Measurement of analyzing power for the reaction \vec p + CH_2 at polarized proton momentum of 7.5 GeV/c (ALPOM2 proposal)

An accurate data base for the analyzing power of thick CH₂ analyzers for high energy protons has been at the basis of several research efforts in a number of laboratories. Starting in the late eighties such data were collected at SATURNE in Saclay, and with the Synchrophasotron in Dubna, and led to an extensive program of study of polarization phenomena in pd interaction, either backward elastic scattering or breakup [1–6]. At about the same time it became evident that measuring polarization observables in elastic ep was going to be the best approach to determine the form factors of the proton, G _Ep and G _Mp , as had been predicted by Akhiezer and Rekalo [7].     

Air temperature stabilization in the thermally isolated optical laboratory

For the studies and calibration of optoelectronic components of the high-precision laser based metrology systems the large volume (50 m³) thermoisolated lab based on seismic isolated concrete block is created. The inside lab volume temperature stabilization for the daily observation at 16.5°C is ±0.05°C with ±0.015°C temperature difference between maximal space separated points. This work was initiated by the needs of high-precision alignment of accelerator components of the CLIC, ILC-type colliders.     

Fragmentation of relativistic oxygen nuclei in interactions with a proton

The data on investigation of inelastic interactions of ¹⁶O nuclei in a hydrogen bubble chamber at an incident momentum of 3.25 A GeV/c are presented. Separate characteristics as fragments isotope composition and topological cross-sections of fragmentation channels are given. The processes of formation of light fragments and unstable nuclei, and the break-up of the ¹⁶O nucleus into multicharge fragments are investigated. A comparison between the experimental data and the calculations of the cascade fragmentation evaporation model (CFEM) is made. The observed singularities of the interactions point out the important role of the nucleus α-cluster structure in the formation of the final products. Received: 9 January 2001 / Accepted: 13 June 2001     

Contribution of excited nuclei 12C* to the channel of three-alpha-particle production in 16Op collisions at a momentum of 3.25 GeV/c per nucleon

Physics of Atomic Nuclei - A phenomenological analysis of the channel involving the production of three alpha particles in collisions of relativistic oxygen nuclei with protons is performed for the...     

The deuteron D-state probability

A method of direct determination of the deuteron D-state probability from the experiment, based on thed ↑p →ppn reaction analyzis is suggested. Using the known results on the vector analyzing power in elasticN N-scattering, the values of the overall nucleon polarization and the deuteron vector polarization have been obtained. The probability of the deuteron D-state is estimated to beW _D =0.078±0.046.     

Supersonic flow past a step downstream of longitudinal grooves

Supersonic flow past a step preceded by longitudinal grooves cut in the plane surface upstream of it is studied experimentally in the presence of a turbulent boundary layer. It is shown that the grooves affect both the shape and the size of the flow separation zone and generate longitudinal vortex cores in the latter.Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 5, pp. 201–206, September–October, 1996.     

Supersonic flow past obstacles on the edges of dihedrals

Supersonic flow with M=3 and P₀=1.2 MPa past cylindrical obstacles located in the plane of symmetry at the edges of exterior and interior dihedrals at a distance ₀=140 mm from the leading edge of a model consisting of two intersecting flat sharp-edged plates is investigated in the presence of a turbulent boundary layer on the faces of the dihedral. The linear angle of the model dihedral was varied discretely from 45 to 310°. Interchangeable cylinders with diameters d=16 and 10 mm and variable height h=0–64 mm were used. The models were tapped along the axis of symmetry and rays starting from the center of the cylinder base and inclined to the edge of the model at angles = 30, 60, and 90°. The pressure was measured with IKD transducers. The results of the measurements were processed on a IVK-1 computer system. The flow past the model was photographed with a Töpler schlieren instrument. Before the experiment the surface of the model was coated with a carbon-oil solution. After the experiment the distribution of the visualizing composition was photographed and the dimensions of the region of separated flow near the obstacle were measured.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 5, pp. 181–184, September–October, 1989.     

Formation of fibrillar aggregates in concentrated solutions of rigid-chain amphiphilic macromolecules with fixed torsion and bend angles

The molecular-dynamics method is used to study solutions of amphiphilic macromolecules with a local helical structure. A deterioration in the solvent quality in concentrated solutions of these macromolecules leads to the formation of intermolecular fibrillar helix bundles with approximately the same lengths and aggregation numbers. The number of chains in a bundle is determined by parameters that characterize the local structure and is weakly dependent on the length of the macromolecule and the volume fraction of the polymer in the solution. In racemic mixtures of these macromolecules, a deterioration in the solvent quality leads to effective demixing; that is, the resultant fibrillar bundles generally contain macromolecules of exclusively the same chirality.