Science.gov

Sample records for 155mm guns skyline

  1. Finite element thermal analysis of 155-mm projectile exudtion inside a hot gun tube.

    SciTech Connect

    Kan, Yih-Renn; Shelton, Timothy R.

    2003-05-01

    The high firing rates of new and developing cannons create higher operating temperatures than projectiles experience. Higher temperatures in-bore bring the possibility of high explosive exudation from chambered shells during misfire, hang-fire, or hold-fire. The development of a finite element thermal model to predict high explosive exudation inside a hot gun tube brings an improved level of insight to existing physical test results. The MI98 towed howitzer and M107 155-mm shell are modeled to compare to physical test results from Morales 1997 and Zimmerman 1980. During creation of the model special focus is taken to simulate the heat flow between the contact of the rotating band and cannon wall. A strong correlation between test results and model is seen with both reports and validates the model setup. Model results suggest that time to exudation predicted by Morales and Zimmerman may be too conservative.

  2. 8. Engineering Drawing of Panama Gun Mount by U.S. Engineering ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. Engineering Drawing of Panama Gun Mount by U.S. Engineering Office, San Francisco, California - Fort Funston, Panama Mounts for 155mm Guns, Skyline Boulevard & Great Highway, San Francisco, San Francisco County, CA

  3. 10. Detail of map showing Battery Davis and Panama Gun ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. Detail of map showing Battery Davis and Panama Gun Mounts at right, by U.S. Engineering Office, San Francisco, California, August 5, 1934. - Fort Funston, Panama Mounts for 155mm Guns, Skyline Boulevard & Great Highway, San Francisco, San Francisco County, CA

  4. Design and performance of a parachute recovery system to recover 155-mm- and 8-inch-diameter artillery shells

    SciTech Connect

    Waye, D.E.; Peterson, C.W.; Botner, W.T.

    1986-01-01

    A parachute recovery system has been developed and demonstrated for the recovery of 155-mm- and 8-inch-diameter artillery shells. The recovery system functions after being subjected to gun launch accelerations of up to 18,000 g's axially and up to 400,000 rad/sec/sup 2/ radially. The parachute is deployed while the shell is still spinning at about 250 revolutions per second. To deploy the parachute while the shell is spinning, a double-swivel system was developed. The deployment signal for the recovery system is provided by an electronic timer. Over 250 tests have been performed on both the 155-mm- and 8-inch-diameter artillery shell. Impact velocities are between 100 and 120 feet per second. The latest version of the recovery systems has been proven to be over 95% successful for the recovery of 8-inch-diameter artillery shells and over 85% successful for the recovery of 155-mm-diameter artillery shells.

  5. Skyline based terrain matching

    NASA Technical Reports Server (NTRS)

    Page, Lance A.

    1990-01-01

    Skyline-based terrain matching, a new method for locating the vantage point of stereo camera or laser range-finding measurements on a global map previously prepared by satellite or aerial mapping is described. The orientation of the vantage is assumed known, but its translational parameters are determined by the algorithm. Skylines, or occluding contours, can be extracted from the sensory measurements taken by an autonomous vehicle. They can also be modeled from the global map, given a vantage estimate from which to start. The two sets of skylines, represented in cylindrical coordinates about either the true or the estimated vantage, are employed as 'features' or reference objects common to both sources of information. The terrain matching problem is formulated in terms of finding a translation between the respective representations of the skylines, by approximating the two sets of skylines as identical features (curves) on the actual terrain. The search for this translation is based on selecting the longest of the minimum-distance vectors between corresponding curves from the two sets of skylines. In successive iterations of the algorithm, the approximation that the two sets of curves are identical becomes more accurate, and the vantage estimate continues to improve. The algorithm was implemented and evaluated on a simulated terrain. Illustrations and examples are included.

  6. An explanation of spin-up instabilities for a 155mm binary projectile

    NASA Astrophysics Data System (ADS)

    Damico, W. P., Jr.

    1984-04-01

    In 1971 during the development testing of the 155mm XM687 binary projectile, liquid-induced flight instabilities were observed. Tests were conducted that indicated unstable behavior for fill ratios of 80 to 100%. However, stable flights occurred for a fill ratio of 65%. A solid, cylindrical spacer was fitted to the interior of the aft end of the rear payload canister, thus shortening the overall interior length of the payload compartment. This simple modification yielded stable flights and was incorporated into the standard projectile. This report presents yawsonde data and analytical models that explain the stabilizing effect of the spacer which was eventually employed in the M687 projectile.

  7. Wind tunnel investigation of aerodynamic characteristics of a scale model of a D5 bulldozer and an M109 self-propelled 155 mm Howitzer

    NASA Technical Reports Server (NTRS)

    Laub, G. H.; Kodani, H. M.

    1974-01-01

    Wind tunnel tests were conducted on a scale model of a D5 bulldozer and an M109 self-propelled 155 MM howitzer to determine the aerodynamic characteristics of these typical externally-suspended heavy lift helicopter cargo configurations. Tests were made over a large range of pitch and yaw attitudes at a nominal Reynolds number per unit length of 1.5 x 10 to the 6th power.

  8. 48. VIEW OF SKYLINE DRIVE FROM THE ROCKY PEAK OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    48. VIEW OF SKYLINE DRIVE FROM THE ROCKY PEAK OF STONY MAN MOUNTAIN (EL. 4,011). LOOKING NORTHEAST. STONY MAN OVERLOOK VISIBLE IN THE DISTANCE. - Skyline Drive, From Front Royal, VA to Rockfish Gap, VA , Luray, Page County, VA

  9. 4. Panama Mount. Note concrete ring and metal rail. Note ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. Panama Mount. Note concrete ring and metal rail. Note cliff erosion under foundation at left center. Looking 297° W. - Fort Funston, Panama Mounts for 155mm Guns, Skyline Boulevard & Great Highway, San Francisco, San Francisco County, CA

  10. OUTERBRIDGE CROSSING BRIDGE LINED UP WITH MANHATTAN SKYLINE IN MIDDLE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    OUTERBRIDGE CROSSING BRIDGE LINED UP WITH MANHATTAN SKYLINE IN MIDDLE OF HORIZON, VERRAZANO NARROWS BRIDGE TO THE RIGHT - Outerbridge Crossing Bridge, Spanning Arthur Kill from New Jersey to Staten Island, Staten Island (subdivision), Richmond County, NY

  11. Gun Play

    ERIC Educational Resources Information Center

    Mechling, Jay

    2008-01-01

    Biology and the particular gun culture of the United States come together to explain the persistent and powerful attraction of American boys to both real guns and toy guns. The 1990s saw adults begin to conflate "the gun problem" with "the boy problem," sparking attempts (largely failed) to banish toy guns from homes and…

  12. Skyline Gathers K-12 Together Under One Roof.

    ERIC Educational Resources Information Center

    American School Board Journal, 1968

    1968-01-01

    Skyline School is a flexible and economical elementary and high school design for 400 pupils. The library, a large resource center serving all ages, and the administration offices are accented by landscaped courts. There are two instructional material centers per grade grouping of K-6 and 7-12. Grades 1-6 surround the kindergarten, which has…

  13. Gun Safety

    MedlinePlus

    Many U.S. households have guns, but they can cause harm if not handled properly. Here are some things you can do to keep yourself and ... safe: Teach children that they shouldn't touch guns and that if they see a gun, to ...

  14. Department of Defense/Department of Energy joint demilitarization technology demonstration program-executive summary of phase I demonstrations-detonation of conventional weapons: 155-mm high-explosive M107 projectiles

    SciTech Connect

    Watkins, B.E., LLNL

    1998-07-01

    Four experiments were executed from December 1996 through March 1997 within X-tunnel--the contained underground facility at the Department of Energy`s Nevada Test Site (NTS). These are the first large-scale detonation experiments performed in a contained environment with sampling of the effluents. These experiments, conducted under the direction of the U.S. Army Defense Ammunition Center in Savanna, Illinois, determined the detonation products from 155-mm, high-explosive (HE) M107 projectiles, destroying 6, 24, 24, and 60 projectiles, respectively. These tests were the first phase of a series designed to examine the environmental effects of open burn/open detonation (OB/OD). The tests included performing continuous sampling with online analysis of chamber gas and discrete sampling with offline analysis of bulk gases, volatile organic compounds (VOCs), semi-volatile organic compounds (SVOCs), metals, and particulates. In addition to these routine measurements, the application of a tunable diode laser (TDL) for measuring bulk gases and a real-time particle analysis instrument was demonstrated in the underground chamber. A series of three rocket motor burn experiments immediately followed these experiments (see the companion to this report, ``Executive Summary of Phase II Demonstrations: The Low-Pressure Rocket Motor Burns in X-Tunnel``). As the first in a series, the data presented here should be considered preliminary. However, several tentative conclusions may be drawn from these detonation experiments: (1) The emissions of the Environmental Protection Agency (EPA) regulated materials were found only in trace levels. (2) In general, metals detected in the residue and particulate samples were dominated by metals already present in the chamber and concrete. (3) There were no releases of metals that exceeded current regulatory limits.

  15. Using GIS to promote Skyline Wilderness Park in Rapid City, SD

    NASA Astrophysics Data System (ADS)

    Eastman, A.; Mannel, S.

    2005-12-01

    Skyline Drive Wilderness Park is a 150-acre open space in Rapid City, South Dakota. The Wilderness Park is located along a sandstone ridge or hogback, which bisects the urban sprawl. Skyline Drive Wilderness Park is a natural meeting place of the Ponderosa Pine forests of the Black Hills and the mixed-grass prairie of western South Dakota. A campaign to save Skyline Drive Wilderness Park began in 1994, when members of the Skyline Drive Preservation Committee grew concerned about the number of new homes being built on Skyline Drive. There are concerns about the long-term ecologic sustainability of Skyline Drive Wilderness Park, which is why this and other monitoring projects are proposed for 2005 and 2006. Development of a GIS database will allow us to collect and analyze data in a meaningful way. This GIS database is needed to begin a series of interrelated research projects, proposed for 2005-2006 that will address questions about the ecologic changes resulting from the urbanization of Skyline Drive. These projects include: a 1: 1,000 topographic survey of the Wilderness Park to identify microhabitat features, creation and maintenance of a herbarium, a breeding bird fidelity study, and establishment of bat-habitat through the installation of bat-houses.

  16. 185. WASHINGTON SKYLINE ACROSS POTOMAC RIVER FROM L.B.J. MEMORIAL PARK ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    185. WASHINGTON SKYLINE ACROSS POTOMAC RIVER FROM L.B.J. MEMORIAL PARK LOOKING NORTH EAST. - George Washington Memorial Parkway, Along Potomac River from McLean to Mount Vernon, VA, Mount Vernon, Fairfax County, VA

  17. Geometry-Based Distributed Spatial Skyline Queries in Wireless Sensor Networks

    PubMed Central

    Wang, Yan; Song, Baoyan; Wang, Junlu; Zhang, Li; Wang, Ling

    2016-01-01

    Algorithms for skyline querying based on wireless sensor networks (WSNs) have been widely used in the field of environmental monitoring. Because of the multi-dimensional nature of the problem of monitoring spatial position, traditional skyline query strategies cause enormous computational costs and energy consumption. To ensure the efficient use of sensor energy, a geometry-based distributed spatial query strategy (GDSSky) is proposed in this paper. Firstly, the paper presents a geometry-based region partition strategy. It uses the skyline area reduction method based on the convex hull vertices, to quickly query the spatial skyline data related to a specific query area, and proposes a regional partition strategy based on the triangulation method, to implement distributed queries in each sub-region and reduce the comparison times between nodes. Secondly, a sub-region clustering strategy is designed to group the data inside into clusters for parallel queries that can save time. Finally, the paper presents a distributed query strategy based on the data node tree to traverse all adjacent sensors’ monitoring locations. It conducts spatial skyline queries for spatial skyline data that have been obtained and not found respectively, so as to realize the parallel queries. A large number of simulation results shows that GDSSky can quickly return the places which are nearer to query locations and have larger pollution capacity, and significantly reduce the WSN energy consumption. PMID:27043563

  18. Geometry-Based Distributed Spatial Skyline Queries in Wireless Sensor Networks.

    PubMed

    Wang, Yan; Song, Baoyan; Wang, Junlu; Zhang, Li; Wang, Ling

    2016-01-01

    Algorithms for skyline querying based on wireless sensor networks (WSNs) have been widely used in the field of environmental monitoring. Because of the multi-dimensional nature of the problem of monitoring spatial position, traditional skyline query strategies cause enormous computational costs and energy consumption. To ensure the efficient use of sensor energy, a geometry-based distributed spatial query strategy (GDSSky) is proposed in this paper. Firstly, the paper presents a geometry-based region partition strategy. It uses the skyline area reduction method based on the convex hull vertices, to quickly query the spatial skyline data related to a specific query area, and proposes a regional partition strategy based on the triangulation method, to implement distributed queries in each sub-region and reduce the comparison times between nodes. Secondly, a sub-region clustering strategy is designed to group the data inside into clusters for parallel queries that can save time. Finally, the paper presents a distributed query strategy based on the data node tree to traverse all adjacent sensors' monitoring locations. It conducts spatial skyline queries for spatial skyline data that have been obtained and not found respectively, so as to realize the parallel queries. A large number of simulation results shows that GDSSky can quickly return the places which are nearer to query locations and have larger pollution capacity, and significantly reduce the WSN energy consumption. PMID:27043563

  19. Gun Control, Gun Ownership, and Suicide Prevention.

    ERIC Educational Resources Information Center

    Lester, David

    1988-01-01

    Explored relationship between the extent of gun ownership and the strictness of gun control laws to suicide and homicide rates in the nine major geographic regions of the United States. Found gun ownership, rather than the strictness of gun control laws, was the strongest correlate of the rates of suicide and homicide by guns. (Author)

  20. Gun control, gun ownership, and suicide prevention.

    PubMed

    Lester, D

    1988-01-01

    The relationship of the extent of gun ownership and the strictness of gun control laws to suicide and homicide rates in the nine major geographic regions of the United States was explored. Gun ownership, rather than the strictness of gun control laws, was found to be the strongest correlate of the rates of suicide and homicide by guns. Regions with a higher extent of gun ownership had higher rates of suicide and homicide by firearms. PMID:3262246

  1. Spectrometer gun

    DOEpatents

    Waechter, David A.; Wolf, Michael A.; Umbarger, C. John

    1985-01-01

    A hand-holdable, battery-operated, microprocessor-based spectrometer gun includes a low-power matrix display and sufficient memory to permit both real-time observation and extended analysis of detected radiation pulses. Universality of the incorporated signal processing circuitry permits operation with various detectors having differing pulse detection and sensitivity parameters.

  2. Spectrometer gun

    DOEpatents

    Waechter, D.A.; Wolf, M.A.; Umbarger, C.J.

    1981-11-03

    A hand-holdable, battery-operated, microprocessor-based spectrometer gun is described that includes a low-power matrix display and sufficient memory to permit both real-time observation and extended analysis of detected radiation pulses. Universality of the incorporated signal processing circuitry permits operation with various detectors having differing pulse detection and sensitivity parameters.

  3. Simulated visual homing in desert ant natural environments: efficiency of skyline cues.

    PubMed

    Basten, Kai; Mallot, Hanspeter A

    2010-05-01

    Desert ants, foraging in cluttered semiarid environments, are thought to be visually guided along individual, habitual routes. While other navigational mechanisms (e.g. path integration) are well studied, the question of how ants extract reliable visual features from a complex visual scene is still largely open. This paper explores the assumption that the upper outline of ground objects formed against the sky, i.e. the skyline, provides sufficient information for visual navigation. We constructed a virtual model of the ant's environment. In the virtual environment, panoramic images were recorded and adapted to the resolution of the desert ant's complex eye. From these images either a skyline code or a pixel-based intensity code were extracted. Further, two homing algorithms were implemented, a modified version of the average landmark vector (ALV) model (Lambrinos et al. Robot Auton Syst 30:39-64, 2000) and a gradient ascent method. Results show less spatial aliasing for skyline coding and best homing performance for ALV homing based on skyline codes. This supports the assumption of skyline coding in visual homing of desert ants and allows novel approaches to technical outdoor navigation. PMID:20300942

  4. Water gun vs air gun: A comparison

    USGS Publications Warehouse

    Hutchinson, D.R.; Detrick, R. S.

    1984-01-01

    The water gun is a relatively new marine seismic sound source that produces an acoustic signal by an implosive rather than explosive mechanism. A comparison of the source characteristics of two different-sized water guns with those of conventional air guns shows the the water gun signature is cleaner and much shorter than that of a comparable-sized air gun: about 60-100 milliseconds (ms) for an 80-in3. (1.31-liter (I)) water gun compared with several hundred ms for an 80-in3. (1.31-1) air gun. The source spectra of water guns are richer in high frequencies (>200 Hz) than are those of air guns, but they also have less energy than those of air guns at low frequencies. A comparison between water gun and air gun reflection profiles in both shallow (Long Island Sound)-and deep (western Bermuda Rise)-water settings suggests that the water gun offers a good compromise between very high resolution, limited penetration systems (e.g. 3.5-kHz profilers and sparkers) and the large volume air guns and tuned air gun arrays generally used where significant penetration is required. ?? 1984 D. Reidel Publishing Company.

  5. Locked lateral patella dislocation: the role for the skyline view in the trauma setting

    PubMed Central

    Fleming, Tom

    2016-01-01

    Objective: Acute traumatic dislocation of the patella is a common problem. These cases often either spontaneously reduce or undergo successful closed reduction in Emergency Departments. We describe a rare case of an irreducible patella dislocation in a 15 year old boy following direct trauma. Method: Intra-operative skyline views revealed lateral dislocation of the patella with the patella ‘locked’ in internal rotation. Result: Closed reduction in theatre failed and open reduction was required. Conclusion: This case illustrates the benefit of the skyline view in the radiograph series following failed closed reduction, aiding the identification of atypical dislocations and osteochondral fracture fragments.

  6. Toyota/Skyline Technical Education Network. Cooperative Demonstration Program. Final Performance Report.

    ERIC Educational Resources Information Center

    Skyline Coll., San Bruno, CA.

    A joint project was conducted between Toyota Motor Sales and Skyline College (in the San Francisco, California, area) to create an automotive technician training program that would serve the needs of working adults. During the project, a model high technology curriculum suitable for adults was developed, the quality of instruction available for…

  7. An Energy-Efficient Skyline Query for Massively Multidimensional Sensing Data.

    PubMed

    Wang, Yan; Wei, Wei; Deng, Qingxu; Liu, Wei; Song, Houbing

    2016-01-01

    Cyber physical systems (CPS) sense the environment based on wireless sensor networks. The sensing data of such systems present the characteristics of massiveness and multi-dimensionality. As one of the major monitoring methods used in in safe production monitoring and disaster early-warning applications, skyline query algorithms are extensively adopted for multiple-objective decision analysis of these sensing data. With the expansion of network sizes, the amount of sensing data increases sharply. Then, how to improve the query efficiency of skyline query algorithms and reduce the transmission energy consumption become pressing and difficult to accomplish issues. Therefore, this paper proposes a new energy-efficient skyline query method for massively multidimensional sensing data. First, the method uses a node cut strategy to dynamically generate filtering tuples with little computational overhead when collecting query results instead of issuing queries with filters. It can judge the domination relationship among different nodes, remove the detected data sets of dominated nodes that are irrelevant to the query, modify the query path dynamically, and reduce the data comparison and computational overhead. The efficient dynamic filter generated by this strategy uses little non-skyline data transmission in the network, and the transmission distance is very short. Second, our method also employs the tuple-cutting strategy inside the node and generates the local cutting tuples by the sub-tree with the node itself as the root node, which will be used to cut the detected data within the nodes of the sub-tree. Therefore, it can further control the non-skyline data uploading. A large number of experimental results show that our method can quickly return an overview of the monitored area and reduce the communication overhead. Additionally, it can shorten the response time and improve the efficiency of the query. PMID:26761010

  8. An Energy-Efficient Skyline Query for Massively Multidimensional Sensing Data

    PubMed Central

    Wang, Yan; Wei, Wei; Deng, Qingxu; Liu, Wei; Song, Houbing

    2016-01-01

    Cyber physical systems (CPS) sense the environment based on wireless sensor networks. The sensing data of such systems present the characteristics of massiveness and multi-dimensionality. As one of the major monitoring methods used in in safe production monitoring and disaster early-warning applications, skyline query algorithms are extensively adopted for multiple-objective decision analysis of these sensing data. With the expansion of network sizes, the amount of sensing data increases sharply. Then, how to improve the query efficiency of skyline query algorithms and reduce the transmission energy consumption become pressing and difficult to accomplish issues. Therefore, this paper proposes a new energy-efficient skyline query method for massively multidimensional sensing data. First, the method uses a node cut strategy to dynamically generate filtering tuples with little computational overhead when collecting query results instead of issuing queries with filters. It can judge the domination relationship among different nodes, remove the detected data sets of dominated nodes that are irrelevant to the query, modify the query path dynamically, and reduce the data comparison and computational overhead. The efficient dynamic filter generated by this strategy uses little non-skyline data transmission in the network, and the transmission distance is very short. Second, our method also employs the tuple-cutting strategy inside the node and generates the local cutting tuples by the sub-tree with the node itself as the root node, which will be used to cut the detected data within the nodes of the sub-tree. Therefore, it can further control the non-skyline data uploading. A large number of experimental results show that our method can quickly return an overview of the monitored area and reduce the communication overhead. Additionally, it can shorten the response time and improve the efficiency of the query. PMID:26761010

  9. Radiographic grading of the patellofemoral joint is more accurate in skyline compared to lateral views

    PubMed Central

    Heng, Hwee-Yee Christian; Mitra, Amit Kanta

    2015-01-01

    Background The patellofemoral joint is perhaps the most commonly involved compartment in knee osteoarthritis (OA). Radiographic studies are routinely ordered and are seen as the first-line investigations for patellofemoral osteoarthritis (PFOA). The Kellgren-Lawrence (K&L) grading scale is often used to quantify the severity of radiographic OA. In this study, we aim to determine the correlation of the K&L grading scale on both the skyline and lateral views with arthroscopic visualization of articular cartilage damage. Methods All patients with clinical and radiographic features of PFOA who underwent knee arthroscopy by a single surgeon from 2006 to 2010 in our institution were reviewed. The study group consisted of 66 patients with PFOA. All patients had skyline and lateral radiographs of the knee taken before surgery. All patients had arthroscopic evidence of PFOA. Blinded investigators graded the radiographs according to the K&L grading scale. At arthroscopy, the patellofemoral joint was graded according to the Outerbridge classification. Correlation and statistical analysis of the radiographic and arthroscopic grade was carried out. Results The general trend shows that the higher the radiographic K&L grading, the greater the severity of articular cartilage degeneration on arthroscopy. However, an increasing K&L grade accounts for only 39.7% and 28.4% of the variation of severity of arthroscopically-determined articular cartilage degeneration on skyline and lateral views respectively. Interestingly, on both views, better correlation with arthroscopic findings was seen in early (K&L grades 1 and 2) PFOA. Skyline views were superior to lateral views in terms of specificity, PPV, NPV and accuracy in predicting early OA. Conclusions Skyline radiographs are more accurate than lateral radiographs in prediction of severity of PFOA. PMID:26605309

  10. ION GUN

    DOEpatents

    Dandl, R.A.

    1961-10-24

    An ion gun is described for the production of an electrically neutral ionized plasma. The ion gun comprises an anode and a cathode mounted in concentric relationship with a narrow annulus between. The facing surfaces of the rear portions of the anode and cathode are recessed to form an annular manifold. Positioned within this manifold is an annular intermediate electrode aligned with the an nulus between the anode and cathode. Gas is fed to the manifold and an arc discharge is established between the anode and cathode. The gas is then withdrawn from the manifold through the annulus between the anode and cathode by a pressure differential. The gas is then ionized by the arc discharge across the annulus. The ionized gas is withdrawn from the annulus by the combined effects of the pressure differential and a collimating magnetic field. In a 3000 gauss magnetic field, an arc voltage of 1800 volts, and an arc current of 0.2 amp, a plasma of about 3 x 10/sup 11/ particles/cc is obtained. (AEC)

  11. ELECTRON GUN

    DOEpatents

    Christofilos, N.C.; Ehlers, K.W.

    1960-04-01

    A pulsed electron gun capable of delivering pulses at voltages of the order of 1 mv and currents of the order of 100 amperes is described. The principal novelty resides in a transformer construction which is disposed in the same vacuum housing as the electron source and accelerating electrode structure of the gun to supply the accelerating potential thereto. The transformer is provided by a plurality of magnetic cores disposed in circumferentially spaced relation and having a plurality of primary windings each inductively coupled to a different one of the cores, and a helical secondary winding which is disposed coaxially of the cores and passes therethrough in circumferential succession. Additional novelty resides in the disposition of the electron source cathode filament input leads interiorly of the transformer secondary winding which is hollow, as well as in the employment of a half-wave filament supply which is synchronously operated with the transformer supply such that the transformer is pulsed during the zero current portions of the half-wave cycle.

  12. Gun ownership and social gun culture.

    PubMed

    Kalesan, Bindu; Villarreal, Marcos D; Keyes, Katherine M; Galea, Sandro

    2016-06-01

    We assessed gun ownership rates in 2013 across the USA and the association between exposure to a social gun culture and gun ownership. We used data from a nationally representative sample of 4000 US adults, from 50 states and District of Columbia, aged >18 years to assess gun ownership and social gun culture performed in October 2013. State-level firearm policy information was obtained from the Brady Law Center and Injury Prevention and Control Center. One-third of Americans reported owning a gun, ranging from 5.2% in Delaware to 61.7% in Alaska. Gun ownership was 2.25-times greater among those reporting social gun culture (PR=2.25, 95% CI 2.02 to 2.52) than those who did not. In conclusion, we found strong association between social gun culture and gun ownership. Gun cultures may need to be considered for public health strategies that aim to change gun ownership in the USA. PMID:26124073

  13. Encyclopedia of Gun Control and Gun Rights.

    ERIC Educational Resources Information Center

    Utter, Glenn H.

    This reference volume provides information on gun control and gun rights, including resources on the debate surrounding the Second Amendment and individuals and organizations focused on gun issues, along with statutes, court cases, events, and publications surrounding this current topic. Highlighted are the important organizations and their…

  14. The Gun Dispute.

    ERIC Educational Resources Information Center

    Spitzer, Robert J.

    1999-01-01

    Explores the debate over gun ownership and gun control in the United States, focusing on the historic place of guns in U.S. society. The current national mood is more receptive than ever to restricting and regulating adolescent access to guns in light of recent school shootings. (SLD)

  15. Gun Sales. Firearm Facts.

    ERIC Educational Resources Information Center

    Duker, Laurie, Ed.

    Minimal federal regulations on firearm sales have facilitated the proliferation of guns, gun owners, and gun dealers in the United States. This fact sheet offers data on the growing number of firearm dealers, the relative ease of obtaining and keeping a license to sell guns from the Federal Bureau of Alcohol, Tobacco, and Firearms, the lack of…

  16. Guns and Violence. Current Controversies.

    ERIC Educational Resources Information Center

    Kim, Henny H., Ed.

    This book focuses on gun violence and gun control, presenting both sides of arguments about firearms ownership and gun control. Each of five chapters poses a question about gun control and provides answers for both sides of the question. The following essays are included: (1) "Gun Violence Is Becoming an Epidemic" (Bob Herbert); (2) "Gun Violence…

  17. Gun Safety (For Kids)

    MedlinePlus

    ... guns are featured in many television shows, video games, computer games, and movies, it's important to know that real ... only happen on TV, in movies, or video games. A real gun is never a toy, and ...

  18. LX-04 VIOLENCE MEASUREMENTS- STEVEN TESTS IMPACTED BY PROJECTILES SHOT FROM A HOWITZER GUN

    SciTech Connect

    Chidester, S K; Vandersall, K S; Switzer, L L; Tarver, C M

    2005-07-18

    Characterization of the reaction violence of LX-04 explosive (85% HMX and 15% Viton A by weight) was obtained from Steven Impact Tests performed above the reaction initiation threshold. A 155 mm Howitzer propellant driven gas gun was used to accelerate the Steven Test projectiles in the range of approximately 170-300 m/s to react (ignite) the LX-04 explosive. Blast overpressure gauges, acoustic microphones, and high-speed photography characterized the level of high explosive reaction violence. A detonation in this velocity range was not observed and when comparing these results (and the Susan test results) with that of other HMX based explosives, LX-04 has a more gradual reaction violence slope as the impact velocity increases. The high binder content (15%) of the LX-04 explosive is believed to be the key factor to the lower level of violence.

  19. Research on construction of Web 3D-GIS based on Skyline

    NASA Astrophysics Data System (ADS)

    Wang, Tingting; Gao, Zhiqiang; Ning, Jicai

    2014-10-01

    This paper further studies the construction, publishing and display of three-dimensional (3D) scenes and their implementation based on Skyline family of software, combining remote sensing images and DEM data. Among them, the SketchUp software is used to build landscape models and the JavaScript programming language is adopted to achieve web browsing of 3D scenes. The study provides a useful exploration for the establishment of Web 3D-GIS combining Web GIS technology and 3D visualization technology.

  20. Survey of SRF guns

    SciTech Connect

    Belomestnykh, S.

    2011-07-25

    Developing Superconducting RF (SRF) electron guns is an active field with several laboratories working on different gun designs. While the first guns were based on elliptic cavity geometries, Quarter Wave Resonator (QWR) option is gaining popularity. QWRs are especially well suited for producing beams with high charge per bunch. In this talk we will describe recent progress in developing both types of SRF guns. SRF guns made excellent progress in the last two years. Several guns generated beams and one, at HZDR, injected beam into an accelerator. By accomplishing this, HZDR/ELBE gun demonstrated feasibility of the SRF gun concept with a normal-conducting Cs{sub 2}Te cathode. The cathode demonstrated very good performance with the lifetime of {approx}1 year. However, for high average current/high bunch charge operation CsK{sub 2}Sb is preferred as it needs green lasers, unlike UV laser for the Cs{sub 2}Te, which makes it easier to build laser/optics systems. Other high QE photocathodes are being developed for SRF guns, most notably diamond-amplified photocathode. Several QWR guns are under development with one producing beam already. They are very promising for high bunch charge operation. The field is very active and we should expect more good results soon.

  1. Women and Guns. Firearm Facts.

    ERIC Educational Resources Information Center

    Duker, Laurie, Ed.

