| 1. |
- Adcox, K, et al.
(författare)
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PHENIX detector overview
- 2003
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0167-5087. ; 499:2-3, s. 469-479
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Tidskriftsartikel (refereegranskat)abstract
- The PHENIX detector is designed to perform a broad study of A-A, p-A, and p-p collisions to investigate nuclear matter under extreme conditions. A wide variety of probes, sensitive to all timescales, are used to study systematic variations with species and energy as well as to measure the spin structure of the nucleon. Designing for the needs of the heavy-ion and polarized-proton programs has produced a detector with unparalleled capabilities. PHENIX measures electron and muon pairs, photons, and hadrons with excellent energy and momentum resolution. The detector consists of a large number of subsystems that are discussed in other papers in this volume. The overall design parameters of the detector are presented. (C) 2002 Elsevier Science B.V. All rights reserved.
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| 2. |
- Aggarwal, MM, et al.
(författare)
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Event-by-event fluctuations in particle multiplicities and transverse energy produced in 158A GeVPb plus Pb collisions
- 2002
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 65:5
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Tidskriftsartikel (refereegranskat)abstract
- Event-by-event fluctuations in the multiplicities of charged particles and photons, and the total transverse energy in 158A GeV Pb+Pb collisions are studied for a wide range of centralities. For narrow centrality bins the multiplicity and transverse energy distributions are found to be near perfect Gaussians. The effect of detector acceptance on the multiplicity fluctuations has been studied and demonstrated to follow statistical considerations. The centrality dependence of the charged particle multiplicity fluctuations in the measured data has been found to agree reasonably well with those obtained from a participant model. However, for photons the multiplicity fluctuations have been found to be lower compared to those obtained from a participant model. The multiplicity and transverse energy fluctuations have also been compared to those obtained from the VENUS event generator.
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| 3. |
- Aggarwal, MM, et al.
(författare)
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Transverse mass distributions of neutral pions from Pb-208-induced reactions at 158 center dot A GeV
- 2002
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 23:2, s. 225-236
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Tidskriftsartikel (refereegranskat)abstract
- Results on transverse mass spectra of neutral pious measured at central rapidity are presented for impact parameter selected 158-A GeV Pb + Pb-1 and Pb + Nb collisions. The distributions cover the range 0.5 GeV/c(2) less than or equal to MT - Mo less than or equal to 4 GeV/c(2). The change of the spectral shape and the multiplicity with centrality is studied in detail. In going from p+p to semi-peripheral Pb+Pb collisions there is a nuclear enhancement increasing with transverse mass similar to the well known Cronin effect, while for very central collisions this enhancement appears to be weaker than expected.
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| 4. |
- Aggarwal, MM, et al.
(författare)
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Centrality dependence of charged-neutral particle fluctuations in 158A (GeVPb)-Pb-208+Pb-208 collisions
- 2003
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 67:4
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Tidskriftsartikel (refereegranskat)abstract
- Results on the study of localized fluctuations in the multiplicity of charged particles and photons produced in 158A GeV/c Pb+Pb collisions are presented for varying centralities. The charged versus neutral particle multiplicity correlations in common phase space regions of varying azimuthal sizes are analyzed by two different methods. Various types of mixed events are constructed to probe fluctuations arising from different sources. The measured results are compared to those from simulations and from mixed events. The comparison indicates the presence of nonstatistical fluctuations in both the charged particle and photon multiplicities in limited azimuthal regions. However, no correlated charged-neutral fluctuations, a possible signature of formation of disoriented chiral condensates, are observed. An upper limit on the production of disoriented chiral condensates is set.
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| 5. |
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| 6. |
- Adler, SS, et al.
