| 11. |
- Schulte, EC, et al.
(author)
-
High energy angular distribution measurements of the exclusive deuteron photodisintegration reaction
- 2002
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In: Physical Review C (Nuclear Physics). - : American Physical Society. - 0556-2813 .- 1089-490X. ; 66:4
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Journal article (peer-reviewed)abstract
- The first complete measurements of the angular distributions of the two-body deuteron photodisintegration differential cross section at photon energies above 1.6 GeV were performed at the Thomas Jefferson National Accelerator Facility. The results show a persistent forward-backward asymmetry up to E-gamma=2.4 GeV, the highest-energy measured in this experiment. The Hard Rescattering and the Quark-Gluon string models are in fair agreement with the results.
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| 12. |
- Wijesooriya, K, et al.
(author)
-
Polarization measurements in neutral pion photoproduction
- 2002
-
In: Physical Review C (Nuclear Physics). - 0556-2813. ; 66:3
-
Journal article (peer-reviewed)abstract
- We present measurements of the recoil proton polarization for the H-1((γ) over right arrow,(p) over right arrow)pi(0) reaction for theta(c.m.)(pi) = 60degrees-135degrees and for photon energies up to 4.1 GeV. These are the first data in this reaction for polarization transfer with circularly polarized photons. Various theoretical models are compared with the results. No evidence for hadron helicity conservation is observed. Models that employ factorization are not favored. It appears from the strong angular dependence of the induced polarization at photon energies of 2.5 and 3.1 GeV that a relatively high spin resonance or background amplitude might exist in this energy region.
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| 13. |
- Hansson, B. A. M., et al.
(author)
-
Characterisation of a liquid-xenon jet laser-plasma extreme-ultraviolet source
- 2004
-
In: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 75:6, s. 2122-2129
-
Journal article (peer-reviewed)abstract
- A liquid-xenon-jet laser-plasma source for extreme-ultraviolet (EUV) and soft-x-ray generation has been characterized. Being a source candidate for EUV lithography (EUVL), we especially focus on parameters important for the integration of the source in EUVL systems. The deep-ultraviolet (DUV) out-of-band radiation (=120–400 nm) was quantified, to within a factor of two, using a flying-circus tool together with a transmission-grating spectrograph resulting in a total DUV conversion efficiency (CE) of ~0.33%/2sr. The size and the shape of the xenon plasma was investigated using an in-band-only EUV microscope, based on a spherical Mo/Si multilayer mirror and a charge-coupled device detector. Scalability of the source size from 20–270 µm full width at half maximum was shown. The maximum repetition-rate sustainable by the liquid-xenon-jet target was simulated by a double-pulse experiment indicating feasibility of >17 kHz operation. The xenon-ion energy distribution from the plasma was determined in a time-of-flight experiment with a Faraday-cup detector showing the presence of multi-kilo-electron-volt ions. Sputtering of silicon witness plates exposed to the plasma was observed, while a xenon background of >1 mbar was shown to eliminate the sputtering. It is concluded that the source has potential to meet the requirements of future EUVL systems.
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| 14. |
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| 15. |
- Choi, Y S, et al.
(author)
-
Fast antenna selection algorithms for MIMO systems
- 2003
-
In: IEEE 58th Vehicular Technology Conference, 2003. VTC 2003-Fall.. - 1090-3038. - 0780379543 ; 3, s. 1733-1737
-
Conference paper (peer-reviewed)abstract
- We consider the capacity of multiple-input-multiple-output (MIMO) systems with reduced complexity. One link end uses all available antennas, while the other chooses the "best" L out of N antennas. The selection of the optimum antenna subset requires an exhaustive search of all possible combinations, involving (/sub L//sup N/) computations of determinants of size L /spl times/ L, which can become prohibitively complex. In this paper, we suggest a class of fast antenna selection algorithm that are based on the correlation or mutual information between the signals at the different antenna elements. It requires less than N/sup 2/ vector multiplications and thus leads to dramatic savings on the computation time. Its performance is very close to the optimum selection procedure: the capacity penalty is less than l bit/s/Hz for the analyzed examples. The algorithm thus offers the possibility of almost-optimum selection even in fast-changing environments.
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| 16. |
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