    Many gun manufacturers market guns to women claiming a gun can provide protection. Statistics provided in this fact sheet indicate gun ownership may provide a false sense of security that can be fatal, since the greatest threat to a woman comes from the people and guns within her own home. Contrary to "typical" scenarios created by advertisers,…

  2. Interior of southeast gun chamber (labeled "Gun Turret No. Two), ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior of southeast gun chamber (labeled "Gun Turret No. Two), showing gun mounting pad, wall rings, small niche, and opening to outside - U.S. Naval Base, Pearl Harbor, Battery Adair, Princeton Place, Pearl City, Honolulu County, HI

  3. Carbon Nanotube Electron Gun

    NASA Technical Reports Server (NTRS)

    Nguyen, Cattien V. (Inventor); Ribaya, Bryan P. (Inventor)

    2013-01-01

    An electron gun, an electron source for an electron gun, an extractor for an electron gun, and a respective method for producing the electron gun, the electron source and the extractor are disclosed. Embodiments provide an electron source utilizing a carbon nanotube (CNT) bonded to a substrate for increased stability, reliability, and durability. An extractor with an aperture in a conductive material is used to extract electrons from the electron source, where the aperture may substantially align with the CNT of the electron source when the extractor and electron source are mated to form the electron gun. The electron source and extractor may have alignment features for aligning the electron source and the extractor, thereby bringing the aperture and CNT into substantial alignment when assembled. The alignment features may provide and maintain this alignment during operation to improve the field emission characteristics and overall system stability of the electron gun.

  4. Carbon nanotube electron gun

    NASA Technical Reports Server (NTRS)

    Nguyen, Cattien V. (Inventor); Ribaya, Bryan P. (Inventor)

    2010-01-01

    An electron gun, an electron source for an electron gun, an extractor for an electron gun, and a respective method for producing the electron gun, the electron source and the extractor are disclosed. Embodiments provide an electron source utilizing a carbon nanotube (CNT) bonded to a substrate for increased stability, reliability, and durability. An extractor with an aperture in a conductive material is used to extract electrons from the electron source, where the aperture may substantially align with the CNT of the electron source when the extractor and electron source are mated to form the electron gun. The electron source and extractor may have alignment features for aligning the electron source and the extractor, thereby bringing the aperture and CNT into substantial alignment when assembled. The alignment features may provide and maintain this alignment during operation to improve the field emission characteristics and overall system stability of the electron gun.

  5. Skyline matching based camera orientation from images and mobile mapping point clouds

    NASA Astrophysics Data System (ADS)

    Hofmann, S.; Eggert, D.; Brenner, C.

    2014-05-01

    Mobile Mapping is widely used for collecting large amounts of geo-referenced data. An important role plays sensor fusion, in order to evaluate multiple sensors such as laser scanner and cameras jointly. This requires to determine the relative orientation between sensors. Based on data of a RIEGL VMX-250 mobile mapping system equipped with two laser scanners, four optional cameras, and a highly precise GNSS/IMU system, we propose an approach to improve camera orientations. A manually determined orientation is used as an initial approximation for matching a large number of points in optical images and the corresponding projected scan images. The search space of the point correspondences is reduced to skylines found in both the optical as well as the scan image. The skyline determination is based on alpha shapes, the actual matching is done via an adapted ICP algorithm. The approximate values of the relative orientation are used as starting values for an iterative resection process. Outliers are removed at several stages of the process. Our approach is fully automatic and improves the camera orientation significantly.

  6. Skyline Wide Educational Plan (SWEP) Product Evaluation Report: Educational Goals for the Future (1980's). SWEP Evaluation Report No. 2.

    ERIC Educational Resources Information Center

    Burns, Robert J.

    The major purpose of this evaluation report is to scrutinize the Skyline Wide Educational Plan (SWEP) research methods and analytical schemes and to communicate the project's constituency priorities relative to the educational programs and processes of the future. A Delphi technique was used as the primary mechanism for gathering and scrutinizing…

  7. Remotely controlled spray gun

    NASA Technical Reports Server (NTRS)

    Cunningham, William C. (Inventor)

    1987-01-01

    A remotely controlled spray gun is described in which a nozzle and orifice plate are held in precise axial alignment by an alignment member, which in turn is held in alignment with the general outlet of the spray gun by insert. By this arrangement, the precise repeatability of spray patterns is insured.

  8. Homing in wood ants, Formica japonica: use of the skyline panorama.

    PubMed

    Fukushi, T

    2001-06-01

    Homeward orientation was studied in wood ants Formica japonica that, while foraging, shuttled back and forth along a 7.9m route between the nest and a feeding site located on a wide terrace platform surrounded by a conspicuous landmark panorama. The return runs of the ants were amazingly straight, not only in the controls (starting at the feeding site) but also in ants displaced for various distances to the left and right of the feeding site. These courses, however, were oriented neither parallel to the predisplacement courses nor directly towards the nest. This result excludes the use of chemical cues and celestial compass cues. Furthermore, the nest itself, or some object close to it, could not have served as a beacon. The extensions of the homeward paths taken by ants that had been displaced to various release sites up to 11m sideways from the training route intersected at a point far (approximately 13m) behind the nest. This result suggests that the ants used distant landmarks seen by them in their frontal fields of view. To test this hypothesis, the distant landmark panorama was concealed by an opaque sheet mounted at right angles to the normal return route of the ants and extending up to different elevations. Shielding the lower part of the landmark panorama had no effect on the homeward paths. However, when the screen was mounted in such a way that the ants could only see the top skyline, represented by the upper edges of a line of trees, for part of their return run, it was only during these parts that their path was oriented in the homeward direction. When, during the course of displacement experiments, the ants were deprived of their familiar skyline panorama, they moved in their home direction only for an extremely short distance (0.1-0.4m rather than the usual 7.9m) and then started a systematic search programme. Hence, in the present context, skylight information is not used, at least not extensively. Instead, ants use the distant skyline as a

  9. Rarefaction wave gun propulsion

    NASA Astrophysics Data System (ADS)

    Kathe, Eric Lee

    A new species of gun propulsion that dramatically reduces recoil momentum imparted to the gun is presented. First conceived by the author on 18 March 1999, the propulsion concept is explained, a methodology for the design of a reasonable apparatus for experimental validation using NATO standard 35mm TP anti-aircraft ammunition is developed, and the experimental results are presented. The firing results are juxtaposed by a simple interior ballistic model to place the experimental findings into a context within which they may better be understood. Rarefaction wave gun (RAVEN) propulsion is an original contribution to the field of armament engineering. No precedent is known, and no experimental results of such a gun have been published until now. Recoil reduction in excess of 50% was experimentally achieved without measured loss in projectile velocity. RAVEN achieves recoil reduction by means of a delayed venting of the breech of the gun chamber that directs the high enthalpy propellant gases through an expansion nozzle to generate forward thrust that abates the rearward momentum applied to the gun prior to venting. The novel feature of RAVEN, relative to prior recoilless rifles, is that sufficiently delayed venting results in a rarefaction wave that follows the projectile though the bore without catching it. Thus, the projectile exits the muzzle without any compromise to its propulsion performance relative to guns that maintain a sealed chamber.

  10. RF Gun Optimization Study

    SciTech Connect

    A. S. Hofler; P. Evtushenko; M. Krasilnikov

    2007-08-01

    Injector gun design is an iterative process where the designer optimizes a few nonlinearly interdependent beam parameters to achieve the required beam quality for a particle accelerator. Few tools exist to automate the optimization process and thoroughly explore the parameter space. The challenging beam requirements of new accelerator applications such as light sources and electron cooling devices drive the development of RF and SRF photo injectors. RF and SRF gun design is further complicated because the bunches are space charge dominated and require additional emittance compensation. A genetic algorithm has been successfully used to optimize DC photo injector designs for Cornell* and Jefferson Lab**, and we propose studying how the genetic algorithm techniques can be applied to the design of RF and SRF gun injectors. In this paper, we report on the initial phase of the study where we model and optimize gun designs that have been benchmarked with beam measurements and simulation.

  11. High Velocity Gas Gun

    NASA Technical Reports Server (NTRS)

    1988-01-01

    A video tape related to orbital debris research is presented. The video tape covers the process of loading a High Velocity Gas Gun and firing it into a mounted metal plate. The process is then repeated in slow motion.

  12. Gas gun dynamics

    NASA Astrophysics Data System (ADS)

    Denny, Mark

    2013-09-01

    The mechanics and thermodynamics of one- and two-stage gas guns are developed. Very high projectile muzzle speed can be obtained by the two-stage version. The physics of simple gas guns, such as air rifles, is accessible to undergraduates and the same level of presentation is used here to understand more complex designs. Numerical solutions to the equations of motion are shown, along with insightful analytic approximations.

  13. Reliable Execution Based on CPN and Skyline Optimization for Web Service Composition

    PubMed Central

    Ha, Weitao; Zhang, Guojun

    2013-01-01

    With development of SOA, the complex problem can be solved by combining available individual services and ordering them to best suit user's requirements. Web services composition is widely used in business environment. With the features of inherent autonomy and heterogeneity for component web services, it is difficult to predict the behavior of the overall composite service. Therefore, transactional properties and nonfunctional quality of service (QoS) properties are crucial for selecting the web services to take part in the composition. Transactional properties ensure reliability of composite Web service, and QoS properties can identify the best candidate web services from a set of functionally equivalent services. In this paper we define a Colored Petri Net (CPN) model which involves transactional properties of web services in the composition process. To ensure reliable and correct execution, unfolding processes of the CPN are followed. The execution of transactional composition Web service (TCWS) is formalized by CPN properties. To identify the best services of QoS properties from candidate service sets formed in the TCSW-CPN, we use skyline computation to retrieve dominant Web service. It can overcome that the reduction of individual scores to an overall similarity leads to significant information loss. We evaluate our approach experimentally using both real and synthetically generated datasets. PMID:23935431

  14. Problems and Cautions With Sequence Mismatch Analysis and Bayesian Skyline Plots to Infer Historical Demography.

    PubMed

    Grant, William Stewart

    2015-01-01

    Sequence mismatch analysis (MMA) and Bayesian skyline plots (BSP) are commonly used to reconstruct historical demography. A survey of 173 research articles (2009-2014), which included estimates of historical population sizes from mtDNA or cpDNA, shows a widespread genetic signature of demographic or spatial population expansion in species of all major taxonomic groups. Associating these expansions with climatic events can provide insights into the origins of lineage diversity, range expansions (or contractions), and speciation. However, several variables can introduce error into reconstructions of demographic history, including levels of sequence polymorphism, sampling scheme, sample size, natural selection, and estimates of mutation rate. Most researchers use substitution rates estimated from divergences in phylogenetic trees dated with fossils, or geological events. Recent studies show that molecular clocks calibrated with phylogenetic divergences can overestimate the timings of population-level events by an order of magnitude. Overestimates disconnect historical population reconstructions from climatic history and confound our understanding of the factors influencing genetic variability. If mismatch distributions and BSPs largely reflect demographic history, the widespread signature of population expansion in vertebrate, invertebrate, and plant populations appears to reflect responses to postglacial climate warming. PMID:25926628

  15. Electromagnetic targeting of guns

    SciTech Connect

    Pogue, E.W.; Boat, R.M.; Holden, D.N.; Lopez, J.R.

    1996-10-01

    This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Electromagnetic pulse (EMP) signals produced from explosives being fired have been reported in the literature for fifty years. When a gun is fired it produces an EMP muzzle blast signal. The strength and nature of these signals was first analyzed in the early 1970s, while the results were interesting, no follow-up studies were conducted. With modern detection and signal processing technology, we believe that these signals could be used to instantaneously locate guns of virtually all calibers as they fire. The objective of our one-year project was to establish the basic nature of these signals and their utility in the concept of electromagnetic targeting of guns.

  16. Mole gun injury.

    PubMed

    Pistré, V; Rezzouk, J

    2013-09-01

    A mole gun is a weapon, which is used to trap and kill moles. This report provides an overview of the state of knowledge of mole gun injuries, comparable to blast injuries caused by fireworks, explosive or gunshot. Over a 2-year period, the authors reported their experience with ten hand injuries caused by mole gun. Radial side of the hand was often concerned, particularly the thumb. The authors explain their choices in the management of such lesions. Surgery was performed primarily and a large debridement currently seemed to offer the best outcome for the patient. Blast, crush, burns and lacerations may explain the higher rate of amputation to the digits. A long period of physiotherapy, specifically of the hand, was needed before the patient could return to work. This ballistic hand trauma encountered by surgeons requires knowledge and understanding of these injuries. It should be in accordance with firearms law because of severe injuries encountered and possible lethal wounds. PMID:23746826

  17. Where the guns come from: the gun industry and gun commerce.

    PubMed

    Wintemute, Garen J

    2002-01-01

    Under federal law, it is illegal for youth under age 18 to purchase rifles or shotguns, and for those under age 21 to purchase handguns. However, fatality and injury statistics clearly show that guns are finding their way into young people's hands. Many of these youth obtain guns through illegal gun markets. This article focuses on how guns in the United States are manufactured, marketed, and sold. The article shows how the legal and illegal gun markets are intimately connected and make guns easily accessible to youth. Although the domestic gun manufacturing industry is relatively small and has experienced declining sales in recent years, it has significant political clout and a large market for its products, and has engaged in aggressive marketing to youth. Lax oversight of licensed firearms dealers, combined with little or no regulation of private sales between gun owners, mean that guns can quickly moved from the legal gun market into the illegal market, where they can be acquired by young people. Certain guns, especially inexpensive, poorly made small handguns, are particularly attractive to criminals and youth. The author observes that several policy innovations--including increased regulation of licensed firearms dealers, intensified screening of prospective buyers, regulation of private sales, gun licensing and registration, and bans on some types of weapons--hold promise for decreasing the flow of guns into the hands of youth. PMID:12194613

  18. Unbalanced field RF electron gun

    DOEpatents

    Hofler, Alicia

    2013-11-12

    A design for an RF electron gun having a gun cavity utilizing an unbalanced electric field arrangement. Essentially, the electric field in the first (partial) cell has higher field strength than the electric field in the second (full) cell of the electron gun. The accompanying method discloses the use of the unbalanced field arrangement in the operation of an RF electron gun in order to accelerate an electron beam.

  19. Hot hollow cathode gun assembly

    DOEpatents

    Zeren, J.D.

    1983-11-22

    A hot hollow cathode deposition gun assembly includes a hollow body having a cylindrical outer surface and an end plate for holding an adjustable heat sink, the hot hollow cathode gun, two magnets for steering the plasma from the gun into a crucible on the heat sink, and a shutter for selectively covering and uncovering the crucible.

  20. Glue Guns: Aiming for Safety

    ERIC Educational Resources Information Center

    Roy, Ken

    2010-01-01

    While glue guns are very useful, there are safety issues. Regardless of the temperature setting, glue guns can burn skin. The teacher should demonstrate and supervise the use of glue guns and have a plan should a student get burned. There should be an initial first aid protocol in place, followed by a visit to the school nurse. An accident report…

  1. Vacuum vapor deposition gun assembly

    DOEpatents

    Zeren, Joseph D.

    1985-01-01

    A vapor deposition gun assembly includes a hollow body having a cylindrical outer surface and an end plate for holding an adjustable heat sink, a hot hollow cathode gun, two magnets for steering the plasma from the gun into a crucible on the heat sink, and a shutter for selectively covering and uncovering the crucible.

  2. Children, Youth, and Gun Violence.

    ERIC Educational Resources Information Center

    Behrman, Richard E., Ed.

    2002-01-01

    This collection of articles summarizes knowledge and research about how gun violence affects children and youth and discusses which policies hold promise for reducing youth gun violence. The papers are: (1) "Statement of Purpose" (Richard E. Behrman); "Children, Youth, and Gun Violence: Analysis and Recommendations" (Kathleen Reich, Patti L.…

  3. Magnetron injection gun scaling

    SciTech Connect

    Lawson, W.

    1988-04-01

    Existing analytic design equations for magnetron injection guns (MIG's) are approximated to obtain a set of scaling laws. The constraints are chosen to examine the maximum peak power capabilities of MIG's. The scaling laws are compared with exact solutions of the design equations and are supported by MIG simulations.

  4. The Rail Gun.

    ERIC Educational Resources Information Center

    Stewart, Gay B.

    1996-01-01

    Presents a rail gun demonstration that addresses a broad group of educational goals in introductory electricity and magnetism. Uses a battery-powered circuit consisting of a movable conductor placed across two conducting rails in a magnetic field to review mechanics, foster approximate reasoning and lateral class discussion, and demonstrate the…

  5. Service Without Guns

    ERIC Educational Resources Information Center

    Eberly, Donald J.; Gal, Reuven

    2006-01-01

    "Service Without Guns"--by Donald J. Eberly and Reuven Gal with a guest chapter by Michael Sherraden--notes the many similarities between military service and civilian National Youth Service (NYS) and concludes that NYS can and should become as large and influential in the 21st Century as military service was in the 20th. The book examines the…

  6. Radar gun hazards

    SciTech Connect

    Not Available

    1991-12-20

    Radar guns - hand-held units used by the law to nail speeders - have been in use since the early '60s. Now they've been accused of causing cancer. Police officers in several states have so far filed eight suits against the manufacturer, claiming that they have contracted rare forms of cancer, such as of the eyelid and the testicle, from frequent proximity to the devices. Spurred by concerns expressed by police groups, researchers at the Rochester Institute of Technology are conducting what they believe to be the first research of its kind in the nation. Last month psychologist John Violanti, an expert in policy psychology and health, sent out a one-page survey to 6,000 active and retired police officers in New York State, asking them about their health and their use of radar guns. Violanti says melanoma, leukemia, and lymph node cancer may be linked to these as well as other electromagnetic devices. The Food and Drug Administration earlier this year issued a warning about radar guns, telling users not to operate them closer than 6 inches from the body. But this may not be a sufficient safeguard since the instruments can give off crisscrossing wave emissions within a police vehicle. The survey will be used to help determine if it would be safer to mount the guns, which are currently either hand-held or mounted on dashboards, outside troopers' cars.

  7. Gun control saves lives.

    PubMed

    Matzopoulos, Richard

    2016-01-01

    Reducing firearm mortality by means of stricter gun control is one of the most important short- to medium-term measures to address the burden of violence in South Africa, while longer-term interventions and policy measures take effect. PMID:27245735

  8. Gun Dealers, USA.

    ERIC Educational Resources Information Center

    Duker, Laurie; And Others

    In the United States, more than 11,500 adolescents' and young adults' lives are taken each year by firearms. Although Federal law prohibits minors from purchasing handguns, they typically get them by asking someone of legal age (18 years or older) to purchase them from one of the 256,771 Federally licensed gun dealers. This pamphlet answers…

  9. SkyLine and SkyGas: Novel automated technologies for automatic GHG flux measurements

    NASA Astrophysics Data System (ADS)

    Ineson, Philip; Stockdale, James

    2014-05-01

    1. Concerns for the future of the Earth's climate centre around the anthropogenically-driven continuing increases in atmospheric concentrations of the major 'greenhouse gases' (GHGs) which include CO2, CH4 and N2O. A major component of the global budgets for all three of these gases is the flux between the atmosphere and terrestrial ecosystems. 2. Currently, these fluxes are poorly quantified, largely due to technical limitations associated with making these flux measurements. Whilst eddy covariance systems have greatly improved such measurements at the ecosystem scale, flux measurements at the plot scale are commonly made using labour intensive traditional 'cover box' approaches; technical limitations have frequently been a bottle-neck in producing adequate and appropriate GHG flux data necessary for making land management decisions. For example, there are almost no night time flux data for N2O fluxes, and frequently such data are only measured over bare soil patches. 3. We have been addressing the design of novel field equipment for the automation of GHG flux measurements at the chamber and plot scale and will present here some of the technical solutions we have developed. These solutions include the development of the SkyLine and SkyGas approaches which resolve many of the common problems associated with making high frequency, sufficiently replicated GHG flux measurements under field conditions. 4. Unlike most other automated systems, these technologies 'fly' a single chamber to the measurement site, rather than have multiple replicated chambers and analysers. We will present data showing how such systems can deliver high time and spatial resolution flux data, with a minimum of operator intervention and, potentially, at relatively low per plot cost. We will also show how such measurements can be extended to monitoring fluxes from freshwater features in the landscape.

  10. The polarized SRF gun experiment.

    SciTech Connect

    Kewisch,J.; Ben-Zvi, I.; Rao, T.; Burrill, A.; Pate, D.; Grover, R.; Todd, R.; Bluem, H.; Holmes, D.; Schultheiss, T.

    2007-09-10

    RF electron guns are capable of producing electron bunches with high brightness, which outperform DC electron guns and may even be able to provide electron beams for the ILC without the need for a damping ring. However, all successful existing guns for polarized electrons are DC guns because the environment inside an RF gun is hostile to the GaAs cathode material necessary for polarization. While the typical vacuum pressure in a DC gun is better than 10{sup -11} torr the vacuum in an RF gun is in the order of 10{sup -9} torr. Experiments at BINP Novosibirsk show that this leads to strong ion back-bombardment and generation of dark currents, which destroy the GaAs cathode in a short time. The situation might be much more favorable in a (super-conducting) SRF gun. The cryogenic pumping of the gun cavity walls may make it possible to maintain a vacuum close to 10{sup -12} torr, solving the problem of ion bombardment and dark currents. Of concern would be contamination of the gun cavity by evaporating cathode material. This report describes an experiment that Brookhaven National Laboratory (BNL) in collaboration with Advanced Energy Systems (AES) is conducting to answer these questions.

  11. Gun Attitudes and Fear of Crime.

    ERIC Educational Resources Information Center

    Heath, Linda; Weeks, Kyle; Murphy, Marie Mackay

    1997-01-01

    Using three studies, examined the relationship between attitudes toward guns and fear of crime. Findings indicate a connection between fear of crime and attitudes toward guns: people higher in fear of crime favored gun control. Results also established a relationship between stereotypical beliefs about gun victims and support for gun control. (RJM)

  12. Friction in rail guns

    NASA Technical Reports Server (NTRS)

    Kay, P. K.

    1984-01-01

    The influence of friction is included in the present equations describing the performance of an inductively driven rail gun. These equations, which have their basis in an empirical formulation, are applied to results from two different experiments. Only an approximate physical description of the problem is attempted, in view of the complexity of details in the interaction among forces of this magnitude over time periods of the order of milisecs.

  13. Improved DC Gun Insulator

    SciTech Connect

    M.L. Neubauer, K.B. Beard, R. Sah, C. Hernandez-Garcia, G. Neil

    2009-05-01

    Many user facilities such as synchrotron light sources and free electron lasers require accelerating structures that support electric fields of 10-100 MV/m, especially at the start of the accelerator chain where ceramic insulators are used for very high gradient DC guns. These insulators are difficult to manufacture, require long commissioning times, and have poor reliability, in part because energetic electrons bury themselves in the ceramic, creating a buildup of charge and causing eventual puncture. A novel ceramic manufacturing process is proposed. It will incorporate bulk resistivity in the region where it is needed to bleed off accumulated charge caused by highly energetic electrons. This process will be optimized to provide an appropriate gradient in bulk resistivity from the vacuum side to the air side of the HV standoff ceramic cylinder. A computer model will be used to determine the optimum cylinder dimensions and required resistivity gradient for an example RF gun application. A ceramic material example with resistivity gradient appropriate for use as a DC gun insulator will be fabricated by glazing using doping compounds and tested.

  14. Wisconsin SRF Electron Gun Commissioning

    SciTech Connect

    Bisognano, Joseph J.; Bissen, M.; Bosch, R.; Efremov, M.; Eisert, D.; Fisher, M.; Green, M.; Jacobs, K.; Keil, R.; Kleman, K.; Rogers, G.; Severson, M.; Yavuz, D. D.; Legg, Robert A.; Bachimanchi, Ramakrishna; Hovater, J. Curtis; Plawski, Tomasz; Powers, Thomas J.

    2013-12-01

    The University of Wisconsin has completed fabrication and commissioning of a low frequency (199.6 MHz) superconducting electron gun based on a quarter wave resonator (QWR) cavity. Its concept was optimized to be the source for a CW free electron laser facility. The gun design includes active tuning and a high temperature superconducting solenoid. We will report on the status of the Wisconsin SRF electron gun program, including commissioning experience and first beam measurements.

  15. Gun muzzle blast and flash

    NASA Astrophysics Data System (ADS)

    Klingenberg, Guenter; Heimerl, Joseph M.

    A repository of fundamental experimental and analytical data concerning the complex phenomena associated with gun-muzzle blast and flash effects is presented, proceeding from gun muzzle signatures to modern gun-propulsion concepts, interior and transitional ballistics, and characterizations of blast-wave research and muzzle flash. Data are presented in support of a novel hypothesis which explains the ignition of secondary flash and elucidates the means for its suppression. Both chemical and mechanical (often competing) methods of flash suppression are treated. The historical work of Kesslau and Ladenburg is noted, together with French, British, Japanese and American research efforts and current techniques of experimental characterization for gun muzzle phenomena.

  16. Resonant optical gun.

    PubMed

    Maslov, A V; Bakunov, M I

    2014-05-01

    We propose a concept of a structure-a resonant optical gun-to realize an efficient propulsion of dielectric microparticles by light forces. The structure is based on a waveguide in which a reversal of the electromagnetic momentum flow of the incident mode is realized by exciting a whispering gallery resonance in the microparticle. The propelling force can reach the value up to the theoretical maximum of twice the momentum flow of the initial wave. The force density oscillates along the particle periphery and has very large amplitude. PMID:24784113

  17. Gun Concerns Personal for Duncan

    ERIC Educational Resources Information Center

    McNeil, Michele

    2013-01-01

    As U.S. Secretary of Education Arne Duncan works with other Obama administration officials on policy responses to the shootings at a Connecticut elementary school, he brings a personal and professional history that has acquainted him with the impact of gun violence. As schools chief in Chicago from 2001 to 2008, he was affected by the gun deaths…

  18. LCLS Gun Solenoid Design Considerations

    SciTech Connect

    Schmerge, John

    2010-12-10

    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 dipole and quadrupole correctors inside the solenoid, increasing the bore to accommodate the correctors, decreasing the mirror plate thickness to allow the solenoid to move closer to the cathode, cutouts in the mirror plate to allow greater optical clearance with grazing incidence cathode illumination, utilizing pancake coil mirror images to compensate the first and second integrals of the transverse fields and incorporating a bipolar power supply to allow for proper magnet standardization and quick polarity changes. This paper describes all these modifications plus the magnetic measurements and operational experience leading to the suggested modifications.

  19. Preventing gun injuries in children.

    PubMed

    Crossen, Eric J; Lewis, Brenna; Hoffman, Benjamin D

    2015-02-01

    Firearms are involved in the injury and death of a large number of children each year from both intentional and unintentional causes. Gun ownership in homes with children is common, and pediatricians should incorporate evidence-based means to discuss firearms and protect children from gun-related injuries and violence. Safe storage of guns, including unloaded guns locked and stored separately from ammunition, can decrease risks to children, and effective tools are available that pediatricians can use in clinical settings to help decrease children's access to firearms. Furthermore, several community-based interventions led by pediatricians have effectively reduced firearm-related injury risks to children. Educational programs that focus on children's behavior around guns have not proven effective. PMID:25646308

  20. Electric arc welding gun

    DOEpatents

    Luttrell, Edward; Turner, Paul W.

    1978-01-01

    This invention relates to improved apparatus for arc welding an interior joint formed by intersecting tubular members. As an example, the invention is well suited for applications where many similar small-diameter vertical lines are to be welded to a long horizontal header. The improved apparatus includes an arc welding gun having a specially designed welding head which is not only very compact but also produces welds that are essentially free from rolled-over solidified metal. The welding head consists of the upper end of the barrel and a reversely extending electrode holder, or tip, which defines an acute angle with the barrel. As used in the above-mentioned example, the gun is positioned to extend upwardly through the vertical member and the joint to be welded, with its welding head disposed within the horizontal header. Depending on the design of the welding head, the barrel then is either rotated or revolved about the axis of the vertical member to cause the electrode to track the joint.

  1. Investigating the Link Between Gun Possession and Gun Assault

    PubMed Central

    Richmond, Therese S.; Culhane, Dennis P.; Ten Have, Thomas R.; Wiebe, Douglas J.

    2009-01-01

    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 a gun were 4.46 (P < .05) times more likely to be shot in an assault than those not in possession. Among gun assaults where the victim had at least some chance to resist, this adjusted odds ratio increased to 5.45 (P < .05). Conclusions. On average, guns did not protect those who possessed them from being shot in an assault. Although successful defensive gun uses occur each year, the probability of success may be low for civilian gun users in urban areas. Such users should reconsider their possession of guns or, at least, understand that regular possession necessitates careful safety countermeasures. PMID:19762675

  2. Gun shows and gun violence: fatally flawed study yields misleading results.

    PubMed

    Wintemute, Garen J; Hemenway, David; Webster, Daniel; Pierce, Glenn; Braga, Anthony A

    2010-10-01

    A widely publicized but unpublished study of the relationship between gun shows and gun violence is being cited in debates about the regulation of gun shows and gun commerce. We believe the study is fatally flawed. A working paper entitled "The Effect of Gun Shows on Gun-Related Deaths: Evidence from California and Texas" outlined this study, which found no association between gun shows and gun-related deaths. We believe the study reflects a limited understanding of gun shows and gun markets and is not statistically powered to detect even an implausibly large effect of gun shows on gun violence. In addition, the research contains serious ascertainment and classification errors, produces results that are sensitive to minor specification changes in key variables and in some cases have no face validity, and is contradicted by 1 of its own authors' prior research. The study should not be used as evidence in formulating gun policy. PMID:20724672

  3. Gun Shows and Gun Violence: Fatally Flawed Study Yields Misleading Results

    PubMed Central

    Hemenway, David; Webster, Daniel; Pierce, Glenn; Braga, Anthony A.

    2010-01-01

    A widely publicized but unpublished study of the relationship between gun shows and gun violence is being cited in debates about the regulation of gun shows and gun commerce. We believe the study is fatally flawed. A working paper entitled “The Effect of Gun Shows on Gun-Related Deaths: Evidence from California and Texas” outlined this study, which found no association between gun shows and gun-related deaths. We believe the study reflects a limited understanding of gun shows and gun markets and is not statistically powered to detect even an implausibly large effect of gun shows on gun violence. In addition, the research contains serious ascertainment and classification errors, produces results that are sensitive to minor specification changes in key variables and in some cases have no face validity, and is contradicted by 1 of its own authors’ prior research. The study should not be used as evidence in formulating gun policy. PMID:20724672

  4. Air gun test evaluation

    SciTech Connect

    Carleton, J.J. II; Fox, L.; Rudy, C.R.

    1992-01-15

    A mechanical shock testing apparatus is used for testing the response of components subject to large accelerations in hostile environments. The test acceleration is provided by the impact of a bullet against a plate on which the component to be tested is mounted. This report describes a series of experiments that were performed to determine the dependence of the air gun test apparatus performance on incremental changes in the hardware configurations, changes in the pressure used to drive the bullet, and different accelerometers. The effect of variation of these experimental factors on the measured acceleration was determined using a Taguchi screening experimental design. Experimental settings were determined that can be used to operate the tester with a measured output within acceleration specifications.

  5. High Intensity Polarized Electron Gun

    SciTech Connect

    Redwine, Robert P.

    2012-07-31

    The goal of the project was to investigate the possibility of building a very high intensity polarized electron gun for the Electron-Ion Collider. This development is crucial for the eRHIC project. The gun implements a large area cathode, ring-shaped laser beam and active cathode cooling. A polarized electron gun chamber with a large area cathode and active cathode cooling has been built and tested. A preparation chamber for cathode activation has been built and initial tests have been performed. Major parts for a load-lock chamber, where cathodes are loaded into the vacuum system, have been manufactured.

