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Small Spherical Focus and Tours

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中国核科技报告 1999年第S4期 358-358页

作者： M.M.Masoud Egypt N.R.C Atomic Energy Authority plasma physics and nuclear fusion department nuclear material division

Small Spherical Focus A spherical focus has been designed recently which for intense X-ray production. The geometry of the system consists of two concentric hemi-spheres insulated from each others by ceramic disc and with two ports at each. Theoretical simulation of the current sheath dynamics shows a simple relation where only radial phase exist. The focus density was one order higher than Mather type which the plasma temperature is in the same order. The construction, theory, and test results are discussed in detail.

关键词： Small Spherical Focus and Tours

Miniature Coaxial plasma Injector for Diagnostics by Beam plasma Interaction

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中国核科技报告 1999年第S4期 387-387页

作者： H.A.M.El-Tayeb N.R.C.Atomic Energy Aythority plasma physics and nuclear fusion department nuclear material division Egypt

A miniature coaxial gun has been used to study the interaction between plasma beam and low density plasma formed in glow discharge. The peak discharge current flow between the coaxial electrodes was 5.25 kA as a singl... 详细信息

关键词： cm Miniature Coaxial plasma Injector for Diagnostics by Beam plasma Interaction

plasma Coaxial Discharge for Thin Film Deposition

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中国核科技报告 1999年第S4期 386-386页

作者： H.A.El-Gamal,H.A.El-Taeb,M.abd-Elmonim plasma physics and nuclear fusion department nuclear material Divsion N.R.C.Atomic Energy Authority Egypt plasma physics and nuclear fusion department nuclear material Divsion N.R.C.Atomic Energy Authority Egypt plasma physics and nuclear fusion department nuclear material Divsion N.R.C.Atomic Energy Authority Egypt

A coaxial discharge, of 6 capacitors each with 7.71 μF, is used to explore plasma thin film coating by insert a graphite powder at the breach of the coaxial head. plasma current sheath reached 25 kA, after 10 μs fro... 详细信息

关键词： plasma Coaxial Discharge for Thin Film Deposition

Development of H− multicusp ion source

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Radiation Detection Technology and Methods 2018年第1期2卷 186-189页

作者： M.Hoseinzade A.Nijatie nuclear Engineering and physics department Amirkabir University of TechnologyTehran 15875-4413Iran plasma physics and nuclear fusion Research department Nuclear Science and Technology Research InstituteAEOIPO Box 14155-1339TehranIran

Introduction The ion source is one of the key devices for the high-intensity cyclotron,which exerts influence on the beam intensity and applications of the *** paper will provide an introduction to current measures and present relevant experimental study as well as the beam test *** The existing ion source of the accelerator has a 2-mA output *** aim is to increase the current to roughly 5 mA to decrease the reaction time of ***,a new ion source was *** this end,some simulations were performed,and the simulated ion source was constructed,and then some measurements were *** and materials The CST code is used to simulate the chamber and extraction *** construction,some materials such as copper and stainless steel are *** wire of 2.1 mm diameter was developed to reach high beam *** and rotary pump is chosen for system *** cup can be used for *** magnets for plasma confinement are made of Nd–Fe–B *** The source assembly consists of a tubular plasma chamber(inner diameter:100 mm;length:150 mm)with 12 columns of permanent magnets(Nd–Fe–B material)to provide a stronger multicusp field,a three-electrode extraction system,and a top cover with a confinement magnet ***,5 mA H−beam can be extracted from the ion source with a plasma electrode aperture of 13 mm under an arc power of 6 *** optimum H2 gas flow rate and the change of pressure found during the tuning process of the ion source are presented.

