Aligning Ion Guns

Ion Tracking in Photocathode RF Guns

Projected next-generation linac-based light sources such as PERL or the TESLA free-electron laser (FEL) generally assume, as essential components of their injector complexes, long-pulse photocathode rf electron guns. These guns, due to the nature in which they are operated, may be more susceptible to ion bombardment damage of their cathodes than conventional rf guns. This paper explores this po...

Guns, Privacy, and Crime

We investigate the impact of an information shock – the public exposure of the names and addresses of holders of handgun carry permits – on criminals’ propensity to commit crimes. In December 2008, a Memphis, TN newspaper published a searchable online database of names, zip codes, and ages of Tennessee handgun carry permit holders. Once news of the database publication spread, an intense and ac...

Developmental Biology: Pipe's Smoking Guns

The formation of the dorso-ventral body pattern of Drosophila involves the restricted activation of a serine protease cascade in the extracellular space between the egg shell and the embryo. Now, the first molecular links have been identified between ventral gene expression during oogenesis and the activation of the protease cascade in the early embryo.

Guns don't die. People do.

In this age of modern era, the use of internet must be maximized. Yeah, internet will help us very much not only for important thing but also for daily activities. Many people now, from any level can use internet. The sources of internet connection can also be enjoyed in many places. As one of the benefits is to get the on-line guns dont die people do book, as the world window, as many people s...

Low Emittance Thermionic Electron Guns*