- Email: [email protected]
137. Nitrogen stripping reaction on light elements
1192
ABSTRACTS
The disintegrations were split into two groups (according to the range of the recoil nucleus) : those associated with light nuclei of the emulsion, i.e. carbon, nitrogen and oxygen, and with h e a v y ones, i.e. boron and silver. The principal feature of the reactions studied is the large relative number of emitted alpha-particles. The ratio of the number of alpha-particles to the number of protons in reactions caused by nitrogen ions is 3.5 =k 0.4; in reactions caused by oxygen ions it is 4 + 0.7. The angular and energy distributions o~f protons and alpha-particles were investigated. In the c.i. system alpha-particles are emitted mostly in the forward direction. The angular distribution of protons appear to be isotropic. The obtained results show t h a t the nitrogen and oxygen-produced reactions proceed via the compound nucleus. The predominance of alpha-particles and their angular distribution m ay be explained by t h a t alpha-particles due to high energy can be able to escape from the compound nucleus at the m o m e n t of collision, keeping the direction of the incident nucleus. A small number of disintegrations was observed (eight compared to the total number of three hundred forty) in which the nitrogen nucleus splits into a boron nucleus (10B) and an alpha particle in the field of target nucleus. The theoretical estimation of the splitting probability of this kind in the Coulomb field of the target nucleus was performed.
136. H e a v y ion nuclear p h y s i c s r e s e a r c h at Oak Ridge National Laboratory. A. ZUCKER. Oak Ridge National Laboratory, Oak Ridge, Tenn., U.S.A. A deflected beam of 26 MeV N 3+ ions is obtained in the 63 inch fixed-frequency cyclotron at Oak Ridge. Compound nuclei with 30 to 40 MeV excitation energy are produced when light elements, from lithium to aluminum, are bombarded with these ions. The total cross-sections for many reactions going through such compound states have been determined. The energy spectra have been measured for protons, deuterons, tritons, and ~-particles from the nitrogen b o m b a r d m e n t of several light elements. Highly excited nuclei are produced by these relatively slow h eav y ions without the added complication of direct interaction reactions. The differential cross-section was measured for elastic scattering of nitrogen by nitrogen at several energies. I t was found t h a t a semi-classical strong absorption model fits the data over the energy range investigated. A nuclear radius of 4.0 × 10 -18 cm for nitrogen can be deduced from the elastic scattering results.
137. N i t r o g e n s t r i p p i n g reaction on Hght e l e m e n t s . A. ZUCKER. Oak Ridge National Laboratory, Oak Ridge, Tenn., U.S.A. Excitation functions have been measured for many reactions produced by nitrogen ions with energies from 15 to 26 MeV on various light elements. In particular, reactions have been found where a neutron or a proton transfers from the nitrogen nucleus to the target, or vice versa. Such reactions were investigated in boron-10, nitrogen, aluminum, and the separated isotopes of magnesium. Above the Coulomb barrier, it was found t h a t for the first two targets the cross-sections of four reactions were each about 5 mb, and flat over the energy range investigated. The reaction 14N(14N, 13N)lSN was found to proceed only to the ground states of both residual nuclei. The angular distribution of 13N from this reaction was measured at four energies and found to be anisotropic. In general, the stripping reaction cross-sections are strongly Q-dependent; this may be explained by the importance of the Coulomb barrier at these low incident energies.
ABSTRACTS
The disintegrations were split into two groups (according to the range of the recoil nucleus) : those associated with light nuclei of the emulsion, i.e. carbon, nitrogen and oxygen, and with h e a v y ones, i.e. boron and silver. The principal feature of the reactions studied is the large relative number of emitted alpha-particles. The ratio of the number of alpha-particles to the number of protons in reactions caused by nitrogen ions is 3.5 =k 0.4; in reactions caused by oxygen ions it is 4 + 0.7. The angular and energy distributions o~f protons and alpha-particles were investigated. In the c.i. system alpha-particles are emitted mostly in the forward direction. The angular distribution of protons appear to be isotropic. The obtained results show t h a t the nitrogen and oxygen-produced reactions proceed via the compound nucleus. The predominance of alpha-particles and their angular distribution m ay be explained by t h a t alpha-particles due to high energy can be able to escape from the compound nucleus at the m o m e n t of collision, keeping the direction of the incident nucleus. A small number of disintegrations was observed (eight compared to the total number of three hundred forty) in which the nitrogen nucleus splits into a boron nucleus (10B) and an alpha particle in the field of target nucleus. The theoretical estimation of the splitting probability of this kind in the Coulomb field of the target nucleus was performed.
136. H e a v y ion nuclear p h y s i c s r e s e a r c h at Oak Ridge National Laboratory. A. ZUCKER. Oak Ridge National Laboratory, Oak Ridge, Tenn., U.S.A. A deflected beam of 26 MeV N 3+ ions is obtained in the 63 inch fixed-frequency cyclotron at Oak Ridge. Compound nuclei with 30 to 40 MeV excitation energy are produced when light elements, from lithium to aluminum, are bombarded with these ions. The total cross-sections for many reactions going through such compound states have been determined. The energy spectra have been measured for protons, deuterons, tritons, and ~-particles from the nitrogen b o m b a r d m e n t of several light elements. Highly excited nuclei are produced by these relatively slow h eav y ions without the added complication of direct interaction reactions. The differential cross-section was measured for elastic scattering of nitrogen by nitrogen at several energies. I t was found t h a t a semi-classical strong absorption model fits the data over the energy range investigated. A nuclear radius of 4.0 × 10 -18 cm for nitrogen can be deduced from the elastic scattering results.
137. N i t r o g e n s t r i p p i n g reaction on Hght e l e m e n t s . A. ZUCKER. Oak Ridge National Laboratory, Oak Ridge, Tenn., U.S.A. Excitation functions have been measured for many reactions produced by nitrogen ions with energies from 15 to 26 MeV on various light elements. In particular, reactions have been found where a neutron or a proton transfers from the nitrogen nucleus to the target, or vice versa. Such reactions were investigated in boron-10, nitrogen, aluminum, and the separated isotopes of magnesium. Above the Coulomb barrier, it was found t h a t for the first two targets the cross-sections of four reactions were each about 5 mb, and flat over the energy range investigated. The reaction 14N(14N, 13N)lSN was found to proceed only to the ground states of both residual nuclei. The angular distribution of 13N from this reaction was measured at four energies and found to be anisotropic. In general, the stripping reaction cross-sections are strongly Q-dependent; this may be explained by the importance of the Coulomb barrier at these low incident energies.