The LCLS photocathode rf gun requires a solenoid immediately downstream for proper emittance compensation. Such a gun and solenoid have been operational at the SSRL Gun Test Facility (GTF) for over eight years. Based on magnetic measurements and operational experience with the GTF gun solenoid multiple modifications are suggested for the LCLS gun solenoid. The modifications include adding dipol...

We report on the design and construction of a new, tuneable, 1.5 cell 17 GHz RF gun and improved beamline. Emittance compensation in the new beamline is achieved with a 6.5 cm long, 0.5 T solenoid placed immediately after the RF Gun. Simulations predict a normalized rms emittance of 0.5 πmm-mrad for a 1 ps, 0.1 nC, 2.4 MeV beam. Emittance measurement diagnostic slits have also been designed and...

From vehicle, gun, projectile and charge system, a basic principle has been presented for the first time in the paper by making use of the random-simulation technology based on the theory of interior ballistic, automat, vibration of self-propelled gun system, initial disturbing and external ballistic etc. The basic principle is achieved by simulating a movement procedure of the gun-vehicle syst...

OBJECTIVES We investigated the possible relationship between being shot in an assault and possession of a gun at the time. METHODS We enrolled 677 case participants that had been shot in an assault and 684 population-based control participants within Philadelphia, PA, from 2003 to 2006. We adjusted odds ratios for confounding variables. RESULTS After adjustment, individuals in possession of...

BACKGROUND Safer storage practices may reduce injury rates by limiting youth access to firearms. OBJECTIVE To determine if a firearm safety counseling and gun lock distribution program improved storage practices. DESIGN Community-based before-after trial. SETTING Urban county in central North Carolina. PARTICIPANTS One hundred twelve adult gun owners recruited through a mass media adver...

Between 1985 and 1991 the homicide rate in the United 'States increased by nearly 25 percent, from 7.9 to 9.8 per 100,000 residents. Almost all of this increase was accounted for by additional gun homicides committed against and by young males. Although the homicide rate has declined substantially during the 1990s, homicide in the United States is still dominated by young people and firearms an...

News stories of gun violence have ignited the debate about what public health measures are appropriate for reducing the epidemic of gun injury and death. Although critics of stricter gun policies cite data showing stable rates of gun-related homicide over the past decade, these statistics ignore the increased rate of shootings and that improved trauma care has stabilized the death rate.1 With t...

The next generation light sources such as energy recovery linac (ERL) light sources and X-ray FEL oscillator require high brightness electron gun with megahertz repetition rate. We have developed a DC photoemission electron gun at JAEA for the Japanese ERL light source project. This DC gun employs a segmented insulator with guard rings to protect the insulator from field emission generated from...

Abstract In view of the fuzziness and uncertainty combat effectiveness evaluation index small bore naval gun, combined with AHP fuzzy method, method gun is studied. Firstly, main influencing factors are analyzed, system established. Then, based on theory, a model Finally, an example given to evaluate gun. This can effectively unify qualitative quantitative indexes in indexes, provide effective ...