40 research outputs found
On the CP-odd Nucleon Potential
The CP-odd nucleon potential for different models of CP violation in the one
meson exchange approximation is studied. It is shown that the main contribution
is due to the -meson exchange which leads to a simple one parameter CP-odd
nucleon potential.Comment: 12 pages, RevTex, UM-P-92/114, OZ-92/3
Possible doublet mechanism for a regular component of parity violation in neutron scattering
A nucleus with octupole deformation of the mean field reveals rotational
doublets with the same angular momentum and opposite parity. Mediated by the
Coriolis-type interaction, the doublet structure leads to a strong regular
component in the parity violation caused by weak interaction. This can explain
sign correlations observed in polarized neutron scattering by Th.Comment: 10 pages, revtex, no figure
Status of “Siberia-2” SR sourse preinjector
Improvements made in linac systems have significantly increased the reliability of its operation. At present time the linac injects an electron beam with an energy of 75 MeV, beam current of 65 mA (DE/E=1%), with a pulse duration of 18 ns at a repetition rate of 1 pps
Tandem proton accelerator as injector for TRAPP
To inject protons to the TRAPP (synchrotron for therapy of cancer) a tandem accelerator has been constructed. Its parameters are: protons energy is 1.4 MeV, current is 3 mA, pulse duration is 2 μs, frequency is up to 1 Hz. Negative hydrogen ions are extracted through the slit from a magnetron discharge on the heated surface of the LaB6 cathode. The beam of negative ions with an initial energy of 25 kV accelerates up to the half energy in the first accelerating tube, than recharges into protons in gas nitrogen target in a tube at a potential of 700 kV. After that, the proton beam doubles its energy in the second accelerating tube. Operating and control of the tandem are by means of computer
From graphene oxide towards aminated graphene facile synthesis, its structure and electronic properties
In this paper we present a facile method for the synthesis of aminated graphene derivative through simultaneous reduction and amination of graphene oxide via two-step liquid phase treatment with hydrobromic acid and ammonia solution in mild conditions. The amination degree of the obtained aminated reduced graphene oxide is of about 4 at.%, whereas C/O ratio is up to 8.8 as determined by means of X-ray photoelectron spectroscopy. The chemical reactivity of the introduced amine groups is further verified by successful test covalent bonding of the obtained aminated graphene with 3-Chlorobenzoyl chloride. The morphological features and electronic properties, namely conductivity, valence band structure and work function are studied as well, illustrating the influence of amine groups on graphene structure and physical properties. Particularly, the increase of the electrical conductivity, reduction of the work function value and tendency to form wrinkled and corrugated graphene layers are observed in the aminated graphene derivative compared to the pristine reduced graphene oxide. As obtained aminated graphene could be used for photovoltaic, biosensing and catalysis application as well as a starting material for further chemical modifications
Unraveling the GO nitrogen doping during the Hummers oxidation, conversion and effect of nitrogen species on the electrical conductivity after thermal annealing
Probing exotic phenomena at the interface of nuclear and particle physics with the electric dipole moments of diamagnetic atoms: A unique window to hadronic and semi-leptonic CP violation
The current status of electric dipole moments of diamagnetic atoms which
involves the synergy between atomic experiments and three different theoretical
areas -- particle, nuclear and atomic is reviewed. Various models of particle
physics that predict CP violation, which is necessary for the existence of such
electric dipole moments, are presented. These include the standard model of
particle physics and various extensions of it. Effective hadron level combined
charge conjugation (C) and parity (P) symmetry violating interactions are
derived taking into consideration different ways in which a nucleon interacts
with other nucleons as well as with electrons. Nuclear structure calculations
of the CP-odd nuclear Schiff moment are discussed using the shell model and
other theoretical approaches. Results of the calculations of atomic electric
dipole moments due to the interaction of the nuclear Schiff moment with the
electrons and the P and time-reversal (T) symmetry violating
tensor-pseudotensor electron-nucleus are elucidated using different
relativistic many-body theories. The principles of the measurement of the
electric dipole moments of diamagnetic atoms are outlined. Upper limits for the
nuclear Schiff moment and tensor-pseudotensor coupling constant are obtained
combining the results of atomic experiments and relativistic many-body
theories. The coefficients for the different sources of CP violation have been
estimated at the elementary particle level for all the diamagnetic atoms of
current experimental interest and their implications for physics beyond the
standard model is discussed. Possible improvements of the current results of
the measurements as well as quantum chromodynamics, nuclear and atomic
calculations are suggested.Comment: 46 pages, 19 tables and 16 figures. A review article accepted for
EPJ
First experimental results obtained using the highpower free electron laser at the siberian center for photochemical research
The first lasing near the wavelength of 140 µm was achieved in April 2003 using a high-power free electron laser (FEL) constructed at the Siberian Center for Photochemical Research. In this paper we briefly describe the design of the FEL driven by an accelerator–recuperator. Characteristics of the electron beam and terahertz laser radiation, obtained in the first experiments, are also presented in the paper.У Сибірському центрі фотохімічних досліджень навесні 2003 року отримана генерація випромінювання з довжиною хвилі 140 мкм на потужному лазері на вільних електронах (ЛВЕ). У роботі коротко описана конструкція ЛВЕ на базі прискорювача рекуператора і представлені результати вимірювання деяких параметрів електронного пучка і терагерцового випромінювання.В Сибирском центре фотохимических исследований весной 2003 года получена генерация излучения с длиной волны 140 мкм на мощном лазере на свободных электронах (ЛСЭ). В работе кратко описана конструкция ЛСЭ на базе ускорителя рекуператора и представлены результаты измерения некоторых параметров электронного пучка и терагерцового излучения
The morphologic changes in the wall of the human urinary tracts after direct electro pulse exposure: the in vitro research
The aim – study of the morphological changes in the wall of the human urinary tracts, developing after direct electro pulse exposure (DEPE). Materials and methods – The fragments of the surgical material obtained after the pelvis (n=25), ureter (n=33) and urinary bladder (n=20) open operations, were used in the research. DEPE was carried out by single (from 1 to 20) nanosecond pulses with the power of 0.8 J (joule) and 1.0 J made by the electro pulse “Urolit-105M” lithotriptor probe on the fragments’ mucous tunic placed in the Petri dishes with 0.9% NaCl solution. The fragments were fixed in the formalin and after the processing, and pouring with paraffin, the tissue slices were prepared. Results – The kidney pelvis wall, where changes like epithelium desquamation, the basal membrane disorganization, paretic capillary expansion did not go beyond sub mucous layer even after exposure by 10 pulses with the power 1.0 J each, aimed at one point, proved to be the most resistant to DEPE. In the fragments of ureter and urinary bladder the same changes were detected after exposure by 5 pulses with the power of 1.0 J each, whereas after exposure by 10 pulses with the power 1.0 J each the changes occurred which were restricted by the muscular layer. Conclusion – The DEPEon the mucous tunic of the isolated urinary tracts fragments by the means of 10 pulses with the power of 1.0 J each looks safe, causes morphologic changes, restricted by the muscular layer and does not lead to the wall perforation