  6. Reduction of Gun Erosion and Correlation of Gun Erosion Measurements

    NASA Technical Reports Server (NTRS)

    Bogdanoff, Dave; Wercinski, Paul (Technical Monitor)

    1997-01-01

    Gun barrel erosion is serious problem with two-stage light gas guns. Excessive barrel erosion can lead to poor or failed launches and frequent barrel changes, with the corresponding down time. Also, excessive barrel erosion can limit the maximum velocity obtainable by loading down the hydrogen working gas with eroded barrel material. Guided by a CFD code, the operating conditions of the Ames 0.5-inch gun were modified to reduce barrel erosion. The changes implemented included: (1) reduction in the piston mass, powder mass and hydrogen fill pressure; and (2) reduction in pump tube volume, while maintaining hydrogen mass. The latter change was found, in particular, to greatly reduce barrel erosion. For muzzle velocity ranges of 6.1 - 6.9 km/sec, the barrel erosion was reduced by a factor of 10. Even for the higher muzzle velocity range of 7.0 - 8.2 km/sec, the barrel erosion was reduced by a factor of 4. Gun erosion data from the Ames 0.5-inch, 1.0-inch, and 1.5-inch guns operated over a wide variety of launch conditions was examined and it was found that this data could be correlated using four different parameters: normalized powder charge energy, normalized hydrogen energy density, normalized pump tube volume and barrel diameter. The development of the correlation and the steps used to collapse the experimental data are presented. Over a certain parameter range in the correlation developed, the barrel erosion per shot is found to increase very rapidly. The correlation should prove useful in the selection of gun operating conditions and the design of new guns. Representative shapes of eroded gun barrels are also presented.

  7. Temporal association between federal gun laws and the diversion of guns to criminals in Milwaukee.

    PubMed

    Webster, Daniel W; Vernick, Jon S; Bulzacchelli, Maria T; Vittes, Katherine A

    2012-02-01

    The practices of licensed gun dealers can threaten the safety of urban residents by facilitating the diversion of guns to criminals. In 2003, changes to federal law shielded gun dealers from the release of gun trace data and provided other protections to gun dealers. The 14-month period during which the dealer did not sell junk guns was associated with a 68% reduction in the diversion of guns to criminals within a year of sale by the dealer and a 43% increase in guns diverted to criminals following sales by other dealers. The laws were associated with a 203% increase in the number of guns diverted to criminals within a year of sale by the gun store, which was the focus of this study. Policies which affect gun dealer accountability appeared to influence the diversion of guns to criminals. PMID:22218834

  8. The polarized SRF gun experiment

    SciTech Connect

    Kewisch,J.; Ben-Zvi, I.; Rao, T.; Burrill, A.; Pate, D.; Todd, R.; Wang, E.; Bluem, H.; Holmes, D.; Shultheiss, T.

    2008-10-01

    An experiment is under way to prove the feasibility of a super-conducting RF gun for the production of polarized electrons. We report on the progress of the experiment and on simulations predicting the possibility of success.

  9. NASA-Ames vertical gun

    NASA Technical Reports Server (NTRS)

    Schultz, P. H.

    1984-01-01

    A national facility, the NASA-Ames vertical gun range (AVGR) has an excellent reputation for revealing fundamental aspects of impact cratering that provide important constraints for planetary processes. The current logistics in accessing the AVGR, some of the past and ongoing experimental programs and their relevance, and the future role of this facility in planetary studies are reviewed. Publications resulting from experiments with the gun (1979 to 1984) are listed as well as the researchers and subjects studied.

  10. The case for moderate gun control.

    PubMed

    DeGrazia, David

    2014-03-01

    In addressing the shape of appropriate gun policy, this essay assumes for the sake of discussion that there is a legal and moral right to private gun ownership. My thesis is that, against the background of this right, the most defensible policy approach in the United States would feature moderate gun control. The first section summarizes the American gun control status quo and characterizes what I call "moderate gun control." The next section states and rebuts six leading arguments against this general approach to gun policy. The section that follows presents a positive case for moderate gun control that emphasizes safety in the home and society as well as rights whose enforcement entails some limits or qualifications on the right to bear arms. A final section shows how the recommended gun regulations address legitimate purposes, rather than imposing arbitrary restrictions on gun rights, and offers concluding reflections. PMID:24783322

  11. Large Bore Powder Gun Qualification (U)

    SciTech Connect

    Rabern, Donald A.; Valdiviez, Robert

    2012-04-02

    A Large Bore Powder Gun (LBPG) is being designed to enable experimentalists to characterize material behavior outside the capabilities of the NNSS JASPER and LANL TA-55 PF-4 guns. The combination of these three guns will create a capability to conduct impact experiments over a wide range of pressures and shock profiles. The Large Bore Powder Gun will be fielded at the Nevada National Security Site (NNSS) U1a Complex. The Complex is nearly 1000 ft below ground with dedicated drifts for testing, instrumentation, and post-shot entombment. To ensure the reliability, safety, and performance of the LBPG, a qualification plan has been established and documented here. Requirements for the LBPG have been established and documented in WE-14-TR-0065 U A, Large Bore Powder Gun Customer Requirements. The document includes the requirements for the physics experiments, the gun and confinement systems, and operations at NNSS. A detailed description of the requirements is established in that document and is referred to and quoted throughout this document. Two Gun and Confinement Systems will be fielded. The Prototype Gun will be used primarily to characterize the gun and confinement performance and be the primary platform for qualification actions. This gun will also be used to investigate and qualify target and diagnostic modifications through the life of the program (U1a.104 Drift). An identical gun, the Physics Gun, will be fielded for confirmatory and Pu experiments (U1a.102D Drift). Both guns will be qualified for operation. The Gun and Confinement System design will be qualified through analysis, inspection, and testing using the Prototype Gun for the majority of process. The Physics Gun will be qualified through inspection and a limited number of qualification tests to ensure performance and behavior equivalent to the Prototype gun. Figure 1.1 shows the partial configuration of U1a and the locations of the Prototype and Physics Gun/Confinement Systems.

  12. [Suicide with home-made gun].

    PubMed

    Safr, M; Hejna, P; Zátopková, L

    2009-04-01

    Three cases of suicide by single bullet injury to head by home-made guns with immediate incapacitation are reported in following article. Zip gun (home-made gun) is a improvised firearm, usually a handgun. Home-made guns are almost always single-shot, as the improvised construction sometimes makes them weak enough to be destroyed by the act of firing. Zip guns are mostly smoothbore. Zip gun injuries, although unique today, represent a special category of missile injury with atypical low velocity terminal ballistics. PMID:19534397

  13. Guns in the home: risky business.

    PubMed

    Wiebe, Douglas J

    2003-05-01

    One in three U.S. households contains at least one firearm. Gun owners cite two main reasons for having a gun: hunting and self-protection. A majority of handgun owners believe that they are protecting their homes and families against violent assaults. But in a country where the majority of homicides and suicides involve a gun, it is reasonable to question whether access to a gun increases or decreases the risk of violent death. This Issue Brief describes case-control studies that investigate links between gun availability and gun death, and supports earlier findings that people with guns in their homes appear to increase their risk of being shot fatally (intentionally or unintentionally) or taking their own life with a gun. PMID:12828174

  14. States with More Gun Owners Have More Gun-Related Suicides: Study

    MedlinePlus

    ... medlineplus/news/fullstory_158931.html States With More Gun Owners Have More Gun-Related Suicides: Study But only association was found, ... HealthDay News) -- In states where there are more gun owners, there are also more gun-related suicides, ...

  15. States with More Gun Owners Have More Gun-Related Suicides: Study

    MedlinePlus

    ... gov/news/fullstory_158931.html States With More Gun Owners Have More Gun-Related Suicides: Study But only association was found, ... HealthDay News) -- In states where there are more gun owners, there are also more gun-related suicides, ...

  16. Automatic targeting of plasma spray gun

    DOEpatents

    Abbatiello, Leonard A.; Neal, Richard E.

    1978-01-01

    A means for monitoring the material portion in the flame of a plasma spray gun during spraying operations is provided. A collimated detector, sensitive to certain wavelengths of light emission, is used to locate the centroid of the material with each pass of the gun. The response from the detector is then relayed to the gun controller to be used to automatically realign the gun.

  17. Unintentional Gun Deaths among Children. Firearm Facts.

    ERIC Educational Resources Information Center

    Duker, Laurie, Ed.

    Children are at risk of being killed or injured by a gun if their parents own a gun because many guns obtained for self-defense are kept loaded and within reach of children. This brief fact sheet presents statistical information relating to accidental deaths involving young people and firearms. Safety measures are suggested for preventing…

  18. Guns in Schools. Firearm Facts.

    ERIC Educational Resources Information Center

    Duker, Laurie, Ed.

    Common reasons that young people choose to carry firearms outside of school--protection, intimidation of others, or to be like their peers--are the same reasons they carry guns into the school. This fact sheet presents statistics regarding the prevalence of firearms amongst students in American schools, including: shooting fatalities and woundings…

  19. RF Design of the LCLS Gun

    SciTech Connect

    Limborg-Deprey, C

    2010-12-13

    Final dimensions for the LCLS RF gun are described. This gun, referred to as the LCLS gun, is a modified version of the UCLA/BNL/SLAC 1.6 cell S-Band RF gun [1], referred to as the prototype gun. The changes include a larger mode separation (15 MHz for the LCLS gun vs. 3.5 MHz for the prototype gun), a larger radius at the iris between the 2 cells, a reduced surface field on the curvature of the iris between the two cells, Z power coupling, increased cooling channels for operation at 120 Hz, dual rf feed, deformation tuning of the full cell, and field probes in both cells. Temporal shaping of the klystron pulse, to reduce the average power dissipated in the gun, has also been adopted. By increasing the mode separation, the amplitude of the 0-mode electric field on the cathode decreases from 10% of the peak on axis field for the prototype gun to less than 3% for the LCLS gun for the steady state fields. Beam performance is improved as shown by the PARMELA simulations. The gun should be designed to accept a future load lock system. Modifications follow the recommendations of our RF review committee [2]. Files and reference documents are compiled in Section IV.

  20. Granny, (don't) get your gun: competency issues in gun ownership by older adults.

    PubMed

    Greene, Edith; Bornstein, Brian H; Dietrich, Hannah

    2007-01-01

    This article explores the possible risks associated with gun ownership by older adults. We summarize existing regulations on who may own firearms, especially with respect to age. We then present data on older gun owners and violence committed by older adults in general, followed by a discussion of gun violence perpetrated by gun owners whose functional and cognitive abilities have declined, perhaps as a result of dementia. For comparison purposes, we review regulations on driving among older adults, drawing parallels to gun ownership. The paper concludes with recommendations for ensuring the safety of older gun owners and others, balanced against citizens' right to bear arms, and with some directions for research. PMID:17559168

  1. A gasdynamic gun driven by gaseous detonation

    NASA Astrophysics Data System (ADS)

    Li, Jinping; Chen, Hong; Zhang, Shizhong; Zhang, Xiaoyuan; Yu, Hongru

    2016-01-01

    A gasdynamic gun driven by gaseous detonation was developed to address the disadvantages of the insufficient driving capability of high-pressure gas and the constraints of gunpowder. The performance of this gasdynamic gun was investigated through experiments and numerical simulations. Much more powerful launching capability was achieved by this gun relative to a conventional high-pressure gas gun, owing to the use of the chemical energy of the driver gas. To achieve the same launching condition, the initial pressure required for this gun was an order of magnitude lower than that for a gun driven by high-pressure H2. Because of the presence of the detonation, however, a more complex internal ballistic process of this gun was observed. Acceleration of projectiles for this gun was accompanied by a series of impulse loads, in contrast with the smooth acceleration for a conventional one, which indicates that this gun should be used conditionally. The practical feasibility of this gun was verified by experiments. The experiments demonstrated the convenience of taking advantage of the techniques developed for detonation-driven shock tubes and tunnels.

  2. A gasdynamic gun driven by gaseous detonation.

    PubMed

    Li, Jinping; Chen, Hong; Zhang, Shizhong; Zhang, Xiaoyuan; Yu, Hongru

    2016-01-01

    A gasdynamic gun driven by gaseous detonation was developed to address the disadvantages of the insufficient driving capability of high-pressure gas and the constraints of gunpowder. The performance of this gasdynamic gun was investigated through experiments and numerical simulations. Much more powerful launching capability was achieved by this gun relative to a conventional high-pressure gas gun, owing to the use of the chemical energy of the driver gas. To achieve the same launching condition, the initial pressure required for this gun was an order of magnitude lower than that for a gun driven by high-pressure H2. Because of the presence of the detonation, however, a more complex internal ballistic process of this gun was observed. Acceleration of projectiles for this gun was accompanied by a series of impulse loads, in contrast with the smooth acceleration for a conventional one, which indicates that this gun should be used conditionally. The practical feasibility of this gun was verified by experiments. The experiments demonstrated the convenience of taking advantage of the techniques developed for detonation-driven shock tubes and tunnels. PMID:26827358

  3. Effects of a gun dealer's change in sales practices on the supply of guns to criminals.

    PubMed

    Webster, Daniel W; Vernick, Jon S; Bulzacchelli, Maria T

    2006-09-01

    Licensed gun dealers are a major conduit for gun trafficking. Prior to May 1999, a single gun store sold more than half of the guns recovered from criminals in Milwaukee, WI, shortly following retail sale. On May 10, 1999, the store stopped selling small, inexpensive handguns popular with criminals, often called "Saturday night specials." The purpose of this study was to estimate the effect of this gun store's changed sales practices on criminals' acquisition of new guns. We used an interrupted time-series design with comparisons to test for changes in the number of guns that police recovered from criminals within a year of retail sale following the gun dealer's new sales policy. The dealer's changed sales policy was associated with a 96% decrease in recently sold, small, inexpensive handguns use in crime in Milwaukee, a 73% decrease in crime guns recently sold by this dealer, and a 44% decrease in the flow of all new, trafficked guns to criminals in Milwaukee. The findings demonstrate the substantial impact that a single gun store's sales practices can have on the supply of new guns to criminals. Proposed anti-gun-trafficking efforts in other cities could benefit from targeting problem retail outlets. PMID:16937085

  4. Effects of a Gun Dealer's Change in Sales Practices on the Supply of Guns to Criminals

    PubMed Central

    Vernick, Jon S.; Bulzacchelli, Maria T.

    2006-01-01

    Licensed gun dealers are a major conduit for gun trafficking. Prior to May 1999, a single gun store sold more than half of the guns recovered from criminals in Milwaukee, WI, shortly following retail sale. On May 10, 1999, the store stopped selling small, inexpensive handguns popular with criminals, often called “Saturday night specials.” The purpose of this study was to estimate the effect of this gun store's changed sales practices on criminals' acquisition of new guns. We used an interrupted time-series design with comparisons to test for changes in the number of guns that police recovered from criminals within a year of retail sale following the gun dealer's new sales policy. The dealer's changed sales policy was associated with a 96% decrease in recently sold, small, inexpensive handguns use in crime in Milwaukee, a 73% decrease in crime guns recently sold by this dealer, and a 44% decrease in the flow of all new, trafficked guns to criminals in Milwaukee. The findings demonstrate the substantial impact that a single gun store's sales practices can have on the supply of new guns to criminals. Proposed anti-gun-trafficking efforts in other cities could benefit from targeting problem retail outlets. PMID:16937085

  5. X-Band RF Gun Development

    SciTech Connect

    Vlieks, Arnold; Dolgashev, Valery; Tantawi, Sami; Anderson, Scott; Hartemann, Fred; Marsh, Roark; /LLNL, Livermore

    2012-06-22

    In support of the MEGa-ray program at LLNL and the High Gradient research program at SLAC, a new X-band multi-cell RF gun is being developed. This gun, similar to earlier guns developed at SLAC for Compton X-ray source program, will be a standing wave structure made of 5.5 cells operating in the pi mode with copper cathode. This gun was designed following criteria used to build SLAC X-band high gradient accelerating structures. It is anticipated that this gun will operate with surface electric fields on the cathode of 200 MeV/m with low breakdown rate. RF will be coupled into the structure through a final cell with symmetric duel feeds and with a shape optimized to minimize quadrupole field components. In addition, geometry changes to the original gun, operated with Compton X-ray source, will include a wider RF mode separation, reduced surface electric and magnetic fields.

  6. Racism, Gun Ownership and Gun Control: Biased Attitudes in US Whites May Influence Policy Decisions

    PubMed Central

    O’Brien, Kerry; Forrest, Walter; Lynott, Dermot; Daly, Michael

    2013-01-01

    Objective Racism is related to policies preferences and behaviors that adversely affect blacks and appear related to a fear of blacks (e.g., increased policing, death penalty). This study examined whether racism is also related to gun ownership and opposition to gun controls in US whites. Method The most recent data from the American National Election Study, a large representative US sample, was used to test relationships between racism, gun ownership, and opposition to gun control in US whites. Explanatory variables known to be related to gun ownership and gun control opposition (i.e., age, gender, education, income, conservatism, anti-government sentiment, southern vs. other states, political identification) were entered in logistic regression models, along with measures of racism, and the stereotype of blacks as violent. Outcome variables included; having a gun in the home, opposition to bans on handguns in the home, support for permits to carry concealed handguns. Results After accounting for all explanatory variables, logistic regressions found that for each 1 point increase in symbolic racism there was a 50% increase in the odds of having a gun at home. After also accounting for having a gun in the home, there was still a 28% increase in support for permits to carry concealed handguns, for each one point increase in symbolic racism. The relationship between symbolic racism and opposition to banning handguns in the home (OR1.27 CI 1.03,1.58) was reduced to non-significant after accounting for having a gun in the home (OR1.17 CI.94,1.46), which likely represents self-interest in retaining property (guns). Conclusions Symbolic racism was related to having a gun in the home and opposition to gun control policies in US whites. The findings help explain US whites’ paradoxical attitudes towards gun ownership and gun control. Such attitudes may adversely influence US gun control policy debates and decisions. PMID:24204867

  7. Improved Orifice Plate for Spray Gun

    NASA Technical Reports Server (NTRS)

    Cunningham, W.

    1986-01-01

    Erratic spray pattern of commercial spray gun changed to repeatable one by simple redesign of two parts. In modified spray gun orifice plate and polytetrafluoroethylene bushing redesigned to assure centering and alignment with nozzle. Such improvement useful in many industrial applications requiring repeatable spray patterns. Might include spraying of foam insulation, paint, other protective coatings, detergents, abrasives, adhesives, process chemicals, or fuels. Unmodified spray gun produces erratic spray because lateral misalignment between orifice plate and nozzle.

  8. Health and Gun Violence. Guns as a Public-Health Issue.

    ERIC Educational Resources Information Center

    Duran, Victoria

    1994-01-01

    Violence in all settings has reached epidemic proportions. Most shootings are committed by friends or relatives following an argument or when playing with guns. The public needs education about nonviolent ways of coping with anger and about the high cost of gun violence. Suggestions for avoiding gun violence and the PTA position on firearms are…

  9. From gun politics to self-defense politics: a feminist critique of the great gun debate.

    PubMed

    Carlson, Jennifer D

    2014-03-01

    This article calls attention to a problematic binary produced by public debates surrounding gun rights and gun control-namely, that women must choose armed self-protection or no self-protection at all. I argue that both anti- and pro-gun discourses, drawing on and reproducing race and class privileges, use assumptions about women's physical inferiority to further their agendas. I highlight how both sides have used guns as the proxy for self-defense and conclude by calling for a shift in public discourse to focus on the broader question of the right to self-defense rather than the narrower question of gun rights. PMID:24686128

  10. Crafting a Gauss Gun Demonstration

    NASA Astrophysics Data System (ADS)

    Blodgett, Matthew E.; Blodgett, E. D.

    2006-12-01

    A Gauss Gun launches a ferromagnetic projectile using a pulsed electromagnet. This demonstration provides a nice counterpoint to the popular Thompson's jumping ring demonstration, which launches a nonferromagnetic ring via repulsion of an induced current. The pulsed current must be short enough in duration so that the projectile is not retarded by lingering current in the launch solenoid, but also large enough to provide a suitably impressive velocity. This project involved an iterative design process, as we worked through balancing all the different design criteria. We recommend it as a very nice electronics design project which will produce a very portable and enjoyable demonstration. AAPT sponsor Earl Blodgett.

  11. The Xygra gun simulation tool.

    SciTech Connect

    Garasi, Christopher Joseph; Lamppa, Derek C.; Aubuchon, Matthew S.; Shirley, David Noyes; Robinson, Allen Conrad; Russo, Thomas V.

    2008-12-01

    Inductive electromagnetic launchers, or coilguns, use discrete solenoidal coils to accelerate a coaxial conductive armature. To date, Sandia has been using an internally developed code, SLINGSHOT, as a point-mass lumped circuit element simulation tool for modeling coilgun behavior for design and verification purposes. This code has shortcomings in terms of accurately modeling gun performance under stressful electromagnetic propulsion environments. To correct for these limitations, it was decided to attempt to closely couple two Sandia simulation codes, Xyce and ALEGRA, to develop a more rigorous simulation capability for demanding launch applications. This report summarizes the modifications made to each respective code and the path forward to completing interfacing between them.

  12. Electromagnetic Gun With Commutated Coils

    NASA Technical Reports Server (NTRS)

    Elliott, David G.

    1991-01-01

    Proposed electromagnetic gun includes electromagnet coil, turns of which commutated in sequence along barrel. Electrical current fed to two armatures by brushes sliding on bus bars in barrel. Interaction between armature currents and magnetic field from coil produces force accelerating armature, which in turn, pushes on projectile. Commutation scheme chosen so magnetic field approximately coincides and moves with cylindrical region defined by armatures. Scheme has disadvantage of complexity, but in return, enables designer to increase driving magnetic field without increasing armature current. Attainable muzzle velocity increased substantially.

  13. Protect Children Instead of Guns, 2002.

    ERIC Educational Resources Information Center

    Children's Defense Fund, Washington, DC.

    Beginning with statistics pertaining to children and gun violence in a single year in the United States, this report details trends in child and youth gun deaths. Tables present information on the following: (1) number of firearms deaths by manner and by race from 1979 to 2000; (2) number of firearms deaths by manner for each state and nationwide,…

  14. Fighting Juvenile Gun Violence. Juvenile Justice Bulletin.

    ERIC Educational Resources Information Center

    Sheppard, David; Grant, Heath; Rowe, Wendy; Jacobs, Nancy

    This bulletin describes the Office of Juvenile Justice and Delinquency Prevention's efforts to fight juvenile gun violence. The Office awarded four community demonstration grants to implement "Partnerships To Reduce Juvenile Gun Violence." Partnership goals include increasing the effectiveness of existing strategies by enhancing and coordinating…

  15. Gun Control: The Debate and Public Policy.

    ERIC Educational Resources Information Center

    Watkins, Christine

    1997-01-01

    Provides an overview and background information on the debate over gun control, as well as several teaching ideas. Handouts include a list of related topics drawn from various disciplines (economics, U.S. history), seven arguments for and against gun control, and a set of policy evaluation guidelines. (MJP)

  16. Light gas gun with reduced timing jitter

    DOEpatents

    Laabs, G.W.; Funk, D.J.; Asay, B.W.

    1998-06-09

    Gas gun with reduced timing jitter is disclosed. A gas gun having a prepressurized projectile held in place with a glass rod in compression is described. The glass rod is destroyed with an explosive at a precise time which allows a restraining pin to be moved and free the projectile. 4 figs.

  17. Superconducting 112 MHz QWR electron gun

    SciTech Connect

    Belomestnykh, S.; Ben-Zvi, I.; Boulware, C.H.; Chang, X.; Grimm, T.L.; Rao, T.; Siegel, B.; Skaritka, J.; Than, R.; Winowski, M.; Wu, Q.; Xin, T.; Xue, L.

    2011-07-25

    Brookhaven National Laboratory and Niowave, Inc. have designed and fabricated a superconducting 112 MHz quarter-wave resonator (QWR) electron gun. The first cold test of the QWR cryomodule has been completed at Niowave. The paper describes the cryomodule design, presents the cold test results, and outline plans to upgrade the cryomodule. Future experiments include studies of different photocathodes and use for the coherent electron cooling proof-of-principle experiment. Two cathode stalk options, one for multi-alkali photocathodes and the other one for a diamond-amplified photocathode, are discussed. A quarter-wave resonator concept of superconducting RF (SRF) electron gun was proposed at BNL for electron cooling hadron beams in RHIC. QWRs can be made sufficiently compact even at low RF frequencies (long wavelengths). The long wavelength allows to produce long electron bunches, thus minimizing space charge effects and enabling high bunch charge. Also, such guns should be suitable for experiments requiring high average current electron beams. A 112 MHz QWR gun was designed, fabricated, and cold-tested in collaboration between BNL and Niowave. This is the lowest frequency SRF gun ever tested successfully. In this paper we describe the gun design and fabrication, present the cold test results, and outline our plans. This gun will also serve as a prototype for a future SRF gun to be used for coherent electron cooling of hadrons in eRHIC.

  18. Light gas gun with reduced timing jitter

    DOEpatents

    Laabs, Gary W.; Funk, David J.; Asay, Blaine W.

    1998-01-01

    Gas gun with reduced timing jitter. A gas gun having a prepressurized projectile held in place with a glass rod in compression is described. The glass rod is destroyed with an explosive at a precise time which allows a restraining pin to be moved and free the projectile.

  19. Youth Homicide and Guns. Firearm Facts.

    ERIC Educational Resources Information Center

    Duker, Laurie, Ed.

    Young Americans are killed with guns at rates far higher than young people in other countries and than older Americans, with young, urban African-American males being most at risk. This fact sheet presents data on gun-related homicides among teenagers in the United States. The high rate of youth homicide in the United States is unique in the…

  20. Experiments and Demonstrations with Soldering Guns.

    ERIC Educational Resources Information Center

    Henry, Dennis C.; Danielson, Sarah A.

    1993-01-01

    Discusses the essential electrical characteristics of a particular model of soldering gun. Presents four classroom demonstrations that utilize the soldering gun to test the following geometrics of wire loops as electromagnets: (1) the original tip; (2) a single circular loop; (3) a Helmholtz coil; and (4) the solenoid. (MDH)

  1. Gun shows across a multistate American gun market: observational evidence of the effects of regulatory policies

    PubMed Central

    Wintemute, Garen J

    2007-01-01

    Objective To describe gun shows and assess the impact of increased regulation on characteristics linked to their importance as sources of guns used in crime. Design Cross‐sectional, observational. Subjects Data were collected at a structured sample of 28 gun shows in California, which regulates these events and prohibits undocumented private party gun sales; and in Arizona, Nevada, Texas and Florida—all leading sources of California's crime guns—where these restrictions do not exist. Main outcome measures Size of shows, measured by numbers of gun vendors and people in attendance; number and nature of guns for sale by gun vendors; measures of private party gun sales and illegal surrogate (“straw”) gun purchases. Results Shows in comparison states were larger, but the number of attendees per gun vendor was higher in California. None of these differences was statistically significant. Armed attendees were more common in other states (median 5.7%, interquartile range (IQR) 3.9–10.0%) than in California (median 1.1%, IQR 0.5–2.2%), p = 0.0007. Thirty percent of gun vendors both in California and elsewhere were identifiable as licensed firearm retailers. There were few differences in the types or numbers of guns offered for sale; vendors elsewhere were more likely to sell assault weapons (34.9% and 13.3%, respectively; p = 0.001). Straw purchases were more common in the comparison states (rate ratio 6.6 (95% CI 0.9 to 49.1), p = 0.06). Conclusions California's regulatory policies were associated with a decreased incidence of anonymous, undocumented gun sales and illegal straw purchases at gun shows. No significant adverse effects of these policies were observed. PMID:17567968

  2. Life-threatening nail gun injuries.

    PubMed

    Beaver, A C; Cheatham, M L

    1999-12-01

    The use of pneumatic and explosive cartridge-activated nail guns is common in the construction industry. The ease and speed of nailing these tools afford enhance productivity at the cost of increased potential for traumatic injury. Although extremity injuries are most common, life-threatening injuries to the head, neck, chest, or abdomen and pelvis may occur. During a 20-month period, eight potentially life-threatening nail gun injuries were admitted to a Level I trauma center, including injuries to the brain, eye, neck, heart, lung, and femoral artery. Mechanism of injury included nail ricochet, nail gun misuse due to inadequate training, and successful suicide. Nail guns have significant potential for causing severe debilitating injury and death. These findings indicate a need for improved safety features and user education. The various types of nail guns, their ballistic potential, and techniques for operative management are discussed. PMID:10597056

  3. Sequential injection gas guns for accelerating projectiles

    DOEpatents

    Lacy, Jeffrey M.; Chu, Henry S.; Novascone, Stephen R.

    2011-11-15

    Gas guns and methods for accelerating projectiles through such gas guns are described. More particularly, gas guns having a first injection port located proximate a breech end of a barrel and a second injection port located longitudinally between the first injection port and a muzzle end of the barrel are described. Additionally, modular gas guns that include a plurality of modules are described, wherein each module may include a barrel segment having one or more longitudinally spaced injection ports. Also, methods of accelerating a projectile through a gas gun, such as injecting a first pressurized gas into a barrel through a first injection port to accelerate the projectile and propel the projectile down the barrel past a second injection port and injecting a second pressurized gas into the barrel through the second injection port after passage of the projectile and to further accelerate the projectile are described.

  4. Electron gun jitter effects on beam bunching

    SciTech Connect

    Liu, M. S.; Iqbal, M.

    2014-02-15

    For routine operation of Beijing Electron Positron Collider II (BEPCII) linac, many factors may affect the beam bunching process directly or indirectly. We present the measurements and analyses of the gun timing jitter, gun high voltage jitter, and beam energy at the exit of the standard acceleration section of the linac quantitatively. Almost 80 mV and more than 200 ps of gun high voltage and time jitters have ever been measured, respectively. It was analyzed that the gun timing jitter produced severe effects on beam energy than the gun high voltage jitter, if the timing jitter exceeded 100 ps which eventually deteriorates both the beam performance and the injection rate to the storage ring.

  5. ECR ion source with electron gun

    DOEpatents

    Xie, Z.Q.; Lyneis, C.M.

    1993-10-26

    An Advanced Electron Cyclotron Resonance ion source having an electron gun for introducing electrons into the plasma chamber of the ion source is described. The ion source has a injection enclosure and a plasma chamber tank. The plasma chamber is defined by a plurality of longitudinal magnets. The electron gun injects electrons axially into the plasma chamber such that ionization within the plasma chamber occurs in the presence of the additional electrons produced by the electron gun. The electron gun has a cathode for emitting electrons therefrom which is heated by current supplied from an AC power supply while bias potential is provided by a bias power supply. A concentric inner conductor and outer conductor carry heating current to a carbon chuck and carbon pusher which hold the cathode in place and also heat the cathode. In the Advanced Electron Cyclotron Resonance ion source, the electron gun replaces the conventional first stage used in prior electron cyclotron resonance ion generators. 5 figures.

