In order to double the positron injection rate into the KEKB ring, a two-bunch acceleration scheme has been studied at the linac, in which bunches separated by 96 ns are accelerated in 50 Hz. In this scheme the stabilization of energy and orbit of each bunch is indispensable. Thus the beam energy and orbit feedback systems have been upgraded. Since beam characteristics are acquired through beam...

the present study is the first to analyze the dynamic response of a poroelastic beam subjected to a moving force. moreover, the influences of attached mass-spring systems and non-ideal supports (with local movements in the supporting points or base due to the presence of factors such as gaps, unbalanced masses, and friction or seismic excitations) on the responses were investigated. non-ideal s...

To improve the ductility and seismic performance of a double coupling beam, authors applied polyethylene terephthalate (PET) sheet steel tube to form fiber-reinforced polymer (FRP)–concrete–steel double-skin tubular (DST) composite beams. A low-cyclic reversed experimental program was carried out which factored in member form, diameter, construction methods. The results indicate that energy dis...

In this paper a new approach is presented to reduce vibrations for oneand two-dimensional mechanical structures, as beam or thin plates, by means of several piezoelectric transducers shunted with a proper electric network system. The governing equations of the whole system are coupled to each other through the direct and converse piezoelectric effect. More in detail, the mechanical equations ar...

The accelerator safety interlock system (ASIS) for the X-ray free electron laser (XFEL) at SPring-8 protects personnel from radiation hazards. We developed an ASIS consisting of three interlock systems: a central interlock system (CIS), an emergency interlock system (EIS), and a beam route interlock system (BIS). The CIS and EIS monitor the safety equipment status and emergency stop buttons, re...

A proposed high-brightness synchrotron light source (PEP-X) is under design at SLAC. The 4.5-GeV PEP-X storage ring has four theoretical minimum emittance (TME) cells to achieve the very low emittance and two double-bend achromat (DBA) cells to provide spaces for IDs. Damping wigglers will be installed in zero-dispersion straights to reduce the emittance below 0.1 nm. Ion induced beam instabili...

Classical molecular dynamics is applied to study the energy dissipation (the Q factor) of the cantilever-type beam oscillators of single wall and double-walled carbon nanotubes (CNTs). The study finds that the Q factor of the CNT beam oscillator varies with the temperature T following the 1/T(0.36) dependence. For single wall CNT, the Q factor drops from 2 x 10(5) at 0.05 K to 1.5 x 10(3) at 29...

We consider a sub-leading twist chiral-odd pion fragmentation function and explore its contribution in single pion semi-inclusive electroproduction. We evaluate the single beam-spin azimuthal asymmetry ALU and the double spin asymmetry ALT in polarized electroproduction of pions from an unpolarized and transversely polarized nucleon respectively. The beam asymmetry is expressed as the product o...

We experimentally address the wave-vector and polarization dependence of the internal conical refraction phenomenon by demonstrating that an input light beam of elliptical transverse profile refracts into two beams after passing along one of the optic axes of a biaxial crystal, i.e. it exhibits double refraction instead of refracting conically. Such double refraction is investigated by the inde...

 ABSTRACTBackgrounds: MD-55-2 is one of the Radiochromic film models with the sensitivity suitable for dose measurements ranging from 5 to 100 Gy.  However, this lower limit makes the film impractical for its applications in many areas such as brachytherapy source dosimetry.Materials and methods: In this project, the useful range of the film has been extended by using a multilayer film techniqu...