Measurement ofL III subshell photoelectric cross-sections in highZ-elements

L _III subshell photoelectric cross-sections in lead, thorium and uranium at 13·596, 16·896 and 17·781 keV respectively have been determined. The results are found to agree well with theory.     

Measurement of positron-rare gas total cross-sections at intermediate energies

Total scattering cross-sections for positrons in the rare gases in the energy range of 2–960 eV have been measured using a time-of-flight system for which the uncertainty arising from forward scattering is substantially lower than in the 1974 experiment of Canter et al. A comparison of these cross-sections with current theoretical estimates is made.     

Temperature-modulated photoluminescence induced by photoexcitation in semiconductors

A new technique of temperature-modulated photoluminescence is reported. The periodic heating is induced by metastable optical radiation. An analysis is made of phase shifts. The technique is applied to GaP : N. The results are compared with those obtained with an external heater.     

Relative differential subshell photoionisation cross-sections (MgKα) from lithium to uranium

Differential subshell photoionisation cross-sections, relative to F1s = 1.00, are derived from new and previously reported XPS (Mg Kα) peak i     

Measurement of the magnetostriction constants,saturation magnetization,and internal stresses of ferrite thin films by the ferromagnetic resonance method

The magnetostriction constants of thin films are calculated by the Soule-Smit method, using external anisotropic stresses produced by deforming the film together with its substrate by means of two pairs of parallel blades. The ferromagnetic resonance technique is used to determine the magnetostriction constant ₁₀₀, the saturation magnetization M₀, and the internal stresses of thin films of nickel-alloyed Mg-Mn ferrite.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 91–95, November, 1976.     

替代法测电阻

介绍了替代法测电阻的原理，给出了不确定度的计算公式，简述了其优点。     

Measurement ofL-shell photoelectric cross-sections in lower intermediateZ elements at 6 keV

L-shell photoelectric cross-sections have been measured at 6 keV for eight elements in the range 40⩽Z⩽53. The measurements agree with theoretical calculations.     

Generation of acoustic surface waves on GaAs by photoexcitation

In the experiments reported here we observed the generation of non-thermal, large amplitude acoustic surface waves at GHz frequencies on the surface of a GaAs crystal under intense illumination with 514.5 nm radiation from an Ar⁺ laser at room temperature. The acoustic surface waves were detected by optical Brillouin spectroscopy.     

Measurement of ionization cross-sections and backscattering factors for use in quantitative AES

For the extraction of quantitative information from Auger electron spectra two parameters (apart from a number of instrumental parameters) are of utmost importance: the ionization cross-section and the backscattering factor. The determination of these two parameters is discussed. Ionization cross-section values for L- and M-shells have been determined based on existing values for K-shells from the literature. The backscattering factor for Si is calculated as a function of energy of the primary electrons and compared with absolute measurements of this factor using an adsorbed monolayer of sulfur or oxygen on a Si (100) surface.     

Photoionization cross section of atomic uranium measured by Delay SRI method

In this paper we have studied the three-step delay DSRI method carefully and note that it excels the normal DSRI method in its simple mathematical model and no light pump effect. The autoionization cross section is measured by this method.     

On photoexcitation of baryon antidecuplet

We show that the photoexcitation of the nonexotic members baryon antidecuplet, suggested by the soliton classification of low-lying baryons, is strongly suppressed on the proton target. The process occurs mostly on the neutron target. This qualitative prediction can be useful in identifying the nonexotic members of the antidecuplet in the known baryon spectrum. We also analyze the interrelation between photocouplings of various baryon multiplets in the soliton picture and in the nonrelativistic quark model.Received: 9 April 2003, Published online: 18 November 2003PACS: 13.30.-a Decays of baryons - 13.60.-r Photon and charged-lepton interactions with hadrons - 14.20.-c Baryons (including antiparticles)     

Luminescence of silver chloride microcrystals upon photoexcitation by different methods

The luminescence spectra of AgCl microcrystals were measured in two different regimes: in the regime of excitation of stationary luminescence and in the regime of photostimulated burst of luminescence. Differences between the spectra of stationary luminescence and the spectra of photostimulated-luminescence burst in the range between 430 and 590 nm have been found. The luminescence spectra are complex; the ratio of intensities for elementary components changes with the technique of excitation. Differences in the form and composition of complex luminescence bands obtained under different conditions of registration are attributed to the recombination interaction of the luminescence centers. It is shown that analysis of the dependences of intensity ratios for the elementary components of a complex luminescence band on the exciting-radiation intensity allows one to evaluate the mechanism of recombination in elementary bands provided that the mechanism is known for at least one luminescence band.__________Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 1, pp. 85–89. January–February, 2005.     

Measurement of dynamic magnetostriction by photometric method

The method of measurements of dynamic magnetostriction based on measuring the amplitude of oscillations of the image whose edge is a straight line boundary of the light field in the microscope is described. The results of measurements obtained for the samples from silicon iron are compared with measurements carried out by other methods.Translated from Izvestiya VUZ. Fizika, No. 6, pp. 7–11, June, 1973.     

Absorption spectra induced by photoexcitation and electrochemical doping in polythiophene

Changes of absorption spectra in a polythiophene film caused by photo- excitation and electrochemical doping are studied. The photoexcitation and the slight doping reveal that the formation of a shallow polaron is responsible to the carrier transport. The doping also induces a deep polaron which can explain the change of spectra upon doping.     

Measurement of neutral and charged current cross-sections in positron-proton collisions at large momentum transfer

The inclusive single and double differential cross-sections for neutral and charged current processes with four-momentum transfer squared between 150 and 30 000 GeV and with Bjorken x between 0.0032 and 0.65 are measured in collisions. The data were taken with the H1 detector at HERA between 1994 and 1997, and they correspond to an integrated luminosity of . The evolution of the parton densities of the proton is tested, yielding no significant deviation from the prediction of perturbative QCD. The proton structure function is determined. An extraction of the u and d quark distributions at high x is presented. At high electroweak effects of the heavy bosons and are observed and found to be consistent with Standard Model expectation. Received: 27 August 1999 / Published online: 25 February 2000     

Determination of neutron-induced fission cross-sections of unstable nuclei via surrogate reaction method

Heavy ion reaction studies around Coulomb barrier energies have been generally used to investigate the effect of the structure of projectile/target on reaction dynamics. Other than providing an understanding of basic physics of the reaction dynamics, some of these reactions have been used as tools to serve as surrogates of neutron-induced compound nuclear fission cross-sections involving unstable targets. In this paper, we report some of the recent results on the determination of neutron-induced fission cross-sections of unstable actinides present in Th–U and U–Pu fuel cycles by surrogate reaction method by employing transfer-induced fission studies with ^6,7Li beams.     

Ultrafast intrachain photoexcitation of polymeric semiconductors

We report on excited state dynamics in isolated poly(9,9-dioctylfluorene) chains obtained by embedding the polymer in an inert plastic matrix. Early events (<300 fs) of intrachain photophysics are detected by pump-probe spectroscopy using tunable UV 25-fs pump pulses and sub-10-fs visible probe pulses. We show that higher-lying optical states, reached by multiphoton transitions, give rise to on-chain charge separation on the ultrafast time scale. The intrachain charge pair decays geminately within 500 fs to the lowest singlet state. Characteristic time scales for internal conversion and intramolecular vibrational redistribution are also determined.