  6. The Ames Vertical Gun Range

    NASA Technical Reports Server (NTRS)

    Karcz, J. S.; Bowling, D.; Cornelison, C.; Parrish, A.; Perez, A.; Raiche, G.; Wiens, J.-P.

    2016-01-01

    The Ames Vertical Gun Range (AVGR) is a national facility for conducting laboratory- scale investigations of high-speed impact processes. It provides a set of light-gas, powder, and compressed gas guns capable of accelerating projectiles to speeds up to 7 km s(exp -1). The AVGR has a unique capability to vary the angle between the projectile-launch and gravity vectors between 0 and 90 deg. The target resides in a large chamber (diameter approximately 2.5 m) that can be held at vacuum or filled with an experiment-specific atmosphere. The chamber provides a number of viewing ports and feed-throughs for data, power, and fluids. Impacts are observed via high-speed digital cameras along with investigation-specific instrumentation, such as spectrometers. Use of the range is available via grant proposals through any Planetary Science Research Program element of the NASA Research Opportunities in Space and Earth Sciences (ROSES) calls. Exploratory experiments (one to two days) are additionally possible in order to develop a new proposal.

  7. Subterranean well casing perforating gun

    SciTech Connect

    Stout, G. W.; Nelson, J. A.

    1984-10-30

    The invention provides a subterranean well casing perforating gun device which employs shaped explosive charges to perforate the well casing. The device generally defines an outer tubular housing assembly concentrically insertable in the well and defining a vertical axis, cylindrical chamber. A tubular carrier of polygonal cross sectional configuration is insertable in the chamber in concentric relationship to the cylindrical wall of the cylindrical chamber. Each of the faces of the carrier have a plurality of spaced passages therethrough, each passage having a configuration substantially corresponding to the configuration of the polygonal face. A shaped charge container has its cylindrical body insertable in any selected one of the passages and a radial flange on the outer end for abutting the polygonal face portion adjacent the respective passage, thereby limiting the insertion of each of the containers into the selected passage. Selectively disengageable fastening means are operable from the exterior of the carrier for clamping the radial flange against the respective polygonal face and for selective disengagement therefrom from the exterior of the carrier. The invention also contemplates a method of utilization of the carrier and the gun, as well as to incorporation of same into a particular perforating and gravel packing method and apparatus.

  8. Gun Violence, Mental Illness, And Laws That Prohibit Gun Possession: Evidence From Two Florida Counties.

    PubMed

    Swanson, Jeffrey W; Easter, Michele M; Robertson, Allison G; Swartz, Marvin S; Alanis-Hirsch, Kelly; Moseley, Daniel; Dion, Charles; Petrila, John

    2016-06-01

    Gun violence kills about ninety people every day in the United States, a toll measured in wasted and ruined lives and with an annual economic price tag exceeding $200 billion. Some policy makers suggest that reforming mental health care systems and improving point-of-purchase background checks to keep guns from mentally disturbed people will address the problem. Epidemiological research shows that serious mental illness contributes little to the risk of interpersonal violence but is a strong factor in suicide, which accounts for most firearm fatalities. Meanwhile, the effectiveness of gun restrictions focused on mental illness remains poorly understood. This article examines gun-related suicide and violent crime in people with serious mental illnesses, and whether legal restrictions on firearm sales to people with a history of mental health adjudication are effective in preventing gun violence. Among the study population in two large Florida counties, we found that 62 percent of violent gun crime arrests and 28 percent of gun suicides involved individuals not legally permitted to have a gun at the time. Suggested policy reforms include enacting risk-based gun removal laws and prohibiting guns from people involuntarily detained in short-term psychiatric hospitalizations. PMID:27269024

  9. Gun Violence, mental health, and Connecticut physicians.

    PubMed

    Dodds, Peter R; Anderson, Caitlyn O; Dodds, Jon H

    2014-01-01

    While there is a public perception that gun violence is associated with mental illness we present evidence that it is a complex public health problem which defies simple characterizations and solutions. Only a small percentage of individuals with mental illness are at risk for extreme violence and they account for only a small percentage of gun-related homicides. Individuals who are at risk for gun violence are difficult to identify and successfully treat. The incidence, and perhaps the demographics, of gun violence vary substantially from state to state. We make a case for Connecticut physicians to study gun violence at the state level. We recommend that Connecticut physicians promote and expand upon the American Academy of Pediatrics' recommendation for creating a "safe home environment. "We suggest that guns be secured in all homes in which there are children. In addition we suggest that guns be voluntarily removed from homes in which there are individuals with a history of violence, threats of violence, depression, drug and/or alcohol abuse, and individuals with major mental illnesses who are not cooperating with therapy. PMID:25745735

  10. Simple light gas guns for hypervelocity studies

    SciTech Connect

    Combs, S.K.; Haselton, H.H.; Milora, S.L.

    1990-01-01

    Two-stage light guns are used extensively in hypervelocity research. The applications of this technology include impact studies and special materials development. Oak Ridge National Laboratory (ORNL) has developed two-stage guns that accelerate small projectiles (4-mm nominal diameter) to velocities of up to {approx}5 km/s. These guns are relatively small and simple (thus, easy to operate), allowing a significant number of test shots to be carried out and data accumulated in a short time. Materials that have been used for projectiles include plastics, frozen isotopes of hydrogen, and lithium hydride. One gun has been used to demonstrate repetitive operation at a rate of 0.7 Hz; and, with a few design improvements, it appears capable of performing at firing frequencies of 1--2 Hz. A schematic of ORNL two-stage device is shown below. Unlike most such devices, no rupture disks are used. Instead, a fast valve (high-flow type) initiates the acceleration process in the first stage. Projectiles can be loaded into the gun breech via the slide mechanism; this action has been automated which allows repetitive firing. Alternatively, the device is equipped with pipe gun'' apparatus in which gas can be frozen in situ in the gun barrel to form the projectile. This equipment operates with high reliability and is well suited for small-scale testing at high velocity. 17 refs., 6 figs., 2 tabs.

  11. Nail-Gun Injuries to the Hand

    PubMed Central

    Pierpont, Yvonne N.; Pappas-Politis, Effie; Naidu, Deepak K.; Salas, R. Emerick; Johnson, Erika L.; Payne, Wyatt G.

    2008-01-01

    Background: The nail gun is a commonly utilized tool in carpentry and construction. When used properly with appropriate safety precautions, it can facilitate production and boost efficiency; however, this powerful tool also has the potential to cause serious injury. The most common site of nail-gun injuries in both industrial and nonoccupational settings is the hand. Materials and Methods: We report on two patients with nail-gun injuries to the hand. A review of the literature and discussion of clinical evaluation and treatment of nail-gun injuries to the hand are presented. Results: Two patients present with soft tissue injuries to the hand with the nail embedded and intact at the injury site. Operative removal of the nail and wound care resulted in successful treatment in both cases. Nail-gun injuries to the hand vary in severity on the basis of the extent of structural damage. Treatment is based on the severity of injury and the presence and location of barbs on the penetrating nail. Conclusion: Healthcare providers must understand and educate patients on the prevention mechanics of nail-gun injuries. Nail-gun injuries to the hand necessitate appropriate evaluation techniques, understanding of surgical management versus nonsurgical management, and awareness of potential pitfalls in treatment. PMID:19079574

  12. Homopolar Gun for Pulsed Spheromak Fusion Reactors II

    SciTech Connect

    Fowler, T

    2004-06-14

    A homopolar gun is discussed that could produce the high currents required for pulsed spheromak fusion reactors even with unit current amplification and open field lines during injection, possible because close coupling between the gun and flux conserver reduces gun losses to acceptable levels. Example parameters are given for a gun compatible with low cost pulsed reactors and for experiments to develop the concept.

  13. Gun Safety Management with Patients at Risk for Suicide

    ERIC Educational Resources Information Center

    Simon, Robert I.

    2007-01-01

    Guns in the home are associated with a five-fold increase in suicide. All patients at risk for suicide must be asked if guns are available at home or easily accessible elsewhere, or if they have intent to buy or purchase a gun. Gun safety management requires a collaborative team approach including the clinician, patient, and designated person…

  14. Alignment Fixtures For Vacuum-Plasma-Spray Gun

    NASA Technical Reports Server (NTRS)

    Woodford, William H.; Mckechnie, Timothy N.; Power, Christopher A.; Daniel, Ronald L., Jr.

    1993-01-01

    Fixtures for alignment of vacuum-plasma-spray guns built. Each fixture designed to fit specific gun and holds small, battery-powered laser on centerline of gun. Laser beam projects small red dot where centerline intersects surface of workpiece to be sprayed. After laser beam positioned on surface of workpiece, fixture removed from gun and spraying proceeds.

  15. Ready, Fire, Aim: The College Campus Gun Fight

    ERIC Educational Resources Information Center

    Birnbaum, Robert

    2013-01-01

    The question of whether guns should be permitted on college and university campuses in the United States reflects the tension between two competing perspectives. America has both a robust gun culture and an equally robust (if less well known) gun-control culture. The gun culture is as American as apple pie: There may be as many as 300 million…

  16. Correlates of Gun Involvement and Aggressiveness among Adolescents.

    ERIC Educational Resources Information Center

    Ding, Cody S.; Nelsen, Edward A.; Lassonde, Cynthia T.

    2002-01-01

    Investigated adolescents' aggressiveness in relation to their experiences, beliefs, and attitudes concerning gun use, also noting family composition, relationships with parents, and emotionality as correlates of gun involvement and aggression. Student surveys indicated links between gun ownership and recreational use, beliefs about gun use, and…

  17. A Two Frequency Thermionic Cathode Electron Gun

    NASA Astrophysics Data System (ADS)

    Edelen, Jon; Biedron, Sandra; Harris, John; Lewellen, John; Milton, Stephen

    2014-03-01

    When an un-gated thermionic cathode is operated in an RF gun, some fraction of the emitted electrons will return to the cathode due to the change in sign of the electric field in the gun. This back-bombardment current causes heating of the cathode, and this reduces the ability of the cathode heater to control the bunch charge. In this paper, we investigate the use of a two frequency TM010 / TM020 electron gun to mitigate this effect. Simulations revealed that for a 100-pC bunch charge operating at 10MV/m gradient the harmonic field produced a 63% reduction in the back-bombardment power.

  18. SSRL photocathode RF gun test stand

    SciTech Connect

    Hernandez, M.; Baltay, M.; Boyce, A.

    1995-12-31

    A photocathode RF gun test stand designed for the production and study of high brightness electron beams will be constructed at SSRL. The beam will be generated from a laser driven third generation photocathode RF gun being developed in collaboration with BNL, LBL, and UCLA. The 3-5 [MeV] beam from the gun will be accelerated using a SLAC three meter S-band accelerator section, in order to achieve the desired low emittance beam, emittance compensation with solenoidal focusing will be employed.

  19. Advances in DC photocathode electron guns

    SciTech Connect

    Bruce M. Dunham; P. Heartmann; Reza Kazimi; Hongxiu Liu; B. M. Poelker; J. S. Price; P. M. Rutt; W. J. Schneider; Charles K. Sinclair

    1998-07-01

    At Jefferson Lab, a DC photoemission gun using GaAs and GaAs-like cathodes provides a source of polarized electrons for the main accelerator. The gun is required to produce high average current with long operational lifetimes and high system throughout. Recent work has shown that careful control of the parameters affecting cathode lifetime lead to dramatic improvements in source operation. These conditions include vacuum and the related effect of ion backbombardment, and precise control of all of the electrons emitted from the cathode. In this paper, the authors will review recent results and discuss implications for future photocathode guns.

  20. Evaluation of Smart Gun Technologies preliminary report

    SciTech Connect

    Weiss, D.R.

    1996-01-01

    The Smart Gun Technology Project has a goal to eliminate the capability of an unauthorized user from firing a law enforcement officer`s firearm by implementing {open_quote}smart{close_quote} technologies. Smart technologies are those that can in some manner identify an officer. This report will identify, describe, and grade various technologies as compared to the requirements that were obtained from officers. This report does not make a final recommendation for a smart gun technology, nor does it give the complete design of a smart gun system.

  1. Performance of the Brookhaven photocathode rf gun

    SciTech Connect

    Batchelor, K.; Ben-Zvi, I.; Fernow, R.C.; Fischer, J.; Fisher, A.S.; Gallardo, J.; Ingold, G.; Kirk, H.G.; Leung, K.P.; Malone, R.; Pogorelsky, I.; Srinivasan-Rao, T.; Rogers, J.; Tsang, T.; Sheehan, J.; Ulc, S.; Woodle, M.; Xie, J.; Zhang, R.S.; Lin, L.Y.; McDonald, K.T.; Russell, D.P.; Hung, C.M.; Wang, X.J.

    1991-12-31

    The Brookhaven Accelerator Test Facility (ATF) uses a photocathode rf gun to provide a high-brightness electron beam intended for FEL and laser-acceleration experiments. The rf gun consists of 1{1/2} cells driven at 2856 MHz in {pi}-mode with a maximum cathode field of 100 MV/m. To achieve long lifetimes, the photocathode development concentrates on robust metals such as copper, yttrium and samarium. We illuminate these cathodes with a 10-ps, frequency-quadrupled Nd:YAG laser. We describe the initial operation of the gun, including measurements of transverse and longitudinal emittance, quantum efficiencies, and peak current. The results are compared to models.

  2. Performance of the Brookhaven photocathode rf gun

    SciTech Connect

    Batchelor, K.; Ben-Zvi, I.; Fernow, R.C.; Fischer, J.; Fisher, A.S.; Gallardo, J.; Ingold, G.; Kirk, H.G.; Leung, K.P.; Malone, R.; Pogorelsky, I.; Srinivasan-Rao, T.; Rogers, J.; Tsang, T.; Sheehan, J.; Ulc, S.; Woodle, M.; Xie, J.; Zhang, R.S. ); Lin, L.Y. . Dept. of Applied Physics); McDonald, K.T.; Russell, D.P. (Pr

    1991-01-01

    The Brookhaven Accelerator Test Facility (ATF) uses a photocathode rf gun to provide a high-brightness electron beam intended for FEL and laser-acceleration experiments. The rf gun consists of 1{1/2} cells driven at 2856 MHz in {pi}-mode with a maximum cathode field of 100 MV/m. To achieve long lifetimes, the photocathode development concentrates on robust metals such as copper, yttrium and samarium. We illuminate these cathodes with a 10-ps, frequency-quadrupled Nd:YAG laser. We describe the initial operation of the gun, including measurements of transverse and longitudinal emittance, quantum efficiencies, and peak current. The results are compared to models.

  3. "Is there a gun in the home?" Assessing the risks of gun ownership in older adults.

    PubMed

    Pinholt, Ellen M; Mitchell, Joshua D; Butler, Jane H; Kumar, Harjinder

    2014-06-01

    An important ethical and safety concern that geriatricians, primary care providers, and home health professionals need to address is gun ownership by elderly adults. Those aged 65 and older now have the highest rate of gun ownership in America, and they also have a high prevalence of depression and suicide. Dementia can add additional layers of risk. Even older gun owners who are otherwise intellectually intact may benefit from information about gun safety with the increasing numbers of children being cared for by grandparents. Health professionals should ask patients, "Is there a gun in the home?" in the clinic and during home visits. Healthcare professionals must have knowledge and skills to address safe gun ownership in elderly adults. The 5 L's (Locked, Loaded, Little children, feeling Low, Learned owner) will assist professionals in addressing all aspects of safe ownership. PMID:24898055

  4. Effects of undercover police stings of gun dealers on the supply of new guns to criminals

    PubMed Central

    Webster, D W; Bulzacchelli, M T; Zeoli, A M; Vernick, J S

    2006-01-01

    Objective To assess the effects of undercover police stings and lawsuits against gun dealers suspected of facilitating illegal gun sales in three US cities (Chicago, Detroit, Gary) on the flow of new firearms to criminals. Methods An interrupted time series design and negative binomial regression analyses were used to test for temporal change in the recovery of guns used in crimes within one year of retail sale in both intervention and comparison cities. Results The stings were associated with an abrupt 46.4% reduction in the flow of new guns to criminals in Chicago (95% confidence interval, −58.6% to −30.5%), and with a gradual reduction in new crime guns recovered in Detroit. There was no significant change associated with the stings in Gary, and no change in comparison cities that was coincident with the stings in Chicago and Detroit. Conclusions The announcement of police stings and lawsuits against suspect gun dealers appeared to have reduced the supply of new guns to criminals in Chicago significantly, and may have contributed to beneficial effects in Detroit. Given the important role that gun stores play in supplying guns to criminals in the US, further efforts of this type are warranted and should be evaluated. PMID:16887943

  5. Separating batterers and guns: a review and analysis of gun removal laws in 50 States.

    PubMed

    Frattaroli, Shannon; Vernick, Jon S

    2006-06-01

    Firearms play an important role in lethal domestic violence incidents. The authors review state laws regarding two policies to separate batterers from firearms: laws authorizing police to remove firearms when responding to a domestic violence complaint ("police gun removal laws") and laws authorizing courts to order guns removed from batterers through a protective order ("court-ordered removal laws"). As of April 2004, 18 states had police gun removal laws; 16 states had court-ordered removal laws. The authors examine relevant characteristics of the laws and recommend that these laws be mandatory, apply to all guns and ammunition possessed by an abuser, and include clear procedures to enhance implementation. PMID:16679498

  6. Circuit Model for Gun Driven Spheromaks

    SciTech Connect

    Thomassen, K I

    2000-07-14

    In this note we derive circuit equations for sustained spheromaks, in the phase after a spheromak is detached from the gun and sustained in a flux conserver. The impedance of the spheromak during the formation and ''bubble burst'' phase has been discussed by Barnes et. al. We assume here that the spheromak is formed and helicity is being delivered to it from the gun, currents are above the threshold current, and the {lambda}-gradients are outward ({lambda} decreasing inward). We follow an open field line that begins and ends at the gun electrodes, encircling the closed flux surfaces of the spheromak, and apply power and helicity balance equations for this gun-driven system. In addition to these equations one will need to know the initial conditions (currents, stored energies) after the ''bubble burst'' in order to project forward in time.

  7. The electric rail gun for space propulsion

    NASA Technical Reports Server (NTRS)

    Bauer, D. P.; Barber, J. P.; Vahlberg, C. J.

    1981-01-01

    An analytic feasibility investigation of an electric propulsion concept for space application is described. In this concept, quasistatic thrust due to inertial reaction to repetitively accelerated pellets by an electric rail gun is used to propel a spacecraft. The study encompasses the major subsystems required in an electric rail gun propulsion system. The mass, performance, and configuration of each subsystem are described. Based on an analytic model of the system mass and performance, the electric rail gun mission performance as a reusable orbital transfer vehicle (OTV) is analyzed and compared to a 30 cm ion thruster system (BIMOD) and a chemical propulsion system (IUS) for payloads with masses of 1150 kg and 2300 kg. For system power levels in the range from 25 kW(e) to 100 kW(e) an electric rail gun OTV is more attractive than a BIMOD system for low Earth orbit to geosynchronous orbit transfer durations in the range from 20 to 120 days.

  8. Arc-driven rail gun research

    NASA Technical Reports Server (NTRS)

    Ray, P. K.

    1984-01-01

    The equations describing the performance of an inductively-driven rail gun are analyzed numerically. Friction between the projectile and rails is included through an empirical formulation. The equations are applied to the experiment of Rashleigh and Marshall to obtain an estimate of energy distribution in rail guns as a function of time. The effect of frictional heat dissipation on the bore of the gun is calculated. The mechanism of plasma and projectile acceleration in a dc rail gun is described from a microscopic point of view through the establishment of the Hall field. The plasma conductivity is shown to be a tensor indicating that there is a small component of current parallel to the direction of acceleration. The plasma characteristics are evaluated as a function of plasma mass through a simple fluid mechanical analysis of the plasma. By equating the energy dissipated in the plasma with the radiation heat loss, the properties of the plasma are determined.

  9. Direct launch using the electric rail gun

    NASA Technical Reports Server (NTRS)

    Barber, J. P.

    1983-01-01

    The concept explored involves using a large single stage electric rail gun to achieve orbital velocities. Exit aerodynamics, launch package design and size, interior ballistics, system and component sizing and design concepts are treated. Technology development status and development requirements are identified and described. The expense of placing payloads in Earth orbit using conventional chemical rockets is considerable. Chemical rockets are very inefficient in converting chemical energy into payload kinetic energy. A rocket motor is relatively expensive and is usually expended on each launch. In addition specialized and expensive forms of fuel are required. Gun launching payloads directly to orbit from the Earth's surface is a possible alternative. Guns are much more energy efficient than rockets. The high capital cost of the gun installation can be recovered by reusing it over and over again. Finally, relatively inexpensive fuel and large quantities of energy are readily available to a fixed installation on the Earth's surface.

  10. Arc Plasma Gun With Coaxial Powder Feed

    NASA Technical Reports Server (NTRS)

    Zaplatynsky, Isidor

    1988-01-01

    Redesigned plasma gun provides improved metallic and ceramic coatings. Particles injected directly through coaxial bore in cathode into central region of plasma jet. Introduced into hotter and faster region of plasma jet.

  11. Lightweight, High-Current Welding Gun

    NASA Technical Reports Server (NTRS)

    Starck, Thomas F.; Brennan, Andrew D.

    1989-01-01

    Lighweight resistance-welding, hand-held gun supplies alternating or direct current over range of 600 to 4,000 A and applies forces from 40 to 60 lb during welding. Used to weld metal sheets in multilayered stacks.

  12. Toroid Joining Gun For Fittings And Couplings

    NASA Technical Reports Server (NTRS)

    Fox, Robert L.; Swaim, Robert J.; Johnson, Samuel D.; Buckley, John D.; Copeland, Carl E.; Coultrip, Robert H.; Johnston, David F.; Phillips, William M.

    1992-01-01

    Hand-held gun used to join metal heat-to-shrink couplings. Uses magnetic induction (eddy currents) to produce heat in metal coupling, and thermocouple to measure temperature and signals end of process. Gun, called "toroid joining gun" concentrates high levels of heat in localized areas. Reconfigured for use on metal heat-to-shrink fitting and coupling applications. Provides rapid heating, operates on low power, lightweight and portable. Safe for use around aircraft fuel and has no detrimental effects on surrounding surfaces or objects. Reliable in any environment and under all weather conditions. Gun logical device for taking full advantage of capabilities of new metal heat-to-shrink couplings and fittings.

  13. Conference on electromagnetic guns and launchers, 1980

    SciTech Connect

    Anon

    1982-01-01

    Proceedings includes 31 papers dealing with the physical principles and engineering technology associated with the development of electromagnetic propulsion, with emphasis on its use for guns, launchers as well as other military equipment. Topics covered include: rail guns, projectiles, mass accelerators, electric motors and generators, nuclear reactors, superconducting devices, plasma acceleration and confinement, traveling magnetic waves, aerospace propulsion, space shuttles, homopolar generators, fusion reactors, tokamaks, impact fusion, and electric power generation. 14 papers are abstracted and indexed separately.

  14. Modifications Of A Commercial Spray Gun

    NASA Technical Reports Server (NTRS)

    Allen, Peter B.

    1993-01-01

    Commercial spray gun modified to increase spray rate and make sprayed coats more nearly uniform. Consists of gun head and pneumatic actuator. Actuator opens valves for two chemical components, called "A" and "B," that react to produce foam. Components flow through orifices, into mixing chamber in head. Mixture then flows through control orifice to spray tip. New spray tip tapered to reduce area available for accumulation of foam and makes tip easier to clean.

  15. NPS Gas Gun for Planar Impact Studies

    NASA Astrophysics Data System (ADS)

    Cheong Ho, Chien; Hixson, Robert

    2009-11-01

    The Naval Postgraduate School (NPS) commissioned a Gas Gun for shock wave studies on 9^th October 2009, by performing the first experiment. The Gas Gun is the key element of NPS Shock Wave Research Program within the Physics Department, where well-characterized planar impacts are essential for obtaining high quality data, to characterize a solid material. This first experiment was very successful, and returned key data on the quality of the impact conditions created. The Gas Gun is designed by SANDIA NATIONAL LABORATORIES, and the NPS spent twelve months fabricating the components of the Gas Gun and six months assembling the Gas Gun. Three inch projectile are launched at velocities up to 0.5 km/s, creating high pressure and temperature states that can be used to characterize the fundamental response of relevant materials to dynamic loading. The projectile is launched from a `wrap around' gas breech where helium gas is pressurized to relatively low pressure. This gas is used to accelerate the projectile down a 3m barrel. Upon impact, the speed of the projectile and the flatness of the impact is measured, via a stepped circular pin array circuit. The next stage of development for the Gas Gun is to integrate a Velocity Interferometer System for Any Reflector (VISAR). The VISAR sees all the waves that flow through the target plate as a result of the impact. This is a key diagnostic for determining material properties under dynamic loading conditions.

  16. Separating Batterers and Guns: A Review and Analysis of Gun Removal Laws in 50 States

    ERIC Educational Resources Information Center

    Frattaroli, Shannon; Vernick, Jon S.

    2006-01-01

    Firearms play an important role in lethal domestic violence incidents. The authors review state laws regarding two policies to separate batterers from firearms: laws authorizing police to remove firearms when responding to a domestic violence complaint ("police gun removal laws") and laws authorizing courts to order guns removed from batterers…

  17. Gun Carrying by High School Students in Boston, MA: Does Overestimation of Peer Gun Carrying Matter?

    ERIC Educational Resources Information Center

    Hemenway, David; Vriniotis, Mary; Johnson, Renee M.; Miller, Matthew; Azrael, Deborah

    2011-01-01

    This paper investigates: (1) whether high school students overestimate gun carrying by their peers, and (2) whether those students who overestimate peer gun carrying are more likely to carry firearms. Data come from a randomly sampled survey conducted in 2008 of over 1700 high school students in Boston, MA. Over 5% of students reported carrying a…

  18. Modeling internal ballistics of gas combustion guns.

    PubMed

    Schorge, Volker; Grossjohann, Rico; Schönekess, Holger C; Herbst, Jörg; Bockholdt, Britta; Ekkernkamp, Axel; Frank, Matthias

    2016-05-01

    Potato guns are popular homemade guns which work on the principle of gas combustion. They are usually constructed for recreational rather than criminal purposes. Yet some serious injuries and fatalities due to these guns are reported. As information on the internal ballistics of homemade gas combustion-powered guns is scarce, it is the aim of this work to provide an experimental model of the internal ballistics of these devices and to investigate their basic physical parameters. A gas combustion gun was constructed with a steel tube as the main component. Gas/air mixtures of acetylene, hydrogen, and ethylene were used as propellants for discharging a 46-mm caliber test projectile. Gas pressure in the combustion chamber was captured with a piezoelectric pressure sensor. Projectile velocity was measured with a ballistic speed measurement system. The maximum gas pressure, the maximum rate of pressure rise, the time parameters of the pressure curve, and the velocity and path of the projectile through the barrel as a function of time were determined according to the pressure-time curve. The maximum gas pressure was measured to be between 1.4 bar (ethylene) and 4.5 bar (acetylene). The highest maximum rate of pressure rise was determined for hydrogen at (dp/dt)max = 607 bar/s. The muzzle energy was calculated to be between 67 J (ethylene) and 204 J (acetylene). To conclude, this work provides basic information on the internal ballistics of homemade gas combustion guns. The risk of injury to the operator or bystanders is high, because accidental explosions of the gun due to the high-pressure rise during combustion of the gas/air mixture may occur. PMID:26239103

  19. The supply and demand for guns to juveniles: Oakland's gun tracing project.

    PubMed

    Calhoun, Deane; Dodge, Andrea Craig; Journel, Coraline S; Zahnd, Elaine

    2005-12-01

    In response to Oakland, California's high level of gun violence affecting young people, the East Oakland Partnership to Reduce Juvenile Gun Violence, a citywide collaboration, was formed in 1997. In 1999, the Partnership established the Oakland Gun Tracing Project to develop evidence-based policy recommendations aimed at reducing the supply of and demand for gun acquisition among urban youth. The advocacy project involved gathering, analyzing, and using police record and gun sale/registration data to inform policy and practice. Such data were collected for all gun crimes committed in Oakland, California between 1998 and 1999 in which a juvenile was either the suspect or the victim. The 213 cases involved 263 juveniles of which 170 were suspects/perpetrators and 93 were victims. Suspects as well as victims were predominantly male and African American. The 213 cases involved 132 recovered guns. Only 55% of the cases were traced to a federally licensed dealer. Three-quarters of the guns were purchased near Oakland, California. Successful traces, defined as the ability to identify federally licensed dealers and initial purchasers, were completed on only 52 of the 132 guns, demonstrating systemic tracing difficulties. Data gathered for the project was used to advocate for numerous policy changes. Recommended policy strategies include initiating a comprehensive gun tracing program so police can track all secondary sales, new laws requiring federal handgun registration which would track ownership changes, required reporting of stolen firearms, and providing effective intervention services to all juveniles the first time they enter the criminal justice system. PMID:16269532

  20. A high-brightness thermionic microwave electron gun

    SciTech Connect

    Borland, M.

    1991-02-01

    In a collaborative effort by SSRL, AET Associates, and Varian Associates, a high-brightness microwave electron gun using a thermionic cathode has been designed, built, tested, and installed for use with the SSRL 150 MeV linear accelerator. This thesis discusses the physics behind the design and operation of the gun and associated systems, presenting predictions and experimental tests of the gun's performance. The microwave gun concept is of increasing interest due to its promise of providing higher-current, lower-emittance electron beams than possible from conventional, DC gun technology. In a DC guns, accelerating gradients are less than 8 MV/m, while those in a microwave gun can exceed 100 MV/m, providing much more rapid initial acceleration, thereby reducing the deleterious effects of space-charge. Microwave guns produce higher momentum beams than DC guns, thus lessening space-charge effects during subsequent beam transport. Typical DC guns produce kinetic energies of 80--400 KeV, compared to 2--3 MeV for the SSRL microwave gun. State-of-the-art'' microwave gun designs employ laser-driven photocathodes, providing excellent performance but with greater complexity and monetary costs. A thermionic microwave gun with a magnetic bunching system is comparable in cost and complexity to a conventional system, but provides performance that is orders of magnitude better. Simulations of the SSRL microwave gun predict a normalized RMS emittance at the gun exist of < 10 {pi} {center dot} m{sub e}c {center dot} {mu}m for a beam consisting of approximately 50% of the particles emitted from the gun, and having a momentum spread {plus minus}10%. These emittances are for up to 5 {times} 10{sup 9}e{sup {minus}} per bunch. Chromatic aberrations in the transport line between the gun and linear accelerator increase this to typically < 30 {pi} {center dot} m{sub e} {center dot} {mu}m.

  1. Development of plasma cathode electron guns

    NASA Astrophysics Data System (ADS)

    Oks, Efim M.; Schanin, Peter M.

