6,351 research outputs found
Identified particle measurements at large transverse momenta from p+p to Au+Au collisions at RHIC
Measurements of various particle species over an extended momentum range
provide a sensitive experimental tool for investigating particle production
mechanisms in hadronic collisions. Comparison of the spectral shapes from
different collision centralities measured with the STAR detector at RHIC allows
one to study the interplay of soft and hard particle production for mesons and
investigate various baryon-meson effects. Systematic studies of identified
particle spectra for various colliding systems and different incident energies
provide additional insights toward the interplay between fragmentation and
non-fragmentation contributions to the particle production. In these
proceedings we present a systematic study of transverse momentum spectra for
charged pions, protons and antiprotons from Au+Au and Cu+Cu data at
sqrt(s_NN)=200 and 62.4 GeV as a function of collision centrality. We compare
those measurements with p+p and d+Au data, investigating the system effects on
energy loss.Comment: 6 pages, 4 figures, proceedings for the Lake Louise Winter Institute
2007, 19th-24th February 2007, Alberta, Canad
Method of construction of a multi-cell solar array
The method of constructing a high voltage, low power, multicell solar array is described. A solar cell base region is formed in a substrate such as but not limited to silicon or sapphire. A protective coating is applied on the base and a patterned etching of the coating and base forms discrete base regions. A semiconductive junction and upper active region are formed in each base region, and defined by photolithography. Thus, discrete cells which are interconnected by metallic electrodes are formed
High and low threshold P-channel metal oxide semiconductor process and description of microelectronics facility
The fabrication techniques and detail procedures for creating P-channel Metal-Oxide-Semiconductor (P-MOS) integrated circuits at George C. Marshall Space Flight Center (MSFC) are described. Examples of P-MOS integrated circuits fabricated at MSFC together with functional descriptions of each are given. Typical electrical characteristics of high and low threshold P-MOS discrete devices under given conditions are provided. A general description of MSFC design, mask making, packaging, and testing procedures is included. The capabilities described in this report are being utilized in: (1) research and development of new technology, (2) education of individuals in the various disciplines and technologies of the field of microelectronics, and (3) fabrication of many types of specially designed integrated circuits which are not commercially feasible in small quantities for in-house research and development programs
System size dependence of freeze-out properties at RHIC
The STAR experiment at RHIC has measured identified pi(+/-), K(+/-) and
p(pbar) spectra and ratios from sqrt(s_NN) = 62.4 and 200 GeV Cu+Cu collisions.
The new Cu+Cu results are studied with hydro-motivated blast-wave and
statistical model frameworks in order to characterize the freeze-out properties
of this system. Along with measurements from Au+Au and p+p collisions, the
obtained freeze-out parameters are discussed as a function of collision energy,
system size, centrality and inferred energy density. This multi-dimensional
systematic study reveals the importance of the collision geometry and furthers
our understanding of the QCD phases.Comment: 6 pages, 6 figures, poster proceedings for the Quark Matter 2006
Conference, Shanghai, China, 14th-20th Novermber 2006, submitted to the
International Journal of Modern Physics
Distributed Roughness Effects on Blunt-Body Transition and Turbulent Heating
An experimental program has been conducted to obtain data on the effects of surface roughness on blunt bodies at laminar, transitional, and turbulent conditions. Wind tunnel models with distributed surface roughness heights from 0.06 mm to 1.75 mm were tested and heating data were obtained using global surface thermography. Heating rates of up to 85% higher than predicted, smooth-surface turbulent levels were measured
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