Proton elastic scattering and proton induced γ-ray emission cross-sections on Na from 2 to 5MeV

Abstract

Differential cross-sections for proton elastic scattering on sodium and for c-ray emission from the reactions 23 Na(p,p 0 c) 23 Na (E c = 440 keV and E c = 1636 keV) and 23 Na(p,a 0 c) 20 Ne (E c = 1634 keV) were measured for proton energies from 2.2 to 5.2 MeV using a 63 lg/cm 2 NaBr target evaporated on a self-supporting thin C film. The c-rays were detected by a 38% relative efficiency Ge detector placed at an angle of 135° with respect to the beam direction, while the backscattered protons were collected by a Si surface barrier detector placed at a scattering angle of 150°. Absolute differential cross-sections were obtained with an overall uncertainty estimated to be better than ±6.0% for elastic scattering and ±12% for c-ray emission, at all the beam energies. To provide a convincing test of the overall validity of the measured elastic scattering cross-section, thick target benchmark experiments at several proton energies are presented.

Proton induced γ-ray emission yields for the analysis of light elements in aerosol samples in an external beam set-up

“…For comparison, the results of previous measurements [11,12] with external beam set-up on the c-ray yields of Fluorine, Sodium and Aluminium, measured for lower proton energies with the KN3000 accelerator available in the old laboratory, are also shown and, after normalisation for the different solid angles subtended, they are found to be in excellent agreement with the new ones. Moreover, we observed a good agreement between the present results and the differential cross-sections data reported in [1,3,5], when energy loss and folding with energy straggling have been taken in account.…”

“…A few papers have been published, also in recent years, on the measurements of proton induced c-ray emission differential or total cross-sections of light elements such as Fluorine [1][2][3], Sodium [4,5] and Aluminium [1], in the proton energy range suitable for PIGE analysis, up to several MeV. These cross-section data are measured with an energy step often exceeding the energy loss of the proton beam in the employed target, possibly missing some fine structure in the cross-section.…”

Benchmarking experiments for the proton backscattering on 23Na, 31P and natS up to 3.5MeV

“…Concerning 23 Na(p,p) backscattering, one can see in Figures 5a-b some of the benchmarks of the present study, using the evaluated cross-section data for the simulations and in Figures 6a-c the ones using the data of Caciolli et al [18] at higher energies, at 150°. The existing evaluation in the case of 23 Na(p,p) covers only a limited energy range, up to 1500 keV, and at such low energies, as it is shown in Figures 5a-b, the spectra are dominated by the signal of the heaviest element in the compound target, which is Br.…”

“…Despite the resulting poor statistics (5% in the worst case), originating from the subtraction of the large Rutherford Br signal from the total experimental one (over the whole integrated region corresponding to 250 keV from the surface), the simulation seems to reproduce the experimental spectra quite well for all the studied angles and the evaluation is thus in principle validated. At higher energies, where the only existing dataset relevant to the detection angles studied in the present work, is the one of Caciolli et al [18] at 150°, covering the energy range between 2210 and 5200 keV, the Rutherford cross section for nat Br(p,p) is reduced and the sodium signal is more pronounced. The simulations using these experimentally determined differential cross sections, as shown in Figures 6a-c, are in excellent agreement with the experimental spectra within the total experimental uncertainty (4%) except for the low energy case (Figure 6a) where the agreement is within 6%.…”

Nuclear Astrophysics at LNL: The 10B(p, \(\alpha \))7Be Reaction Studied at the AN2000 Accelerator

“…Those parameters, and in particular the cross sections, are important for stellar models in order to have precise prediction of stellar nucleosynthesis [1]. Nuclear reaction cross sections involving light charged particles are also important in many other fields of research and there has been a great deal of effort to study these reactions for applied physics in recent years [2][3][4].…”