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- Aamodt, K., et al.
(författare)
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The ALICE experiment at the CERN LHC
- 2008
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Ingår i: Journal of Instrumentation. - 1748-0221. ; 3:S08002
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Forskningsöversikt (refereegranskat)abstract
- ALICE (A Large Ion Collider Experiment) is a general-purpose, heavy-ion detector at the CERN LHC which focuses on QCD, the strong-interaction sector of the Standard Model. It is designed to address the physics of strongly interacting matter and the quark-gluon plasma at extreme values of energy density and temperature in nucleus-nucleus collisions. Besides running with Pb ions, the physics programme includes collisions with lighter ions, lower energy running and dedicated proton-nucleus runs. ALICE will also take data with proton beams at the top LHC energy to collect reference data for the heavy-ion programme and to address several QCD topics for which ALICE is complementary to the other LHC detectors. The ALICE detector has been built by a collaboration including currently over 1000 physicists and engineers from 105 Institutes in 30 countries, Its overall dimensions are 16 x 16 x 26 m(3) with a total weight of approximately 10 000 t. The experiment consists of 18 different detector systems each with its own specific technology choice and design constraints, driven both by the physics requirements and the experimental conditions expected at LHC. The most stringent design constraint is to cope with the extreme particle multiplicity anticipated in central Pb-Pb collisions. The different subsystems were optimized to provide high-momentum resolution as well as excellent Particle Identification (PID) over a broad range in momentum, up to the highest multiplicities predicted for LHC. This will allow for comprehensive studies of hadrons, electrons, muons, and photons produced in the collision of heavy nuclei. Most detector systems are scheduled to be installed and ready for data taking by mid-2008 when the LHC is scheduled to start operation, with the exception of parts of the Photon Spectrometer (PHOS), Transition Radiation Detector (TRD) and Electro Magnetic Calorimeter (EMCal). These detectors will be completed for the high-luminosity ion run expected in 2010. This paper describes in detail the detector components as installed for the first data taking in the summer of 2008.
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| 2. |
- Deperas-Kaminska, Marta, et al.
(författare)
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Inter-chromosomal variation in aberration frequencies in human lymphocytes exposed to charged particles of LET between 0.5 and 55 keV/mu m
- 2010
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Ingår i: International Journal of Radiation Biology. - : Informa UK Limited. - 0955-3002 .- 1362-3095. ; 86:11, s. 975-985
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To investigate the distribution of chromosomal aberrations in chromosomes 2, 8 and 14 induced by charged particles, using the fluorescence in situ hybridisation (FISH) technique. Methods: Irradiation of peripheral blood from six healthy volunteers (four male and two female) was performed at the accelerators of the Joint Institute for Nuclear Research (JINR) in Dubna (Russia). Whole blood samples were irradiated with 2 and 3 Gy of protons (170 MeV/nucleon (n), linear energy transfer (LET) approximate to 0.5 keV/mu m), 3.5 Gy of C-12 ions (480 MeV/n, LET = 10.6 keV/mu m), 3 Gy of C-12 ions 500 MeV/n, LET = 12 keV/mu m), 4 Gy of Li-7 ions (30 MeV/n, LET approximate to 20 keV/mu m) and 3 Gy of B-11 ions (32 MeV/n, LET approximate to 55 keV/mu m). Chromosomal aberrations were analysed in metaphase and prematurely condensed chromosomes (PCC) induced in G(2)-cells using calyculin A. Chromosomes 2, 8 and 14 were painted in different colours and aberrations scored with the help of an image-analysis system. Results: Chromosome 2 was generally less sensitive than expected on the basis of its DNA content. A higher than expected frequency of exchanges was found in chromosomes 8 and 14. On average, the dicentric frequency in chromosome 2 was higher than the translocation frequency, whereas variable dicentric to translocation ratios were observed in chromosomes 8 and 14. When aberrations in all painted chromosomes were summed up the ratio was close to 1. The frequency of complex aberrations correlated with LET. Conclusion: In lymphocytes of donors studied in this work chromosome 2 appears to be consistently less sensitive to protons and heavy ions than chromosomes 8 and 14. Complex aberrations appear to be a potential marker of radiation quality.
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