| 1. |
- Adcox, K, et al.
(författare)
-
PHENIX detector overview
- 2003
-
Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0167-5087. ; 499:2-3, s. 469-479
-
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.
|
|
| 2. |
- Adcox, K, et al.
(författare)
-
PHENIX central arm tracking detectors
- 2003
-
Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0167-5087. ; 499:2-3, s. 489-507
-
Tidskriftsartikel (refereegranskat)abstract
- The PHENIX tracking system consists of Drift Chambers (DC), Pad Chambers (PC) and the Time Expansion Chamber (TEC). PC1/DC and PC2/TEC/PC3 form the inner and outer tracking units, respectively. These units link the track segments that transverse the RICH and extend to the EMCal. The DC measures charged particle trajectories in the r-phi direction to determine P-T of the particles and the invariant mass of particle pairs. The PCs perform 3D spatial point measurements for pattern recognition and longitudinal momentum reconstruction and provide spatial resolution of a few mm in both r-phi and z. The TEC tracks particles passing through the region between the RICH and the EMCal. The design and operational parameters of the detectors are presented and running experience during the first year of data taking with PHENIX is discussed. The observed spatial and momentum resolution is given which imposes a limitation on the identification and characterization of charged particles in various momentum ranges. (C) 2002 Published by Elsevier Science B.V.
|
|
| 3. |
|
|
| 4. |
- Strokan, N.B., et al.
(författare)
-
Silicon carbide transistor structures as detectors of weakly ionizing radiation
- 2003
-
Ingår i: Semiconductors (Woodbury, N.Y.). - : Pleiades Publishing Ltd. - 1063-7826 .- 1090-6479. ; 37:1, s. 65-69
-
Tidskriftsartikel (refereegranskat)abstract
- SiC-based nuclear radiation detectors figured prominently in the very first attempts of the 1960s to replace gas in ionization chambers with a more condensed semiconducting medium. However, the dynamics of improvement of SiC in those years was markedly inferior to the progress made in the development of competing materials. This study continues with the investigation of triode detector structures based on "pure" SiC films. It is established that for weakly ionizing radiation (as also in the case of strongly ionizing alpha particles) the signal is amplified by no less than a factor of several tens. This allows SiC films with a thickness of about 10 µm to be used to detect penetrating radiation, e.g., X-rays, since the effective thickness of the films is on the order of hundreds of micrometers. © 2003 MAIK "Nauka/Interperiodica".
|
|
| 5. |
- Buyanova, Irina, 1960-, et al.
(författare)
-
Direct experimental evidence for unusual effects of hydrogen on the electronic and vibrational properties of GaNxP1−x alloys : a proof for a general property of dilute nitrides
- 2004
-
Ingår i: Physical Review B Condensed Matter. - 0163-1829 .- 1095-3795. ; 70:24, s. 245215-245219
-
Tidskriftsartikel (refereegranskat)abstract
- Direct experimental evidence for dramatic effects of hydrogen incorporation on the electronic structure and lattice properties of GaNxP1−x alloys is presented. By employing photoluminescence excitation spectroscopy, postgrowth hydrogenation is shown to reopen the band gap of the GaNP alloys and to efficiently reduce the N-induced coupling between the conduction band states. By Raman spectroscopy, these effects are shown to be accompanied by hydrogen-induced breaking of the Ga-P bond in the alloy, evident from disappearance of the corresponding vibrational mode. According to the performed Raman and x-ray diffraction measurements, the hydrogenation is also found to cause a strong expansion of the GaNP lattice, which changes the sign of strain from tensile in the as-grown GaNP epilayers to compressive in the posthydrogenated structures, due to the formation of complexes between N and H.
|
|
| 6. |
|
|
| 7. |
- Donchev, V., et al.
(författare)
-
High-temperature excitons in GaAs quantum wells embedded in AlAs/GaAs superlattices
- 2000
-
Ingår i: Vacuum. - 0042-207X .- 1879-2715. ; 58:2, s. 478-484
-
Tidskriftsartikel (refereegranskat)abstract
- Photoluminescence (PL) spectra of GaAs quantum wells embedded in short-period AlAs/GaAs superlattices have been measured at 2 K and at room temperature. Two approaches have been applied in order to investigate the mechanisms of radiative recombination in these structures. In the first one, we studied the excitation density dependence of the PL intensity. In the second approach a line-shape analysis of the PL spectra is performed by means of a statistical model, which includes both free exciton, and free carrier recombinations. The fit based on this model reproduces with high accuracy the experimental spectra and allows to assess the relative contributions of excitons and free carriers to the radiative recombination process. The results of both approaches indicate the predominance of free excitons in the radiative recombination at room temperature.
|
|
| 8. |
|
|
| 9. |
- Huang, M, et al.
(författare)
-
Small scale integrated technology for HTS RSFQ circuits
- 2001
-
Ingår i: IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 1051-8223. ; 11:1, s. 558-561
-
Tidskriftsartikel (refereegranskat)abstract
- A technology for fabrication of YBCO ramp junctions on a superconducting ground plane Is developed and evaluated. The technology is based on a two-layer, S-I, structure or on a four-layer, S-I-S-I, structure grown in situ with YBCO superconductor and with
|
|
| 10. |
|
|
