scholarly journals The scattering of 4·2 MeV protons by deuterium, helium and other light elements

1947 ◽  
Vol 190 (1021) ◽  
pp. 180-195 ◽  
Keyword(s):  
Angular Distribution ◽  
Elastic Scattering ◽  
Scattered Wave ◽  
Angular Distributions ◽  
Light Elements ◽  
Coulomb Term ◽  
Collision Processes ◽  
Mev Protons

The methods previously described have been applied to a study of the elastic scattering of 4·2 MeV protons by deuterium, helium, nitrogen, oxygen, neon, argon, chlorine and bromine. The results obtained with deuterium and helium as the scattering gases are compared with those of other experimenters working with protons of different energies. The angular distributions of the protons elastically scattered by nitrogen and oxygen, together with the results for carbon obtained in previous measurements, can be simply described in terms of an S -component interacting with the Coulomb term in the formula for the scattered wave. Values are obtained in each case for the magnitude of the parameter which defines the amplitude and phase of the S -wave. The angular distribution of the protons inelastically scattered by neon has been investigated and evidence obtained for similar collision processes in experiments with argon and chlorine.

scholarly journals The elastic scattering of 6.5 MeV deuterons by deuterium, helium and other light elements

1947 ◽  
Vol 190 (1021) ◽  
pp. 196-218 ◽  
Keyword(s):  
Elastic Scattering ◽  
Excited States ◽  
Scattered Wave ◽  
Energy Relation ◽  
Light Elements ◽  
Scattered Intensity ◽  
Angular Variation ◽  
Coulomb Term ◽  
Nuclear Processes

The methods previously described have been applied to a study of the scattering of 6.5 MeV deuterons by deuterium, helium, carbon, nitrogen, oxygen and neon. In the case of deuterium, helium and oxygen the elastically scattered deuterons can be clearly distinguished at all angles of scattering from groups of particles due to other nuclear processes. In experiments with these gases it is thus possible to determine the angular variation of the scattered intensity. The results show that P and D terms make appreciable contributions to the amplitude of the scattered wave. This result is in contrast with that obtained previously in experiments with protons of approximately the same speed, in which it was found that the scattered intensity could be described by an interaction of the Coulomb term with an S -wave only. In experiments with carbon, nitrogen and neon, the peaks in the range distributions due to the elastically scattered deuterons are confused with those produced by protons or α -particles from ( d - p ) and ( d - α ) reactions, and the results are less reliable or are confined to restricted intervals in the angle of scattering. The Q values of the reactions giving rise to the proton groups have been determined and values thus obtained of the energy of a number of excited states in the product nuclei. A study of the variation with the angle of scattering of the range of deuterons elastically scattered by helium nuclei is shown to afford a method of investigating the range-energy relation for an emulsion which has advantages over that previously employed.

Proton?Capture Gamma Rays from Nitrogen?13

1962 ◽  
Vol 15 (3) ◽  
pp. 443 ◽  
Author(s):  
AW Parker ◽  
GG Shute
Keyword(s):  
Angular Distribution ◽  
Excited State ◽  
Elastic Scattering ◽  
Gamma Rays ◽  
Ground State ◽  
Recent Experiment ◽  
Gamma Ray ◽  
Angular Distributions ◽  
Proton Capture ◽  
Yield Curves

From a recent experiment in this laboratory (Shute et al. 1962) on the elastic scattering of protons from 12C, resonance levels (E13N, J1t) of 13N were obtained at the laboratory bombarding energies (Ep) shown in Table 1. To confirm these results, an investigation of the yield and angular distribution of gamma rays from the reaction 12C(p'YO)13N and 12C(p'Yl)13N was undertaken. Accordingly, the theoretical angular distributions, W(8), for the gamma ray (Yo) to the ground state of 13Na-) and also for the gamma ray (Yl) to the 1st excited state of 13Na+) were evaluated on the assumptions that overlap of levels in 13N is small and lowest order multipoles are involved. As angular distributions are parity insensitive, these were found to be identical for the two gamma rays expected. The simpler of these angular distributions are also shown on the table. The expected angular distributions indicate that 90� is a suitable angle for yield curves.

