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| 2. |
- Möller, Per, et al.
(författare)
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Glacial and palaeo-environmental history of the Cape Chelyuskin area, Arctic Russia
- 2008
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Ingår i: Polar Research. - : Norwegian Polar Institute. - 0800-0395 .- 1751-8369. ; 27:2, s. 222-248
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Tidskriftsartikel (refereegranskat)abstract
- Quaternary glacial stratigraphy and relative sea-level changes reveal at least two glacial expansions over the Chelyuskin Peninsula, bordering the Kara Sea at about 77°N in the Russian Arctic, as indicated from tills interbedded with marine sediments, exposed in stratigraphic superposition, and from raised beach sequences mapped to altitudes of at least up to ca. 80 m a.s.l. Chronological control is provided by accelerator mass spectrometry 14C dating, electron-spin resonance and optically stimulated luminescence geochronology. Major glaciations, followed by deglaciation and marine inundation, occurred during marine oxygen isotope stages 6–5e (MIS 6–5e) and stages MIS 5d–5c. These glacial sediments overlie marine sediments of Pliocene age, which are draped by fluvial sediment of a pre-Saalian age, thereby forming palaeovalley/basin fills in the post-Cretaceous topography. Till fabrics and glacial Tectonics record expansions of local ice caps exclusively, suggesting wet-based ice cap advance, followed by cold-based regional ice-sheet expansion. Local ice caps over highland sites along the perimeter of the shallow Kara Sea, including the Byrranga Mountains and the Severnaya Zemlya archipelago, appear to have repeatedly fostered initiation of a large Kara Sea ice sheet, with the exception of the Last Glacial Maximum (MIS 2), when Kara Sea ice neither impacted the Chelyuskin Peninsula nor Severnaya Zemlya, and barely touched the northern coastal areas of the Taymyr Peninsula.
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| 3. |
- Möller, Per, et al.
(författare)
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Severnaya Zemlya, Arctic Russia: a nucleation area for Kara Sea ice sheets during the Middle to Late Quaternary
- 2006
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Ingår i: Quaternary Science Reviews. - : Elsevier BV. - 0277-3791. ; 25:21-22, s. 2894-2936
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Tidskriftsartikel (refereegranskat)abstract
- Quaternary glacial stratigraphy and relative sea-level changes reveal at least four expansions of the Kara Sea ice sheet over the Severnaya Zemlya Archipelago at 79 degrees N in the Russian Arctic, as indicated from tills interbedded with marine sediments, exposed in stratigraphic superposition, and from raised-beach sequences that occur at altitudes up to 140 m a.s.l. Chronologic control is provided by AMS C-14, electron-spin resonance, green-stimulated luminescence, and aspartic-acid geochronology. Major glaciations followed by deglaciation and marine inundation occurred during MIS 10-9, MIS 8-7, MIS 6-5e and MIS 5d-3. The MIS 6-5e event, associated with the high marine limit, implies ice-sheet thickness of > 2000m only 200km from the deep Arctic Ocean, consistent with published evidence of ice grounding at similar to 1000m water depth in the central Arctic Ocean. Till fabrics and glacial tectonics record repeated expansions of local ice caps exclusively, suggesting wet-based ice cap advance followed by cold-based regional ice-sheet expansion. Local ice caps over highland sites along the perimeter of the shallow Kara Sea, including the Byrranga Mountains, appear to have repeatedly fostered initiation of a large Kara Sea ice sheet, with exception of the Last Glacial Maximum (MIS 2), when Kara Sea ice did not impact Severnaya Zemlya and barely graced northernmost Taymyr Peninsula.
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| 4. |
- Titarenko, Y., et al.
(författare)
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Beam dump and local shielding layout around the itep radiation test facility
- 2009
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Ingår i: Nuclear Technology. - 0029-5450 .- 1943-7471. ; 168:2, s. 472-476
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Tidskriftsartikel (refereegranskat)abstract
- The Radiation Test Facility (RTF) is under construction at the Institute for Theoretical and Experimental Physics to control the electronics under irradiation of particles that imitate cosmic rays (protons, carbon, aluminum, iron, tin, bismuth, and uranium). For the norms of radiation safety of personnel and users of the RTF to be observed, a local shielding and beam dump must be designed. Simulations of the dose rates around the designed shielding and beam dump are carried out in the present work.
