arXiv subjects

G. P. Skoro

Publications and source records attributed to G. P. Skoro.

7 recordsLinked to original sources

arXiv2011

Tungsten material properties at high temperature and high stress

Recently reported results on the long lifetime of the tungsten samples under high temperature and high stress conditions expected in the Neutrino Factory target have strengthened the case for a solid target option for the Neutrino Factory. In order to study in more details the behaviour of basic material properties of tungsten, a new method has been developed for measurement of tungsten Young's modulus at high stress, high strain-rates (> 1000 s^-1) and very high temperatures (up to 2650 C). The method is based on measurements of the surface motion of tungsten wires, stressed by a pulsed current, using a Laser Doppler Vibrometer. The measured characteristic frequencies of wire expansion and contraction under the thermal loading have been used to directly obtain the tungsten Young's modulus as a function of applied stress and temperature. The experimental results have been compared with modelling results and we have found that they agree very well. From the point of view of future use of tungsten as a high power target material, the most important result of this study is that Young's modulus of tungsten remains high at high temperature, high stress and high strain-rates.

cond-mat.mtrl-sci↗

arXiv2011

Experimental results and constitutive modelling for tungsten and tantalum at high strain rates and very high temperatures

Recently reported results of the high strain rates, high temperature measurements of the yield stress of tungsten and tantalum have been analyzed. The highest temperature reached in the experiment, based on heating and stressing a thin wire by a fast, high current pulse, was 2520 K and 2720 K, for tantalum and tungsten, respectively. The strain-rates in both the tungsten and tantalum tests were in the range from 500 to 1500 1/s. The parameters for the constitutive equation developed by Zerilli and Armstrong have been determined from the experimental data and the results have been compared with the data obtained at lower temperatures.

cond-mat.mtrl-sci↗

arXiv2005

Z-Scaling and Inclusive Particle Production in p-p Collisions at High-pT

The properties of particle production in pp collisions are basis for analysis of pA and AA interactions and verification of theory. We analyzed inclusive particle production using z-scaling established in proton-proton and proton-antiproton collisions at the U70, ISR, Tevatron and RHIC. This scaling reflects symmetry of hadron structure, interaction and particle formation. It is shown that new data on charged hadron and pi0-meson spectra obtained in pp collisions at the Relativistic Heavy Ion Collider confirm the z-scaling.

hep-ph↗

arXiv2004

Jet Energy Density in Hadron-Hadron Collisions at High Energies

The average particle multiplicity density dN/deta is the dynamical quantity which reflects some regularities of particle production in low-pT range. The quantity is an important ingredient of z-scaling. Experimental results on charged particle density are available for pp, pA and AA collisions while experimental properties of the jet density are still an open question. The goal of this work is to find the variable which will reflect the main features of the jet production in low transverse energy range and play the role of the scale factor for the scaling function psi(z) and variable z in data z-presentation. The appropriate candidate is the variable we called "scaled jet energy density". Scaled jet energy density is the probability to have a jet with defined ET in defined xT and pseudorapidity regions. The PYTHIA6.2 Monte Carlo generator is used for calculation of scaled jet energy density in proton-proton collisions over a high energy range (sqrt s = 200-14000 GeV) and at eta = 0. The properties of the new variable are discussed and sensitivity to "physical scenarios" applied in the standard Monte Carlo generator is noted. The results of scaled jet energy density at LHC energies are presented and compared with predictions based on z-scaling.

hep-ph↗

arXiv2002

Scaling properties of hadron production in pi-p and pi-A collisions at high-pT

Scaling features of particles produced in pi-p and pi-A collisions over a high-pT range at high energies are studied. The general concept of z-scaling is applied for the analysis of pi-p and pi-A experimental data on the inclusive cross section. The scaling function psi(z) and scaling variable z are constructed and the anomalous dimension delta_pi is found. The A-dependence of particle production in pion-nucleus collisions is studied. The predictions of the inclusive cross section of the pi0-mesons produced in pi-A collisions in the central rapidity range at high energies have been made.

hep-ph↗

arXiv2000

Asymmetry of p(->)+p(->)->gamma+jet+X process and problem of Delta G

The gamma +jet production in p(->)-p(->) collisions at high energies is studied. Double-spin asymmetry A{LL} of the process is calculated by using Monte Carlo code SPHINX. The predictions for A{LL} of the gamma +jet production in the p(->)-p(->) collisions using the spin-dependent gluon distributions with positive and negative sign of $ΔG(x,Q^2)$ are made at RHIC energies. A possibility to extract the spin-dependent gluon distributions Delta G at STAR experiment and to discriminate between different theoretical scenarios is discussed.

hep-ph↗

arXiv1999

Asymmetry of prompt photon production in p-p collisions at RHIC

The prompt photon production in p-p collisions at high energies is studied. Double-spin asymmetry of the process is calculated by using Monte Carlo code SPHINX. A possibility to discriminate the spin-dependent gluon distributions and to determine sign of Delta G is discussed. Detailed study of expected background, such as pi0 production and decay, is given. The predictions for the longitudinal asymmetry of the prompt photons and pi0-meson production in the p-p collisions at RHIC energies have been made.

hep-ph↗