EXPERIMENTAL CROSS SECTIONS FOR LIGHT CHARGED PARTICLE PRODUCTION INDUCED BY NEUTRONS WITH ENERGIES BETWEEN 25 AND 75 MeV INCIDENT ON CARBON

Abstract

Experimental double-differential cross sections (d 2 σ/d d E)for fast neutron-induced production of proton, deuteron, triton, and alpha particle in carbon are reported at several incident neutron energies between 25 and 75 MeV. Angular distributions were measured in the laboratory angular range of 20 • to 160 • . Reliable extrapolated spectra are obtained at very forward (2.5 • and 10 • ) and very backward (170 • and 177.5 • ) angles. Based on these experimental data, energy differential (dσ/d E), angle differential (dσ/d ), and total cross sections (σ T ) are reported for each detected particle. C INTRODUCTIONDue to obvious experimental difficulties, measurements of charged particle production in fast (20 to 80 MeV) neutroninduced reactions are rather scarce. This type of data offers an important experimental base both for fundamental research and for many important applications. These data can be used for testing the nuclear reaction models; they also offer a wealth of information concerning the nuclear structure of the involved nuclei.Applications are particularly important in the case of light target nuclei such as carbon and oxygen. Essential information can be obtained for use in neutron dosimetry and radiobiology. A detailed knowledge of cross sections makes it possible to evaluate the contribution to charged particle production of a given element as a constituent of human tissue [1,2] in clinical applications.With the advent of the new accelerator-driven technologies, knowledge of neutron-induced reactions above 20 MeV may also play an imporant role in projects such as the transmutation of radioactive waste or alternative nuclear energy production. Experimental MethodsExperimental data were obtained at the fast neutron facility of the Louvain-la-Neuve cyclotron, CYCLONE. An accelerated incident proton beam is focused on a 3-mm-thick natural lithium target. With a beam current of 10 −5 A, about 10 6 neutrons/s are available at the location of our reaction chamber (about 3.3 m downstream of the lithium target). The resulting neutron energy spectrum at 0 • consists of a welldefined peak (2 MeV full-width-at-half-maximum) containing about 50% of the neutrons, plus a flat continuum of low energy neutrons (inset in Fig. 1). In the main neutron peak there are about 10 times more neutrons/MeV than in the low neutron energy continuum [3][4][5].The measurements were done with an elemental carbon target (5 × 5 cm 2 surface and 1 mm thick). Four charged particle detector telescopes were used simultaneously. Each of them consists of a E detector (NE102 plastic scintillator) and an E detector (CsI(Tl) crystal). The E detector can stop up to 80 MeV protons. A coincidence is required between E and E detectors in order to suppress an important part of the background present in such type of experiments [6,7]. The collimation system of each charged particle detector telescope had an angular opening between 2 • and 3 • .Protons and deuterons recoiling from, respectively, a polypropylene and a deuterated polypropylene targ...

Experimental cross sections for light-charged particle production induced by neutrons with energies between 25 and 65 MeV incident on aluminum

“…The results compare well with some of the exist-ing experimental data obtained by microdosimetric integral measurements. The present work complements earlier results on oxygen [15] and carbon [16] EXPLANATION OF TABLE TABLE. Light…”

Experimental kerma coefficients of biologically important materials at neutron energies below 75 MeV

“…14 Experimental cross sections were obtained at incident neutron energies between 25 and 75 MeV. [15][16][17] With the advent of the new accelerator-driven technologies our measurements are now dedicated mostly to medium-weight and heavy targets: iron, cobalt, lead, bismuth, uranium, etc. All these elements, including the light ones, are present in accelerator and shielding materials which utilize spallation neutrons, particularly the transmutation of radioactive waste.…”

Neutron-induced reaction cross-section measurements using a small multi-detector array and description of a large array

“…A wealth of results have been already obtained with the following setup and have been published elsewhere [2][3][4][5][6]. As example, figure 5 shows, in 3-D representation, the complete measured angular distributions of proton energy spectra for Al.…”

“…With the advent of the new accelerator-driven systems, considered for the transmutation of long-lived nuclear waste into shorter-lived products, we restricted mostly our studies to medium and heavy targets: iron, cobalt, lead, bismuth, uranium. Experimental cross-sections were obtained at incident neutron energies between 25 and 75 MeV [2][3][4][5]. The main body of our experimental results is the doubledifferential cross-sections for the´Ò Ôܵ ´Ò ܵ ´Ò Øܵ and´Ò «Üµ reactions.…”

“…Therefore, probably due to these kind of experimental difficulties, measurements of charged particle production for fast neutron induced reactions in the incident energy range 30 to 80 MeV are rather scarce. Our first measurements were mainly dedicated to light elements: hydrogen [1], carbon [2], oxygen [3,4], aluminium [5] and silicon. With the advent of the new accelerator-driven systems, considered for the transmutation of long-lived nuclear waste into shorter-lived products, we restricted mostly our studies to medium and heavy targets: iron, cobalt, lead, bismuth, uranium.…”