The decay time of YAG:Ce(3+) phosphor was studied using a CMOS camera with a frame rate of 1302000 s(-1) and pulsed X-rays from SPring-8. A high-resolution X-ray detector with YAG:Ce(3+) was used with the camera to view the focused beam from the helical undulator. Mismatch between the ring circulation time and the frame time gave rise to a periodic variation of beam intensity in successive fram...

New electron linac designs incorporate substantial advances in critical beam parameters such as beam loading and bunch length and will require new levels of performance in stability and phase space control. In the coming decade, e(and e+) linacs will be built for a high power linear collider (TESLA, CLIC, JLC/NLC), for fourth generation X-ray sources (TESLA FEL, LCLS, Spring 8 FEL) and for basi...

An X-ray stereo imaging system with synchrotron radiation was developed at BL20B2, SPring-8. A portion of a wide X-ray beam was Bragg-reflected by a silicon crystal to produce an X-ray beam which intersects with the direct X-ray beam. Samples were placed at the intersection point of the two beam paths. X-ray stereo images were recorded simultaneously by a detector with a large field of view pla...

We have constructed a new laser-Compton-scattering facility, called the LEPS2 beamline, at 8-GeV electron storage ring, SPring-8. This facility provides linearly polarized photon beam in tagged energy range of 1.3--2.4 GeV. Thanks to small divergence low-emittance storage-ring electrons, has size (sigma) suppressed about 4 mm even after it travels 130 m experimental building that is independent...

We study samples with full and partial occlusion causing streak artifacts, and propose two modifications of filtered backprojection for artifact removal. Data is obtained by the SPring-8 synchrotron using a monochromatic parallel-beam scan [1]. Thresholding in the sinogram segments the metal, resulting in edges on which we apply 1) a smooth transition, or 2) a Dirichlet boundary condition.

This paper presents the design, fabrication and characterization of an electromagnetic MEMS energy harvester with ultra-broad operating bandwidth. The beam stretching induced nonlinear spring stiffness enables the resonance to extend from 65 Hz to 340 Hz and 400 Hz at accelerations of 0.5g and 1.0g, respectively. The ultra-wide bandwidth could benefit the harvester device for more efficient vib...

The assembly and installation of the vacuum system of SACLA, XFEL in SPring-8 was done. The average pressure with beam achieved without bake out was 9.3×10 Pa. The flanges of C-band and S-band developed for XFEL hardly cause leak even when the damage on the seal edge was found. Magnetic shielding for components was also carried out.

Adaptive reduced-order methods are explored for simulating continuous vibrating structures. The Galerkin method is used to convert the governing partial differential equation (PDE) into a finite-dimensional system of ordinary differential equations (ODEs) whose solution approximates that of the original PDE. Sparse projections of the approximate ODE solution are then found at each integration t...

The purpose of the PEPPO experiment is to demonstrate, for the first time, the production of polarized positrons from a polarized electron beam. The experiment was performed in Spring 2012 at the CEBAF injector of Jefferson Laboratory (JLab) using a highly spin polarized electron beam. The positron polarization was measured by means of a Compton transmission polarimeter. This work discuss the e...

There are several idealizations in numerical analysis of structures. In the joints and supports, which is usually assumed to be pinned or rigid, semi-rigid connection should be considered to obtain more realistic, reliable and also economical results. In this study, rotational spring stiffness-connection ratio relation is clearly explained and revealed. A finite element program SEMIFEM is devel...