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...

Current approaches to 3D imaging at subcellular resolution using confocal microscopy and electron tomography, while powerful, are limited to relatively thin and transparent specimens. Here we report on the use of a new generation of dual beam electron microscopes capable of site-specific imaging of the interior of cellular and tissue specimens at spatial resolutions about an order of magnitude ...

The lateral buildup ratio (LBR) used to estimate the depth dose distribution of electron beams for an irregular cutout field was obtained for a 4-MeV energy beam from a Varian 21 EX linear accelerator. The depth-dose curves for a group of circular cutout fields starting from a 2-cm diameter were measured. Electron diodes were used in a large water tank to measure the LBR values for 6, 9, 12, an...

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...

InSb nanowire arrays have been fabricated by direct current electrodeposition inside the nanochannels of anodic alumina membranes without subsequent annealing. After Au contacts were patterned to the nanowires using electron beam lithography, photoresponse studies were conducted. Absorbance peaks were also recorded from free suspending nanowires. A significant response was observed when the wir...

The SPEAR 3 upgrade lattice will provide much reduced beam emittance to increase the brightness of synchrotron radiation beams from wigglers and undulators. Seven existing insertion devices will be used in the lattice. In this paper we review the wiggler parameters, outline the wiggler compensation scheme, and evaluate wiggler effect on the optics and dynamic aperture. Abstract The SPEAR 3 upgr...

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 this paper, several schemes of soft X-ray and hard X-ray free electron lasers (XFEL) and their progress are reviewed. Self-amplified spontaneous emission (SASE) schemes, the high gain harmonic generation (HGHG) scheme and various enhancement schemes through seeding and beam manipulations are discussed, especially in view of the generation of attosecond X-ray pulses. Our recent work on the ge...

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...