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in creator/contributor: "Hidaka, Y."  
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MODEL STUDY OF THE SIGN PROBLEM IN A MEAN-FIELD APPROXIMATION.

Description: We study the sign problem of the fermion determinant at nonzero baryon chemical potential. For this purpose we apply a simple model derived from Quantum Chromodynamics, in the limit of large chemical potential and mass. For SU(2) color, there is no sign problem and the mean-field approximation is similar to data from the lattice. For SU(3) color the sign problem is unavoidable, even in a mean-field approximation. We apply a phase-reweighting method, combined with the mean-field approximation, t… more
Date: July 30, 2007
Creator: Hidaka, Y.
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Partner: UNT Libraries Government Documents Department
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Antiferromagnetism in NdBa/sub 2/Cu/sub 3/O/sub 6. 1/

Description: Neutron scattering experiments performed on single crystals of NdBa/sub 2/Cu/sub 3/O/sub 6.1/ reveal antiferromagnetic order for T < T/sub N/ = 385 +- 2K in which the structure is characterized by the magnetic wave vector (1/2 1/2 1/2). The magnetic intensities are accounted for the Cu/sup + +/ spins coupled antiferromagnetically in the CuO/sub 2/ planes. The oxygen deficient layers exhibit a small staggered magnetization epsilonS which induces the spin ordering /minus/S, /minus/epsilonS, /minu… more
Date: January 1, 1988
Creator: Moudden, A.H.; Shirane, G.; Tranquada, J.M.; Birgeneau, R.J.; Endoh, Y.; Yamada, K. et al.
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Partner: UNT Libraries Government Documents Department
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SOURCE OF MICROBUNCHING AT BNL NSLS SOURCE DEVELOPMENT LABORATORY

Description: We report experimental studies of the origins of electron beam microbunching instability at BNL Source Development Laboratory (SDL). We eliminated laser-induced microbunching by utilizing an ultra-short photocathode laser. The measurements of the resulting electron beam led us to conclude that, at SDL, microbunching arising from shot noise is not amplified to any significant level. Our results demonstrated that the only source of microbunching instability at SDL is the longitudinal modulation o… more
Date: March 28, 2011
Creator: Seletskiy, S.; Hidaka, Y.; Murphy, J.B.; Podobedov, B.; Qian, H.; Shen, Y. et al.
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Partner: UNT Libraries Government Documents Department
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Timing Jitter Characterization at the NSLS SDL

Description: Two novel timing jitter measurement techniques with a 100 fs resolution are presented in this paper. The first technique based on the Schottky effect, is used to measure the timing jitter between the photoinjector drive laser and the RF system; and it was employed to characterize the environment effects on the timing jitter. The I/Q beam monitor based on a stripline beam position monitor (BPM) is used to characterize the electron beam arrival time jitter.
Date: May 4, 2009
Creator: Qian,H.; Hidaka, Y.; Murphy, J. B.; Podobedov, B.; Seletskiy, Shen, Y.; Yang, X. et al.
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Partner: UNT Libraries Government Documents Department
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High Brightness Electron Beam Studies at the NSLS SDL

Description: Experimental optimization of electron beam brightness at the NSLS SDL is reported in this paper. Using a high quantum efficiency (QE) Mg metal cathode and the S-band BNL-type RF gun, we have systematically studied electron beams transverse and longitudinal emittance. The measured thermal emittance for the Mg cathode is 0.85{+-}0.04 mm-mrad/mm, which contradicts the current thermal emittance model. For a 50 pC beam, measured normalized transverse and longitudinal RMS emittance are 0.6 mm-mrd and… more
Date: May 4, 2009
Creator: Qian,H.; Hidaka, Y.; Murphy, J. B.; Podobedov, B.; Seletskiy, S.; Shen, Y. et al.
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Partner: UNT Libraries Government Documents Department
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Comparison between muon spin rotation and neutron scattering studies on the 3-dimensional magnetic ordering of La/sub 2/CuO/sub 4-y/

Description: Muon spin rotation and neutron scattering studies on powder and single-crystal specimens of La/sub 2/CuO/sub 4-v/ are compared. The apparent difference between the muon and neutron results for the ordered moment in the antiferromagnetic state is interpreted as the signature of increasingly short-ranged spatial spin correlations with increasing oxygen content.
Date: January 1, 1988
Creator: Uemura, Y. J.; Kossler, W. J.; Kempton, J. R.; Yu, X. H.; Schone, H. E.; Opie, D. et al.
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Partner: UNT Libraries Government Documents Department
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Neutron diffraction study of the magnetic ordering of the Cu{sup ++} spins in Nd{sub 1.5}Ba{sub 1.5}Cu{sub 3}O{sub 6+x}

Description: Elastic neutron scattering experiments performed on single crystals of Nd{sub 1.5}Ba{sub 1.5}Cu{sub 3}O{sub 6+y} reveal successive antiferromagnetic (AF) ordering of the Cu{sup ++} spins. The as grown single crystals show an AF structure characterized by a Neel temperature T{sub N1} {approximately} 390K and a magnetic wave vector (1/2 1/2 0) referring to the tetragonal structure of NdBa{sub 2}Cu{sub 3}O{sub 6}. As the temperature is lowered below T{sub N2} {approximately} 150K, a spin reorienta… more
Date: December 31, 1991
Creator: Moudden, A. H.; Hennion, B.; Schweiss, P.; Gehring, P. M.; Shirane, G. & Hidaka, Y.
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Partner: UNT Libraries Government Documents Department
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Experimental Investigation of Superradiance in a Tapered Free-Electron Laser Amplifier

Description: We report experimental studies of the effect of undulator tapering on superradiance in a single-pass high-gain free-electron laser (FEL) amplifier. The experiments were performed at the Source Development Laboratory (SDL) of National Synchrotron Light Source (NSLS). Efficiency was nearly tripled with tapering. Both the temporal and spectral properties of the superradiant FEL along the uniform and tapered undulator were experimentally characterized using frequency-resolved optical gating (FROG) … more
Date: March 28, 2011
Creator: Hidaka, Y.; She, Y.; Murphy, J.B.; Podobedov, B.; Seletskiy, S. & Yang, X.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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