| 1. |
- Bevilacqua, Riccardo, 1974-, et al.
(author)
-
Medley spectrometer for light ions in neutron-induced reactions at 175 MeV
- 2011
-
In: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 646:1, s. 100-107
-
Journal article (peer-reviewed)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.
|
|
| 2. |
- Tesinsky, Milan, et al.
(author)
-
MCNPX simulations of the SCANDAL setup for measurement of neutron scattering cross section at 175MeV
- 2010
-
In: Physica Scripta. - : IOP Publishing. - 0031-8949 .- 1402-4896. ; 81:6, s. 065202-
-
Journal article (peer-reviewed)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.
|
|