    1999-05-01

    The status of experimental research and ongoing development of plasma cathode electron guns in recent years is reviewed, including some novel upgrades and applications to various technological fields. The attractiveness of this kind of e-gun is due to its capability of creating high current, broad or focused beams, both in pulsed and steady-state modes of operation. An important characteristic of the plasma cathode electron gun is the absence of a thermionic cathode, a feature which leads to long lifetime and reliable operation even in the presence of aggressive background gas media and at fore-vacuum gas pressure ranges such as achieved by mechanical pumps. Depending on the required beam parameters, different kinds of plasma discharge systems can be used in plasma cathode electron guns, such as vacuum arcs, constricted gaseous arcs, hollow cathode glows, and two kinds of discharges in crossed E×B fields: Penning and magnetron. At the present time, plasma cathode electron guns provide beams with transverse dimension from fractional millimeter up to about one meter, beam current from microamperes to kiloamperes, beam current density up to about 100 A/cm2, pulse duration from nanoseconds to dc, and electron energy from several keV to hundreds of keV. Applications include electron beam melting and welding, surface treatment, plasma chemistry, radiation technologies, laser pumping, microwave generation, and more.

  2. Electron gun system for NSC KIPT linac

    NASA Astrophysics Data System (ADS)

    Zhou, Zu-Sheng; He, Da-Yong; Chi, Yun-Long

    2014-06-01

    In the NSC KIPT linac, a neutron source based on a subcritical assembly driven by a 100 MeV/100 kW electron linear accelerator is under design and development. The linear accelerator needs a new high current electron gun. In this paper, the physical design, mechanical fabrication and beam test of this new electron gun are described. The emission current is designed to be higher than 2 A for the pulse width of 3 μs with repetition rate of 50 Hz. The gun will operate with a DC high voltage power supply that can provide a high voltage up to 150 kV. Computer simulations and optimizations have been carried out in the design stage, including the gun geometry and beam transport line. The test results of high voltage conditioning and beam test are presented. The operation status of the electron gun system is also included. The basic test results show that the design, manufacture, and operation of the new electron system are basically successful.

  3. ECR ion source with electron gun

    DOEpatents

    Xie, Zu Q.; Lyneis, Claude M.

    1993-01-01

    An Advanced Electron Cyclotron Resonance ion source (10) having an electron gun (52) for introducing electrons into the plasma chamber (18) of the ion source (10). The ion source (10) has a injection enclosure (12) and a plasma chamber tank (14). The plasma chamber (18) is defined by a plurality of longitudinal magnets (16). The electron gun (52) injects electrons axially into the plasma chamber (18) such that ionization within the plasma chamber (18) occurs in the presence of the additional electrons produced by the electron gun (52). The electron gun (52) has a cathode (116) for emitting electrons therefrom which is heated by current supplied from an AC power supply (96) while bias potential is provided by a bias power supply (118). A concentric inner conductor (60) and Outer conductor (62) carry heating current to a carbon chuck (104) and carbon pusher (114) Which hold the cathode (116) in place and also heat the cathode (16). In the Advanced Electron Cyclotron Resonance ion source (10), the electron gun (52) replaces the conventional first stage used in prior art electron cyclotron resonance ion generators.

  4. [Comparison of wound morphology following gunshots by machine guns and sub-machine guns].

    PubMed

    Grellner, W; Madea, B

    1999-01-01

    Automatic weapons such as machine guns and submachine guns are found in the German-speaking region only in special army and police units and appear accordingly rarely in homicides, suicides and accidents. In the following, the findings in two cases of death with the use of machine and submachine guns are presented. The first case was a fatal accident during shooting on a training area (current machine gun of the German army, calibre 7.62 x 51 mm), the second case was a killing during a physical conflict (submachine gun MP 40 from World War II, calibre 9 x 19 mm). In the case with the machine gun autopsy disclosed typical entry holes corresponding to the calibre, but unusually large exit wounds with tissue bridges in the wound ground, measuring 4 x 2.5 cm in diameter. By contrast, the second case (submachine gun) showed "normal" entry and exit wounds. The differences are mainly caused by deviating ballistic data of the ammunition used. They are discussed against the background of literature on wound ballistics. PMID:10198694

  5. 13. BUILDING NO. 445, PHYSICS LAB (FORMERLY GUN BAG LOADING), ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. BUILDING NO. 445, PHYSICS LAB (FORMERLY GUN BAG LOADING), VIEW NORTH AT SOUTH END OF BUILDING. - Picatinny Arsenal, 400 Area, Gun Bag Loading District, State Route 15 near I-80, Dover, Morris County, NJ

  6. FEATURE 1, SMALL GUN POSITION, VIEW FACING NORTH. Naval ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FEATURE 1, SMALL GUN POSITION, VIEW FACING NORTH. - Naval Air Station Barbers Point, Anti-Aircraft Battery Complex-Small Gun Position, East of Coral Sea Road, northwest of Hamilton Road, Ewa, Honolulu County, HI

  7. FEATURE 3, LARGE GUN POSITION, SHOWING MULTIPLE COMPARTMENTS, VIEW FACING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FEATURE 3, LARGE GUN POSITION, SHOWING MULTIPLE COMPARTMENTS, VIEW FACING SOUTH. - Naval Air Station Barbers Point, Anti-Aircraft Battery Complex-Large Gun Position, East of Coral Sea Road, northwest of Hamilton Road, Ewa, Honolulu County, HI

  8. FEATURE C. MACHINE GUN POSITION WITH REMNANT OF MOUNT, VIEW ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FEATURE C. MACHINE GUN POSITION WITH REMNANT OF MOUNT, VIEW FACING SOUTH-SOUTHEAST. - Naval Air Station Barbers Point, Battery-Machine Gun Positions, South of Point Cruz Road & west of Coral Sea Road, Ewa, Honolulu County, HI

  9. 6. INTERIOR DETAIL OF GUN MOUNT ON TERRACE, LOOKING EAST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. INTERIOR DETAIL OF GUN MOUNT ON TERRACE, LOOKING EAST (1992). - Wright-Patterson Air Force Base, Area B, Building 22, Armament Laboratory & Gun Range, On flightline between Tenth & Eleventh Streets, Dayton, Montgomery County, OH

  10. FEATURE A. CONCRETE ANTIAIRCRAFT GUN POSITION, VIEW FACING NORTHNORTHEAST. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FEATURE A. CONCRETE ANTI-AIRCRAFT GUN POSITION, VIEW FACING NORTH-NORTHEAST. - Naval Air Station Barbers Point, Battery-Anti-Aircraft Gun Position, South of Point Cruz Road & west of Coral Sea Road, Ewa, Honolulu County, HI

  11. FEATURE 1, SMALL GUN POSITION, VIEW FACING NORTH, (with scale ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FEATURE 1, SMALL GUN POSITION, VIEW FACING NORTH, (with scale stick). - Naval Air Station Barbers Point, Anti-Aircraft Battery Complex-Small Gun Position, East of Coral Sea Road, northwest of Hamilton Road, Ewa, Honolulu County, HI

  12. FEATURE B. MACHINE GUN POSITION WITH LEWIS MOUNT, VIEW FACING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FEATURE B. MACHINE GUN POSITION WITH LEWIS MOUNT, VIEW FACING NORTHWEST. - Naval Air Station Barbers Point, Battery-Machine Gun Positions, South of Point Cruz Road & west of Coral Sea Road, Ewa, Honolulu County, HI

  13. FEATURE A. CONCRETE ANTIAIRCRAFT GUN POSITION, VIEW FACING NORTH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FEATURE A. CONCRETE ANTI-AIRCRAFT GUN POSITION, VIEW FACING NORTH - NORTHEAST (with scale stick). - Naval Air Station Barbers Point, Battery-Anti-Aircraft Gun Position, South of Point Cruz Road & west of Coral Sea Road, Ewa, Honolulu County, HI

  14. FEATURE A. CONCRETE ANTIAIRCRAFT GUN POSITION, SHOWING CORAL RUBBLE BERM, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FEATURE A. CONCRETE ANTI-AIRCRAFT GUN POSITION, SHOWING CORAL RUBBLE BERM, VIEW FACING SOUTHEAST. - Naval Air Station Barbers Point, Battery-Anti-Aircraft Gun Position, South of Point Cruz Road & west of Coral Sea Road, Ewa, Honolulu County, HI

  15. FEATURE B. MACHINE GUN POSITION WITH LEWIS MOUNT, VIEW FACING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FEATURE B. MACHINE GUN POSITION WITH LEWIS MOUNT, VIEW FACING NORTHWEST (with scale stick). - Naval Air Station Barbers Point, Battery-Machine Gun Positions, South of Point Cruz Road & west of Coral Sea Road, Ewa, Honolulu County, HI

  16. The Real Costs of Gun Violence

    SciTech Connect

    Cook, Philip J.

    2001-03-14

    I will report some of the results in my new book, 'Gun Violence: The Real Costs' (Oxford University Press, 2000; with Jens Ludwig). The problem of gun violence is usually summarized by statistics on deaths and injuries. Those statistics tell only part of the story. All of us bear some of the burden of gun violence, at least in the form of higher taxes and waiting to go through the airport security checks. But that's just the beginning. The extraordinary reductions in lethal violence that occurred during the 1990s help account for rising property values and urban renewal; further reductions are possible and would do still more to enhance the average standard of living. This talk will explain why the economic perspective provides a fresh, useful point of view on violence, and will discuss the technique used to arrive at an estimate of the magnitude of the burden.

  17. Electromagnetic theta gun and tubular projectiles

    SciTech Connect

    Burgess, T.J.; Cnare, E.C.; Oberkampf, W.L.; Beard, S.G.; Cowan, M.

    1980-12-01

    Unlike the better known rail gun, the theta gun applies the propelling force along the length of its projectile. This is shown to allow much greater acceleration of high fineness ratio projectiles for a given barrel pressure, allowing much shorter barrels for military applications. A computer code which simulates performance of the theta gun is described and experimental results from a few simple, low energy experiments show close agreement with code predictions. Trajectories and aerodynamic heating for three candidate military projectiles are calculated for vertical and horizontal atmospheric launches where initial velocity is as high as 3 km/s. The calculations indicate that in some cases a thin layer of heatshield (ablator) will be required to control projectile heating.

  18. An analysis of electron guns for welding

    NASA Astrophysics Data System (ADS)

    Sabchevski, S. P.; Mladenov, G. M.; Wojcicki, S.; Dabek, J.

    1996-06-01

    Results from numerical experiments and direct measurements for the analysis of an axially symmetric triode electron gun with thermionic cathode for electron beam welding are presented and discussed. Computer simulation is carried out using the new version of the GUN-EBT software package. The self-consistent model takes into account the energy spectrum of emitted electrons and formation of a potential minimum in front of the cathode. The method underlying the investigation incorporates not only the commonly used trajectory analysis (ray tracing) but also an analysis in the phase space (phase analysis) which allows the emittance of the beams to be evaluated. It is demonstrated that computer simulation of beam formation provides ample information for the assessment both of the quality of generated beams and operational performance of the guns.

  19. Pulser for the Tevatron electron lens gun

    SciTech Connect

    Iouri Terechkine et al.

    2004-05-18

    To compensate for beam-beam interaction in Tevatron, an ''electron lens'' is considered to be an effective instrument. When a bunch of electrons with energy in the range (10-16) kV is overlapping with a bunch of antiprotons, the resulting focusing force for antiprotons can be adjusted by changing the electron beam current and by profiling its radial distribution. There exist several scenarios of how the system must function. According to one of them, an electron gun that supplies electrons must be fed by voltage pulses that follow with the frequency of antiproton bunches circulating in the Tevatron, which is about 2.5 MHz. To provide focusing tailored for each individual antiproton bunch, a modulator of the gun (pulser) must allow pulse-to-pulse voltage change. This report will cover main approaches to a design of a pulser for use with the gun of the Tevatron Electron Lens.

  20. Secondary emission electron gun using external primaries

    DOEpatents

    Srinivasan-Rao, Triveni; Ben-Zvi, Ilan; Kewisch, Jorg; Chang, Xiangyun

    2007-06-05

    An electron gun for generating an electron beam is provided, which includes a secondary emitter. The secondary emitter includes a non-contaminating negative-electron-affinity (NEA) material and emitting surface. The gun includes an accelerating region which accelerates the secondaries from the emitting surface. The secondaries are emitted in response to a primary beam generated external to the accelerating region. The accelerating region may include a superconducting radio frequency (RF) cavity, and the gun may be operated in a continuous wave (CW) mode. The secondary emitter includes hydrogenated diamond. A uniform electrically conductive layer is superposed on the emitter to replenish the extracted current, preventing charging of the emitter. An encapsulated secondary emission enhanced cathode device, useful in a superconducting RF cavity, includes a housing for maintaining vacuum, a cathode, e.g., a photocathode, and the non-contaminating NEA secondary emitter with the uniform electrically conductive layer superposed thereon.

  1. Secondary emission electron gun using external primaries

    DOEpatents

    Srinivasan-Rao, Triveni; Ben-Zvi, Ilan

    2009-10-13

    An electron gun for generating an electron beam is provided, which includes a secondary emitter. The secondary emitter includes a non-contaminating negative-electron-affinity (NEA) material and emitting surface. The gun includes an accelerating region which accelerates the secondaries from the emitting surface. The secondaries are emitted in response to a primary beam generated external to the accelerating region. The accelerating region may include a superconducting radio frequency (RF) cavity, and the gun may be operated in a continuous wave (CW) mode. The secondary emitter includes hydrogenated diamond. A uniform electrically conductive layer is superposed on the emitter to replenish the extracted current, preventing charging of the emitter. An encapsulated secondary emission enhanced cathode device, useful in a superconducting RF cavity, includes a housing for maintaining vacuum, a cathode, e.g., a photocathode, and the non-contaminating NEA secondary emitter with the uniform electrically conductive layer superposed thereon.

  2. Novel ignition systems for heavy calibre guns

    NASA Astrophysics Data System (ADS)

    Bowden, C. N.; Cook, G. G.; Henning, P. S.

    1986-01-01

    In recent years there was a trend towards steadily rising gun pressures, especially in direct fire weapons and this has caused many functional problems to arise with conventional vent tube ignition systems. To overcome these problems and to allow the process of gun development to continue, the United Kingdom is performing a program of research into a number of ignition systems for heavy caliber guns. These include: spark ignition, laser ignition, and electrical impulse ignition. A number of different spark plug configurations were evaluated. Extensive trials were performed on the ignition characteristics of black powders and black powder substitutes using an experimental 4 J neodymium laser. Work was also performed on the development of high pressure sapphire windows. A study into methods of charge ignition by electrical impulse techniques was also performed.

  3. Improved DC Gun and Insulator Assembly

    SciTech Connect

    Neubauer, Michael; Johnson, Rolland P

    2015-01-11

    Many user facilities such as synchrotron radiation light sources and free electron lasers rely on DC high voltage photoguns with internal field gradients as high as 10 to 15 MV/m. These high gradients often lead to field emission which poses serious problems for the photocathode used to generate the electron beam and the ceramic insulators used to bias the photocathode at high voltage. Ceramic insulators are difficult to manufacture, require long commissioning times, and have poor reliability, in part because energetic electrons bury themselves in the ceramic causing a buildup of charge and eventual puncture, and also because large diameter ceramics are difficult to braze reliably. The lifetimes of photo cathodes inside high current DC guns exhibiting field emission are limited to less than a hundred hours. Reducing the surface gradients on the metals reduces the field emission, which serves to maintain the required ultrahigh vacuum condition. A novel gun design with gradients around 5 MV/m and operating at 350 kV, a major improvement over existing designs, was proposed that allows for the in-situ replacement of photo cathodes in axially symmetric designs using inverted ceramics. In this project, the existing JLAB CEBAF asymmetric gun design with an inverted ceramic support was modeled and the beam dynamics characterized. An improved structure was designed that reduces the surface gradients and improves the beam optics. To minimize the surface gradients, a number of electrostatic gun designs were studied to determine the optimum configuration of the critical electrodes within the gun structure. Coating experiments were carried out to create a charge dissipative coating for cylindrical ceramics. The phase II proposal, which was not granted, included the design and fabrication of an axially symmetric DC Gun with an inverted ceramic that would operate with less than 5 MV/m at 350 kV and would be designed with an in-situ replaceable photo-cathode.

  4. Simulations of Gaussian electron guns for RHIC electron lens

    SciTech Connect

    Pikin, A.

    2014-02-28

    Simulations of two versions of the electron gun for RHIC electron lens are presented. The electron guns have to generate an electron beam with Gaussian radial profile of the electron beam density. To achieve the Gaussian electron emission profile on the cathode we used a combination of the gun electrodes and shaping of the cathode surface. Dependence of electron gun performance parameters on the geometry of electrodes and the margins for electrodes positioning are presented.

  5. Nb-Pb Superconducting RF Gun

    SciTech Connect

    Sekutowicz, J.; Iversen, J.; Kreps, G.; Moller, W.D.; Singer, W.; Singer, X.; Ben-Zvi, I.; Burrill, A.; Smedley, J.; Rao, T.; Ferrario, M.; Kneisel, P.; Langner, J.; Strzyzewski, P.; Lefferts, R.; Lipski, A.; Szalowski, K.; Ko, K.; Xiao, L.; /SLAC

    2006-03-29

    We report on the status of an electron RF-gun made of two superconductors: niobium and lead. The presented design combines the advantages of the RF performance of bulk niobium superconducting cavities and the reasonably high quantum efficiency of lead, as compared to other superconducting metals. The concept, mentioned in a previous paper, follows the attractive approach of all niobium superconducting RF-gun as it has been proposed by the BNL group. Measured values of quantum efficiency for lead at various photon energies, analysis of recombination time of photon-broken Cooper pairs for lead and niobium, and preliminary cold test results are discussed in this paper.

  6. Nb-Pb superconducting RF gun

    SciTech Connect

    J. Sekutowicz; J. Iversen; G. Kreps; W.D. Moller; W. Singer; X. Singer; I. Ben-Zvi; A. Burrill; J. Smedley; T. Rao; M. Ferrario; P. Kneisel; J. Langner; P. Strzyzewski; R. Lefferts; A. Lipski; K. Szalowski; K. Ko; L. Xiao

    2006-04-14

    We report on the status of an electron RF-gun made of two superconductors: niobium and lead. The presented design combines the advantages of the RF performance of bulk niobium superconducting cavities and the reasonably high quantum efficiency of lead, as compared to other superconducting metals. The concept, mentioned in a previous paper, follows the attractive approach of all niobium superconducting RF-gun as it has been proposed by the BNL group. Measured values of quantum efficiency for lead at various photon energies, analysis of recombination time of photon-broken Cooper pairs for lead and niobium, and preliminary cold test results are discussed in this paper.

  7. Electron trapping mechanisms in magnetron injection guns

    NASA Astrophysics Data System (ADS)

    Pagonakis, Ioannis Gr.; Piosczyk, Bernhard; Zhang, Jianhua; Illy, Stefan; Rzesnicki, Tomasz; Hogge, Jean-Philippe; Avramidis, Konstantinos; Gantenbein, Gerd; Thumm, Manfred; Jelonnek, John

    2016-02-01

    A key parameter for the gyrotron operation and efficiency is the presence of trapped electrons. Two electron trapping mechanisms can take place in gyrotrons: (i) the adiabatic trap and (ii) the magnetic potential well. Their influence on the gyrotron operation is analyzed. Two gun design criteria are then proposed to suppress both mechanisms in order to minimize the risk of possible problems. Experimental results of three high power gyrotrons are presented and their performance is correlated to the presence of populations of trapped electrons. Finally, some very general gun design principles are presented for the limitation of harmful electron trapping.

  8. Transverse-longitudinal correlations in electron guns

    NASA Astrophysics Data System (ADS)

    Harris, J. R.; Lewellen, J. W.; Poole, B. R.

    2012-07-01

    When a modulated beam is produced in a DC electron gun, the time-dependent space charge force and the time-independent focusing force produce a correlation between current, position along the beam, and the beam's radius and divergence. This has implications for beam extraction and downstream beam transport. Here, we simulate an electrostatically-focused DC electron gun to study this correlation. Beam radius and divergence at the anode are found to be approximately linear functions of beam current, and the consequences for beam loss and extraction are considered.

  9. Dynamics Modelling of Biolistic Gene Guns

    SciTech Connect

    Zhang, M.; Tao, W.; Pianetta, P.A.

    2009-06-04

    The gene transfer process using biolistic gene guns is a highly dynamic process. To achieve good performance, the process needs to be well understood and controlled. Unfortunately, no dynamic model is available in the open literature for analysing and controlling the process. This paper proposes such a model. Relationships of the penetration depth with the helium pressure, the penetration depth with the acceleration distance, and the penetration depth with the micro-carrier radius are presented. Simulations have also been conducted. The results agree well with experimental results in the open literature. The contribution of this paper includes a dynamic model for improving and manipulating performance of the biolistic gene gun.

  10. Do guns provide safety? At what cost?

    PubMed

    Narang, Puneet; Paladugu, Anubha; Manda, Sainath Reddy; Smock, William; Gosnay, Cynthia; Lippmann, Steven

    2010-02-01

    Many people feel that having a gun provides greater safety for them and their family. Actually, having a firearm in the home escalates the risk for death or injury, while using it to shoot someone who endangers the household is much less common. The resultant injuries, deaths, emotional turmoil, and/or disabilities lead to greater utilization of health care and legal/police services. Payment for these expenses is provided by higher insurance premiums and tax rates. This financial aspect has become a part of our country's current political concern over firearm ownership rights, gun violence or regulation, health care costs, the economy, and taxes. PMID:20065902

  11. Controlled-Temperature Hot-Air Gun

    NASA Technical Reports Server (NTRS)

    Munoz, M. C.

    1986-01-01

    Materials that find applications in wind tunnels first tested in laboratory. Hot-Air Gun differs from commercial units in that flow rate and temperature monitored and controlled. With typical compressed-airsupply pressure of 25 to 38 psi (170 to 260 kPa), flow rate and maximum temperature are 34 stdft3/min (0.96 stdm3/min) and 1,090 degrees F (590 degrees C), respectively. Resembling elaborate but carefully regulated hot-air gun, setup used to apply blasts of air temperatures above 1,500 degrees F (815 degrees C) to test specimens.

  12. Gun Injuries More Often Fatal Now, Study Finds

    MedlinePlus

    ... in 2013. Regardless of how people feel about gun control, "there are a number of things we can all agree upon," Sauaia suggested. These include: Children and people who are mentally unstable should not have access to unlocked, loaded guns. Use technology to improve the safety of guns. ...

  13. Aspirator Gun for High-Throughput Mosquito Bioassays

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We describe an innovative aspirator gun designed to transfer anaesthetized mosquitoes directly into glass bioassay tubes. The gun has been used for thousands of transfers with extremely low associated mortality and is the central component of a high-throughput bioassay system. The gun is constructed...

  14. Aspirator gun for high-throughput mosquito bioassays.

    PubMed

    Aldridge, Robert L; Wynn, W Wayne; Britch, Seth C; Linthicum, Kenneth J

    2012-03-01

    We describe an innovative aspirator gun designed to transfer individual anesthetized mosquitoes directly into glass bioassay tubes. The gun has been used for thousands of transfers with extremely low associated mortality and is the central component of a high-throughput bioassay system. The gun is constructed using readily obtainable materials and can be modified for a range of insects. PMID:22533090

  15. Youth, Guns, and the Juvenile Justice System. Research Report.

    ERIC Educational Resources Information Center

    Butts, Jeffrey; Coggeshall, Mark; Gouvis, Caterina; Mears, Daniel; Travis, Jeremy; Waul, Michelle; White, Ruth

    This report documents trends in youth gun violence and the response within the justice system, noting the growing variety of data resources available to investigate the effect of new gun laws on youth, communities, and public safety. The first section reviews recent trends, examining the major wave of gun violence in the United States during the…

  16. Product-oriented approaches to reducing youth gun violence.

    PubMed

    Teret, Stephen P; Culross, Patti L

    2002-01-01

    Injury prevention experts have suggested that gun manufacturers could reduce youth violence by changing the design of guns. Product safety features could make guns more difficult for children to fire unintentionally and more difficult to use if stolen or obtained illegally. This article gives a brief history of efforts to make safer, smarter guns and assesses the potential of the product safety approach for reducing youth gun violence. Among the article's key findings: Research from the injury prevention field suggests that changing product design may be more effective in preventing injuries than trying to change personal behaviors; Existing product safety technologies for guns could reduce unintentional gun injuries, especially to young children. In addition, emerging technologies will enable gun manufacturers to "personalize" guns, which could prevent unauthorized users of any age from firing the weapons. Personalization could decrease access to guns by adolescents; Gun manufacturers have been slow to incorporate safety features into their products; but legislative, regulatory, and litigation efforts are under way to mandate safer guns. The authors envision a future when the law requires product safety features--including personalization--on all new firearms. These product safety features have the potential to reduce both intentional and unintentional firearm injury and death. PMID:12194606

  17. Should Gun Safety Be Taught in Schools? Perspectives of Teachers

    ERIC Educational Resources Information Center

    Obeng, Cecilia

    2010-01-01

    Background: Gun-related injuries and deaths among children occur at disproportionately high rates in the United States. Children who live in homes with guns are the most likely victims. This study describes teachers' views on whether gun safety should be taught to children in the preschool and elementary years. Methods: A total of 150 survey…

  18. Gun Violence and Children: Factors Related To Exposure and Trauma.

    ERIC Educational Resources Information Center

    Slovak, Karen

    2002-01-01

    Study investigated relationship between access to firearms and parental monitoring on rural youths' exposure to gun violence, and examined the effect of gun violence exposure on mental health. Results indicated a substantial number were exposed to gun violence. Exposure was related to firearm access and parental monitoring. Implications for social…

  19. VIEW OF SOUTH GUN EMPLACEMENT. NOTE THE EXCAVATED EDGE OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF SOUTH GUN EMPLACEMENT. NOTE THE EXCAVATED EDGE OF THE GUN BLOCK IN THE FOREGROUND. VIEW FACING NORTH - U.S. Naval Base, Pearl Harbor, Ford Island 5-Inch Antiaircraft Battery, South Gun Emplacement, Ford Island, Pearl City, Honolulu County, HI

  20. Spot-Welding Gun Is Easy To Use

    NASA Technical Reports Server (NTRS)

    Morgan, Gene E.; Nguyen, Francis H.

    1991-01-01

    Electrical-resistance spot-welding gun designed to produce more welds per unit time by decreasing technician's effort and fatigue. Vacuum cups on frame secure welding gun to workpiece while compressed air drives welding tip against workpiece to make spot resistance weld. When weld completed, vacuum in frame cups released so frame and gun moved to position of next spot weld.

  1. Gun ownership and suicide in the United States.

    PubMed

    Lester, D

    1989-05-01

    The circulation of firearm magazines was used as an index of gun ownership in the states of the USA. States with a higher per capita circulation of firearm magazines had higher suicide rates by gun and higher overall suicide rates. Homicide rates were unrelated to this measure of gun availability. Implications for the prevention of suicide are discussed. PMID:2788293

  2. Is There a Gun in the House? Gun Safety in the Home.

    ERIC Educational Resources Information Center

    Keller, Rosanne

    Written in a conversational style with illustrations, this booklet from a series of home literacy readers is directed at the Alaskan environment where guns are a way of life, used for food and defense from animals. But more than 10% of the 1,300 U.S. deaths from gun accidents occur in Alaska, and more than 70%, at home. Nearly half the victims are…

  3. Recreational Gun Use by California Adolescents

    ERIC Educational Resources Information Center

    Vittes, Katherine A.; Sorenson, Susan B.

    2005-01-01

    Most research on adolescents and firearms focuses on urban populations, handguns, and homicide. This study examines the prevalence and correlates of recreational gun use (RGU)--for hunting or target shooting--among 5,801 community-residing 12- to 17-year-old Californians. Data are from the first statewide California Health Interview Survey (CHIS),…

  4. Simulation of an rf thermionic gun

    NASA Astrophysics Data System (ADS)

    Liu, Hongxiu

    1991-07-01

    An rf thermionic gun is simulated using Superfish and Parmela. A strong front-end compression for the bunch is demonstrated. The energy spread, phase spread and emittance of a single electron micropulse are examined subtly by cutting the bunch into slices corresponding to different initial emission phases of the particles.

  5. Gene gun immunization to combat malaria.

    PubMed

    Bergmann-Leitner, Elke S; Leitner, Wolfgang W

    2013-01-01

    DNA immunization by gene gun against a variety of infectious diseases has yielded promising results in animal models. Skin-based DNA vaccination against these diseases is not only an attractive option for the clinic but can aid in the discovery and optimization of vaccine candidates. Vaccination against the protozoan parasite Plasmodium presents unique challenges: (a) most parasite-associated antigens are stage-specific; (b) antibodies capable of neutralizing the parasite during the probing of the mosquitoes have to be available at high titers in order to prevent infection of the liver; (c) immunity to liver-stage infection needs to be absolute in order to prevent subsequent blood-stage parasitemia. Gene gun vaccination has successfully been used to prevent the infection of mice with the rodent malaria strain P. berghei and has been employed in a macaque model of human P. falciparum. DNA plasmid delivery by gene gun offers the opportunity to economically and efficiently test novel malaria vaccine candidates and vaccination strategies, which include the evaluation of novel molecular adjuvant strategies. Here we describe the procedures involved in making and delivering a pre-clinical malaria DNA vaccine by gene gun as well as the correct approach for the in vivo evaluation of the vaccine. Furthermore, we discuss various approaches that either have already been tested or could be employed to improve DNA vaccines against malaria. PMID:23104349

  6. Witness gun for the Argonne Wakefield Accelerator

    SciTech Connect

    Power, J.; Simpson, J.; Chojnacki, E.; Konecny, R.

    1995-06-01

    The witness gun for the Argonne Wakefield Accelerator (AWA) is a six-cell, copper, iris loaded, rf photocathode operating at 1.3 GHz in a {pi}/2 standing wave mode. An intense drive beam (up to 100 nC {at} 20 psec FWHM) used in the AWA project to excite (i.e. drive) wakefields in at least two separate test devices: a dielectric loaded cylindrical waveguide and a plasma cell. In both cases a low charge, low emittance witness beam (0.1 nC charge, 1 {pi}mm-mrad 90% physical emittance) is required to probe (i.e. witness) the wakefields left behind by the drive beam. This paper will primarily discuss the recent progress in the construction of the witness gun, while also briefly summarizing the central design issues of the gun. A brief status report on the dielectric witness gun option is also included. The authors conclude with a short statement on the near term future plans.

