Formation of light isotopes by protons and deuterons of 3.65 GeV/nucleon on separated tin isotopes

We measure cross sections for residual nuclide formation in the mass range 7 ≤ A ≤ 96 caused by bombardment with protons and deuterons of 3.65-GeV/nucleon energy of enriched tin isotopes (^{112,118,120,124}Sn). The experimental data are compared with calculations by the codes FLUKA, LAHET, CEM03, and LAQGSM03. Scaling behavior is observed for the whole mass region of residual nuclei, showing a possible multifragmentation mechanism for the formation of light products (7 ≤ A ≤ 30). Our analysis of the isoscaling dependence also shows a possible contribution of multifragmentation to the production of heavier nuclides, in the mass region 40 ≤ A ≤ 80. The text was submitted by the authors in English.     

Investigation of spallation reactions on 120Sn and (d, xn), (d, pxn), (p, xn), and (p, pxn) reactions on enriched tin isotopes

The cross sections for (d, xn), (d, pxn), (p, xn), and (p, pxn) reactions on enriched tin isotopes are obtained at a projectile energy of 3.65 GeV per nucleon. The yields in the energy range 0.66–8.1 GeV are analyzed with resort to experimental data obtained previously. Experimental data are compared with the results of theoretical calculations performed within the cascade-evaporation model. The dependence of the yields on the number of emitted neutrons, the projectile type, and the isotopic composition of a target is investigated. The cross sections for the (p, xpyn) reactions on a ¹²⁰Sn target are presented at a primary-proton energy of 0.66 GeV.     

Systematization of cross sections for the production of residual nuclei on separated tin isotopes in reactions induced by various-energy protons

Cross sections for the production of residual nuclei on the isotopes ^{112,118,120,124}Sn irradiated with 0.66-, 1.0-, 3.65-, and 8.1-GeV proton beams were investigated. A ten-parameter semiempirical formula was used to systematize the cross sections in question. A comparative analysis of parameter values obtained at different proton energies was performed.     

Method of induced activity for studying nuclear reactions on Pb and Sn isotopes

Nuclear reactions at the interaction of particles with heavy targets were studied using the method of induced activity. This method permits an investigation of the mechanism of residual nuclei formation in a wide range of nuclear masses beginning from light nuclei up to the nuclei with masses near to the target mass. The results of investigations of nuclear reactions on separated isotopes of lead (²⁰⁶Pb, ²⁰⁷Pb, ²⁰⁸Pb) and tin (¹¹⁸Sn) isotope performed using the method of induced activity are given.     

Isotopic Dependence of Fragment Production Cross Sections in the Reactions of Deuterons on Enriched Lead and Tin Isotopes

Physics of Atomic Nuclei - The isoscaling behavior of the fragment production cross section was studied for reactions with deuterons on enriched lead targets (204Pb, 206Pb, 207Pb, 208Pb). The...     

Recoil studies in the reaction of 12C ions with the enriched isotope 118Sn

The recoil properties of the product nuclei from the interaction of 2.2 GeV/nucleon ¹²C ions from Nuclotron of the Laboratory of High Energies, Joint Institute for Nuclear Research at Dubna with a ¹¹⁸Sn target have been studied via catcher foils method. The experimental data were analyzed using the mathematical formalism of the standard two-step vector model. The results for ¹²C ions are compared with those for deuterons and protons. Three different Los Alamos versions of the Quark-Gluon String Model were used for comparison with our experimental data.     

Recoil products from p+118Sn and d+118Sn at 3.65 GeV/A

The recoil properties of the product nuclei from the interaction of 3.65-GeV/nucleon protons and deuterons from the Nuclotron and Synchrophasotron of the Laboratory of High Energies (LHE), Joint Institute for Nuclear Research (JINR) at Dubna, with a ¹¹⁸Sn target have been studied using catcher foils. The experimental data were analyzed using the mathematical formalism of the standard two-step vector model. The analysis of kinematical characteristics of the light and medium-mass reaction products confirmed the contribution of fragmentation (or multifragmentation) processes in the production of these nuclei. The comparison of the results for protons and deuterons was made. The longitudinal momenta transferred to the target in the interaction with protons and deuterons were similar and was shown to depend only on the velocity, but not on the mass of projectile. Three different Los Alamos versions of the quark—gluon-string model (LAQGSM) were used for the discussion of our experimental results. The text was submitted by the authors in English.     

Isoscaling and fission modes in the yields of the Kr and Xe isotopes from photofission of actinides

Yields of Kr and Xe isotopes in photofission of ²³²Th, ²³⁸U, ²³⁷Np, ²⁴⁴Pu, ²⁴³Am, and ²⁴⁸Cm were tested for isoscaling dependence. Isoscaling for Kr is revealed. For Xe, isoscaling is found to be affected by the STI and STII fission modes governed by the N = 82 and N = 88 neutron shells. The work was performed at the Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research (JINR).     

Novel polyesters with amino‐sulfone azobenzene chromophores in the main chain

The synthesis and optical properties of a series of amorphous polyesters with amino‐sulfone azobenzene chromophores in the main chain are presented. The condensation of alkyl diacid chlorides with 4‐[(2‐hydroxyethyl)ethylamino]‐4′‐(2‐hydroxyethylsulfonyl)azobenzene (7) gave polymers that showed low and unstable photoinduced birefringence because of their low glass‐transition temperature. The condensation of 7 with mixtures of adipoyl chloride and terephthaloyl chloride gave a polymer with a higher glass‐transition temperature and a stable reversible photoinduced birefringence. A photostationary birefringence of 0.07 was observed. Surface profile gratings were optically inscribed and produced diffraction efficiencies less than or equal to 19%. Photostationary, long‐term stable birefringence and surface‐grating efficiency increased with polymer rigidity. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2245–2253, 2000