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...

We report the fabrication of a photonic platform consisting of single wire light-emitting diodes (LED) and photodetectors optically coupled by waveguides. MOVPE-grown (metal-organic vapor-phase epitaxy) InGaN/GaN p-n junction core-shell nanowires have been used for device fabrication. To achieve a good spectral matching between the emission wavelength and the detection range, different active r...

The mechanism of electron multipacting in long bunched proton machine has been quantitatively described by the electron energy gain and electron motion. Some important parameters related to electron multipacting are investigated in detail. It is proved that multipacting is sensitive to beam intensity, longitudinal beam profile shape and transverse beam size. Agreements are achieved among our an...

The SPEAR 3 light source [1] has two 7.6 m straight sections one of which is available for new insertion devices (ID). By reducing the vertical β y function at the center of the straight from 9.8 m to 1.5 m, the beam size can be decreased from 44 µm to 17 µm to reduce the ID gap, but the ID length may be limited by the increased β y variation in the ID. Alternatively , a " double waist " optics...

Interactions between the intercalant and the host have been studied in homogeneous amorphous Li(x)WO3 prepared by electron beam evaporation, using electrochemical experiments with films of different thickness (100-400 nm). We have related the intercalation thermodynamics, described previously by us [Solid State Ionics 2005, 176, 1701] with other models that take into account film volume dilatat...

We describe a self-limiting, low-energy argon-ion-milling process that enables noncircular device patterns, such as squares or hexagons, to be formed using precursor arrays of uniform circular openings in poly(methyl methacrylate) defined using electron beam lithography. The proposed patterning technique is of particular interest for bit-patterned magnetic recording medium fabrication, where sq...

In many accelerators running positively charged beams, ionization of residual gas and secondary electron emission in the beam pipe will give rise to an electron cloud which can cause beam blow-up or the loss of the circulating beam. One solution to avoid the electron cloud is to ensure that the vacuum wall has low secondary emission yield (SEY). The SEY of thin films of TiN and sputter-deposite...

A nonlinear model of two-beam free-electron laser (FEL) in the absence of slippage is presented. The two beams are assumed to be cold with different energies and the fundamental resonance of the higher energy beam is at the third harmonic of lower energy beam. By using Maxwell’s equations and full Lorentz force equations of motion for the electron beams, coupled differential equations are deriv...