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| 5. |
- Titarenko, Yu. E., et al.
(författare)
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Cross sections for nuclide production in a Fe-56 target irradiated by 300, 500, 750, 1000, 1500, and 2600 MeV protons compared with data on a hydrogen target irradiated by 300, 500, 750, 1000, and 1500 MeV/nucleon Fe-56 ions
- 2008
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 78:3, s. 034615-
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Forskningsöversikt (refereegranskat)abstract
- This work presents the cross sections for radioactive nuclide production in Fe-56( p, x) reactions determined in six experiments using 300, 500, 750, 1000, 1500, and 2600 MeV protons of the external beam from the ITEP U-10 proton accelerator. In total, 221 independent and cumulative yields of radioactive residuals of half-lives from 6.6 min to 312 d have been obtained. The radioactive product nuclide yields were determined by direct gamma-spectrometry. The measured data have been compared with the experimental data obtained elsewhere by the direct and inverse kinematics methods and with calculation results of 15 different codes that simulated hadron-nucleus interactions: MCNPX (INCL, CEM2K, BERTINI, ISABEL), LAHET (BERTINI, ISABEL), CEM03 (.01,. G1,. S1), LAQGSM03 (.01,. G1,. S1), CASCADE-2004, LAHETO, and BRIEFF. Most of the data obtained here are in a good agreement with the inverse kinematics results and disprove the results of some earlier activation measurements that were quite different from the inverse kinematics measurements. The most significant calculation-to-experiment differences are observed in the yields of the A < 30 light nuclei, indicating that further improvements in nuclear reaction models are needed, and pointing out as well to a necessity of more complete experimental measurements of such reaction products.
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| 6. |
- Titarenko, Yu. E., et al.
(författare)
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High-energy threshold reaction rates on 0.8 GeV proton-irradiated thick Pb-target
- 2008
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Ingår i: INTERNATIONAL CONFERENCE ON NUCLEAR DATA FOR SCIENCE AND TECHNOLOGY, VOL 2, PROCEEDINGS. - Les Ulis, France : E D P SCIENCES. ; , s. 1209-
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Konferensbidrag (refereegranskat)abstract
- This works presents results of activation-aided determination of threshold reaction rates in 92 Bi-209, Pb-nat, Au-197, Ta-181, Tm-169, In-nat, Nb-93, Zn-64, Cu-65, Cu-63, Co-59, F-19, and C-12 samples and in 121 Al-27 samples. All the samples are aligned with the proton beam axis inside and outside the demountable 92-cm thick Pb target of 15-cm diameter assembled of 23 4-cm thick discs. The samples are placed on 12 target disks to reproduce the long axis distribution of protons and neutrons. In June 2006, the target was exposed for 18 hours to a 800-MeV proton beam extracted from the ITEP U-10 accelerator. The proton fluence and the proton beam shape were determined using the 27Al (p,X)7 Be monitor reaction. The total number of protons onto the target was (6.0 +/- 0.5). 10(15). The reaction rates were determined by the direct gamma-spectrometry techniques. The GC-2518 detectors of 1.8 keV resolution and the DGDK-60V detectors of 2.9 keV resolution at the 1332 keV gamma-line were used to take the measurements. In total, 1196 gamma-spectra have been measured, and about 1500 reaction rates determined. The measured reaction rates were simulated by the MCNPX code using the following databases: ENDF/B6 for neutrons below 20 MeV, MENDL2 for 20-100 MeV neutrons, and MENDL2P for proton cross sections up to 200 MeV. An acceptable agreement of simulations with experimental data has been found.
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| 7. |
- Titarenko, Yu. E., et al.