The inelastic scattering of protons by magnesium, aluminium and other light elements

1950 ◽  
Vol 201 (1066) ◽  
pp. 348-365 ◽  
Keyword(s):  
Angular Distribution ◽  
Energy Spectrum ◽  
Inelastic Scattering ◽  
Excitation Function ◽  
Ground State ◽  
Proportional Counter ◽  
Complex Structure ◽  
Theoretical Discussion ◽  
Light Elements ◽  
Mev Protons

The energy spectrum of 4.5 MeV protons scattered by some light elements was determined by using a proportional counter in conjunction with absorbing foils. Magnesium gave groups attributed to levels at 1.36 ± 0.03 and 1.82 ± 0.04 MeV respectively above the ground state, the former being almost certainly associated with 24 Mg. The angular distribution and excitation function of this group were examined in some detail. The proton groups from aluminium corresponded to levels at about 1 and 2.15 ± 0.05 MeV respectively above the ground state. The lower level has a complex structure and probably consists of two levels at about 0.80 and 0.97 ± 0.02 MeV, the amplitudes of the corresponding proton groups showing a marked angular dependence. No inelastically scattered protons were observed from carbon, oxygen, or copper, while beryllium gave a group consistent with the existence of a metastable state in 9 Be at 2.39 ± 0.05 MeV above the ground state. A short theoretical discussion of the mechanism of the process is given which suggests that inelastic scattering is predominantly a ( p, p ) process involving formation of a compound nucleus.

ELASTIC SCATTERING OF 20-MEV. PROTONS BY OXYGEN AND NITROGEN

1957 ◽  
Vol 35 (2) ◽  
pp. 184-194 ◽  
Author(s):  
R. H. Chow ◽  
Byron T. Wright
Keyword(s):  
Elastic Scattering ◽  
Los Angeles ◽  
Cross Sections ◽  
University Of California ◽  
Angular Distributions ◽  
Diffraction Effect ◽  
Laboratory System ◽  
External Beam ◽  
The University ◽  
Mev Protons

The absolute angular distributions for 20-Mev. protons elastically scattered by O16 and N14 were determined using the external beam of the frequency-modulated cyclotron at the University of California, Los Angeles. The distributions for the two elements were found to be similar except for the appearance of a more pronounced first minimum in the O16 distribution. The locations of the maxima and minima seem to indicate that simple diffraction effect is responsible for their presence. The cross sections range from about 1 barn per sterad. to 4 mb. per sterad. between 15° and 165° in the laboratory system. The standard deviations due to statistics range from [Formula: see text] to 10%.

SECOND-ORDER EIKONAL MODEL ANALYSIS OF16O+16OELASTIC SCATTERING

2001 ◽  
Vol 10 (04n05) ◽  
pp. 373-386 ◽  
Author(s):  
YONG JOO KIM ◽  
MOON HOE CHA
Keyword(s):  
Angular Distribution ◽  
Elastic Scattering ◽  
Scattering Amplitudes ◽  
Optical Potential ◽  
Second Order ◽  
Angular Distributions ◽  
Eikonal Model ◽  
Oscillatory Structure ◽  
Nuclear Rainbow ◽  
Elastic Angular Distribution

We analyze the elastic scattering angular distributions of the16O +16O system at Elab=480 MeV and 704 MeV within the framework of the second-order eikonal model based on Coulomb trajectories of colliding nuclei. The diffractive oscillatory structure observed in the elastic angular distribution could be explained due to the interference between the near- and far-side scattering amplitudes. The presence of a nuclear rainbow in this system is evidenced through a classical deflection function. The effective optical potential is developed from the second-order non-eikonal phase shifts.

scholarly journals The inelastic scattering of slow electrons in gases.—III

1933 ◽  
Vol 142 (846) ◽  
pp. 320-332 ◽  
Keyword(s):  
Angular Distribution ◽  
Elastic Scattering ◽  
Inelastic Scattering ◽  
Electron Scattering ◽  
Wide Range ◽  
Mechanical Study ◽  
Discrete Amount ◽  
The Subject ◽  
Collision Processes ◽  
Slow Electrons