  7. Capital Punishment, Gun Ownership, and Homicide.

    ERIC Educational Resources Information Center

    Kleck, Gary

    1979-01-01

    Examines two controversial questions related to the problem of interpersonal violence in America: (1) Does use of the death penalty exert any measurable influence on the rate of homicide in the United States? (2) What relationship, if any, exists between the level of gun ownership and the level of homicide violence? (Author)

  8. College Students Opinions on Gun Violence.

    PubMed

    Lewis, Rhonda K; LoCurto, Jamie; Brown, Kyrah; Stowell, David; Maryman, J'Vonnah; Dean, Amber; McNair, Thoi; Ojeda, Debbie; Siwierka, Julia

    2016-06-01

    Gun violence and control issues have become serious public health problems. This study gathered the opinions from 419 college students from a Midwestern University. Participants were asked about beliefs about purchasing assault weapons, beliefs about bringing handguns to college campuses and beliefs about contributing factors that lead to gun violence. Participants completed surveys online. The findings showed that overall 54 % of respondents believed that military assault weapons should be banned and 53 % agree that teachers should be allowed to carry a registered handgun on campus. There were statistically significant differences between males and females on these issues. For instance, females believed military assault weapons and high capacity magazines should be banned more than 1.9 times (p = .004) p < .05 compared to male students. On the other hand, female students were more likely to believe that school teachers should be allowed to carry registered handguns on school campuses more than 1.55 times (p = .046) p < .05 compared to their male student counterparts. There were no statistically significant differences between ethnic groups. The top four contributing factors that students believed led to gun violence were decline in parenting and family values (17 %), gang involvement (14 %), bullying (13.8 %) and guns being easy to obtain (13.8 %). Limitations and implications for policy work are discussed. PMID:26516018

  9. Performance of photocathode rf gun electron accelerators

    SciTech Connect

    Ben-Zvi, I.

    1993-07-01

    In Photo-Injectors (PI) electron guns, electrons are emitted from a photocathode by a short laser pulse and then accelerated by intense rf fields in a resonant cavity. The best known advantage of this technique is the high peak current with a good emittance (high brightness). This is important for short wavelength Free-Electron Lasers and linear colliders. PIs are in operation in many electron accelerator facilities and a large number of new guns are under construction. Some applications have emerged, providing, for example, very high pulse charges. PIs have been operated over a wide range of frequencies, from 144 to 3000 MHz (a 17 GHz gun is being developed). An exciting new possibility is the development of superconducting PIs. A significant body of experimental and theoretical work exists by now, indicating the criticality of the accelerator elements that follow the gun for the preservation of the PI`s performance as well as possible avenues of improvements in brightness. Considerable research is being done on the laser and photocathode material of the PI, and improvement is expected in this area.

  10. Performance of photocathode rf gun electron accelerators

    SciTech Connect

    Ben-Zvi, I.

    1993-01-01

    In Photo-Injectors (PI) electron guns, electrons are emitted from a photocathode by a short laser pulse and then accelerated by intense rf fields in a resonant cavity. The best known advantage of this technique is the high peak current with a good emittance (high brightness). This is important for short wavelength Free-Electron Lasers and linear colliders. PIs are in operation in many electron accelerator facilities and a large number of new guns are under construction. Some applications have emerged, providing, for example, very high pulse charges. PIs have been operated over a wide range of frequencies, from 144 to 3000 MHz (a 17 GHz gun is being developed). An exciting new possibility is the development of superconducting PIs. A significant body of experimental and theoretical work exists by now, indicating the criticality of the accelerator elements that follow the gun for the preservation of the PI's performance as well as possible avenues of improvements in brightness. Considerable research is being done on the laser and photocathode material of the PI, and improvement is expected in this area.

  11. Toward a terahertz-driven electron gun

    PubMed Central

    Huang, W. Ronny; Nanni, Emilio A.; Ravi, Koustuban; Hong, Kyung-Han; Fallahi, Arya; Wong, Liang Jie; Keathley, Phillip D.; Zapata, Luis E.; Kärtner, Franz X.

    2015-01-01

    Femtosecond electron bunches with keV energies and eV energy spread are needed by condensed matter physicists to resolve state transitions in carbon nanotubes, molecular structures, organic salts, and charge density wave materials. These semirelativistic electron sources are not only of interest for ultrafast electron diffraction, but also for electron energy-loss spectroscopy and as a seed for x-ray FELs. Thus far, the output energy spread (hence pulse duration) of ultrafast electron guns has been limited by the achievable electric field at the surface of the emitter, which is 10 MV/m for DC guns and 200 MV/m for RF guns. A single-cycle THz electron gun provides a unique opportunity to not only achieve GV/m surface electric fields but also with relatively low THz pulse energies, since a single-cycle transform-limited waveform is the most efficient way to achieve intense electric fields. Here, electron bunches of 50 fC from a flat copper photocathode are accelerated from rest to tens of eV by a microjoule THz pulse with peak electric field of 72 MV/m at 1 kHz repetition rate. We show that scaling to the readily-available GV/m THz field regime would translate to monoenergetic electron beams of ~100 keV. PMID:26486697

  12. Protect Children Instead of Guns, 2000.

    ERIC Educational Resources Information Center

    Children's Defense Fund, Washington, DC.

    Noting that firearms outnumber children by a margin of almost three to one in the United States, this report advocates gun safety policies to protect children. The report provides information on trends in youth firearm deaths from 1994 and 1999 and comparisons of U.S. data to those of other industrialized countries. A table delineates 1996-1998…

  13. Common Sense Copper and RF Guns

    SciTech Connect

    Mulhollan, G.

    2005-01-18

    The purpose of this document is to gather together both fundamental information on copper and on the cleaning and operation of copper in RF gun structures. While incomplete, this is a living document and will be added to and updated as necessary.

  14. How Sociology Texts Address Gun Control

    ERIC Educational Resources Information Center

    Tonso, William R.

    2004-01-01

    William R. Tonso has chosen an issue that he knows something about to examine how sociology textbooks address controversy. Appealing for gun control is fashionable, but it is at odds with a fondness that ordinary Americans have for their firearms--one that is supported by a growing body of research on deterrence to crime. There are two sides to…

  15. Protect Children Instead of Guns, 2001.

    ERIC Educational Resources Information Center

    Children's Defense Fund, Washington, DC.

    Noting that firearms outnumber children by a margin of almost three to one in the United States, this report advocates gun safety policies to protect children. The report provides information on trends in youth firearm deaths and finds the statistics alarming, despite recent decline. The first of three tables in the report delineates 1979-1999…

  16. Issue Management and the Australian Gun Debate.

    ERIC Educational Resources Information Center

    Reynolds, Christopher

    1997-01-01

    Examines the rise and fall of media coverage of the issues of gun control and political conflict in Australia after an incident of mass murder in April 1996. Aims to reveal the issue management process that occurred and the hidden agendas that motivated the political and media activity. Demonstrates the media's role in the creation of issue…

  17. Youth Suicide and Guns. Firearm Facts.

    ERIC Educational Resources Information Center

    Duker, Laurie, Ed.

    Whether or not a suicide attempt results in death depends in large part on the method chosen. If a teenager attempts suicide with a gun, his or her death is nearly guaranteed. This brief fact sheet presents data on firearms and suicide, the third leading cause of death for adolescents and young adults in the United States. Any number of societal…

  18. Safety Plan for Schools: No Guns

    ERIC Educational Resources Information Center

    Shah, Nirvi

    2013-01-01

    In a pre-emptive move against a school safety proposal from the National Rifle Association that is expected to include a call for more people trained and approved to carry guns at schools, a coalition of civil rights and education groups unveiled its own safety plan last week. It seeks the creation of positive school climates, thoughtful and…

  19. Guns on Campus: A Chilling Effect

    ERIC Educational Resources Information Center

    Mash, Kenneth M.

    2013-01-01

    The author of this article observes that, while much has been written on the overall topic of safety with regard to allowing guns on college campuses, little has been said about how allowing the possession of deadly weapons can create a "chilling effect" on academic discussions. This article considers how some universities have…

  20. RF Gun Photocathode Research at SLAC

    SciTech Connect

    Jongewaard, E.; Akre, R.; Brachmann, A.; Corbett, J.; Gilevich, S.; Grouev, K.; Hering, P.; P.Krejcik,; Lewandowski, J.; Loos, H.; Montagne, T.; Sheppard, J.C.; Stefan, P.; Vlieks, A.; Weathersby, S.; Zhou, F.; /SLAC

    2012-05-16

    LCLS is presently operating with a third copper photocathode in the original rf gun, with a quantum efficiency (QE) of {approx}1 x 10{sup -4} and projected emittance {gamma}{var_epsilon}{sub x,y} = 0.45 {micro}m at 250 pC bunch charge. The spare LCLS gun is installed in the SLAC Accelerator Structure Test Area (ASTA), fully processed to high rf power. As part of a wider photocathode R and D program, a UV laser system and additional gun diagnostics are being installed at ASTA to measure QE, QE lifetime, and electron beam emittance under a variety of operating conditions. The near-term goals are to test and verify the spare photocathode production/installation sequence, including transfer from the final holding chamber to the rf gun. Mid- and longer-term goals include development of a rigorous understanding of plasma and laser-assisted surface conditioning and investigation of new, high-QE photocathode materials. In parallel, an x-ray photoemission spectroscopy station is nearing completion, to analyze Cu photocathode surface chemistry. In this paper we review the status and anticipated operating parameters of ASTA and the spectroscopy test chamber.

  1. Spray Gun With Constant Mixing Ratio

    NASA Technical Reports Server (NTRS)

    Simpson, William G.

    1987-01-01

    Conceptual mechanism mounted in handle of spray gun maintains constant ratio between volumetric flow rates in two channels leading to spray head. With mechanism, possible to keep flow ratio near 1:1 (or another desired ratio) over range of temperatures, orifice or channel sizes, or clogging conditions.

  2. Nerf Guns Strike a Nerve on Campuses

    ERIC Educational Resources Information Center

    Young, Jeffrey R.

    2008-01-01

    Killing zombies on campus just isn't as much fun as it used to be. Students at Bowling Green State University once carried Nerf guns for a week each semester, shooting the zombies before the creatures could tag them. Participants were seen by most bystanders as nerdy but harmless kids who liked role-playing. These days, bright plastic Nerf guns…

  3. Light gas gun with reduced timing jitter

    SciTech Connect

    Laabs, Gary W.; Funk, David J.; Asay, Blaine W.

    1996-12-01

    A gas gun having a prepressurized projectile held in place with a glass rod in compression is described. The glass rod is destroyed with an explosive at a precise time which allows a restraining pin to be moved by pneumatic means and free the projectile.

  4. Toward a terahertz-driven electron gun.

    PubMed

    Huang, W Ronny; Nanni, Emilio A; Ravi, Koustuban; Hong, Kyung-Han; Fallahi, Arya; Wong, Liang Jie; Keathley, Phillip D; Zapata, Luis E; Kärtner, Franz X

    2015-01-01

    Femtosecond electron bunches with keV energies and eV energy spread are needed by condensed matter physicists to resolve state transitions in carbon nanotubes, molecular structures, organic salts, and charge density wave materials. These semirelativistic electron sources are not only of interest for ultrafast electron diffraction, but also for electron energy-loss spectroscopy and as a seed for x-ray FELs. Thus far, the output energy spread (hence pulse duration) of ultrafast electron guns has been limited by the achievable electric field at the surface of the emitter, which is 10 MV/m for DC guns and 200 MV/m for RF guns. A single-cycle THz electron gun provides a unique opportunity to not only achieve GV/m surface electric fields but also with relatively low THz pulse energies, since a single-cycle transform-limited waveform is the most efficient way to achieve intense electric fields. Here, electron bunches of 50 fC from a flat copper photocathode are accelerated from rest to tens of eV by a microjoule THz pulse with peak electric field of 72 MV/m at 1 kHz repetition rate. We show that scaling to the readily-available GV/m THz field regime would translate to monoenergetic electron beams of ~100 keV. PMID:26486697

  5. Collapsible pistons for light-gas guns

    NASA Technical Reports Server (NTRS)

    Teng, R. N.

    1973-01-01

    Moving and expandable parts of gun consist of pump-tube diaphragm, piston, launch-tube diaphragm, and saboted projectile. As a result of improved piston design, pressure cycle has been significantly improved by smoother buildup, increasing muzzle velocities up to 50%.

  6. Acute alcohol consumption, alcohol outlets, and gun suicide.

    PubMed

    Branas, Charles C; Richmond, Therese S; Ten Have, Thomas R; Wiebe, Douglas J

    2011-01-01

    A case-control study of 149 intentionally self-inflicted gun injury cases (including completed gun suicides) and 302 population-based controls was conducted from 2003 to 2006 in a major US city. Two focal independent variables, acute alcohol consumption and alcohol outlet availability, were measured. Conditional logistic regression was adjusted for confounding variables. Gun suicide risk to individuals in areas of high alcohol outlet availability was less than the gun suicide risk they incurred from acute alcohol consumption, especially to excess. This corroborates prior work but also uncovers new information about the relationships between acute alcohol consumption, alcohol outlets, and gun suicide. Study limitations and implications are discussed. PMID:21929327

  7. Design studies for the LCLS 120 Hz RF gun

    SciTech Connect

    Wang, X.J.; Babzien, M.; Ben-Zvi, I.; Chang, X.Y.; Pjerov, S.; Woodle, M.

    2000-11-01

    A preliminary design studies were carried out at Brookhaven National Laboratory for a photocathode RF gun injection system for LCLS 120 Hz operation. The starting point for the design is 50 Hz BNL Gun IV developed by a BNL/KEK/SHI collaboration. The basic parameters of the 120 Hz gun is discussed in this report. The complete photocathode RF gun injection system is described for a 120 Hz operation. The injector system includes photocathode RF gun, emittance compensation solenoid magnet, laser system and laser beam delivery system, and electron beam diagnostics. The basic design parameters, mechanical modification and the performance will be presented in this report.

  8. Acute Alcohol Consumption, Alcohol Outlets, and Gun Suicide

    PubMed Central

    Branas, Charles C.; Richmond, Therese S.; Ten Have, Thomas R.; Wiebe, Douglas J.

    2014-01-01

    A case–control study of 149 intentionally self-inflicted gun injury cases (including completed gun suicides) and 302 population-based controls was conducted from 2003 to 2006 in a major US city. Two focal independent variables, acute alcohol consumption and alcohol outlet availability, were measured. Conditional logistic regression was adjusted for confounding variables. Gun suicide risk to individuals in areas of high alcohol outlet availability was less than the gun suicide risk they incurred from acute alcohol consumption, especially to excess. This corroborates prior work but also uncovers new information about the relationships between acute alcohol consumption, alcohol outlets, and gun suicide. Study limitations and implications are discussed. PMID:21929327

  9. Improved DC Gun Insulator Assembly

    SciTech Connect

    Sah, R.; Dudas, A.; Neubauer, M. L.; Poelker, M.; Surles-Law, K. E.L.

    2010-05-23

    Many user fa­cil­i­ties such as syn­chrotron ra­di­a­tion light sources and free elec­tron lasers re­quire ac­cel­er­at­ing struc­tures that sup­port elec­tric fields of 10-100 MV/m, es­pe­cial­ly at the start of the ac­cel­er­a­tor chain where ce­ram­ic in­su­la­tors are used for very high gra­di­ent DC guns. These in­su­la­tors are dif­fi­cult to man­u­fac­ture, re­quire long com­mis­sion­ing times, and often ex­hib­it poor re­li­a­bil­i­ty. Two tech­ni­cal ap­proach­es to solv­ing this prob­lem will be in­ves­ti­gat­ed. First­ly, in­vert­ed ce­ram­ics offer so­lu­tions for re­duced gra­di­ents be­tween the elec­trodes and ground. An in­vert­ed de­sign will be pre­sent­ed for 350 kV, with max­i­mum gra­di­ents in the range of 5-10 MV/m. Sec­ond­ly, novel ce­ram­ic man­u­fac­tur­ing pro­cess­es will be stud­ied, in order to pro­tect triple junc­tion lo­ca­tions from emis­sion, by ap­ply­ing a coat­ing with a bulk re­sis­tiv­i­ty. The pro­cess­es for cre­at­ing this coat­ing will be op­ti­mized to pro­vide pro­tec­tion as well as be used to coat a ce­ram­ic with an ap­pro­pri­ate gra­di­ent in bulk re­sis­tiv­i­ty from the vac­u­um side to the air side of an HV stand­off ce­ram­ic cylin­der. Ex­am­ple in­su­la­tor de­signs are being com­put­er mod­elled, and in­su­la­tor sam­ples are being man­u­fac­tured and test­ed

  10. Interpreting the empirical evidence on illegal gun market dynamics.

    PubMed

    Braga, Anthony A; Wintemute, Garen J; Pierce, Glenn L; Cook, Philip J; Ridgeway, Greg

    2012-10-01

    Thousands of Americans are killed by gunfire each year, and hundreds of thousands more are injured or threatened with guns in robberies and assaults. The burden of gun violence in urban areas is particularly high. Critics suggest that the results of firearm trace data and gun trafficking investigation studies cannot be used to understand the illegal supply of guns to criminals and, therefore, that regulatory and enforcement efforts designed to disrupt illegal firearms markets are futile in addressing criminal access to firearms. In this paper, we present new data to address three key arguments used by skeptics to undermine research on illegal gun market dynamics. We find that criminals rely upon a diverse set of illegal diversion pathways to acquire guns, gun traffickers usually divert small numbers of guns, newer guns are diverted through close-to-retail diversions from legal firearms commerce, and that a diverse set of gun trafficking indicators are needed to identify and shut down gun trafficking pathways. PMID:22669643

  11. Gun safety management with patients at risk for suicide.

    PubMed

    Simon, Robert I

    2007-10-01

    Guns in the home are associated with a five-fold increase in suicide. All patients at risk for suicide must be asked if guns are available at home or easily accessible elsewhere, or if they have intent to buy or purchase a gun. Gun safety management requires a collaborative team approach including the clinician, patient, and designated person responsible for removing guns from the home. A call-back to the clinician from the designated person is required confirming that guns have been removed and secured according to plan. The principle of gun safety management applies to outpatients, inpatients, and emergency patients, although its implementation varies according to the clinical setting. PMID:17967118

  12. Gun utopias? Firearm access and ownership in Israel and Switzerland.

    PubMed

    Rosenbaum, Janet E

    2012-02-01

    The 2011 attempted assassination of a US representative renewed the national gun control debate. Gun advocates claim mass-casualty events are mitigated and deterred with three policies: (a) permissive gun laws, (b) widespread gun ownership, (c) and encouragement of armed civilians who can intercept shooters. They cite Switzerland and Israel as exemplars. We evaluate these claims with analysis of International Crime Victimization Survey (ICVS) data and translation of laws and original source material. Swiss and Israeli laws limit firearm ownership and require permit renewal one to four times annually. ICVS analysis finds the United States has more firearms per capita and per household than either country. Switzerland and Israel curtail off-duty soldiers' firearm access to prevent firearm deaths. Suicide among soldiers decreased by 40 per cent after the Israeli army's 2006 reforms. Compared with the United States, Switzerland and Israel have lower gun ownership and stricter gun laws, and their policies discourage personal gun ownership. PMID:22089893

  13. An X-Band Gun Test Area at SLAC

    SciTech Connect

    Limborg-Deprey, C.; Adolphsen, C.; Chu, T.S.; Dunning, M.P.; Jobe, R.K.; Jongewaard, E.N.; Hast, C.; Vlieks, A.E.; Wang, F.; Walz, D.R.; Marsh, R.A.; Anderson, S.G.; Hartemann, F.V.; Houck, T.L.; /LLNL, Livermore

    2012-09-07

    The X-Band Test Area (XTA) is being assembled in the NLCTA tunnel at SLAC to serve as a test facility for new RF guns. The first gun to be tested will be an upgraded version of the 5.6 cell, 200 MV/m peak field X-band gun designed at SLAC in 2003 for the Compton Scattering experiment run in ASTA. This new version includes some features implemented in 2006 on the LCLS gun such as racetrack couplers, increased mode separation and elliptical irises. These upgrades were developed in collaboration with LLNL since the same gun will be used in an injector for a LLNL Gamma-ray Source. Our beamline includes an X-band acceleration section which takes the electron beam up to 100 MeV and an electron beam measurement station. Other X-Band guns such as the UCLA Hybrid gun will be characterized at our facility.

  14. Gun utopias? Firearm access and ownership in Israel and Switzerland

    PubMed Central

    Rosenbaum, Janet

    2011-01-01

    The 2011 attempted assassination of a US representative renewed the national gun control debate. Gun advocates claim that mass-casualty events are mitigated and deterred with three policies: (1) permissive gun laws, (2) widespread gun ownership, (3) encouragement of armed civilians who can intercept shooters, and cite Switzerland and Israel as exemplars. We evaluate these claims with analysis of International Crime Victimization Survey (ICVS) data and translation of laws and original source material. Swiss and Israeli laws limit firearm ownership and require permit renewal 14 times annually. ICVS analysis finds that the US has more firearms per capita and per household than either country. Switzerland and Israel curtail off-duty soldiers firearm access to prevent firearm deaths. Suicide among soldiers decreased by 40% after the Israeli armys 2006 reforms. Compared with the US, Switzerland and Israel have lower gun ownership and stricter gun laws, and their policies discourage personal gun ownership. PMID:22089893

  15. A high-brightness thermionic microwave electron gun

    SciTech Connect

    Borland, M.

    1991-02-01

    In a collaborative effort by SSRL, AET Associates, and Varian Associates, a high-brightness microwave electron gun using a thermionic cathode has been designed, built, tested, and installed for use with the SSRL 150 MeV linear accelerator. This thesis discusses the physics behind the design and operation of the gun and associated systems, presenting predictions and experimental tests of the gun`s performance. The microwave gun concept is of increasing interest due to its promise of providing higher-current, lower-emittance electron beams than possible from conventional, DC gun technology. In a DC guns, accelerating gradients are less than 8 MV/m, while those in a microwave gun can exceed 100 MV/m, providing much more rapid initial acceleration, thereby reducing the deleterious effects of space-charge. Microwave guns produce higher momentum beams than DC guns, thus lessening space-charge effects during subsequent beam transport. Typical DC guns produce kinetic energies of 80--400 KeV, compared to 2--3 MeV for the SSRL microwave gun. ``State-of-the-art`` microwave gun designs employ laser-driven photocathodes, providing excellent performance but with greater complexity and monetary costs. A thermionic microwave gun with a magnetic bunching system is comparable in cost and complexity to a conventional system, but provides performance that is orders of magnitude better. Simulations of the SSRL microwave gun predict a normalized RMS emittance at the gun exist of < 10 {pi} {center_dot} m{sub e}c {center_dot} {mu}m for a beam consisting of approximately 50% of the particles emitted from the gun, and having a momentum spread {plus_minus}10%. These emittances are for up to 5 {times} 10{sup 9}e{sup {minus}} per bunch. Chromatic aberrations in the transport line between the gun and linear accelerator increase this to typically < 30 {pi} {center_dot} m{sub e} {center_dot} {mu}m.

  16. Field Test Kit for Gun Residue Detection

    SciTech Connect

    WALKER, PAMELA K.; RODACY, PHILIP J.

    2002-01-01

    One of the major needs of the law enforcement field is a product that quickly, accurately, and inexpensively identifies whether a person has recently fired a gun--even if the suspect has attempted to wash the traces of gunpowder off. The Field Test Kit for Gunshot Residue Identification based on Sandia National Laboratories technology works with a wide variety of handguns and other weaponry using gunpowder. There are several organic chemicals in small arms propellants such as nitrocellulose, nitroglycerine, dinitrotoluene, and nitrites left behind after the firing of a gun that result from the incomplete combustion of the gunpowder. Sandia has developed a colorimetric shooter identification kit for in situ detection of gunshot residue (GSR) from a suspect. The test kit is the first of its kind and is small, inexpensive, and easily transported by individual law enforcement personnel requiring minimal training for effective use. It will provide immediate information identifying gunshot residue.

  17. 46 CFR 160.031-4 - Equipment for shoulder gun type line-throwing appliance.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 6 2013-10-01 2013-10-01 false Equipment for shoulder gun type line-throwing appliance... Appliance, Shoulder Gun Type (and Equipment) § 160.031-4 Equipment for shoulder gun type line-throwing... the gun. The line canister shall be secured by clamps or brackets below the barrel of the gun. (c)...

  18. 46 CFR 160.031-4 - Equipment for shoulder gun type line-throwing appliance.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 6 2014-10-01 2014-10-01 false Equipment for shoulder gun type line-throwing appliance... Appliance, Shoulder Gun Type (and Equipment) § 160.031-4 Equipment for shoulder gun type line-throwing... the gun. The line canister shall be secured by clamps or brackets below the barrel of the gun. (c)...

  19. 46 CFR 160.031-4 - Equipment for shoulder gun type line-throwing appliance.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 6 2012-10-01 2012-10-01 false Equipment for shoulder gun type line-throwing appliance... Appliance, Shoulder Gun Type (and Equipment) § 160.031-4 Equipment for shoulder gun type line-throwing... the gun. The line canister shall be secured by clamps or brackets below the barrel of the gun. (c)...

  20. 46 CFR 160.031-4 - Equipment for shoulder gun type line-throwing appliance.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 6 2011-10-01 2011-10-01 false Equipment for shoulder gun type line-throwing appliance... Appliance, Shoulder Gun Type (and Equipment) § 160.031-4 Equipment for shoulder gun type line-throwing... the gun. The line canister shall be secured by clamps or brackets below the barrel of the gun. (c)...

  1. 46 CFR 160.031-4 - Equipment for shoulder gun type line-throwing appliance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 6 2010-10-01 2010-10-01 false Equipment for shoulder gun type line-throwing appliance... Appliance, Shoulder Gun Type (and Equipment) § 160.031-4 Equipment for shoulder gun type line-throwing... the gun. The line canister shall be secured by clamps or brackets below the barrel of the gun. (c)...

  2. Media violence, gun control, and public policy.

    PubMed

    Zuckerman, D M

    1996-07-01

    Public concern with the national level of violence is discussed, and the complexity of the issue delineated. Research findings in two key areas of the topic, media violence and availability of firearms, are examined, as is their applicability to public policy efforts and recommendations for the prevention of violence. An approach that combines efforts to counteract media violence with those aimed at effective gun control is outlined in terms of bringing about changes in attitudes toward violence and firearm possession. PMID:8827261

  3. Nozzle Extension for Safety Air Gun

    NASA Technical Reports Server (NTRS)

    Zumbrun, H. N.; Croom, Delwin R., Jr.

    1986-01-01

    New nozzle-extension design overcomes problems and incorporates original commercial nozzle, retaining intrinsic safety features. Components include extension tube, length of which made to suit application; adaptor fitting, and nozzle adaptor repinned to maintain original safety features. Design moves conical airstream to end of extension to blow machine chips away from operator. Nozzle-extension modification allows safe and efficient operation of machine tools while maintaining integrity of orginial safety-air-gun design.

  4. An experimental study on microwave electron gun

    SciTech Connect

    Wang, G.; Wu, J.; Wang, Y.

    1995-12-31

    We report both the simulation and experimental results of using a ring cathode instead of the solid cathode to reduce the back bombardment effect of a thermionic cathode microwave electron gun. The result shows that the back bombardment power is decreased about 2/3 without changing the beam quality apparently which allows operation at higher repetition rate. Experimental results are compared with the simulation with good agreement.

  5. Cylinder Fragmentation Using Gas Gun Techniques

    NASA Astrophysics Data System (ADS)

    Thornhill, T. F.; Reinhart, W. D.; Chhabildas, L. C.; Grady, D. E.; Wilson, L. T.

    2002-07-01

    In this study an experimental technique for study of cylinder fracture fragmentation characteristics has been developed on a two-stage light gas gun. This test method allows the study of cylinder fracture fragmentation in a laboratory environment under well-controlled loading conditions. Application of this technique allows measure of failure strain, strain rates, expansion velocity, and fragmentation toughness. Results of several experiments on Aermet steel are presented.

  6. The Development of the Linac Coherent Light Source RF Gun

    SciTech Connect

    Dowell, David H.; Jongewaard, Erik; Lewandowski, James; Limborg-Deprey, Cecile; Li, Zenghai; Schmerge, John; Vlieks, Arnold; Wang, Juwen; Xiao, Liling; /SLAC

    2008-09-24

    The Linac Coherent Light Source (LCLS) is the first x-ray laser user facility based upon a free electron laser (FEL) requiring extraordinary beam quality to saturate at 1.5 angstroms within a 100 meter undulator.[1] This new type of light source is using the last kilometer of the three kilometer linac at SLAC to accelerate the beam to an energy as high as 13.6 GeV and required a new electron gun and injector to produce a very bright beam for acceleration. At the outset of the project it was recognized that existing RF guns had the potential to produce the desired beam but none had demonstrated it. Therefore a new RF gun or at least the modification of an existing gun was necessary. The parameters listed in Table 1 illustrate the unique characteristics of LCLS which drive the requirements for the electron gun as given in Table 2. The gun beam quality needs to accommodate emittance growth as the beam is travels through approximately one kilometer of linac and two bunch compressors before reaching the undulator. These beam requirements were demonstrated during the recent commissioning runs of the LCLS injector and linac [2] due to the successful design, fabrication, testing and operation of the LCLS gun. The goal of this paper is to relate the technical background of how the gun was able to achieve and in some cases exceed these requirements by understanding and correcting the deficiencies of the prototype s-band RF photocathode gun, the BNL/SLAC/UCLA Gun III. This paper begins with a brief history and technical description of Gun III and the Gun Test Facility (GTF) at SLAC, and studies of the gun's RF and emittance compensation solenoid. The work at the GTF identified the gun and solenoid deficiencies, and helped to define the specifications for the LCLS gun. Section 1.1.5 describes the modeling used to compute and correct the gun RF fields and Section 1.1.6 describes the use of these fields in the electron beam simulations. The magnetic design and measurements of

  7. Diagnostics Beamline for the SRF Gun Project

    SciTech Connect

    T. Kamps; V. Durr; K. Goldammer; D. Kramer; P. Kuske; J. Kuszynski; D. Lipka; F. Marhauser; T. Quast; D. Richter; U. Lehnert; P. Michel; J. Teichert; P. Evtushenko; I. Will

    2005-08-22

    A superconducting radio-frequency photo electron injector (SRF gun) is currently under construction by a collaboration of BESSY, DESY, FZR and MBI. The project aims at the design and setup of a CW SRF gun including a diagnostics beamline for the ELBE FEL and to address R&D issues on low emittance injectors for future light sources such as the BESSY FEL. Of critical importance for the injector performance is the control of the electron beam parameters. For this reason a compact diagnostics beamline is under development serving a multitude of operation settings ranging from low-charge (77pC), low-emittance (1 mm mrad) mode to high-charge (2.5nC) operation of the gun. For these operation modes beam dynamics simulations are resulting in boundary conditions for the beam instrumentation. Proven and mature technology is projected wherever possible, for example for current and beam position monitoring. The layout of the beam profile and emittance measurement systems is described. For the bunch length, which varies between 5 ps and 50 ps, two schemes using electro-optical sampling and Cherenkov radiation are detailed. The beam energy and energy spread is measured with a 180-degree spectrometer.

