著者 Totsuji, Hiroo| Liman, M. Sanusi| Totsuji, Chieko| Tsuruta, Kenji|
発行日 2004-7
出版物タイトル Physical Review E
70巻
1号
資料タイプ 学術雑誌論文
JaLCDOI 10.18926/46949
フルテキストURL mfe_38_1-2_029_032.pdf
著者 Totsuji, Hiroo| Totsuji, Chieko| Ogawa, Takafumi| Tsuruta, Kenji|
抄録 The structure of dust particles in dusty plasmas under microgravity has been analyzed by molecular dynamics simulation. The charge neutrality condition satisfied by the system composed of dust particles and ambient plasma is properly taken into account. It is shown that dust particles form shell structures at low temperatures and the number of shells are obtained as a phase diagram in the plane of two parameters characterizing the system: the number of particles and the strength of screening. It is also shown that these structures are almost independent of the strength of screening.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2004-03
38巻
1-2号
開始ページ 29
終了ページ 32
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 80016863328
JaLCDOI 10.18926/46950
フルテキストURL mfe_38_1-2_033_037.pdf
著者 Liman, M. Sanusi| Totsuji, Chieko| Tsuruta, Kenji| Totsuji, Hiroo|
抄録 The dynamic structure factor and the spectrum of the momentum-density fluctuations of 2D Yukawa liquids are analyzed in the domain of weak and intermediate coupling and screenlng parameters. The dispersion relations of the longitudinal and transverse collective excitations are obtained and compared with the random phase approximation (RPA) and harmonic approximation for triangular lattice.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2004-03
38巻
1-2号
開始ページ 33
終了ページ 37
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 80016863329
JaLCDOI 10.18926/46968
フルテキストURL mfe_37_1_011_014.pdf
著者 Totsuji, Chieko| Limant, Muhammad S.| Tsuruta, Kenji| Totsuji, Hiroo|
抄録 A theoretical approach which has been successful in reproducing results of molecular-dynamics simulations on dusty plasmas is applied to estimate the screening length and the electric charge of two-dimensional dust crystals of melamine particles in the discharge chamber experiment. It has been found that the screening length is of the same order of magnitude as the inter-particle distance and the electric charge decreases on increasing number density of dust particles.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2002-11
37巻
1号
開始ページ 11
終了ページ 14
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 80015784816
JaLCDOI 10.18926/46999
フルテキストURL mfe_36_1_041_049.pdf
著者 Totsuji, Hiroo| Kishimoto, Tokunari| Totsuji, Chieko| Tsuruta, Kenji|
抄録 The ground state of spherical clusters of charged particles of one species confined by the three-dimensional parabolic potential is investigated by molecular dynamics simulations with the system size from N = 5000 to N = 1.2 × 10(5) . The cohesive energy per particle is compared between the shell-structured clusters and spherical finite bcc lattices with relaxed surfaces, the former and the latter being the ground states for small systems and for the large enough systems, respectively. It is shown that, when N > N(c)(N(c) > N), finite bcc lattices with relaxed surfaces (the shell structures) have stronger cohesion than the shell structures (finite bcc lattices with relaxed surfaces) and the critical value of the transition N(c) is estimated to be 10(4) < N(c) < 1.4 × 10(4) . The nucleation of the bcc lattice in the shell-structured cluster of 2 × 10(4) ions is observed.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2001-12
36巻
1号
開始ページ 41
終了ページ 49
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 80015112663
JaLCDOI 10.18926/15358
フルテキストURL Mem_Fac_Eng_OU_35_63.pdf
著者 Shinomiya Shigeru| 東辻 千枝子| 鶴田 健二| 東辻 浩夫|
抄録 We present a theoretical study of Si(1-x)Ge(x) alloys based on tight-binding molecular dynamics (TBMD) calculations. First, we introduce a new set of nonorthogonal tight-binding parameters for silicon and germanium based on the previous work by Menon and Subbaswamy [Phys. Rev. B 55, 9231 (1997); J. Phys: Condens. Matter 10, 10991 (1998)]. We then apply the method to structural analyses of Si(1-x)Ge(x) alloys. The equilibrium volume and atomic structure for a given x are obtained by the TBMD method. We also calculate the bulk modulus B, elastic constants C(11), C(12) and C(44) as a function of x. The results show that the moduli vary monotonically, but nonlinearly, between the values of Si crystal and Ge crystal. The validity of the results is also discussed.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2001-03-27
35巻
1-2号
開始ページ 63
終了ページ 75
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307673
JaLCDOI 10.18926/15361
フルテキストURL Mem_Fac_Eng_OU_35_77.pdf
著者 Kishimoto Tokunari| 東辻 千枝子| 鶴田 健二| 東辻 浩夫|
抄録 In order to perform the large-scale molecular dynamics simulation of the Yukawa system, a mathematical expression for molecular dynamics using the fast multipole method is described. The model simulations are also performed to test the performance of our implementation of the FMM.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2001-03-27
35巻
1-2号
開始ページ 77
終了ページ 95
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307940
JaLCDOI 10.18926/19674
フルテキストURL Mem_Fac_Eng_OU_33_2_71.pdf
著者 鶴田 健二| 東辻 浩夫| 東辻 千枝子|
抄録 A parallel tight-binding molecular dynamics with an order-N [O(N))] algorithm is implemented to perform large-scale simulation of nanostructured materials. The algorithm is based on the Fermi-operator expansion of an electronic energy and force, and we present its basic formalisms. Accuracy necessary for molecular-dynamics simulations can be obtained by a proper truncation in the expansion. Parallel efficiency on a parallel PC cluster shows nearly ideal scaling behavior with respect to the number of processors. Applicability of the method to a silicon-carbide system is examined.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1999-04-27
33巻
2号
開始ページ 71
終了ページ 77
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002309027
JaLCDOI 10.18926/19673
フルテキストURL Mem_Fac_Eng_OU_33_2_61.pdf
著者 東辻 浩夫| 鶴田 健二| 東辻 千枝子|
抄録 The behavior of multicomponent plasmas in the Penning-Malmberg traps is discussed with the parameters corresponding to experiments with antiprotons and cryogenic electrons. The relaxation times for the energy transfer antiprotons to electrons and between parallel and perpendicular components of electrons are estimated. It is shown that, depending on the values of parameters, both the former and the latter can be the bottleneck in the cooling process.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1999-04-27
33巻
2号
開始ページ 61
終了ページ 69
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002309106
JaLCDOI 10.18926/19671
フルテキストURL Mem_Fac_Eng_OU_33_2_51.pdf
著者 東辻 浩夫| 鶴田 健二| 東辻 千枝子|
抄録 Density functional molecular dynamics method is applied to hydrogen plasma in the domain of liquid metallic hydrogen. Tentative results for the proton-proton pair distribution function and the electron-proton pair distribution function are obtained. It is shown that with the increase of the parameter γ(s), we have increasingly strong screening of proton charge by electrons and the decrease of electron density in the domain between protons.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1999-04-27
33巻
2号
開始ページ 51
終了ページ 59
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002309192