(författare)
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PHENIX on-line systems
- 2003
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0167-5087. ; 499:2-3, s. 560-592
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Tidskriftsartikel (refereegranskat)abstract
- The PHENIX On-Line system takes signals from the Front End Modules (FEM) on each detector subsystem for the purpose of generating events for physics analysis. Processing of event data begins when the Data Collection Modules (DCM) receive data via fiber-optic links from the FEMs. The DCMs format and zero suppress the data and generate data packets. These packets go to the Event Builders (EvB) that assemble the events in final form. The Level-1 trigger (LVL1) generates a decision for each beam crossing and eliminates uninteresting events. The FEMs carry out all detector processing of the data so that it is delivered to the DCMs using a standard format. The FEMs also provide buffering for LVL1 trigger processing and DCM data collection. This is carried out using an architecture that is pipelined and deadtimeless. All of this is controlled by the Master Timing System (MTS) that distributes the RHIC clocks. A Level-2 trigger (LVL2) gives additional discrimination. A description of the components and operation of the PHENIX On-Line system is given and the solution to a number of electronic infrastructure problems are discussed. (C) 2002 Elsevier Science B.V. All rights reserved.
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| 7. |
- Neusser, A, et al.
(författare)
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Superdeformed band at very high spin in Nd-140
- 2004
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 70:6
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Tidskriftsartikel (refereegranskat)abstract
- A new high-spin superdeformed band has been discovered in Nd-140(60)80. It was populated in the Zr-96(Ca-48,4n) reaction and investigated using the EUROBALL gamma-ray spectrometer array. The band is observed in the approximate spin range of I=36 to 66. It is associated with shell gaps around Z=60 and at N=80 at large deformation. These gaps produce a pronounced minimum in the calculated total Routhian surfaces at a quadrupole deformation of epsilon(2)=0.45. The new band which lies between the high-deformation bands in the Aapproximate to130 region and the superdeformed bands in Aapproximate to150 nuclei provides insight into the development of the deformation between these two regions. Two possible configurations are suggested involving four neutrons of i(13/2) origin (nu6(4)) and either six protons of h(11/2)/h(9/2) origin (pi5(6)) or five protons of h(11/2)/h(9/2) and one of i(13/2) origin (pi5(5)6(1)).
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| 8. |
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| 9. |
- Saravanan, P., et al.
(författare)
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Study of plasma- and detonation gun-sprayed alumina coatings using Taguchi experimental design
- 2000
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Ingår i: Journal of thermal spray technology (Print). - Materials Park, OH, United States : ASM International. - 1059-9630 .- 1544-1016. ; 9:4, s. 505-512
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Tidskriftsartikel (refereegranskat)abstract
- Atmospheric plasma spraying (APS) is a most versatile thermal spray method for depositing alumina (Al2O3) coatings, and detonation gun (D-gun) spraying is an alternative thermal spray technology for depositing such coatings with extremely good wear characteristics. The present study is aimed at comparing the characteristics of Al2O3 coatings deposited using the above techniques by using Taguchi experimental design. Alumina coating experiments were conducted using a Taguchi fractional-factorial (L8) design parametric study to optimize the spray process parameters for both APS and D-gun. The Taguchi design evaluated the effect of four APS and D-gun spray variables on the measured coating attributes. The coating qualities evaluated were surface roughness, porosity, microhardness, abrasion, and sliding wear. The results show that the coating quality is directly related to the corresponding coating microstructure, which is significantly influenced by the spray parameters employed. Though it is evident that the D-gun-sprayed coatings consistently exhibit dense and uniform microstructure, higher hardness, and superior tribological performance, the attainment of suitable plasma-sprayed coatings can be improved by employing the Taguchi analysis.
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| 10. |
- Akerman, J. J., et al.
(författare)
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Two-stage crossover from thermal to quantum flux creep of dilute vortex ensembles in various high-T-c superconducting thin films
- 2001
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Ingår i: Physical Review B Condensed Matter. - 0163-1829 .- 1095-3795. ; 64:9
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Tidskriftsartikel (refereegranskat)abstract
- The thermal-to-quantum flux creep crossover at low vortex densities has been studied in YBa2Cu3O7, TlBa2CaCu2O7-delta, and HgBa2CaCu2O6+delta thin films using ac susceptibility. The crossover temperatures T-cr are 10-11, 17, and 30 K, respectively. Both thermal and quantum flux creep is suppressed as the vortex density is decreased. We observe a two-stage nature in the crossover behavior which appears to be a general property of all the three materials studied.
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