| 1. |
- Andersson, Pernilla, et al.
(författare)
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An upgrade of the SCANDAL facility for neutron scattering measurements at 175 MeV
- 2009
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The experimental setup SCANDAL (SCAttered Nucleon Detection AssembLy) at the The Svedberg Laboratory (TSL), previously used for measurements of the differential cross section of elastic and inelastic neutron scattering in the 50 – 130 MeV range, has recently been upgraded with new Na doped CsI scintillating detectors for measurements at 175 MeV. The performance of the new setup is described and illustrated by the early steps in the analysis of the first experimental campaign, carried out in January and February 2009.
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| 2. |
- Bevilacqua, Riccardo, 1974-, et al.
(författare)
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Light-ion production in the interaction of 175 MeV neutrons with iron and bismuth
- 2011
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Ingår i: Journal of Korean Physical Society.
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Konferensbidrag (refereegranskat)abstract
- We have measured double-differential (angle and energy) cross sections for light-ion (p, d, t, 3He and α) production in the interaction of quasi-monoenergetic 175 MeV neutrons with iron and bismuth. Measurements have been performed at the The Svedberg Laboratory, Uppsala (Sweden), using the Medley setup which allows low-energy thresholds and wide energy and angular ranges. Medley is a spectrometer system consisting of eight three-element telescopes placed at angles from 20◦ to 160◦, in steps of 20◦. Each telescope is composed of two silicon surface barrier detectors and a CsI(Tl) scintillator, to perform particle identification,fully stop the produced light-ions and measure their kinetic energy. The time-of-flight was used to reduce the contribution from the low energy tail in the accepted incident neutron spectrum. We report double-differential production cross sections for protons, deuterons, tritons, 3He and α particles and compare them with model calculations with TALYS-1.2.
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| 3. |
- Bevilacqua, Riccardo, 1974-, et al.
(författare)
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Medley spectrometer for light ions in neutron-induced reactions at 175 MeV
- 2011
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 646:1, s. 100-107
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Tidskriftsartikel (refereegranskat)abstract
- We have upgraded the Medley spectrometer to measure neutron-induced double differential cross-sections for light-ion production, with neutron energies up to 175 MeV. Measurements were performed at the quasi-monoenergetic neutron beam line at the The Svedberg Laboratory, in Uppsala (Sweden). Medley is a spectrometer system composed of eight three-element telescope detectors; Delta E-E technique is used for particle identification and total kinetic energy measurement. We have improved particle separation and installed new detectors that fully stop ions with kinetic energy up to 170 MeV. To reduce the contribution of the low energy tail in the quasi-monoenergetic neutron spectrum, we have applied time-of-flight techniques and investigated the results for measurements with 175 MeV neutrons. We have investigated the response function of the CsI(Tl) scintillators and describe a method for efficiency correction. We have studied the signal-to-background ratio of the new configuration of the spectrometer and of the collimation system. A method to obtain absolute cross-section normalization, separating the peak neutrons from the low-energy tail, is proposed. Finally we have characterized the 175 MeV quasi-monoenergetic neutron spectrum with the Medley spectrometer. This upgraded configuration has been used in 2007 and 2009 for light-ion production measurements at 175 MeV from C, Si, O, Fe, Bi and U.
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| 4. |
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| 5. |
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| 6. |
- Tesinsky, Milan, et al.
(författare)
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MCNPX simulations of the SCANDAL setup for measurement of neutron scattering cross section at 175MeV
- 2010
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Ingår i: Physica Scripta. - : IOP Publishing. - 0031-8949 .- 1402-4896. ; 81:6, s. 065202-
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Tidskriftsartikel (refereegranskat)abstract
- The Scattered Nucleon Detection Assembly (SCANDAL) setup at The Svedberg Laboratory has been used to produce neutron elastic scattering cross section data at 175MeV for bismuth and iron. This work presents MCNPX simulations of the experimental setup and aims to describe processes and data important for the upcoming off-line data analysis. In the experiment, neutrons scattered off the target are converted to protons, which are stopped in scintillator crystals. The results include a description of the proton spectra dependence on the neutron-to-proton conversion angle, suggesting a cut at a conversion angle of 15.2 degrees. Calculation of the hit position gates indicates high proton leakage from the crystals. A study of the converter describes the role of its chemical composition and also the role of other plastic scintillators on the proton spectra. The neutron-to-proton conversion efficiency of the converter simulated by MCNPX is 5.1x10(-4) and corresponds to theoretical predictions.
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| 7. |
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| 8. |
- Tippawan, Udomrat, et al.
(författare)
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Light-ion Production in 175 MeV Neutron-induced Reactions on Oxygen
- 2011
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Ingår i: Journal of the Korean Physical Society. - : Korean Physical Society. - 0374-4884 .- 1976-8524. ; 59:2, s. 1979-1982
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Tidskriftsartikel (refereegranskat)abstract
- Data on light-ion production in light nuclei such as carbon, nitrogen and oxygen are particularly important in calculations of dose distributions in human tissue for radiation therapy at neutron beams, and for dosimetry of high energy neutrons produced by high-energy cosmic radiation interacting with nuclei (nitrogen and oxygen) in the atmosphere. When studying neutron dose effects, special consideration on carbon and oxygen is needed since they are, by weight, the most abundant elements in human tissue. The MEDLEY setup at The Svedberg Laboratory (TSL), Uppsala, Sweden has been used to measure such data with double-differential cross sections (DDX) for the (n, xp), (n, xd), xt), (n,(3)He), and (n,alpha) reactions from C, 0, Si, Ca, Fe, Pb, and U around 96 MeV. At the new Uppsala neutron beam facility the available energy range of quasi mono-energetic neutron beams is extended up to 175 MeV. The detector setup used in MEDLEY consists of eight so-called telescopes mounted at different angles inside all evacuated reaction chamber. Each of the telescopes consists of two fully depleted Delta E silicon surface barrier detectors (SSBD) and a CsI(Tl) crystal. In order to make measurements at this higher neutron energy possible some changes in the detector setup compared to the campaign at 96 MeV were applied Accordingly, the second Delta E detectors have been replaced by 1000 mu m thick SSBDs as well as the size of the crystals used as E detectors was increased to a total length of 100 mm and a diameter of 50 mm. The Delta E - E technique is used to identify the light ions, and cutoff energies as low as 2.5 MeV for protons and 4.0 MeV for alpha particles are achieved. The data are normalised relative to elastic up scattering measured in one of the telescopes at 20 degrees. Preliminary DDXs for oxygen are presented and compared with theoretical calculations.
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