with theoretical predictions. Results from the interaction with CNO and AgBr target nuclei are analysed in terms of negative binomial (NB) distribution. Data from other nucleus-emulsion coll...

The multiplicity distributions and the correlations of different types of slow particles produced in 200A GeV oxygen-induced interactions with emulsion nuclei are presented. The experimental distributions are studied within the framework of the generalized Andersson-Otterlund-Stenlund (AOS) model for nucleus-nucleus interactions. The generalized (A...

Summary The shower particles multiplicity distribution produced in 60A GeV16O-Em collisions is studied in the framework of an extended Glauber model in which terms higher than the first (optical limit) in the phase shift expansion are considered. These are the so-called eclipse correction terms. The calculated distribution shows satisfactory agreem...

The angular distributions of the relativistic particles emitted in the inelastic interactions of7Li-nuclei were studied in terms of the pseudorapidity variable. These distributions are fitted by Gaussian curves. The distributions are compared with the distributions obtained using12C-emulsion at similar energy and others incident beams at higher ene...

Central collisions of24Mg nuclei with the heavy (AgBr) group of emulsion nuclei are selected and analysed according to several selecting criteria. Theoretical calculations concerning cross sections for central events, average number of interacting protons from both projectile and target nuclei, multiplicity distributions of shower particles and dis...

40Ar-emulsion interactions are studied, to investigate the question of anomalons, in twoG- 5 emulsion stacks. In about 4600 primary interactions, projectile fragments of Z2 for all generations have been followed until they interact or leave the stack. After careful estimation of charges of these fragments, variation of their mean free paths is stud...

Results are presented from an investigation of the mean free path in nuclear emulsion of multiply charged fragments, produced by 1.8A-GeV argon nuclei. Charge identification of 6965 fragments with charges Z> or =2, producing 2192 secondary interactions, has been made. No dependence of the mean free path on the distance from the preceding collision...

An analysis for 2,000 events produced by 2.1 GeV/c/n alpha particles in nuclear emulsion has been carried out. Multiplicity and angular distributions of charged secondaries have been measured and correlation among them are discussed. The presented data are compared with relevant values from proton and14N interactions with nuclei. The multiplicity d...

Pion-nucleus interactions in nuclear emulsions from 340-GeV/c π- H2 beam at CERN SPS are studied. The average values of produced showers 〈ns〉, gray 〈ng〉, black 〈nb〉, and heavily ionizing particles 〈nh〉 are measured. Linear correlations between these numbers were obtained. The Koba-Nielsen-Olesen—type scaling behavior of the shower particles is inve...

The central collisions of 70 GeV/c protons with Ag, Br and Pb nuclei have been studied, with the help of BR-2 photoemulsion and emulsion of the same constitution loaded with Pb nuclei. It is shown that the average multiplicity of produced particles (s-particles) increases slowly with increasing the atomic weight of the target nucleus. The ratio of...

Tracks of 69.0 GeV/c protons are followed in nuclear emulsion. In 768 m of proton tracks, 1887 inelastic stars are found, yielding a mean free path of proton inelastic interactions with emulsion nucleons and nuclei of 38.74±1.01 cm. The average charged multiplicities of p-p and p-n interactions are found to be 6.93±0.26 and 5.62± 0.20, respectively...

The correlations between different charge combinations of pion pairs from inelastic collisions of negative pions with nuclei are investigated at 50 GeV energy. It is shown that the two-particle inclusive correlations in pion--nucleus collisions depend on the charges of the pions and are different from those in the elementary pion--nucleus interacti...

Thesis (Ph. D.)--University of Salford, 1980.