K E Y W O R D S SEM, electron beam induced current, EBIC, REBIC, grain boundaries, electroceramics,

We present results of measurements of spot size and angular divergence of a 30 GeV electron beam though use of optical transition radiation (OTR). The OTR near field pattern and far field distribution are measured as a function of beam spot size and divergence at wavelengths of 441, 532, and 800 nm, for both the single and double foil configurations. Electron beam spot sizes of 50μm rms have be...

Electron beam welding (EBW) shows certain problems with the control of focus regime. The electron beam focus can be controlled in electron-beam welding based on the parameters of a secondary signal. In this case, the parameters like secondary emissions and focus coil current have extreme relationships. There are two values of focus coil current which provide equal value signal parameters. There...

Intense ion beams are difficult to maintain as non-neutral plasmas. Experiments and simulations are used to study the complex interactions between beam ions and unwanted electrons. Such “electron clouds” limit the performance of many accelerators. To characterize electron clouds, a number of parameters are measured, including total and local electron production and loss for each of three major ...

This article summarizes the 13th ICFA Beam Dynamics Mini-Workshop Beam-Induced Pressure Rise in Rings (BNL, Dec. 9-12, 2003) [1]. BACKGROUND OF WORKSHOP Beam induced pressure rise was an intensity limit at CERN ISR during the early 1970's. The beam gas ionization created pressure rise caused more gas ionization, resulting in pressure run-away at high beam intensity. Extensive baking, chamber tr...

The electron beam generated in a self-modulated laser-wakefield accelerator is characterized in detail. A transverse normalized emittance of 0.06 p mm mrad, the lowest ever for an electron injector, was measured for 2 MeV electrons. The electron beam was observed to have a multicomponent beam profile and energy distribution. The latter also undergoes discrete transitions as the laser power or p...

A low-energy plasma focus device was used as an electron beam source. A technique was developed to simultaneously measure the electron beam intensity and energy. The system was operated in Argon filling at an optimum pressure of 1.7 mbar. A Faraday cup was used together with an array of filtered PIN diodes. The beam-target X-rays were registered through X-ray spectrometry. Copper and lead line ...

In the beam pipe of the positron damping ring of the Next Linear Collider, electrons will be created by beam interaction with the surrounding vacuum chamber wall and give rise to an electron cloud. Several solutions are possible for avoiding the electron cloud, without changing the bunch structure or the diameter of the vacuum chamber. Some of the currently available solutions for preventing th...

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...