(p,n) and (p,pxn) reactions in 127I

1968 ◽  
Vol 46 (20) ◽  
pp. 3171-3176 ◽  
Author(s):  
V. P. Narang ◽  
L. Yaffe
Keyword(s):  
Monte Carlo ◽  
Excitation Function ◽  
Compound Nucleus ◽  
Cross Sections ◽  
Direct Interaction ◽  
Incident Proton ◽  
Initial Portion ◽  
Evaporation Model ◽  
Monte Carlo Calculations ◽  
Radiochemical Methods

Absolute values of the cross sections of (p,n), (p,pn), (p,p2n), and (p,p3n) reactions in 127I have been measured by radiochemical methods for incident proton of energies up to 80 MeV. The initial portion of the excitation function for the (p,n) reaction is characteristic of the compound nucleus mechanism, but evidence for direct interaction is present at higher energies. Above 50 MeV, cross sections are close to the predictions of Monte Carlo calculations based on the cascade–evaporation model. This is particularly true in the case of the (p,pn) and (p,p2n) reactions.

Reactions of 88Sr with protons of energies7–85 MeV

1967 ◽  
Vol 45 (10) ◽  
pp. 1149-1160 ◽  
Author(s):  
D. R. Sachdev ◽  
N. T. Porile ◽  
L. Yaffe
Keyword(s):  
Monte Carlo ◽  
Compound Nucleus ◽  
Cross Sections ◽  
Experimental Results ◽  
Excitation Functions ◽  
Monte Carlo Calculations ◽  
High Energies ◽  
The Individual ◽  
Two Peaks ◽  
Evaporation Stage

Excitation functions for the (p,xn) (x = 1–5), (p,p3n), and (p,2pxn) (x = 1, 3, 4) reactions induced in 88Sr by protons of energy from 7 to 85 MeV have been measured by radiochemical methods. Cross sections for the individual isomeric species for the products of (p,2n), (p,3n), (p,4n), and (p,p3n) reactions are also presented.Excitation functions for each of the (p,2p3n) and (p,2p4n) reactions exhibit two peaks, the first of which is assigned to (p,α n) or (p,α 2n) reactions from threshold considerations. The experimental results are compared with Monte Carlo calculations using the codes of Chen et al. for the cascade stage and Dostrovsky et al. for the evaporation stage. The comparison suggests that the calculations of Chen et al. overestimate the extent of compound nucleus contribution at high energies.

A STUDY OF THE Be9(He3, n)C11 REACTION

1963 ◽  
Vol 41 (7) ◽  
pp. 1036-1046 ◽  
Author(s):  
L. van der Zwan ◽  
A. T. Stewart ◽  
J. Y. Park ◽  
E. Merzbacher
Keyword(s):  
Compound Nucleus ◽  
Cross Sections ◽  
Interaction Mechanism ◽  
Direct Interaction ◽  
Particle Energy ◽  
Energy Spectra ◽  
Angular Distributions ◽  
Proton Recoil ◽  
The Cross ◽  
Photographic Emulsions

The energy spectra and angular distributions of the emergent neutrons from the Be9(He3, n)C11 reaction have been obtained for an incident He3-particle energy of 2 Mev with the technique of observing proton recoil in photographic emulsions. The cross sections were normalized to Be9(He3, p)B11 data observed simultaneously at 90° to the beam. The lack of similarity in the (He3, n) and (He3, p) mirror reactions to some residual states suggests a direct interaction mechanism rather than compound nucleus. An attempt to analyze some of the data in terms of double particle stripping has been made.

scholarly journals ISOSPIN DEPENDENCE OF REACTIONS 48Ca+243-251Bk

2008 ◽  
Vol 17 (supp01) ◽  
pp. 66-79 ◽  
Author(s):  
CAIWAN SHEN ◽  
YASUHISA ABE ◽  
DAVID BOILLEY ◽  
GRIGORY KOSENKO ◽  
ENGUANG ZHAO
Keyword(s):  
Compound Nucleus ◽  
Cross Sections ◽  
Coulomb Barrier ◽  
Fusion Process ◽  
Evaporation Model ◽  
Formation Stage ◽  
Step Model ◽  
Isospin Dependence ◽  
Two Stages ◽  
Neutron Evaporation

