Experimental studies of nuclear fission dynamics near the scission point

Conditions for formation of angular and energy distributions of light particles emitted in ternary fission of ^{233, 235}U, ²³⁹Pu, and ²⁴⁵Cm nuclei induced by cold polarized neutrons have been studied in the course of investigating T-odd asymmetry in emission of these particles with respect to the plane formed by the fission axis and the polarization axis of the fissioning nucleus. The results obtained lead to the conclusion that in ternary fission charged particles are emitted by the fissioning nuclear system rotating around the polarization direction.     

Observation of multiparton interactions in proton-nucleus collisions at 70 GeV

The production of noncoplanar hadron pairs in proton-nucleus interactions is studied experimentally for the case where the transverse momenta of product particles are in excess of 1 GeV/c. The values obtained for the exponent in the A dependence of the cross section for the production of noncoplanar hadron pairs are substantially greater than those for coplanar pairs. This nuclear-mass-number dependence for the production of hadron pairs can be explained by the contribution of multiparton interactions in proton-nucleus collisions.     

Pair production of pions with symmetric momenta in the range 0.5⩽pT⩽2.0 GeV/c In 70 GeV p-p collisions

The invariant cross-section slope of the pp→π⁺π^?+X process as a function of p_T is found to have a break near 1 GeV/c. Fitting the cross section by a sum of two exponents gives the values of powers (12.3±0.9)(GeV/c)^?1 and (8.7±0.6)(GeV/c)^?1. The experimental points at p_T?1 GeV/c are significantly higher than predictions based on hard scattering models such as QCD and CIM.     

Extraction of pertechnetate anion as a ligand in a cerium(IV) tributyl phosphate complex

Extraction of technetium has been studied in the tributyl phosphate—dodecanenitric acid—cerium(IV) system. It is established that in the system under study, technetium is extracted as a mixed solvate with cerium(IV) with a component ratio equal to 1. It is shown on the basis of studying the effect of the TBP concentration on the extraction of technetium and cerium(IV) that technetium is extracted as a monosolvate, while cerium(IV) is extracted as a disolvate.     

Single-spin asymmetry for charged hadrons produced in proton-nucleus collisions at 40 GeV for c.m. production angles in the range 40°–79°

The transverse single-spin asymmetry for charged hadrons (π ^±, K ^±, p, $\bar p$ ) produced in proton-nucleus collisions was measured for c.m. production angles in the range 40°–79°. The measurements were performed with the FODS-2 setup by using a 40-GeV polarized proton beam originating from the accelerator of the Institute for High Energy Physics (Protvino) and hitting carbon and copper nuclear targets. The data in question were obtained in the polarized-proton-fragmentation region (0.0 < x _F < 0.7, 0.6 < p T < 2.5 GeV/c). In agreement with data obtained at other energies, the single-spin asymmetry for π ^± mesons is significant at high x _F. For the first time, a sizable analyzing power, which changes sign at x _F = 0.43, is observed for protons. The dependence of the analyzing power on the target-nucleus mass is insignificant.     

Forward particle production in proton–nucleus interactions at momenta of 25 and 50 GeV/<Emphasis Type="Italic">с</Emphasis> and сarbon–nucleus interactions at an energy of 25 GeV per nucleon

Relative yields of high-x _F charged hadrons (π ^±, К^±, р, \(\overline p \), and d) in proton–nucleus interactions at incident-proton momenta of 25 and 50 GeV/c were measured at an angle of 0° in the momentum range between 15 and 40 GeV/c. An upper limit on the forward production of two protons in proton–nucleus interactions at 50 GeV/c was estimated. The properties of a carbon beam with an energy of 25 GeV per nucleon and fragment yields in its interaction with nuclear targets were measured within a short exposure.     

Recovery of Gold(I) Thiocyanate Complexes by Some Anion-Exchangers

Some regularities are studied for the ion-exchange extraction of the gold(I) thiocyanate complexes by ion-exchangers of various physical and chemical structure. It is shown that gold is present in the resin phase as a [Au(SCN)₂]^- species and is held by the positively charged sorbent functional groups. The conclusion is drawn that high ion-exchanger affinity for this ion is caused by the high polarizability, linear structure, and small charge of the latter.     

Single-spin asymmetry for high-p T charged hadrons at negative x F in proton-nucleus collisions at an energy of 40 GeV

The transverse single-spin asymmetry was measured for charged hadrons (π ^±, K ^±, p, $\bar p$ ) produced in proton-nucleus collisions. The measurements were performed with the aid of the FODS-2 spectrometer by using a 40-GeV polarized proton beam from the accelerator of the Institute for High Energy Physics (IHEP, Protvino) and carbon and copper nuclear targets. The data subjected to the analysis in the present study were obtained for c.m. angles in the range 95°–112° in the vicinity of the central region (?0.08 < x _F < ?0.06, 0.7 < p _T < 3.4 GeV/c). The analyzing power is found to be only slightly dependent on the mass number of the target nucleus. The basic results obtained by measuring the single-spin asymmetry at three values of the particle-detection angle are discussed.     

Composites Synthesized from Titanium,Carbon and Aluminum Powder Compositions

Russian Physics Journal - The paper presents the results of the X-ray diffraction analysis, scanning electron microscopy, and electron probe micro-analysis of the products synthesized from the...