2,013 research outputs found
Letter, Montgomery C. Meigs to Peleg Clarke Jr., November 22, 1865
This handwritten letter, dated November 22, 1865, is written from Montgomery C. Meigs to Peleg Clarke Jr. insisting that the United States Army does not owe Clarke any money for the lumber, supplies, and corn Clarke is claiming were taken by the Army due to Clarke\u27s alleged dealings with the Rebels. Meigs claims that the items were taken as prize of war after the Rebels were forced to abandon them when the Union forced them out of Fredericksburg. The letter is written on Quartermaster General\u27s Office letterhead.https://scholarsjunction.msstate.edu/fvw-manuscripts-clarke/1053/thumbnail.jp
Letter, M. C. Meigs to R. J. Atkinson with Atkinson\u27s Response, March 12, 1863
This handwritten letter, dated May 12, 1863, is from M. C. Meigs to R. J. Atkinson requesting permission for Peleg Clarke to obtain copies of the returns of Captain Springsteed relating to Peleg\u27s property that Springsteed was in possession of. Atkinson\u27s reply on the back of the letter informs Meigs that he had already informed Clarke that he would not be able to share the returns with him and explained how and with whom to make his case.https://scholarsjunction.msstate.edu/fvw-manuscripts-clarke/1041/thumbnail.jp
Effect of toroidal field ripple on plasma rotation in JET
Dedicated experiments on TF ripple effects on the performance of tokamak plasmas have been carried out at JET. The TF ripple was found to have a profound effect on the plasma rotation. The central Mach number, M, defined as the ratio of the rotation velocity and the thermal velocity, was found to drop as a function of TF ripple amplitude (3) from an average value of M = 0.40-0.55 for operations at the standard JET ripple of 6 = 0.08% to M = 0.25-0.40 for 6 = 0.5% and M = 0.1-0.3 for delta = 1%. TF ripple effects should be considered when estimating the plasma rotation in ITER. With standard co-current injection of neutral beam injection (NBI), plasmas were found to rotate in the co-current direction. However, for higher TF ripple amplitudes (delta similar to 1%) an area of counter rotation developed at the edge of the plasma, while the core kept its co-rotation. The edge counter rotation was found to depend, besides on the TF ripple amplitude, on the edge temperature. The observed reduction of toroidal plasma rotation with increasing TF ripple could partly be explained by TF ripple induced losses of energetic ions, injected by NBI. However, the calculated torque due to these losses was insufficient to explain the observed counter rotation and its scaling with edge parameters. It is suggested that additional TF ripple induced losses of thermal ions contribute to this effect
Control System for the Holifield Radioactive Ion Beam Facility
A new accelerator control system is being impfemented as part of the development of the Holifield Radioactive Ion Beam Facility (HRIBF), a first generation radioactive ion beam (RIB) facility. The pre-existing accelerator control systems are based on 1970's technology and addition or alteration of controls is cumbersome and costly. A new, unified control system for the cyclotron and tandem accelerators. the RIB injector, ion sources, and accelerator beam lines is based on a commercial product from Vista Control Systems. Inc. Several other accelerator facilities. as well as numerous industrial sites, are now using this system. The control system is distributed over a number of computers which communicate over Ethernet and is easily extensible. Presently. implementation at the HRIBF is based on VAXNMS. VAX/ELN, VME, and Allen-Bradley PLCS programmable logic controller architectures. Expansion to include UMX platforms and CAMAC hardware support is planned. Operator interface is via X-terminals. The system has proven to be quite powerful, yet it has been easy to implement with a small staff. A Vista users group has resulted in shared software to implement specific controls. This paper details present system features and future implementations at the HRIBF
Deuterium Balmer/Stark spectroscopy and impurity profiles: first results from mirror-link divertor spectroscopy system on the JET ITER-like wall
For the ITER-like wall, the JET mirror link divertor spectroscopy system was
redesigned to fully cover the tungsten horizontal strike plate with faster time
resolution and improved near-UV performance. Since the ITER-like wall project
involves a change in JET from a carbon dominated machine to a beryllium and
tungsten dominated machine with residual carbon, the aim of the system is to
provide the recycling flux, equivalent, to the impinging deuterium ion flux,
the impurity fluxes (C, Be, O) and tungsten sputtering fluxes and hence give
information on the tungsten divertor source. In order to do this
self-consistently, the system also needs to provide plasma characterization
through the deuterium Balmer spectra measurements of electron density and
temperature during high density. L-Mode results at the density limit from Stark
broadening/line ratio analysis will be presented and compared to Langmuir probe
profiles and 2D-tomography of low-n Balmer emission [1]. Comparison with other
diagnostics will be vital for modelling attempts with the EDGE2D-EIRENE code[2]
as the best possible data sets need to be provided to study detachment
behaviour.Comment: 18 pages, 11 figure
A Classifier-based approach to identify genetic similarities between diseases
Motivation: Genome-wide association studies are commonly used to identify possible associations between genetic variations and diseases. These studies mainly focus on identifying individual single nucleotide polymorphisms (SNPs) potentially linked with one disease of interest. In this work, we introduce a novel methodology that identifies similarities between diseases using information from a large number of SNPs. We separate the diseases for which we have individual genotype data into one reference disease and several query diseases. We train a classifier that distinguishes between individuals that have the reference disease and a set of control individuals. This classifier is then used to classify the individuals that have the query diseases. We can then rank query diseases according to the average classification of the individuals in each disease set, and identify which of the query diseases are more similar to the reference disease. We repeat these classification and comparison steps so that each disease is used once as reference disease
Contrasting H-mode behaviour with fuelling and nitrogen seeding in the all-carbon and metallic versions of JET
An all-metal ITER-Like Wall (JET-ILW), consisting of beryllium in the main chamber and tungsten surfaces in the divertor, has now been installed in JET to pursue low retention of fuel species and to explore the impact on next-step-relevant plasmas. Its implementation has offered a unique opportunity to compare behaviour with that in the previous all-Carbon lining (JET-C), notably for high-triangularity Type I H-modes with impurity seeding. This technique is recognised to be necessary for power handling both in ITER and in JET at full performance. Contrasting results are reported for closely-matched deuterium-fuelling plus nitrogen-seeding scans in each JET environment. Attention is focused upon neutral-beam-heated plasmas with total input power 1517MW at 2.65T, 2.5MA, q95 3.5 , average triangularity d 0.4 , elongation k 1.7 and gas inputs spanning ranges 0.75 FD 3.3 , 0 FD 4.7 (1022 electrons / s assuming full ionisation). JET-C cases also included 12MW of central ion-cyclotron-resonance-frequency heating, so far absent from JET-ILW pulses, with possible consequences for respective core sawtooth and impurity-concentration results.Preprint of Paper to be submitted for publication in Proceedings of the 40th EPS Conference on Plasma Physics, Espoo, Finland 1st July 2013 - 5th July 201
Comparisons between EDGE2D/EIRENE simulations and D and low Z impurity spectral emission from JET ITER-like wall L-mode plasmas
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