469 research outputs found
Local momentum balance in electromagnetic gyrokinetic systems
No full textORCID 0000-0001-5444-1758The Eulerian variational formulation is presented to obtain governing equations of the electromagnetic turbulent gyrokinetic system. A local momentum balance in the system is derived from the invariance of the Lagrangian of the system under an arbitrary spatial coordinate transformation by extending the previous work [H. Sugama et al., Phys. Plasmas 28, 022312 (2021)]. Polarization and magnetization due to finite gyroradii and electromagnetic microturbulence are correctly described by the gyrokinetic Poisson equation and Ampère's law which are derived from the variational principle. Also shown is how the momentum balance is influenced by including collisions and external sources. Momentum transport due to collisions and turbulence is represented by a symmetric pressure tensor, which originates in a variational derivative of the Lagrangian with respect to the metric tensor. The relations of the axisymmetry and quasi-axisymmetry of the toroidal background magnetic field to a conservation form of the local momentum balance equation are clarified. In addition, an ensemble-averaged total momentum balance equation is shown to take the conservation form even in the background field with no symmetry when a constraint condition representing the macroscopic Ampère's law is imposed on the background field. Using the WKB representation, the ensemble-averaged pressure tensor due to the microturbulence is expressed in detail and it is verified to reproduce the toroidal momentum transport derived in previous works for axisymmetric systems. The local momentum balance equation and the pressure tensor obtained in this work present a useful reference for elaborate gyrokinetic simulation studies of momentum transport processes.journal articl
Notes on George Hideo Nakamura's work history
No full textNotes on dates and places of employment for George Hideo Nakamura.The Japanese American Archival Collection documents the people, places, and daily life of Japanese Americans, primarily those who lived in the once thriving community of pre-war Florin in the Sacramento region, as well as the conditions in American incarceration camps during World War II. The approximately 7,000 original items include personal and official letters, photographs, diaries, arts and crafts, newsletters, textiles, camps artifacts, yearbooks and other publications
Letter from Hideo Hashimoto to the Japanese Methodist Church, April 13, 1942
No full textTyped correspondence from Hideo Hashimoto, Pastor of the Japanese Methodist Church, to his congregation and friends. He expresses his feelings towards the current state of the country the day before the mass removal order.The Bishop James Chamberlain Baker Collection includes letters, documents, and articles about Japanese Americans during World War II. Subjects in the collection include Japanese Americans mass removal, Pearl Harbor and the aftermath, religion, and support from the non-Japanese American community. The collection was digitized and made accessible online by CSUDH Gerth Archives and Special Collections
Draft letter from George Hideo Nakamura to Dear Sir, November 1943
No full textDraft correspondence from George Hideo Nakamura to Dear Sir regarding Nakamura's removal from the Comet Model Airplane Company and loyalty to the United States. See also sac_jaac_2250.The Japanese American Archival Collection documents the people, places, and daily life of Japanese Americans, primarily those who lived in the once thriving community of pre-war Florin in the Sacramento region, as well as the conditions in American incarceration camps during World War II. The approximately 7,000 original items include personal and official letters, photographs, diaries, arts and crafts, newsletters, textiles, camps artifacts, yearbooks and other publications
Japanese translations of English announcements from Captain Hideo Hiraide, the Imperial Japanese Navy
No full textJapanese translations of two English announcements which were broadcast from Tokyo, Japan. The announcements were presumably made by Captain Hideo Hiraide, the Imperial Japanese Navy and addressing citizens in the U.S. sometime in January 1944. One of the incarcerees in the Tule Lake Segregation Center obtained them, and they were translated into Japanese. Itsuhei Takano copied out all by hand.The Itsuhei Takno Camp Journal is comprised of seven volumes of his accounts from the time of the Attack on Pearl Harbor, during the mass removal and incarceration, and after being released from the Gila River camp. Also included are Japanese translations of English announcements presumably made by Captain Hide Hiraide, the Imperial Japanese Navy addressing citizens in the United Sates, and some issues from the Gila River Co-op newsletters, which contain his essays. English translations have been provided by CSUDH translation contractor