关键词： Multicusp ion source Extraction Electron tracking Perveance Angular divergence

New scheme to trigger fusion in a compact magnetic fusion device by combining muon catalysis and alpha heating effects

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High Power Laser Science and Engineering 2016年第4期4卷 1-7页

作者： S.D.Moustaizis P.Lalousis H.Hora Z.Henis S.Eliezer I.Ploumistakis Technical University of Crete Lab of Matter Structure and Laser Physics Institute of Electronic Structure and Laser FORTH department of Theoretical physics University of New South Wales Applied physics division Soreq NRC nuclear fusion Institute Polytechnique University of MadridETSII

The application of laser pulses with psec or shorter duration enables nonthermal efficient ultrahigh acceleration of plasma blocks with homogeneous high ion energies exceeding ion current densities of 10^(12) A cm^(-2). The effects of ultrahigh acceleration of plasma blocks with high energy proton beams are proposed for muon production in a compact magnetic fusion device. The proposed new scheme consists of an ignition fusion spark by muon catalyzed fusion(μCF) in a small mirror-like configuration where low temperature D–T plasma is trapped for a duration of 1 μs. This initial fusion spark produces sufficient alpha heating in order to initiate the fusion process in the main device. The use of a multi-fluid global particle and energy balance code allows us to follow the temporal evolution of the reaction rate of the fusion process in the device. Recent progress on the ICAN and IZEST projects for high efficient high power and high repetition rate laser systems allows development of the proposed device for clean energy production. With the proposed approaches,experiments on fusion nuclear reactions and μCF process can be performed in magnetized plasmas in existing kJ/PW laser facilities as the GEKKO-LFEX, the PETAL and the ORION or in the near future laser facilities as the ELI-NP Romanian pillar.

关键词： alpha heating effect high energy density physics laser plasmas interaction laser proton acceleration high energy density physics muon catalyzed fusion ultra-intense ultra-short pulse laser interaction with matters

Phase analysis of AlFe2B2 by synchrotron X-ray diffraction,magnetic and M?ssbauer studies

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Progress in Natural Science:materials International 2017年第2期27卷 251-256页

作者： Tahir Ali M.N.Khan E.Ahmed Asad Ali physics division Pakistan Institute of Nuclear Science and technology department of physics Abdul Wali Khan University PINSAT Preston University

The structural and magnetic properties of essentially phase pure AlFe2B2prepared by arc melting were compared with a sample containing impurities. Analysis was carried out by means of synchrotron X-ray diffraction, magnetic measurements and M?ssbauer spectroscopy. The analysis of synchrotron X-ray diffraction data confirmed the orthorhombic structure of space group Cmmm for AlFe2B2with Al13Fe4as main impurity phase. The magnetic measurements revealed an unsaturated ferromagnetic state in AlFe2B2with a transition temperature（Tc） of 286 K. Isothermal magnetization measurment at 5 K gave a saturation magnetization of 0.7 μB per Fe atom while Arrott plots establish the second order nature of ferromagnetic transition. The thermal evolution of M?ssbauer spectra confirmed the ferromagnetic nature of this material revealing an hyperfine field of 73 kOe and an isomer shift of 0.46 mm/s at 100 K. The M?ssbauer spectra of a phase pure sample was compared with the one containing impurity phases. It is suggested that the low temperature paramagnetic contribution in M?ssbauer spectra of phase pure material may have its origin in some intrinsic phenomena arising from defects or inhomogeneities in crystal structure.

关键词： AlFe2B2 Synchrotron X-ray diffraction Ferromagnetism Mossbauer effect spectroscopy

Influence of thyroid volume reduction on absorbed dose in ^(131)I therapy studied by using Geant4 Monte Carlo simulation

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Chinese physics C 2014年第5期38卷 62-68页

作者： Ziaur Rahman Sikander M Mirza Waheed Arshed Nasir M Mirza Waheed Ahmed Health physics division Pakistan Institute of Nuclear Science and Technology department of physics and Applied Mathematics Pakistan Institute of Engineering and Applied Sciences