  8. Gas Gun Studies of Interface Wear Effects

    NASA Astrophysics Data System (ADS)

    Jackson, Tyler; Kennedy, Greg; Thadhani, Naresh

    2011-06-01

    The characteristics of interface wear were studied by performing gas gun experiments at velocities up to 1 km/s. The approach involved developing coefficients of constitutive strength models for Al 6061 and OFHC-Cu, then using those to design die geometry for interface wear gas gun experiments. Taylor rod-on-anvil impact experiments were performed to obtain coefficients of the Johnson-Cook constitutive strength model by correlating experimentally obtained deformed states of impacted samples with those predicted using ANSYS AUTODYN hydrocode. Simulations were used with validated strength models to design geometry involving acceleration of Al rods through a copper concentric cylindrical angular extrusion die. Experiments were conducted using 7.62 mm and 80 mm diameter gas guns. Differences in the microstructure of the interface layer and microhardness values illustrate that stress-strain conditions produced during acceleration of Al through the hollow concentric copper die, at velocities less than 800 m/s, result in formation of a layer via solid state alloying due to severe plastic deformation, while higher velocities produce an interface layer consisting of melted and re-solidified aluminum.

  9. Altitude, Gun Ownership, Rural Areas, and Suicide

    PubMed Central

    Kim, Namkug; Mickelson, Jennie B.; Brenner, Barry E.; Haws, Charlotte A.; Yurgelun-Todd, Deborah A.; Renshaw, Perry F.

    2015-01-01

    Objective The authors recently observed a correlation between state altitude and suicide rate in the United States, which could be explained by higher rates of gun ownership and lower population density in the intermountain West. The present study evaluated the relationship between mean county and state altitude in the United States and total age-adjusted suicide rates, firearm-related suicide rates, and non-firearm-related suicide rates. The authors hypothesized that altitude would be significantly associated with suicide rate. Method Elevation data were calculated with an approximate spatial resolution of 0.5 km, using zonal statistics on data sets compiled from the National Geospatial-Intelligence Agency and the National Aeronautics and Space Administration. Suicide and population density data were obtained through the Centers for Disease Control and Prevention (CDC) WONDER database. Gun ownership data were obtained through the CDC’s Behavioral Risk Factor Surveillance System. Results A significant positive correlation was observed between age-adjusted suicide rate and county elevation (r=0.51). Firearm (r=0.41) and non-firearm suicide rates (r=0.32) were also positively correlated with mean county elevation. Conclusions When altitude, gun ownership, and population density are considered as predictor variables for suicide rates on a state basis, altitude appears to be a significant independent risk factor. This association may be related to the effects of metabolic stress associated with mild hypoxia in individuals with mood disorders. PMID:20843869

  10. A Robust High Current Density Electron Gun

    NASA Astrophysics Data System (ADS)

    Mako, F.; Peter, W.; Shiloh, J.; Len, L. K.

    1996-11-01

    Proof-of-principle experiments are proposed to validate a new concept for a robust, high-current density Pierce electron gun (RPG) for use in klystrons and high brightness electron sources for accelerators. This rugged, long-life electron gun avoids the difficulties associated with plasma cathodes, thermionic emitters, and field emission cathodes. The RPG concept employs the emission of secondary electrons in a transmission mode as opposed to the conventional mode of reflection, i.e., electrons exit from the back face of a thin negative electron affinity (NEA) material, and in the same direction as the incident beam. Current amplification through one stage of a NEA material could be over 50 times. The amplification is accomplished in one or more stages consisting of one primary emitter and one or more secondary emitters. The primary emitter is a low current density robust emitter (e.g., thoriated tungsten). The secondary emitters are thin NEA electrodes which emit secondary electrons in the same direction as the incident beam. Specific application is targeted for a klystron gun to be used by SLAC with a cold cathode at 30-40 amps/cm^2 output from the secondary emission stage, a ~2 μs pulse length, and ~200 pulses/second.

  11. Overview of Plasma Guns for PLX

    NASA Astrophysics Data System (ADS)

    Witherspoon, F. Douglas; Bomgardner, Richard; Case, Andrew; Messer, Sarah; Brockington, Samuel; Wu, Linchun; Elton, Raymond; Hsu, Scott; Cassibry, Jason; Gilmore, Mark

    2010-11-01

    Plasma guns are being developed for use on the Plasma Liner Experiment (PLX) located at LANL. The collapsing plasma liner will be formed via merging of 30-60 dense, high Mach number plasma jets (n˜10^16-17 cm-3, M˜10--35, v˜50--70 km/s, rjet˜5 cm) in a spherically convergent geometry. Small parallel-plate railguns are being developed for this purpose. Each gun will operate at ˜300-600 kA peak current, and launch up to ˜8000 μg of high-Z plasma (Ar, Xe) using a ˜50 kJ pfn. We are now successfully operating with very fast gas valve injection of Ar, and have already achieved good performance of 1200 μg at 42 km/s, and 4000 μg at 20-25 km/s at low current. Work is underway to increase both the mass and velocity using higher current. We describe experimental development of the minirailguns and their present and projected performance. We also discuss options for modest size coaxial guns that might achieve the same performance and provide additional control of the plasmoid structure.

  12. Design of an electron gun for terahertz radiation source

    NASA Astrophysics Data System (ADS)

    Li, Ji; Pei, Yuan-Ji; Hu, Tong-Ning; Chen, Qu-Shan; Feng, Guang-Yao; Shang, Lei; Li, Cheng-Long

    2014-04-01

    An EC-ITC (External-Cathode Independently Tunable Cells) RF gun was employed with the aim of obtaining short-pulse bunches with high peak current for a terahertz radiation source. A gridded DC gun plays a key role as the external injecting electron source of the ITC RF gun, the performance of which determines the beam quality in the injector and transport line. In order to make the beam well compressed in the ITC RF gun, the energy of the electrons acquired from the gridded DC gun should be 15 keV at most. A proper structure of the gridded gun with double-anode is shown to overcome the strong space- charge force on the cathode, which is able to generate 6 μs beam with 4.5 A current successfully.

  13. Nail Gun Induced Open Head Injury: A Case Report.

    PubMed

    Oh, Hyun Ho; Kim, Young; Park, Sung Choon; Ha, Young Soo; Lee, Kyu Chang

    2014-10-01

    Increasing use of the nail gun has led to higher injury rates from the use of tools with sequential actuation. Nail gun injury can occur to various parts of the body. Very deep penetration in the brain can have fatal results. A 46-year-old male fired shots from a nail gun into his brain in a suicide attempt. This case demonstrated successful surgical management of the resultant open head injury. PMID:27169051

  14. High Peak Power Gyroklystron with an Inverted Magnetron Injection Gun

    NASA Astrophysics Data System (ADS)

    Read, Michael; Neilson, Jeff; Borchard, Philipp; Ives, Lawrence; Lawson, Wes

    2006-01-01

    This paper describes the design of a 25 MW, 30 GHz gyroklystron amplifier based on a coaxial RF structure. The design includes an inverted magnetron injection gun (MIG) for positioning and cooling the inner conductor. The gun produces a very low spread beam that contributes to a device efficiency of 54%. Details are given of the gun, RF structure, input and output couplers and collector.

  15. Progress on using NEA cathodes in an RF gun

    SciTech Connect

    Fliller, R.P., III; Anderson, T.; Edwards, H.; Bluem, H.; Schultheiss, T.; Sinclair, C.; Huening, M.; /DESY

    2005-05-01

    RF guns have proven useful in multiple accelerator applications, and are an attractive electron source for the ILC. Using a NEA GaAs photocathode in such a gun allows for the production of polarized electron beams. However the lifetime of a NEA cathode in this environment is reduced by ion and electron bombardment and residual gas oxidation. We report progress made with studies to produce a RF gun using a NEA GaAs photocathode to produce polarized electron beams. We discuss simulations of ion back bombardment and attempts to reduce the residual gas pressure in the gun are discussed. Future directions are also discussed.

  16. Tearing and MHD Instability During Gun Injection into a Spheromak

    SciTech Connect

    Fowler, T K

    2000-05-11

    Linear stability analysis of a two-cylinder approximation to gun injection--one cylinder to represent the confined spheromak and another to represent the gun--is shown to yield equilibria in which tearing modes exist simultaneously at the magnetic axis and at the geometric (gun) axis, as might be required to sustain helicity injection. These equilibria are MHD stable at the two axes but may have localized MHD instability at an interior minimum in the q profile. The theory predicts two tearing thresholds with successively deeper q minima as the gun current is increased at constant bias flux.

  17. Effects of gun admonitions on the behaviors and attitudes of school-aged boys.

    PubMed

    Hardy, Marjorie S

    2003-10-01

    Gun-safety programs frequently warn children not to touch guns with little consideration that the messages may enhance the allure of the guns. In the current study, boys rated and ranked their preference for a gun in comparison with other desirable objects. One week later, when left alone in the room with the objects, they were forbidden to touch either the gun or some other object. Observations of their behavior and reevaluation of their attitudes followed. Although the boys forbidden to touch the gun did not report an increased preference for it, all participants were significantly more likely to touch the forbidden gun than to touch other forbidden objects. Age, parent- and coach-reported simulated gun-play, and coach-reported risky behavior predicted gun-touching behavior. The results of the current study indicate that guns hold a unique allure and cast further doubt on the ability of gun admonitions to keep children safe around guns. PMID:14578696

  18. Low Emittance Guns for the ILC Polarized Electron Beam

    SciTech Connect

    Clendenin, J.E.; Brachmann, A.; Ioakeimidi, K.; Kirby, R.E.; Maruyama, T.; Miller, R.H.; Wang, J.W.; Zhou, F.; /SLAC

    2006-12-01

    Polarized electron beams generated by DC guns are routinely available at several accelerators including JLAB, Mainz and SLAC. These guns operate with a cathode bias on the order of -100 kV. To minimize space charge effects, relatively long bunches are generated at the gun and then compressed longitudinally external to the gun just before and during initial acceleration. For linear colliders, this compression is accomplished using a combination of rf bunchers. For the basic design of the International Linear Collider (ILC), a 120 kV DC photocathode gun is used to produce a series of nanosecond bunches that are each compressed by two sub-harmonic bunchers (SHBs) followed by an L-band buncher and capture section. The longitudinal bunching process results in a significantly higher emittance than produced by the gun alone. While high-energy experiments using polarized beams are not generally sensitive to the source emittance, there are several benefits to a lower source emittance including a simpler more efficient injector system and a lower radiation load during transport especially at bends as at the damping ring. For the ILC, the SHBs could be eliminated if the voltage of the gun is raised sufficiently. Simulations using the General Particle Tracer (GPT) package indicate that a cathode bias voltage of {ge}200 kV should allow both SHBs to be operated at 433 or even 650 MHz, while {ge}500 kV would be required to eliminate the SHBs altogether. Simulations can be used to determine the minimum emittance possible if the injector is designed for a given increased voltage. A possible alternative to the DC gun is an rf gun. Emittance compensation, routinely used with rf guns, is discussed for higher-voltage DC guns.

  19. Low Emittance Guns for the ILC Polarized Electron Beam

    SciTech Connect

    Clendenin, J. E.; Brachmann, A.; Ioakeimidi, K.; Kirby, R. E.; Maruyama, T.; Miller, R. H.; Wang, J. W.; Zhou, F.

    2007-06-13

    Polarized electron beams generated by DC guns are routinely available at several accelerators including JLAB, Mainz and SLAC. These guns operate with a cathode bias on the order of -100 kV. To minimize space charge effects, relatively long bunches are generated at the gun and then compressed longitudinally external to the gun just before and during initial acceleration. For linear colliders, this compression is accomplished using a combination of rf bunchers. For the basic design of the International Linear Collider (ILC), a 120 kV DC photocathode gun is used to produce a series of nanosecond bunches that are each compressed by two sub-harmonic bunchers (SHBs) followed by an L-band buncher and capture section. The longitudinal bunching process results in a significantly higher emittance than produced by the gun alone. While high-energy experiments using polarized beams are not generally sensitive to the source emittance, there are several benefits to a lower source emittance including a simpler more efficient injector system and a lower radiation load during transport especially at bends as at the damping ring. For the ILC, the SHBs could be eliminated if the voltage of the gun is raised sufficiently. Simulations using the General Particle Tracer (GPT) package indicate that a cathode bias voltage of {>=}200 kV should allow both SHBs to be operated at 433 or even 650 MHz, while {>=}500 kV would be required to eliminate the SHBs altogether. Simulations can be used to determine the minimum emittance possible if the injector is designed for a given increased voltage. A possible alternative to the DC gun is an rf gun. Emittance compensation, routinely used with rf guns, is discussed for higher-voltage DC guns.

  20. Action Alters Object Identification: Wielding a Gun Increases the Bias to See Guns

    ERIC Educational Resources Information Center

    Witt, Jessica K.; Brockmole, James R.

    2012-01-01

    Stereotypes, expectations, and emotions influence an observer's ability to detect and categorize objects as guns. In light of recent work in action-perception interactions, however, there is another unexplored factor that may be critical: The action choices available to the perceiver. In five experiments, participants determined whether another…

  1. Cyclic Gun--Human Evolution: Soldiers, Guns, Machine Logic, and the Future

    ERIC Educational Resources Information Center

    Blackmore, Tim

    2006-01-01

    Guns, slug-throwing weapons, have evolved as humans have increased their grasp of the mechanical arts. In the near future, however, it seems likely that soldiers' rifles operating at punishing cyclic rates of fire face the limits of physics and materials science--heat and speed will cost accuracy and distance. This article considers not only the…

  2. Testing a GaAs cathode in SRF gun

    SciTech Connect

    Wang, E.; Kewisch, J.; Ben-Zvi, I.; Burrill, A.; Rao, T.; Wu, Q.; Holmes, D.

    2011-03-28

    RF electron guns with a strained superlattice GaAs cathode are expected to generate polarized electron beams of higher brightness and lower emittance than do DC guns, due to their higher field gradient at the cathode's surface and lower cathode temperature. We plan to install a bulk GaAs:Cs in a SRF gun to evaluate the performance of both the gun and the cathode in this environment. The status of this project is: In our 1.3 GHz 1/2 cell SRF gun, the vacuum can be maintained at nearly 10{sup -12} Torr because of cryo-pumping at 2K. With conventional activation of bulk GaAs, we obtained a QE of 10% at 532 nm, with lifetime of more than 3 days in the preparation chamber and have shown that it can survive in transport from the preparation chamber to the gun. The beam line has been assembled and we are exploring the best conditions for baking the cathode under vacuum. We report here the progress of our test of the GaAs cathode in the SRF gun. Future particle accelerators, such as eRHIC and the ILC require high-brightness, high-current polarized electrons. Strained superlattice GaAs:Cs has been shown to be an efficient cathode for producing polarized electrons. Activation of GaAs with Cs,O(F) lowers the electron affinity and makes it energetically possible for all the electrons, excited into the conduction band that drift or diffuse to the emission surface, to escape into the vacuum. Presently, all operating polarized electron sources, such as the CEBAF, are DC guns. In these devices, the excellent ultra-high vacuum extends the lifetime of the cathode. However, the low field gradient on the photocathode's emission surface of the DC guns limits the beam quality. The higher accelerating gradients, possible in the RF guns, generate a far better beam. Until recently, most RF guns operated at room temperature, limiting the vacuum to {approx}10{sup -9} Torr. This destroys the GaAs's NEA surface. The SRF guns combine the excellent vacuum conditions of DC guns and the high

  3. Gun blast - Its propagation and determination

    NASA Astrophysics Data System (ADS)

    Schmidt, E. M.; Kahl, G. D.; Shear, D. D.

    1980-06-01

    Muzzle blast overpressure levels are limiting the operation of high performance gun systems. The pressures at crew stations are of particular concern and have not been well defined either experimentally or analytically. The present paper presents measurement and analysis of the blast fields about a range of weapons from small arms through artillery. The effects of near muzzle flow upon the blast wave are discussed and a scaling relationship is developed from experimental data which is extended to various weapons and shown to predict pressure acceptably.

  4. Electron gun simulation for 95 GHz gyrotron

    SciTech Connect

    Singh, Udaybir; Kumar, Nitin; Sinha, A.K. E-mail: aksinha@ceeri.ernet.in; Purohit, L.P.

    2011-07-01

    A triode type Magnetron Injection Gun (MIG) for a 2 MW, 95 GHz Gyrotron has been designed by using commercially available code EGUN and another in-house developed code MIGANS. The operating mode of the gyrotron is TE{sub 24.8} and it is operated in the fundamental harmonic. The operating voltages of the modulating anode and the accelerating anode are 61 kV and 85 kV respectively. The parametric dependences of modulating anode voltage and cathode magnetic field on the beam quality have also been studied. (author)

  5. Smart gun technology requirements preliminary report

    SciTech Connect

    Weiss, D.R.; Brandt, D.J.; Tweet, K.D.

    1995-05-01

    Goal of the Smart Gun Technology project is to eliminate the capability of an unauthorized user from firing a law enforcement officer`s firearm by implementing user-recognizing-and-authorizing surety technologies. This project is funded by the National Institute of Justice. This document reports the projects first objective: to find and document the requirements for a user-recognizing-and-authorizing firearm technology that law enforcement officers will value. This report details the problem of firearm takeaways in law enforcement, the methodology used to develop the law enforcement officers` requirements, and the requirements themselves.

  6. Characterisation of plasma in a rail gun

    NASA Technical Reports Server (NTRS)

    Ray, P. K.

    1986-01-01

    The mechanism of plasma and projectile acceleration in a DC rail gun is described from a microscopic point of view through the establishment of the Hall field. The plasma conductivity is shown to be a tensor, indicating that there is a small component of current parallel to the direction of acceleration. The plasma characteristics are evaluated in the experiment of Bauer et. al., as a function of plasma mass through a simple fluid mechanical analysis of the plasma. By equating the energy dissipatated in the plasma with the radiation heat loss, the properties of the plasma are determined.

  7. Catalytic Ignitor for Regenerative Propellant Gun

    NASA Technical Reports Server (NTRS)

    Voecks, Gerald E. (Inventor); Ferraro, Ned W. (Inventor)

    1997-01-01

    An ignitor initiates combustion of liquid propellant in a gun by utilizing a heated catalyst onto which the liquid propellant is sprayed in a manner which mitigates the occurrence of undesirable combustion chamber oscillations. The heater heats the catalyst sufficiently to provide the activation necessary to initiate combustion of the liquid propellant sprayed thereonto. Two embodiments of the igniter and three alternative mountings thereof within the combustion chamber are disclosed. The ignitor may also be utilized to dispose of contaminated, excess, or waste liquid propellant in a safe, controlled, simple, and reliable manner.

  8. Catalytic ignitor for regenerative propellant gun

    NASA Technical Reports Server (NTRS)

    Voecks, Gerald E. (Inventor); Ferraro, Ned W. (Inventor)

    1994-01-01

    An ignitor initiates combustion of liquid propellant in a gun by utilizing a heated catalyst onto which the liquid propellant is sprayed in a manner which mitigates the occurrence of undesirable combustion chamber oscillations. The heater heats the catalyst sufficiently to provide the activation necessary to initiate combustion of the liquid propellant sprayed thereonto. Two embodiments of the ignitor and three alternative mountings thereof within the combustion chamber are disclosed. The ignitor may also be utilized to dispose of contaminated, excess, or waste liquid propellant in a safe, controlled, simple, and reliable manner.

  9. Gas powered fluid gun with recoil mitigation

    DOEpatents

    Grubelich, Mark C.; Yonas, Gerold

    2016-03-01

    A gas powered fluid gun for propelling a stream or slug of a fluid at high velocity toward a target. Recoil mitigation is provided that reduces or eliminates the associated recoil forces, with minimal or no backwash. By launching a quantity of water in the opposite direction, net momentum forces are reduced or eliminated. Examples of recoil mitigation devices include a cone for making a conical fluid sheet, a device forming multiple impinging streams of fluid, a cavitating venturi, one or more spinning vanes, or an annular tangential entry/exit.

  10. Gas powered fluid gun with recoil mitigation

    DOEpatents

    Grubelich, Mark C; Yonas, Gerold

    2013-11-12

    A gas powered fluid gun for propelling a stream or slug of a fluid at high velocity toward a target. Recoil mitigation is provided that reduces or eliminates the associated recoil forces, with minimal or no backwash. By launching a quantity of water in the opposite direction, net momentum forces are reduced or eliminated. Examples of recoil mitigation devices include a cone for making a conical fluid sheet, a device forming multiple impinging streams of fluid, a cavitating venturi, one or more spinning vanes, or an annular tangential entry/exit.

  11. Gun Possession among American Youth: A Discovery-Based Approach to Understand Gun Violence

    PubMed Central

    Ruggles, Kelly V.; Rajan, Sonali

    2014-01-01

    Objective To apply discovery-based computational methods to nationally representative data from the Centers for Disease Control and Preventions’ Youth Risk Behavior Surveillance System to better understand and visualize the behavioral factors associated with gun possession among adolescent youth. Results Our study uncovered the multidimensional nature of gun possession across nearly five million unique data points over a ten year period (2001–2011). Specifically, we automated odds ratio calculations for 55 risk behaviors to assemble a comprehensive table of associations for every behavior combination. Downstream analyses included the hierarchical clustering of risk behaviors based on their association “fingerprint” to 1) visualize and assess which behaviors frequently co-occur and 2) evaluate which risk behaviors are consistently found to be associated with gun possession. From these analyses, we identified more than 40 behavioral factors, including heroin use, using snuff on school property, having been injured in a fight, and having been a victim of sexual violence, that have and continue to be strongly associated with gun possession. Additionally, we identified six behavioral clusters based on association similarities: 1) physical activity and nutrition; 2) disordered eating, suicide and sexual violence; 3) weapon carrying and physical safety; 4) alcohol, marijuana and cigarette use; 5) drug use on school property and 6) overall drug use. Conclusions Use of computational methodologies identified multiple risk behaviors, beyond more commonly discussed indicators of poor mental health, that are associated with gun possession among youth. Implications for prevention efforts and future interdisciplinary work applying computational methods to behavioral science data are described. PMID:25372864

  12. Gun facilitates adhesive bonding of studs to surfaces

    NASA Technical Reports Server (NTRS)

    Davis, B. K.; Simpson, W. G.

    1969-01-01

    Gun facilitates adhesive bonding of thermoplastic-backed studs to smooth, hard surfaces. Such studs can be used for mounting loads where defacement with drilled holes cannot be tolerated. These studs can be easily removed by softening the plastic bonding with heat from the gun.

  13. Contributions to the velocity spread of magnetron injection guns

    SciTech Connect

    Danly, B.G.; Kimura, T.; Kreischer, K.E.

    1995-12-31

    Various contributions to the velocity spread in magnetron injection guns for gyrotron applications have been studied, including the effects of misalignments, field errors, and cathode surface roughness. The net result of these effects is a substantial increase in spread over the ballistic spread usually calculated with typical gun codes.

  14. Turbulent electron beams generated by magnetron injection guns

    NASA Astrophysics Data System (ADS)

    Kalinin, Yu. A.; Starodubov, A. V.; Mushtakov, A. V.

    2011-06-01

    A detailed experimental investigation of oscillators based on a magnetron injection gun is carried out. Experimental data show that such oscillators offer a considerable advantage over other similar devices; namely, they are capable of generating powerful wideband noiselike microwave oscillations. This is because magnetron injection guns generate turbulent electron beams at their exit.

  15. Gun Access and Safety Practices among Older Adults

    PubMed Central

    Lum, Hillary D.; Flaten, Hanna K.; Betz, Marian E.

    2016-01-01

    Background. Given high rates of gun ownership among older adults, geriatric providers can assess firearm safety practices using a “5 Ls” approach: Locked; Loaded; Little children; feeling Low; and Learned owner. This study describes gun access and the “5 Ls” among US older adults. Methods. Data on the “5 Ls” from the Second Injury Control and Risk Survey (ICARIS-2), a national telephone survey conducted by the Centers for Disease Control and Prevention, were analyzed. Weighted variables were used to generate national estimates regarding prevalence of gun ownership and associated gun safety among older adults (≥55 years). Results. Of 2939 older adults, 39% (95% CI 37%–42%) reported ≥1 gun stored at home. Among those with guns at home, 21% (95% CI 18–24%) stored guns loaded and unlocked; 9.2% (95% CI 6.6–12%) had ≥1 child in household; 5.1% (95% CI 3.5–6.8%) reported past-year suicidal ideation and 3.6% (95% CI 2.1–5.2%) reported history of a suicide attempt; and 55% (95% CI 51–59%) stated that ≥1 adult had attended firearm safety workshop. Conclusion. Some older adults may be at elevated risk of firearm injury because of storage practices, suicidal thoughts, or limited safety training. Future work should assess effective approaches to reduce the risk of gun-related injuries among older adults. PMID:26949391

  16. Carbon-fiber low-voltage electron guns

    SciTech Connect

    Drori, R.; Jerby, E.

    1995-12-31

    Carbon-fiber cathodes am used in cold electron-guns in our laboratory. They operate in low-voltage (< 10 kV) free-electron maser and cyclotron-resonance maser experiments. The paper presents I-V characteristics of various carbon-fiber electron-guns and show results of the corresponding maser experiments.

  17. A theory for coupling gridded gun design with PPM focussing

    NASA Astrophysics Data System (ADS)

    True, R.

    1984-03-01

    It is pointed out that a major fraction of Pierce guns in use today are gridded to allow beam current control and on/off switching by grid voltage levels roughly two orders of magnitude less than the applied cathode-to-anode voltage. Such guns are used in various electron-beam devices, such as microwave and millimeter-wave tubes, linear accelerators, and ubitrons or free electron lasers. It has been customary practice in the design of a gridded gun, to develop first a suitable ungridded or diode gun. In the considered case, difficulties begin to arise after the design of the ungridded gun. In the present paper, a description is given of the theoretical and experimental methods which are useful in the design of gridded guns. Simplified relationships are developed from which the optimum periodic permanent magnetic (PPM) field level for a given gun can be determined in a priori fashion. Attention is given to the concept of tunnel emittance, focussing stability criteria for nonlaminar beams, and the coupling between the gun and PPM focussing problems.

  18. [Dangerousness of blank fright guns and salute rifles].

    PubMed

    Schöning, R; Krause, D; Lichtenberg, W; Schmidt, U; Effenberger, O

    1997-01-01

    According to the German law salute-fire guns altered weapons with a barrel length of more than 60 cm. They have inside the barrel special constructions, which are guiding the gunshot residues under high pressure to the muzzle. Therefore they own an high potential of injury, like blank-cartridge guns with short barrels. PMID:9313063

  19. Self-contained hot-hollow cathode gun source assembly

    DOEpatents

    Zeren, J.D.

    1984-08-01

    A self-contained hot-hollow cathode gun source assembly for use in a vacuum chamber includes a crucible block having a hot-hollow cathode gun mounted underneath and providing a hole for the magnetic deflection of the ion/electron beam into a crucible on top the block.

  20. Self-contained hot-hollow cathode gun source assembly

    DOEpatents

    Zeren, Joseph D.

    1986-01-01

    A self-contained hot-hollow cathode gun source assembly for use in a vacuum chamber includes a crucible block having a hot-hollow cathode gun mounted underneath and providing a hole for the magnetic deflection of the ion/electron beam into a crucible on top the block.

  1. 78 FR 11902 - Review of Gun Safety Technologies

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-20

    ... comments or information are directed to the following Web site: https://www.justnet.org/gun_safety_technology/ . Relevant comments or information may also be emailed to the following address... to help inform its technology assessment and market research of existing and emerging gun...

  2. What we know about gun use among adolescents.

    PubMed

    Wilkinson, D L; Fagan, J

    2001-06-01

    The current generation of American teenagers has grown up surrounded by gun violence. Guns have played a significant role in shaping the developmental trajectories and behaviors of many inner-city youths. In this essay, we examine the role of guns in the lives of young people, and especially in the social and symbolic construction of violent events among adolescents, primarily focusing on males. First, we review studies of gun attitudes and behaviors as well as several epidemiological studies of firearm experiences and risk factors for violence among youth. Second, we summarize several recent studies on the trends in youth violence in relation to firearms. Next, we review findings from our original research based on in-depth interviews with 377 active gun offenders from two socially isolated inner-city neighborhoods. We present descriptive counts for the sample on variables relating to gun acquisition and use. Data on the use of guns in violent events among adolescents are generally lacking in prior research. We attempt to fill that knowledge gap by presenting a summary of our more detailed analysis of gun and nongun use in violent events reported by our respondents. PMID:11771792

  3. A Gridded Electron Gun for a Sheet Beam Klystron

    SciTech Connect

    Read, M.E.; Miram, G.; Ives, R.L.; Ivanov, V.; Krasnykh, A.; /SLAC

    2008-04-25

    This paper describes the development of an electron gun for a sheet beam klystron. Initially intended for accelerator applications, the gun can operate at a higher perveance than one with a cylindrically symmetric beam. Results of 2D and 3D simulations are discussed.

  4. Gun Access and Safety Practices among Older Adults.

    PubMed

    Lum, Hillary D; Flaten, Hanna K; Betz, Marian E

    2016-01-01

    Background. Given high rates of gun ownership among older adults, geriatric providers can assess firearm safety practices using a "5 Ls" approach: Locked; Loaded; Little children; feeling Low; and Learned owner. This study describes gun access and the "5 Ls" among US older adults. Methods. Data on the "5 Ls" from the Second Injury Control and Risk Survey (ICARIS-2), a national telephone survey conducted by the Centers for Disease Control and Prevention, were analyzed. Weighted variables were used to generate national estimates regarding prevalence of gun ownership and associated gun safety among older adults (≥55 years). Results. Of 2939 older adults, 39% (95% CI 37%-42%) reported ≥1 gun stored at home. Among those with guns at home, 21% (95% CI 18-24%) stored guns loaded and unlocked; 9.2% (95% CI 6.6-12%) had ≥1 child in household; 5.1% (95% CI 3.5-6.8%) reported past-year suicidal ideation and 3.6% (95% CI 2.1-5.2%) reported history of a suicide attempt; and 55% (95% CI 51-59%) stated that ≥1 adult had attended firearm safety workshop. Conclusion. Some older adults may be at elevated risk of firearm injury because of storage practices, suicidal thoughts, or limited safety training. Future work should assess effective approaches to reduce the risk of gun-related injuries among older adults. PMID:26949391

  5. Fatal cranial shot by blank cartridge gun: two suicide cases.

    PubMed

    Buyuk, Yalcin; Cagdir, Sadi; Avsar, Abdullah; Duman, Gokce U; Melez, D Oguzhan; Sahin, Feyzi

    2009-08-01

    Blank firing pistols are generally considered to be harmless and these guns are not accepted as being firearms in most countries. Due to lack of legal regulations these guns are easily purchased by anyone aged over 18 years. Reports of serious injuries and even fatalities due to these guns are increasing in the literature. These guns when modified or even unmodified can cause serious and potentially fatal injuries. Without doing any changes to the barrel, using blank or tear gas cartridges, firing at contact range can cause penetration of gas into the body including bone originated from gun powder. We report two suicide cases shooting themselves at temporal region with a blank cartridge gun at contact range. There was no foreign body on radiological examination and there was no trajectory of a bullet inside the brain. In both cases the wound was at the right temporal region and there was defect at temporal bone. There was circular soot around this bone defect. The injury of the brain tissue was localized at the level of the defect but there was widespread subarachnoidal bleeding. We discussed the potential danger of these guns and stressed the need of legal regulations concerning these guns. PMID:19573850

  6. Guns and Crime: Protection versus Peril. Firearm Facts.

    ERIC Educational Resources Information Center

    Duker, Laurie, Ed.

