Elastic scattering of 2–11 MeV protons by He4

Barnard, Andries; Jones, C.M.; Weil, J.L.

doi:10.1016/0029-5582(64)90233-0

Cited by 76 publications

(57 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The incident proton beam used in these cross section measurements, ranging between 1.2 and 3. accelerator energy was calibrated using nuclear resonance reactions such as 27 Al(p,) 28 Si at 992 keV, 13 C(p,) 14 N at 1748 and 19 F(p,) 16 O at 872 keV. A set of collimating slits defined the beam to a size of 0.6 mm with a full angular divergence of 0.05°before hitting the target.…”

Section: Experimental Apparatusmentioning

confidence: 99%

Measurements of the elastic scattering cross sections for proton on T, 4He

Cai

Wang

et al. 2010

Nuclear Instruments and Methods in Physics Research Section B:

View full text Add to dashboard Cite

Section: Experimental Apparatusmentioning

confidence: 99%

Measurements of the elastic scattering cross sections for proton on T, 4He

Cai

Wang

et al. 2010

Nuclear Instruments and Methods in Physics Research Section B:

View full text Add to dashboard Cite

“…This is considerably smaller than the conventional minimum value of the channel radius (Lane and Thomas 1958;Lane 1960), given by a = 1· 45(Al /3 + Aj/3) fm = 3·75 fm. The experimental s1l2 phase shifts are well represented by hard-sphere scattering with a ::::: 2· 5 fm (Barnard et al 1964;Brown et al 1967;Morgan and Walter 1968), consequently fitting them with a ::::: 2·9 fm would imply a small resonance contribution and so a very high-energy i + level, e.g. at about 28 MeV in 5Li .…”

Section: Introductionmentioning

confidence: 97%

States of 5He and 5Li

Barker¹,

Woods²

1985

Aust. J. Phys.

View full text Add to dashboard Cite

A recent shell model calculation has predicted a low-lying! + level in 5He, in apparent conflict with experimental results. We have confirmed the prediction with an alternative shell model interaction chosen specifically to fit properties of light nuclei. The level is expected to be very broad so that it would not be easily seen in reactions. It should contribute significantly to n-a phase shifts, but did not appear in previous analyses because of the small value of about 3 fm chosen for the channel radius a. A ! + level at the expected energy of about 7 MeV is obtained for a ::::: 5·1 fm. Broad ~ + and ~ + levels are then found at about 14 MeV in agreement with the shell model calculations. Properties of the low-lying ~ -and! -levels in 5He and 5Li are discussed, but the measured values now available do not favour a particular value of the channel radius.

show abstract

“…Experimentally the elastic scattering of protons on 4 He has been studied extensively in the past [3][4][5][6][7][8], but only a somewhat limited number of measurements were performed in the energy range of interest for ionbeam analysis, and inconsistencies among different data sets remain [9][10][11][12][13][14][15]. Consequently, cross sections deduced from R-matrix analyses of data usually stand as references [8,[15][16][17].…”

mentioning

confidence: 99%

“…• are compared to measurements in the range of incident energies up to 12 MeV [3][4][5][6]10] . The agreement with data is excellent both at forward and backward angles.…”

mentioning

confidence: 99%

Predictive theory for elastic scattering and recoil of protons fromHe4

2014

View full text Add to dashboard Cite

Low-energy cross sections for elastic scattering and recoil of protons from4 He nuclei (also known as α particles) are calculated directly by solving the Schrödinger equation for five nucleons interacting through accurate two-and three-nucleon forces derived within the framework of chiral effective field theory. Precise knowledge of these processes at various proton backscattering/recoil angles and energies is needed for the ion-beam analysis of numerous materials, from the surface layers of solids, to thin films, to fusion-reactor materials. Indeed, the same elastic scattering process, in two different kinematic configurations, can be used to probe concentrations and depth profiles of either hydrogen or helium. We compare our results to available experimental data and show that direct calculations with modern nuclear potentials can help to resolve remaining inconsistencies among different data sets and can be used to predict these cross sections when measurements are not available. He proton elastic recoil reactions are the leading means for determining the concentrations and depth profiles of, respectively, helium and hydrogen at the surface of materials or in thin films. Such analyses, known among specialists as (non-)Rutherford backscattering spectroscopy and elastic recoil detection analysis, are very important for characterizing the physical, chemical and electrical behavior of materials, for which hydrogen is one of the most common impurities, and for studying the implantation of helium for applications in, e.g., waveguides or fusion energy research [1,2]. To achieve good resolution e.g. in the case of thick samples, measurements are often performed at energies above the Rutherford threshold where the purely Coulomb elastic scattering paradigm does not hold anymore. In this regime, in which the incident particle energy is on the order of a few MeV per nucleon, nuclear physics becomes the main driver of the scattering process, particularly near low-lying resonances where the cross section can be enhanced by orders of magnitude with respect to the Rutherford rate. Therefore, the availability of accurate reference differential cross sections for a variety of proton/ 4 He incident energies and detection angles are key to the feasibility and quality of these analyses.

show abstract

Elastic scattering of 2–11 MeV protons by He4

Cited by 76 publications

References 16 publications

Measurements of the elastic scattering cross sections for proton on T, 4He

Measurements of the elastic scattering cross sections for proton on T, 4He

States of 5He and 5Li

Predictive theory for elastic scattering and recoil of protons fromHe4

Contact Info

Product

Resources

About