(författare)
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Residual nuclide formation in Pb-206,Pb-207,Pb-208,Pb-nat and Bi-209 induced by 0.04-2.6 GeV protons as well as in Fe-56 induced by 0.3-2.6 GeV protons
- 2008
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Ingår i: INTERNATIONAL CONFERENCE ON NUCLEAR DATA FOR SCIENCE AND TECHNOLOGY, VOL 2, PROCEEDINGS. - Les Ulis, France : E D P SCIENCES. ; , s. 1099-
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Konferensbidrag (refereegranskat)abstract
- This work is aimed at experimental determination of independent and cumulative yields of radioactive residual product nuclei in the intermediate energy proton-irradiated thin targets made of highly isotopic enriched and natural lead (Pb-206,Pb-207,Pb-208,Pb-nat), bismuth (Bi-209), and highly isotopic enriched iron (Fe-56). 5972 independent and cumulative yields of radioactive residuals nuclei have been measured in 55 thin Pb and Bi targets irradiated by 0.04, 0.07, 0.10, 0.15, 0.25, 0.6, 0.8, 1.2, 1.4, 1.6, and 2.6 GeV protons. Besides, 219 yields have been measured in 0.3, 0.5, 0.75, 1.0, 1.5, and 2.6 GeV proton-irradiated Fe target. In both cases, the protons were extracted from the ITEP U-10 synchrotron. The measured data are compared with experimental results obtained elsewhere and with theoretical calculations by seven codes. The predictive power was found to be different for each of the codes tested, but was satisfactory on the whole in the case of spallation products. At the same time, none of the codes can describe well the product yields throughout the whole product mass range, and all codes must be further improved.
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| 8. |
- Titarenko, Y., et al.
(författare)
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Residual radioactive nuclide formation in 0.8-GeV proton-irradiated extended Pb target
- 2009
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Ingår i: Nuclear Technology. - 0029-5450 .- 1943-7471. ; 168:3, s. 631-636
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Tidskriftsartikel (refereegranskat)abstract
- This work presents results of activation-aided determination of threshold reaction rates (RRs) in 92 samples of 209Bi, natPb, 197Au, 181Ta, 169Tm, natIn, 93Nb, ,64Zn, 65Cu, 63Cu, 59Co, 19F, and 12C and in 121 samples of 27Al. All the samples are aligned with the proton beam axis inside and outside the demountable 92-cm-thick Pb target of 15-cm diameter assembled of 23 4-cm-thick discs. The samples are placed on 12 target disks to reproduce the long axis distribution of protons and neutrons. The target was exposed to an 800-MeV proton beam. The total number of protons onto the target was (6.0 ± 0.5) X1015. The RRs were determined by the direct gamma spectrometry techniques. In total, 1196 gamma spectra have been measured, and about 1500 RRs have been determined. The measured RRs were simulated by the MCNPX and SHIELD codes. A generally acceptable agreement of simulations with experimental data has been found.
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| 9. |
- Yamamoto, A., et al.
(författare)
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The ATLAS central solenoid
- 2008
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 584:1, s. 53-74
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Tidskriftsartikel (refereegranskat)abstract
- The ATLAS detector at the CERN LHC is equipped with a superconducting magnet system consisting of three large toroids and a solenoid. The 2.3 m diameter, 5.3 m long solenoid is located at the heart of the experiment where it provides a 2 T field for spectrometry of the particles emanating from the interaction of the counter-rotating beams of hadrons. As the electromagnetic calorimeter of the experiment is situated outside the solenoid, the coil must be as transparent as possible to traversing particles. The magnet, which was designed at KEK, incorporates progress in technology coming from the development of previous solenoids of this type, in particular that of a new type of reinforced superconductor addressing the requirement of transparency. Special attention has been paid to ensuring reliability and ease of operation of the magnet, through the application of sufficiently conservative guidelines for the mechanical and electrical design, stringent testing during manufacture, and a comprehensive commissioning program. This report gives an overview of the design, manufacture, test, installation and commissioning of the ATLAS central solenoid.
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