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

The cross sections for the elastic scattering of protons from tritium at 151° and from helium at 155° angles in the laboratory frame, over the energy range of 1.2-3.4 MeV, have been measured in the present work, as a supplement to previous cross section measurements determined at different scattering angles recently. The currently measured cross section data are compared to data available in literature. The cross section enhancement was also investigated for both reactions. It was found that over the whole measured energy range, the elastic cross section for protons on tritium increases linearly with energy and is about 1000 times greater than the Rutherford cross section at 3.4 MeV. On the other hand, in the case of the elastic scattering of protons from helium, the cross section below 2.3 MeV increases almost linearly, and reaches a maximum of about 300 mb/str at the energy of 2.4 MeV for the scattering angle of 165°, and then, after this energy, it keeps oscillating around the maximum.     

Neutron yield in inelastic collisions of 14-Mev neutrons with nuclei and cross section for the (n, 2n) reaction

A measurement has been made of , the number of neutrons produced in one inelastic scattering event between a neutron and a number of elements of natural isotopic composition: Fe, Cu, Mo, Cd, Sn, Sb, Hg, Pb, Bi and U. The measurements were performed by determining the relative change in the total neutron flux and the attenuation of the primary neutrons after passage through samples of the materials being investigated. It was also possible to obtain data on the cross section _in for inelastic collisions of neutrons with the above-mentioned nuclei. The values of and _in, in conjunction with the known cross sections for neutron capture, were then used to compute the cross section for the (n, 2n) reaction (averaged over the isotopic composition) in nonfissile nuclei.This work was completed in 1952.The authors wish to thank A.A. Malinkin for comparing the neutron yields from sources used to measure the dependence of counter sensitivity on neutron energy.     

B3Y-FETAL effective interaction in the folding analysis of elastic scattering of 16O+16O

In this paper,a new M3Y-type effective nucleon-nucleon interaction,derived based on the lowest order constrained variational approach(LOCV)and termed B3Y-Fetal,...     

用屏栅电离室测量~6Li(n,t)~4He反应微分截面

用屏栅电离室对 3.6 7MeV与 4 .4 2MeV中子6Li(n ,t) 4He反应微分截面进行了测量。利用氘气体靶通过D(d ,n) 3 He反应产生中子 ,用BF3 和液闪探测器 (NE2 13)进行相对中子通量监测 ,绝对中子通量用2 3 8U(n ,f)与H(n ,p)反应来刻度。测量结果表明 ,氚的质心系微分截面在中子能量为 3.6 7MeV时很接近 90°对称 ,而到 4 .4 2MeV时则明显前倾     

Determination of the neutron skin thickness from interaction cross section and charge-changing cross section for B,C, N,O, F isotopes

The effective neutron and proton root-meansquare radius of stable and unstable nuclei(~(12-15,17)B,~(12-20)C,~(14-21)N,~(16-24)O and ~(18-21,23-26)F) were deduced from the charge-changing cross section,σ_(cc),and the interaction cross sections,σ_I,by using a statistical abrasion-ablation model calculation.The extracted proton radii are in good agreement with the data from the Atomic Data and Nuclear Data Tables within the errors.Furthermore,we can observe that the neutron skin thickness increases monotonously with the increasing neutron number in these isotopes,which is consistent with the systematical trend of theoretical calculations.     

The calculation of the differential cross sections for recoil protons in 4He-p Scattering

The equation relating phase shift to energy given by the effective range theory for charged particle reactions and the effective range parameters which can well fit the experimental data of P-⁴He elastic scattering have been used to obtain the phase shifts and differential cross sections of protons in p-⁴He elastic scattering. Thereafter the differential cross section of recoil protons in ⁴He-p elastic scattering are calculated through the principle of detailed balance and compared with the experimental data and Rutherford cross sections. Better consistency between experimental and theoretical values than in previous work is achieved.     

Analysis of the single differential neutron scattering cross section from disordered systems by maximum entropy

A procedure for the analysis of neutron single-differential scattering cross sections measured by diffraction experiments in amorphous solid or liquid molecular systems is presented. The method incorporates a convenient scheme for applying the inelasticity or Placzek corrections up to a first order. A substantial improvement over conventional fitting procedures is illustrated by the analysis of a reactor and pulsed neutrons datasets. Finally, the dangers of performing oversimple corrections as well as the need of incorporating additional information in the separation between “self” and “distinct” terms is discussed.     

Triple differential cross section for the ionization of helium by electronic impact

We report results of analytical triple differential cross sections (tdcs) for the single ionization of the helium iso-electronic ions by the electron impact. A two variational parameters wave function is used to evaluate the tdcs. This study shows the accuracy of the tdcs for helium atom and helium like ions in the first Born approximation (fba) at high incident energy domain. The theory is quite acceptable as a fast calculation of the triple differential cross section, particularly at high energies where other theories and methods are cumbersome. A comparison is made of our calculations with previous results of the other theoretical methods and experiment. The fba results obtained here with the two variational parameters wave function are in good agreement with the experiment data at high incident energy. The results show that the electron correlation effects are important around the maxima and influence only the extrema magnitude but not their positions. The calculations presented here are extanded to the cases where the energies of the outgoing electrons are more equal.     

Absolute thick-target gamma-ray yields for the light elements induced by 12C, 14N and 16O ions

Thick-target gamma-ray yields for elements with Z=3–30 (excluding elements Z=10, 18, 21) at ¹²C ion energies of 22 and 28 MeV, for elements with Z=3–9 at ¹⁴N ion energy of 28 MeV and at ¹⁶O ion energies of 28 and 33 MeV have been determined. Tables of the most suitable gamma-ray lines for elemental analysis are given. The general applicability of ¹²C, ¹⁴N and ¹⁶O ions for prompt gamma-ray spectrometry simultaneously with backscattering analyses is discussed.