Programmes d'exploitation des expériences de diffusion de neutrons de 17 à 20 MEV sur le carbone 12.

Thèse de doctorat -- Université catholique de Louvain, 196

Fast neutron yields and spectra from targets of varying atomic number bombarded with deuterons from 16 to 50 MeV [for radiobiology and radiotherapy]

Neutron production from targets of Be, C, Mo, Cu, Ta and Au has been studied at the isochronous cyclotron at Louvain-la-Neuve. Neutron spectra were measured by the time of flight method. The yields of neutrons and gamma rays were also measured, and the greatest ratio of neutrons to gamma rays in the forward direction was found to occur with 50 MeV deuterons on a Be target. The angular distribution of neutrons from Be was measured at 16, 33 and 50 MeV, and neutron spectra were measured as a function of angle with 50 MeV deuterons on Be.Anglai

13.5 MeV(d,p)(d,n) stripping to /sup 29/Si-/sup 29/P iso-states

The authors observed proton peaks corresponding to the g.s., 1.27, 2.03, 2.43, 3.07, 3.62, 4.08, 4.93, 5.65, 5.95 and (6.1+6.19) MeV-levels in /sup 29/Si, and neutron peaks corresponding to the g.s., 1.38, 1.96, 3.45, 4.34 and 4.76 MeV-levels in /sup 29/P. The protons and neutrons angular distributions were compared with D.W.B.A. calculations performed with the DWUCK code, in the Z.R.L. approximation. The deuteron optical parameters were extracted from an analysis of elastic scattering data.Anglai

Neutron-detector efficiency measurements from 7 to 14 MeV

The neutron efficiency of an Ne 102 plastic scintillator is measured for neutron energies from 7 to 14 MeV, using the D(d,n)/sup 3 /He reaction. The experimental results are compared with the prediction of two program codes. Different values of the /sup 12/C(n, alpha )/sup 9/Be reaction cross sections are introduced in the calculations; they strongly affect the calculated efficiency.Anglai

Kerma values deduced from neutron-induced charged-particle spectra of carbon from 40 to 75 MeV.

The double-differential cross-sections for the 12C(n, px), 12C(n, dx), 12C(n, tx) and 12C(n, alpha x) reactions have been measured at three incident neutron energies, 42.5, 62.7 and 72.8 MeV, at laboratory angles between 20 degrees and 160 degrees. From these measurements, the energy-differential cross-sections have been determined and consequently the partial and total kerma values. Results of the experimental double-differential and energy-differential cross-sections at the three incident neutron energies are presented. The deduced kerma values are compared with previous measurements and theoretical predictions

Geometry and Energy-loss Features of Charged-particle Production in Fast-neutron Induced Reactions

Raw data reduction of charged particle production in fast neutron induced reactions must take into account specific characteristics of this type of experiment. A calculation procedure is presented which considers particular features such as: the thickness of targets, beam dimensions on the target, the beam profile, relative target-telescope angular position etc. It results in a simulation programme (Perten) of the experiment. The way the above mentioned particularities are considered, is exemplified in calculating solid angles and fractions of target producing charged particles with enough energy to be registered by the detector

Kerma values deduced from neutron-induced charged-particle spectra of carbon from 40 to 75 MeV.

The double-differential cross-sections for the 12C(n, px), 12C(n, dx), 12C(n, tx) and 12C(n, alpha x) reactions have been measured at three incident neutron energies, 42.5, 62.7 and 72.8 MeV, at laboratory angles between 20 degrees and 160 degrees. From these measurements, the energy-differential cross-sections have been determined and consequently the partial and total kerma values. Results of the experimental double-differential and energy-differential cross-sections at the three incident neutron energies are presented. The deduced kerma values are compared with previous measurements and theoretical predictions