Linear Landau damping, Schrödinger equation, and fluctuation theorem
No full textORCID 0000-0001-5444-1758A linearized Vlasov–Poisson system of equations is transformed into a Schrödinger equation, which is used to demonstrate that the fluctuation theorem holds for the relative stochastic entropy, defined in terms of the probability density functional of the particle velocity distribution function in the Landau damping process. The difference between the energy perturbation, normalized by the equilibrium temperature, and the entropy perturbation constitutes a time-independent invariant of the system. This invariant takes the quadratic form of the perturbed velocity distribution function and corresponds to the squared amplitude of the state vector that satisfies the Schrödinger equation. Exact solutions, constructed from a discrete set of Hamiltonian eigenvectors, are employed to formulate and numerically validate the fluctuation theorem for the Landau damping process. The results offer new insight into the formulations of collisionless plasma processes within the framework of nonequilibrium statistical mechanics.journal articl
Gyrokinetic Vlasov Code Including Full Three-dimensional Geometry of Experiments
No full textA new gyrokinetic Vlasov simulation code, GKV-X, is developed for investigating the turbulent transport in magnetic confinement devices with non-axisymmetric configurations. Effects of the magnetic surface shapes in three-dimensional equilibrium obtained from the VMEC code are accurately incorporated. Linear simulations of ion temperature gradient (ITG) instabilities and zonal flows in the Large Helical Device (LHD) [O. Motojima, N. Oyabu, A. Komori et al., Nucl. Fusion 43, 1674 (2003)] configuration are carried out by the GKV-X code as benchmark tests against the GKV code [T.-H. Watanabe and H. Sugama, Nucl. Fusion 46, 24 (2006)]. For high poloidal wavenumbers, the frequency, growth rate, and mode structure of the ITG instability are influenced by the VMEC geometrical data such as the metric tensor components of the Boozer coordinates, while the difference between the zonal flow responses obtained by the GKV and GKV-X codes is found to be small in the core LHD region.journal articl
Letter from Donna Nakamura to George Hideo Nakamura
No full textCorrespondence from Donna Nakamura to "Daddy," that is, George Hideo Nakamura, during his service in the armed forces.The Japanese American Archival Collection documents the people, places, and daily life of Japanese Americans, primarily those who lived in the once thriving community of pre-war Florin in the Sacramento region, as well as the conditions in American incarceration camps during World War II. The approximately 7,000 original items include personal and official letters, photographs, diaries, arts and crafts, newsletters, textiles, camps artifacts, yearbooks and other publications
Letter from C.E. Hostetler, Chief, Vocational Rehabilitation and Education Division, to George Hideo Nakamura
No full textCorrespondence from C.E. Hostetler to George Hideo Nakamura regarding Nakamura's request for educational benefits.The Japanese American Archival Collection documents the people, places, and daily life of Japanese Americans, primarily those who lived in the once thriving community of pre-war Florin in the Sacramento region, as well as the conditions in American incarceration camps during World War II. The approximately 7,000 original items include personal and official letters, photographs, diaries, arts and crafts, newsletters, textiles, camps artifacts, yearbooks and other publications
Letter From Hideo Hashimoto to friends
No full textLetter written from Fresno Assembly Center to friends in the "outside" world describing the harsh effects of incarceration including quotes from the letters of incarcerees in other camps as well as from cited publications. Lists ways and actions to help the incarcerees. Also includes descriptions of recreation, education, and church activities.The Japanese American Relocation Collection is composed of ephemera related to the relocation program during World War II. Items include the official government report of Manzanar Relocation Center, a photo album, post-war activism materials related to preserving and remembering the camps, various clippings, and documents. The strength of this collection is found in its many perspectives on the controversial relocation program and how it has been presented since World War II
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