The fusion process of 48 Ca induced reactions is studied with the two-step model. In this model, the fusion process is devided into two stages: first, the sticking stage where projectile and target come to the touching point over the Coulomb barrier from infinite distance, and second, the formation stage where the di-nucleus formed with projectile and target evolve to form the spherical compound nucleus from the touching point. By the use of the statistical evaporation model, the residue cross sections for different neutron evaporation channels are analyzed. From the results, optimum reactions are given to synthesize Z=117 element with 48 Ca induced reactions.

Reaction mechanism of the 16O + d reactions

1970 ◽  
Vol 48 (19) ◽  
pp. 2235-2253 ◽  
Author(s):  
N. E. Davison ◽  
W. K. Dawson ◽  
G. Roy ◽  
W. J. McDonald
Keyword(s):  
Experimental Data ◽  
Compound Nucleus ◽  
Cross Sections ◽  
Direct Interaction ◽  
Scattering Data ◽  
Orbit Potential ◽  
Spectroscopic Factors ◽  
Theoretical Predictions ◽  
Using Data ◽  
Good Agreement

The reactions 16O(d,d)16O, 16O(d,p)17O, and 16O(d,n)17F have been studied in the deuteron energy range 4.00–6.00 MeV in order to determine to what extent current theories can satisfactorily describe these reactions. It was found that the theoretical curves from both the optical and DWBA models fit the experimental data significantly better when the deuteron optical-model potentials had been obtained using a spin–orbit potential in the analysis of the elastic scattering data. Spectroscopic factors obtained for the ground and first-excited states of 17O and 17F using the DWBA theory are in satisfactory agreement with theoretical predictions and with values obtained by previous workers. Small, but nonzero, spectroscopic factors have been obtained for the states at 3.058 and 3.846 MeV excitation in 17O using data measured in this work and in previous experiments. The sum of the calculated direct interaction and compound-nucleus cross sections is in good agreement with experimental data for all states studied, whether they were populated primarily by direct or compound-nucleus reactions. The calculated compound-nucleus lifetimes are also in agreement with values obtained from an analysis of the fluctuations in the yield curves.

Electron-beam spreading in thin foils at 40keV

1983 ◽  
Vol 41 ◽  
pp. 370-371
Author(s):  
T.A. Stephenson ◽  
M.H. Loretto ◽  
I.P. Jones ◽  
P. Augustus
Keyword(s):  
Monte Carlo ◽  
Single Crystal ◽  
Cross Sections ◽  
Single Crystal Silicon ◽  
Orientation Dependence ◽  
High Angle ◽  
Crystal Silicon ◽  
Beam Spreading ◽  
Monte Carlo Calculations ◽  
Thin Foils

Experiments have been performed to determine the effects of thickness, and crystallinity on beam spreading in thin foils. The experimental technique consists of measuring an incident and exit electron probe size as shown in Fig. 1. Beam spreading is defined as the difference between these two quantities. Results were compared with Monte Carlo calculations.Beam spreading experiments in single crystal silicon oriented positive of a 440 reflection have shown that the experimental measurements are adequately described by Monte Carlo calculations using Doyle and Turner elastic scattering cross-sections (Fig.2). The addition of an inelastic component via the Bethe continuous loss approximation produces an insignificant change. Adjustment for the generation and scattering of fast secondary electrons is reserved for future work.Two experiments were performed to elucidate the effects of crystallinity. The first involved single crystal silicon in which exit grobe size measurgments were performed with diffracting conditions s=+0.0027Å-1 and s=-0.0034Å-1 from 220 (Table 1). Since beam spreading is dependent on high angle scattering, these results are qualitatively consistent with the orientation dependence of high angle diffuse scattering.

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