The subject of electron scattering in gases has received considerable attention within the last four years, and the very interesting results obtained have greatly assisted the wave mechanical study of collision processes. The investigation of the angular distribution of the scattered electrons has proved particularly valuable. The elastic scattering has been studied systematically in a number of gases over a wide range of velocities and angles of scattering. The inelastic scattering, however, has not been so exhaustively studied, the measurements in general being limited to small angles of scattering (less than 60°) and to high velocities of impact (above 50 volts). Recently Hughes and McMillen have investigated the inelastic scattering of 25-, 35-, and 50-volt electrons in hydrogen for angles of scattering between 10° and 165°; the curves were found to rise slightly at large angles. Tate and Palmer, and Hughes and McMillen have measured the angular distribution of electrons which have been ejected from the atom with only a few volts energy; the curves obtained were on the whole fairly flat, although the latter observers find in some experiments sharp peaks at large angles. In two previous papers, the angular distribution of inelastically scattered electrons which have lost a discrete amount of energy were investigated in several gases for large angles of scattering, and for electrons with energies greater than about 40 volts. At large angles, diffraction maxima and minima were found similar to those which occur for the elastic scattering, although the similarity between the two sets of curves was less marked at the lower velocities. The present work was therefore undertaken to investigate this more interesting region. While the previous apparatus proved entirely satisfactory for the purposes for which it was used, it was found that at low velocities troubles due to intensity and "background" indicated that it was desirable to construct an apparatus in which every possible precaution was taken to avoid these difficulties.

Electron Scattering in Solids

1990 ◽  
Vol 48 (2) ◽  
pp. 4-5
Author(s):  
Ryuichi Shimizu ◽  
Ze-Jun Ding
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Angular Distribution ◽  
Elastic Scattering ◽  
Electron Scattering ◽  
Cross Sections ◽  
Expansion Method ◽  
Electron Excitation ◽  
Partial Wave Expansion ◽  
Backscattered Electrons

Monte Carlo simulation has been becoming most powerful tool to describe the electron scattering in solids, leading to more comprehensive understanding of the complicated mechanism of generation of various types of signals for microbeam analysis.The present paper proposes a practical model for the Monte Carlo simulation of scattering processes of a penetrating electron and the generation of the slow secondaries in solids. The model is based on the combined use of Gryzinski’s inner-shell electron excitation function and the dielectric function for taking into account the valence electron contribution in inelastic scattering processes, while the cross-sections derived by partial wave expansion method are used for describing elastic scattering processes. An improvement of the use of this elastic scattering cross-section can be seen in the success to describe the anisotropy of angular distribution of elastically backscattered electrons from Au in low energy region, shown in Fig.l. Fig.l(a) shows the elastic cross-sections of 600 eV electron for single Au-atom, clearly indicating that the angular distribution is no more smooth as expected from Rutherford scattering formula, but has the socalled lobes appearing at the large scattering angle.

Disintegrations produced in the light elements of nuclear emulsions by 950 MeV protons

1956 ◽  
Vol 236 (1204) ◽  
pp. 104-111 ◽  
Keyword(s):  
Potential Barrier ◽  
Coulomb Barrier ◽  
Light Nucleus ◽  
Light Nuclei ◽  
Light Elements ◽  
Heavy Nuclei ◽  
Particle Track ◽  
Proton Track ◽  
Photographic Emulsions ◽  
Mev Protons

Ilford G 5 photographic emulsions have been exposed to 950 MeV protons from the Birmingham synchrotron, and 430 m of proton track searched for nuclear disintegrations. Disintegrations of carbon, nitrogen and oxygen were selected by the potential barrier criterion; the adequacy of this method, which depends on the presence of a short a-particle track indicating the low Coulomb barrier of a disintegrating light nucleus, is discussed. The characteristics of the disintegrations occurring in the light nuclei are described and compared with those for heavy nuclei; most of the observed differences can be explained as features of the complete break-up of a nucleus consisting of a small number of nucleons.

Elastic Scattering of 9.76-Mev Protons by Helium

1955 ◽  
Vol 98 (1) ◽  
pp. 56-57 ◽  
Author(s):  
John H. Williams ◽  
Stanley W. Rasmussen
Keyword(s):  
Elastic Scattering ◽  
Mev Protons
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