A simulation study has been performed to quantify the effect of volume reduction on the thyroid absorbed dose per decay and to investigate the variation of energy deposition per decay due to β- and γ-activity of 131I with volume/mass of thyroid, for water, ICRP- and ICRU-soft tissue taken as thyroid material. A Monte Carlo model of the thyroid, in the Geant4 radiation transport simulation toolkit was constructed to compute the β- and γ-absorbed dose in the simulated thyroid phantom for various values of its volume. The effect of the size and shape of the thyroid on energy deposition per decay has also been studied by using spherical, ellipsoidal and cylindrical models for the thyroid and varying its volume in 1-25 cm3 range. The relative differences of Geant4 results for different models with each other and MCNP results lie well below 1.870%. The maximum relative difference among the Geant4 estimated results for water with ICRP and ICRU soft tissues is not more than 0.225%. S-values for ellipsoidal, spherical and cylindrical thyroid models were estimated and the relative difference with published results lies within 3.095%. The absorbed fraction values for beta particles show a good agreement with published values within 2.105% deviation. The Geant4 based simulation results of absorbed fractions for gammas again show a good agreement with the corresponding MCNP and EGS4 results （±6.667%） but have 29.032% higher values than that of MIRD calculated values. Consistent with previous studies, the reduction of the thyroid volume is found to have a substantial effect on the absorbed dose. Geant4 simulations confirm dose dependence on the volume/mass of thyroid in agreement with MCNP and EGS4 computed values but are substantially different from MIRD8 data. Therefore, inclusion of size/mass dependence is indicated for 131I radiotherapy of the thyroid.

关键词： mean absorbed dose rate Geant4 Monte Carlo simulation and 131I therapy

Measurement of(n,α)and(n,2n)reaction cross sections at a neutron energy of 14.92±0.02 MeV for potassium and copper with uncertainty propagation

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Chinese physics C 2022年第1期46卷 110-117页

作者： A.Gandhi Aman Sharma Rebecca Pachuau1 Namrata Singh L.S.Danu S.V.Suryanarayana B.K.Nayak A.Kumar department of physics Banaras Hindu UniversityVaranasi 221005India nuclear physics division Bhabha Atomic Research CentreMumbai 400085India

Experimentally measured neutron activation cross sections are presented for the ^(65)Cu(n,0)^(62m)Cu,^(41) K(n,a)^(38C)l,and ^(65)Cu(n.2n)^(64)Cu reactions with detailed uncertainty *** neutron cross secions were measured at an incident energy of 14.92±0.02 MeV,and the neutrons were based on the(d,n)a fusion *** ^(27) Al(n,a)^(24)Na reaction was used as a reference reaction for the normalization of the neutron *** pre-calib-rated lead-shielded HPGe detector was used to detect the residues'γ-ray *** data from the measured cross sections are compared to the previously measured cross sections from the EXFOR database,theoretically calculated cross sections using the TALYS and EMPIRE codes,and evaluated nuclear data.

关键词： nuclear reactions (n,a)and(n,2n)reactions t(c/,n)a neutron source uncertainty propagation covariance analysis TALYS-1.9 and EMPIRE-3.2 code

Spectroscopy of Low-lying States in Odd-Z Odd-A Nuclei Beyond Lead

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原子核物理评论 2016年第2期33卷 141-145页

作者： U.Jakobsson J.Uusitalo K.Auranen H.Badran B.Cederwall D.M.Cox T.Grahn P.T.Greenlees R.Julin S.Juutinen A.Herzán J.Konki M.Leino M.Mallaburn J.Pakarinen P.Papadakis J.Partanen P.Rahkila M.Sandzelius J.Sarén C.Scholey J.Sorri S.Stolze KTH The Division of Nuclear PhysicsAlba Nova University Center University of Jyvaskyla Department of Physics

Low-lying states in odd-Z odd-mass nuclei at the proton drip-line beyond lead have recently been studied through fusion-evaporation reactions using a gas-filled recoil separator. Isomeric 1/2+and13/2+states have been observed in odd-mass astatine and francium nuclei. The systematic behaviour of the level energies of these states have been studied and a similarity between the 1/2+state in astatine and francium has been found. Furthermore, the 13/2+state has been observed in the francium nuclei with an oblate behaviour suggesting a coupling of the i13/2proton to the 2p- 2h intruder excitation.

关键词： nuclear spectroscopy isomeric states Z > 82