    Many Americans, terrified of violent crime, attempt to protect themselves by owning guns. However, statistics provided in this brief fact sheet reveal that people who choose to have a gun easily available are in fact putting their families and friends into greater danger since far more homicides occur during domestic arguments than during…

  7. 10. BUILDING NO. 445, PHYSICS LAB (FORMERLY GUN BAG LOADING), ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. BUILDING NO. 445, PHYSICS LAB (FORMERLY GUN BAG LOADING), LOOKING AT SOUTHEAST CORNER. BUILDING NO. 332, CHANGE HOUSE, IN RIGHT BACKGROUND; BUILDING NO. 445-F, MAGAZINE, IN LEFT BACKGROUND. - Picatinny Arsenal, 400 Area, Gun Bag Loading District, State Route 15 near I-80, Dover, Morris County, NJ

  8. Normative Considerations in the Aftermath of Gun Violence in Schools

    ERIC Educational Resources Information Center

    Gereluk, Dianne T.; Donlevy, J. Kent; Thompson, Merlin B.

    2015-01-01

    Gun violence in American and Canadian schools is an ongoing tragedy that goes substantially beyond its roots in the interlocking emotional and behavioral issues of mental health and bullying. In light of the need for effective policy development, Dianne T. Gereluk, J. Kent Donlevy, and Merlin B. Thompson examine gun violence in schools from…

  9. FEATURE 3, LARGE GUN POSITION, ARMCO HUT (FEATURE 4) IN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FEATURE 3, LARGE GUN POSITION, ARMCO HUT (FEATURE 4) IN BACKGROUND, VIEW FACING NORTH. - Naval Air Station Barbers Point, Anti-Aircraft Battery Complex-Large Gun Position, East of Coral Sea Road, northwest of Hamilton Road, Ewa, Honolulu County, HI

  10. Taking Aim at Gun Violence: Rebuilding Community Education & Employment Pathways

    ERIC Educational Resources Information Center

    Bryant, Rhonda

    2013-01-01

    In January 2013, President Obama released a plan for protecting children and communities by reducing gun violence. This plan has generated serious debate from both sides of the issue. The ensuing conversations about how to solve the issue of gun violence have been volatile. The President's plan includes reforms to close loopholes on background…

  11. Gun Possession among Massachusetts Batterer Intervention Program Enrollees

    ERIC Educational Resources Information Center

    Rothman, Emily F.; Johnson, Renee M.; Hemenway, David

    2006-01-01

    Batterers with access to firearms present a serious lethal threat to their partners. The purpose of this exploratory study is to estimate the prevalence of and risk markers for gun possession among Massachusetts men enrolled in batterer intervention programs. The authors found that 1.8% of the men reported having a gun in or around their home.…

  12. 15. BUILDING NO. 445, PHYSICS LAB (FORMERLY GUN BAG LOADING), ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. BUILDING NO. 445, PHYSICS LAB (FORMERLY GUN BAG LOADING), INTERIOR, FOURTH LEVEL. POWDER HOPPER AT TOP OF ELEVATOR SHAFT. POWDER DISTRIBUTED FROM HERE TO LOADING ROOMS BY TUBES. - Picatinny Arsenal, 400 Area, Gun Bag Loading District, State Route 15 near I-80, Dover, Morris County, NJ

  13. Guns and Fear: A One-Way Street?

    ERIC Educational Resources Information Center

    Hauser, Will; Kleck, Gary

    2013-01-01

    Surveys show that more than one half of gun owners report owning their firearm for self-protection. Although research has examined the effect of fear of crime on gun ownership, the issue of reciprocity and temporal order has been largely ignored. Furthermore, the effect of firearm acquisition and relinquishment on fear has not been evaluated…

  14. NASCAP simulation of laboratory charging tests using multiple electron guns

    NASA Technical Reports Server (NTRS)

    Mandell, M. J.; Katz, I.; Parks, D. E.

    1981-01-01

    NASCAP calculations have been performed simulating exposure of a spacecraft-like model to multiple electron guns. The results agree well with experiment. It is found that magnetic field effects are fairly small, but substantial differential charging can result from electron gun placement. Conditions for surface flashover are readily achieved.

  15. 62. SIXTEEN INCH GUN MOUNTED ON THE MACHINING LATHE; LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    62. SIXTEEN INCH GUN MOUNTED ON THE MACHINING LATHE; LOOKING WSW. THE GUN ITSELF EXTENDS BEYOND THE BRICK ARCHES OF THE MAIN SHOP FLOOR'S W WALL AND INTO THE W AISLE. THE LATHE'S CUTTING HEAD CAN BE SEEN AT THE RIGHT CENTER OF THE VIEW. (Ryan) - Watervliet Arsenal, Building No. 110, Hagner Road between Schull & Whittemore Roads, Watervliet, Albany County, NY

  16. 16. BUILDING NO. 445, PHYSICS LAB (FORMERLY GUN BAG LOADING), ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. BUILDING NO. 445, PHYSICS LAB (FORMERLY GUN BAG LOADING), INTERIOR, SECOND LEVEL. LOOKING UP AT POWDER AND DISTRIBUTION TUBES. ELEVATOR SHAFT ON LEFT. - Picatinny Arsenal, 400 Area, Gun Bag Loading District, State Route 15 near I-80, Dover, Morris County, NJ

  17. Fluidized bed combustor and coal gun-tube assembly therefor

    DOEpatents

    Hosek, William S.; Garruto, Edward J.

    1984-01-01

    A coal supply gun assembly for a fluidized bed combustor which includes heat exchange elements extending above the bed's distributor plate assembly and in which the gun's nozzles are disposed relative to the heat exchange elements to only discharge granular coal material between adjacent heat exchange elements and in a path which is substantially equidistant from adjacent heat exchange elements.

  18. View forward of five inch gun mounted in sponson; note ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View forward of five inch gun mounted in sponson; note glass windows which would be removed in combat, gudgeons below window allowed attachment of armor plate which could be swung up to protect gun crew in battle; also note lower section of flag rack at top left center of photograph. (p39) - USS Olympia, Penn's Landing, 211 South Columbus Boulevard, Philadelphia, Philadelphia County, PA

  19. VIEW OF EAST GUN EMPLACEMENT. NOTE THE STEEL REINFORCING RODS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF EAST GUN EMPLACEMENT. NOTE THE STEEL REINFORCING RODS PROTRUDING FROM THE BROKEN TOP OF THE RETAINING WALL. VIEW FACING NORTHEAST - U.S. Naval Base, Pearl Harbor, Ford Island 5-Inch Antiaircraft Battery, East Gun Emplacement, Ford Island, Pearl City, Honolulu County, HI

  20. 83. GENERAL VIEW FROM NORTH END OF GUN HILL PLATFORM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    83. GENERAL VIEW FROM NORTH END OF GUN HILL PLATFORM OF 3RD AVENUE EL SHOWING THE SOUTHBOUND TRACK APPROACH INTO GUN HILL STATION. 7TH AVENUE EXPRESS EL ABOVE. - Interborough Rapid Transit Company, Third Avenue Elevated Line, Borough of the Bronx, New York County, NY

  1. 14. BUILDING NO. 445, PHYSICS LAB (FORMERLY GUN BAG LOADING), ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. BUILDING NO. 445, PHYSICS LAB (FORMERLY GUN BAG LOADING), LOOKING EAST AT SOUTHWEST END OF BUILDING. HVAC EQUIPMENT LOCATED OUTDOORS IN FOREGROUND. DUCTS CONDUCT HOT OR COLD AIR INDOORS. ROUND PIPES ARE INSULATED STEAM LINES. BUILDING NO. 448, ORDNANCE FACILITY, IN BACKGROUND. - Picatinny Arsenal, 400 Area, Gun Bag Loading District, State Route 15 near I-80, Dover, Morris County, NJ

  2. VIEW OF GUN EMPLACEMENT AND THE TABLELIKE CAST CONCRETE STRUCTURE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF GUN EMPLACEMENT AND THE TABLE-LIKE CAST CONCRETE STRUCTURE SHOWING THE SPALLED AREA ON ITS EAST SIDE (LEFT) WHERE THE SECOND PROJECTING ARM WAS BROKEN OFF. NOTE THE SLOPED CONCRETE PAD IN THE BACKGROUND. VIEW FACING SOUTHWEST - U.S. Naval Base, Pearl Harbor, Ford Island 5-Inch Antiaircraft Battery, East Gun Emplacement, Ford Island, Pearl City, Honolulu County, HI

  3. FEATURE 3, LARGE GUN POSITION, SHOWING MULTIPLE COMPARTMENTS, VIEW FACING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FEATURE 3, LARGE GUN POSITION, SHOWING MULTIPLE COMPARTMENTS, VIEW FACING SOUTH (with scale stick). - Naval Air Station Barbers Point, Anti-Aircraft Battery Complex-Large Gun Position, East of Coral Sea Road, northwest of Hamilton Road, Ewa, Honolulu County, HI

  4. Everyday Engineering: What Makes a Squirt Gun Squirt?

    ERIC Educational Resources Information Center

    Moyer, Richard; Everett, Susan

    2009-01-01

    You may not think of engineering and squirt guns in the same sentence. However, like many examples of engineering design, the squirt gun pump mechanism is uncomplicated, yet elegant, and very inexpensive to manufacture. The design is widely used because of its simplicity and low cost. With only a few moving parts, it is able to deliver a stream of…

  5. Preventing Clogging In A Vacuum Plasma Spray Gun

    NASA Technical Reports Server (NTRS)

    Krotz, Phillip D.; Daniel, Ronald L., Jr.; Davis, William M.

    1994-01-01

    Modification of powder-injection ports enables lengthy, high-temperature deposition operations. Graphite inserts prevent clogging of ports through which copper powder injected into vacuum plasma spray (VPS) gun. Graphite liners eliminate need to spend production time refurbishing VPS gun, reducing cost of production and increasing productivity. Concept also applied to other material systems used for net-shape fabrication via VPS.

  6. Plans: Aft Gun Platform, Quarters for 16 Gunmen, Poop Deck, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Plans: Aft Gun Platform, Quarters for 16 Gunmen, Poop Deck, Boat Deck, House Top, Bridge Deck, Upper Bridge Deck, Navigating Bridge, Forecastle Deck, Gun Platform, Upper Deck, Second Deck and Hold Plan - Mission Santa Ynez, Suisun Bay Reserve Fleet, Benicia, Solano County, CA

  7. Teaching Safety Skills to Children to Prevent Gun Play

    ERIC Educational Resources Information Center

    Himle, Michael B.; Miltenberger, Raymond G.; Flessner, Christopher; Gatheridge, Brian

    2004-01-01

    Research has shown that children often engage in gun play when they find a firearm and that this behavior is often involved in unintentional firearm injuries. Previous research has shown existing programs to be ineffective for teaching children safety skills to reduce gun play. This study examined the effectiveness of a behavioral skills training…

  8. Guns, Mental Illness, and the Law: Introduction to This Issue.

    PubMed

    Swanson, Jeffrey W; Felthous, Alan R

    2015-06-01

    Firearm violence is a top-tier public health problem in the U.S., killing 33,563 and injuring an additional 81,396 people in 2012 (Centers for Disease Control and Prevention, CDC, ). Given constitutional protection and the cultural entrenchment of private gun ownership in the U.S., it is likely that guns will remain widely accessible--and largely unrestricted--for the foreseeable future. Therefore, most policies and laws intended to reduce firearm violence focus selectively on preventing "dangerous people" from having access to guns. That is a formidable challenge. How do we think productively about guns and mental illness in this context, and about the role of law in lessening the toll of gun violence? PMID:25874748

  9. Cure violence: a public health model to reduce gun violence.

    PubMed

    Butts, Jeffrey A; Roman, Caterina Gouvis; Bostwick, Lindsay; Porter, Jeremy R

    2015-03-18

    Scholars and practitioners alike in recent years have suggested that real and lasting progress in the fight against gun violence requires changing the social norms and attitudes that perpetuate violence and the use of guns. The Cure Violence model is a public health approach to gun violence reduction that seeks to change individual and community attitudes and norms about gun violence. It considers gun violence to be analogous to a communicable disease that passes from person to person when left untreated. Cure Violence operates independently of, while hopefully not undermining, law enforcement. In this article, we describe the theoretical basis for the program, review existing program evaluations, identify several challenges facing evaluators, and offer directions for future research. PMID:25581151

  10. ONEGUN: an interior ballistics code for closed breech guns

    SciTech Connect

    Reis, G.E.

    1982-07-01

    This program computes the gun and projectile motion and the gas thermodynamic properties (the internal ballistics) of a closed breech gun. Heat losses and friction losses are taken into account. A dual grain charge can be used. The inputs required are the usual propellant characteristics (density, impetus, gamma, burn rate coefficient and exponent, grain geometry, covolume and isochoric flame temperature). The gun characteristics (chamber volume and length, rifle twist rate, bore diameter, gun weight and start pressure) and the projectile characteristics (projectile weight, radius of gyration and start pressure). The output consists of the motion (displacement, velocity, and acceleration) of both the projectile and the recoiling gun and the gas pressures and temperature, all as a function of time.

  11. Polarized Electron Gun Development at the Brookhaven National Laboratoy

    NASA Astrophysics Data System (ADS)

    Kewisch, J.; Chang, X. Y.; Ben-Zvi, I.; Litvinenko, V.; Rao, T.; Skaritka, J.; Sheehy, B.; Pikin, A.; Meng, W.; Wang, E.; Wu, Q.; Pate, D.; Burrill, A.; Xin, T.; Holmes, D.

    2011-05-01

    Development of two different polarized electron guns is ongoing at BNL. One aims at extremely high brightness at a moderate beam current. This design uses a superconducting RF gun and a test setup is built to show that a Gallium-Arsenide cathode with negative affinity has a sufficiently long quantum efficiency lifetime in such an environment. An electron injector using this technology may eliminate the need of the electron damping ring and a long transport line at the International Linear Collider. The other project aims at producing a high beam current with moderate emittance requirements, dubbed the "Gatling gun". In this DC gun, bunches are extracted from 20 separate cathodes and merged into a single beam using a rotating magnetic field. Such an electron gun could serve as an injector for the electron-ion collider eRHIC, which is planned at BNL. We will report on the status of these projects.

  12. Cylinder Fragmentation Using Gas Gun Methods

    NASA Astrophysics Data System (ADS)

    Thornhill, Tom; Reinhart, William; Chhabildas, Lalit; Grady, Dennis; Wilson, Leonard

    2001-06-01

    An experimental technique for investigating fracture and fragmentation characteristics of materials has been developed for use on the gas guns. In this method the candidate material is in the cylindrical form. This technique involves the precision alignment of the candidate cylinder, and symmetric impact of a stationary cylinder plug with the moving projectile from the gun. This test method allows the study of cylinder fragmentation in a laboratory environment under well-controlled loading conditions. In this presentation, results of several experiments on Aermet steel will be presented. The fragmentation toughness of the material can be estimated through knowledge of the material strain-rate and mean fragment size derived from the statistical distribution of the fragments. The values for fragmentation toughness will be compared with those obtained from other experimental methods such as explosives loading or ball on plate impact methods. Future developments and directions in test geometry, test methods and diagnostics will also be reported. This work was supported by the U. S. Department of Energy under contract DE-AC04-94AL85000.

  13. Behavior-oriented approaches to reducing youth gun violence.

    PubMed

    Hardy, Marjorie S

    2002-01-01

    Advocacy groups on both sides of the guns issue frequently point to changing personal behavior--of both parents and children--as a key element in reducing gun violence among youth. Efforts to bring about these changes range from community-based campaigns, to laws and programs that encourage parents to store their guns safely, to educational initiatives that focus on keeping young children away from guns and encouraging youth to resolve disputes without violence. Unfortunately, these behavior-oriented programs have not shown great success in reducing youth gun violence. This article reviews the research surrounding behavioral approaches to gun violence prevention and highlights obstacles that hamper the effectiveness of these programs. Supportive communities can play a key role in protecting youth from violence in general, but the few community-based violence prevention programs that focus on youth have not been shown to decrease youth access to or use of guns. By and large, behavioral programs and legal interventions aimed at parents have not been proven to reduce youth gun violence. This may be due in part to parental misperceptions about children's risk of injury and ability to protect themselves. Children and youth are particularly difficult targets for behavioral change programs. Cognitive immaturity among younger children and perceptions of invulnerability among adolescents may be part of the reason. Most programs that seek to persuade youth to stay away from guns have not been proven effective. The author concludes that, although behavioral programs could be improved, overall they hold only limited promise for reducing youth gun violence. PMID:12194605

  14. African-American adults' perceptions of guns and violence.

    PubMed Central

    Price, J. H.; Kandakai, T. L.; Casler, S.; Everett, S.; Smith, D.

    1994-01-01

    This study examined African-American adults' perceptions of guns and violence. Through a mall intercept type study, 347 adults, ages 20 to 75, responded to a 54-item questionnaire. One third of the respondents claimed they owned one or more types of guns, three fourths had personally known someone who had been shot, more than one third had actually seen someone shot, and one third had a gun pulled on them. While the vast majority (84%) believed guns are too easy to obtain, the majority (62%) also believed that having a gun at home would help protect them. There were no significant differences in perceptions of guns based on age, gender, level of education, or socioeconomic status. The results of this study tend to substantiate the concern and fear of personal harm that African Americans have to contend with on a regular basis. The results also suggest the need for some form of educational intervention and gun safety training in order to help reduce the risk of death and injury among African Americans. PMID:8078079

  15. A photocathode RF gun for x-ray FEL

    SciTech Connect

    Wang, X.J.; Batchelor, K.; Ben-Zvi, I.

    1995-12-31

    A 1.6 cell photocathode RF gun was developed by a BNL/SLAC/UCLA collaboration for X-ray FEL and other applications. The objective of the collaboration is to develop a cost effective and more reliable photocathode RF gun based on the operational experience of the original BNL gun. The new photocathode RF gun is cable of producing 1 mm-mrad normalized rms emittance photocurrent with a peak current of 100 A. The half-cell length of the new RF gun was lengthened to reduce the peak field on the cavity surface, the side-coupled scheme for cavity and waveguide coupling was replaced by a symmetrized coupling to the full-cell. The cavity aperture was increased to improve the coupling between two cells and for flat beam application. The experimental results of cold testing the RF gun will be presented. We will also present an injector design based on the new photocathode RF gun and emittance compensation technique.

  16. Development program on a cold cathode electron gun

    NASA Technical Reports Server (NTRS)

    Spindt, C. A.

    1979-01-01

    A prototype electron gun with a field emitter cathode capable of producing 95 mA in a 1/4 mm diameter beam at 12 kV was produced. Achievement of this goal required supporting studies in cathode fabrication, cathode performance, gun design, cathode mounting and gun fabrication. A series of empirical investigations advanced fabrication technology: More stable emitters were produced and multiple cone failure caused by chain reaction discharges were reduced. The cathode is capable of producing well over 95 mA, but a substantial collector development effort was required to demonstrate emission levels in the 100 mA region. Space charge problems made these levels difficult to achieve. Recommendations are made for future process and materials investigation. Electron gun designs were modeled and tested. A pair of two-electrode gun structures were fabricated and tested; one gun was delivered to NASA. Cathodes were pretested up to 100 mA at SRI and delivered to NASA for test in the gun structure.

  17. Gas detonation gun for thermal spraying

    SciTech Connect

    Kadyrov, E.; Kadyrov, V.

    1995-08-01

    High-velocity oxy-fuel and gas detonation are competing spray coating processes well known for providing premium quality coatings with low porosity and high adhesion. They are favored for applications in environments of extreme wear, heat, and aggressive corrosion. Nevertheless, they both have limitations. For the HVOF process, these include excessive gas consumption, high rate of heat transfer to the sprayed substrate, and the short life of the (supersonic) Laval nozzle. On the other hand, the traditional gas detonation gun also has drawbacks, and the purpose of this article is to outline some factors that led to the design of an improved gas detonation coating process called Demeton, produced by Demeton USA Inc., Garden City Park, N.Y.

  18. An autoneutralizing neutral molecular beam gun

    SciTech Connect

    Delmore, J.E.; Appelhans, A.D.; Dahl, D.A. )

    1990-01-01

    A high-energy (up to 28 keV) neutral molecular beam gun has been developed and put into routine use that takes advantage of the autoneutralization properties of the sulfur hexafluoride anion for the production of high-energy sulfur hexafluoride neutral molecules. The anions are produced in an electron-capture source, accelerated, and focused in a lens assembly designed to minimize residence time, allowed to drift at their terminal velocity for a suitable distance during which up to 30% auto-eject an electron, and all remaining charged particles are electrostatically skimmed, resulting in a focused neutral beam. Rasterable neutral beams focused to a 5-mm spot size up to 3 m from the source have been produced with beam currents up to 40 pA equivalent. Spot sizes of 1 mm can be produced with intensity levels of a few picoamperes equivalent.

  19. Temperature Controller System for Gas Gun Targets

    NASA Astrophysics Data System (ADS)

    Bucholtz, S. M.; Gehr, R. J.; Rupp, T. D.; Sheffield, S. A.; Robbins, D. L.

    2006-07-01

    A temperature controller system capable of heating and cooling gas gun targets over the range -75°C to +120°C was designed and tested. The system uses cold nitrogen gas from a liquid nitrogen Dewar for cooling and compressed air for heating. Two gas flow heaters control the gas temperature for both heating and cooling. One heater controls the temperature of the target mounting plate and the other the temperature of a copper tubing coil surrounding the target. Each heater is separately adjustable, so the target material will achieve a uniform temperature throughout its volume. A magnetic gauge membrane with integrated thermocouples was developed to measure the internal temperature of the target. Using this system, multiple magnetic gauge shock experiments, including equation-of-state measurements and shock initiation of high explosives, can be performed over a range of initial temperatures. Successful heating and cooling tests were completed on Teflon samples.

  20. Smart Gun Technology project. Final report

    SciTech Connect

    Weiss, D.R.

    1996-05-01

    The goal of the Smart Gun Technology project is to eliminate the capability of an unauthorized user form firing a law officer`s firearm by implementing user-recognizing-and-authorizing (or {open_quotes}smart{close_quotes}) surety technologies. This project was funded by the National Institute of Justice. This report lists the findings and results of the project`s three primary objectives. First, to find and document the requirements for a smart firearm technology that law enforcement officers will value. Second, to investigate, evaluate, and prioritize technologies that meet the requirements for a law enforcement officer`s smart firearm. Third, to demonstrate and document the most promising technology`s usefulness in models of a smart firearm.

  1. The Internal Ballistics of an Air Gun

    NASA Astrophysics Data System (ADS)

    Denny, Mark

    2011-02-01

    The internal ballistics of a firearm or artillery piece considers the pellet, bullet, or shell motion while it is still inside the barrel. In general, deriving the muzzle speed of a gunpowder firearm from first principles is difficult because powder combustion is fast and it very rapidly raises the temperature of gas (generated by gunpowder deflagration, or burning), which greatly complicates the analysis. A simple case is provided by air guns, for which we can make reasonable approximations that permit a derivation of muzzle speed. It is perhaps surprising that muzzle speed depends upon barrel length (artillerymen debated this dependence for centuries, until it was established experimentally and, later, theoretically ). Here we see that a simple physical analysis, accessible to high school or freshmen undergraduate physics students, not only derives realistic muzzle speed but also shows how it depends upon barrel length.

  2. Preliminary design of Viking Armored Gun System

    SciTech Connect

    Gogolewski, R.P.; Cunningham, B.J.

    1990-10-24

    We have completed the preliminary design of our third lightweight armored fighting vehicle -- the Viking Armored Gun System (AGS). The AGS vehicle features a two-man crew, the Ares 75mm Universal Turret System, and the John Deere 4026R Rotary Engine. In the spirit of our earlier AFV designs, our primary concern is to provide the AGS with sufficient firepower and survivability while utilizing off-the-shelf'' sub-systems and components in order to reduce developmental time and acquisition cost. We still envision that prototypic vehicles could be built within a thirty (30) month developmental/demonstration program. We still believe that vehicles of this class should be built and tested soon to assess their full tactical, operational, and strategic utilities.

  3. Improved computer modelling of magnetron injection guns for gyrotrons

    SciTech Connect

    Caplan, M.; Thorington, C.

    1984-01-01

    A variable mesh finite-element electron gun design code has been developed to simulate hollow beams produced by magnetron injection guns. Very accurate solutions of the self-consistent space charge forces are obtained by using a computational mesh, distorted in a way which allows a high density of mesh points within the hollow beam. A generalized hybrid model for cathode emission has been incorporated which combines temperature limited and space charge limited emission in a way justified from empirical and physical arguments. Beam characteristics of a magnetron injection gun are presented as the transition from temperature limited to space charge limited operation is made. Limited comparisons with experimental results are presented.

  4. Commentary: evidence to guide gun violence prevention in America.

    PubMed

    Webster, Daniel W

    2015-03-18

    Gun violence is a major threat to the public's health and safety in the United States. The articles in this volume's symposium on gun violence reveal the scope of the problem and new trends in mortality rates from gunfire. Leading scholars synthesize research evidence that demonstrates the ability of numerous policies and programs-each consistent with lessons learned from successful efforts to combat public health problems-to prevent gun violence. Each approach presents challenges to successful implementation. Future research should inform efforts to assess which approaches are most effective and how to implement evidence-based interventions most effectively. PMID:25581156

  5. Summary, Working Group 1: Electron guns and injector designs

    NASA Astrophysics Data System (ADS)

    Ben-Zvi, I.; Bazarov, I. V.

    2006-02-01

    We summarize the proceedings of Working Group 1 of the 2005 Energy Recovery Linac (ERL) Workshop. The subject of this working group, the electron gun and injector design, is arguably the most critical part of the ERL as it determines the ultimate performance of this type of accelerators. Working Group 1 dealt with a variety of subjects: The technology of DC, normal-conducting RF and superconducting RF guns; beam dynamics in the gun and injector; the cathode and laser package; modeling and computational issues; magnetized beams and polarization. A short overview of these issues covered in the Working Group is presented in this paper.

  6. Analysis of Slice Transverse Emittance Evolution ina Photocathode RF Gun

    SciTech Connect

    Huang, Z.; Ding, Y.; Qiang, J.; /LBL, Berkeley

    2007-10-17

    The slice transverse emittance of an electron beam is of critical significance for an x-ray FEL. In a photocathode RF gun, the slice transverse emittance is not only determined by the emission process, but also influenced strongly by the non-linear space charge effect. In this paper, we study the slice transverse emittance evolution in a photocathode RF gun using a simple model that includes effects of RF acceleration, focusing, and space charge force. The results are compared with IMPACT-T space charge simulations and may be used to understand the development of the slice emittance in an RF gun.

  7. Note: Characteristic beam parameter for the line electron gun

    NASA Astrophysics Data System (ADS)

    Iqbal, M.; Islam, G. U.; Zhou, Z.; Chi, Y.

    2013-11-01

    We have optimized the beam parameters of line source electron gun using Stanford Linear Accelerator Centre electron beam trajectory program (EGUN), utilizing electrostatic focusing only. We measured minimum beam diameter as 0.5 mm that corresponds to power density of 68.9 kW/cm2 at 13.5 mm in the post-anode region which is more than two-fold (33 kW/cm2), of the previously reported results. The gun was operated for the validation of the theoretical results and found in good agreement. The gun is now without any magnetic and electrostatic focusing thus much simpler and more powerful.

  8. Energy partitioning in an inductively driven rail gun

    NASA Technical Reports Server (NTRS)

    Sen, K. K.; Ray, P. K.

    1984-01-01

    The equations describing the performance of an inductively driven rail are analyzed numerically. Friction between the projectile and rails is included through an empirical formulation. The equations are applied to the experiment of Rashleigh and Marshall to obtain an estimate of energy distribution in rail guns as a function of time. It is found that only 15 percent of energy delivered by the inductor to the gun is transformed into the kinetic energy of the projectile. This study provides an insight into the nature of nonlinear coupling involved in the electromechanical interactions in a rail gun.

  9. Air gun pellet: cardiac penetration and peripheral embolization.

    PubMed

    Işık, Onur; Engin, Çağatay; Daylan, Ahmet; Şahutoğlu, Cengiz

    2016-05-01

    Use of high-velocity air guns can to lead to serious injuries. Management options of cardiac pellet gun injuries are based on patient stability, and course and location of the pellet. Presently reported is the case of a boy who was shot with an air gun pellet. Following right ventricular entry, the pellet lodged in the left atrium and embolized to the right iliac and femoral artery. Following pellet localization, right ventricular injury was repaired, and the pellet was removed successfully. PMID:27598599

  10. Note: Characteristic beam parameter for the line electron gun

    SciTech Connect

    Iqbal, M.; Islam, G. U.; Zhou, Z.; Chi, Y.

    2013-11-15

    We have optimized the beam parameters of line source electron gun using Stanford Linear Accelerator Centre electron beam trajectory program (EGUN), utilizing electrostatic focusing only. We measured minimum beam diameter as 0.5 mm that corresponds to power density of 68.9 kW/cm{sup 2} at 13.5 mm in the post-anode region which is more than two-fold (33 kW/cm{sup 2}), of the previously reported results. The gun was operated for the validation of the theoretical results and found in good agreement. The gun is now without any magnetic and electrostatic focusing thus much simpler and more powerful.

  11. A numerical model for ETC gun interior ballistics applications

    NASA Astrophysics Data System (ADS)

    Hsiao, C.-C.; Phillips, G. T.; Su, F. Y.

    1993-01-01

    A multidimensional, transient, fluid dynamic model, BISON, has been developed to study the interior ballistic processes in an electrothermal chemical (ETC) gun. The model solves the full Navier-Stokes equations and uses a high-order numerical scheme to integrate the governing equations. Most of the important physical processes pertinent to ETC gun interior ballistics, including multiphase flow, chemical reactions, and plasma dynamics, are incorporated. Examples of applications to the study of ETC gun phenomena, such as plasma jet penetration and real gun design component analyses, are discussed. The modeling results not only compare well with experimental data, but also provide a better understanding of interior ballistics physics. The multidimensional BISON model is useful for ETC simulations.

  12. Penetrating Cardiac Nail Gun Injury in a Child.

    PubMed

    Kulaylat, Afif N; Chesnut, Charles H; Patel, Sunil; Rocourt, Dorothy V; Clark, Joseph B

    2016-08-01

    Nail gun injuries primarily occur in the extremities of adult males as a consequence of accidental occupational trauma. Such injury involving the thorax is much less common, and penetrating cardiac injury secondary to pneumatic nail gun discharge is rare. Although potentially lethal, most cases with cardiac trauma are survivable with expedient surgical intervention. Despite improvements in engineered safety mechanisms, the incidence of nail gun injuries has risen as use of the devices has increased. The widespread availability of these tools to nonprofessional consumers exposes a broader population to the potential hazards associated with these devices. We describe the presentation and successful management of the first reported case of penetrating cardiac nail gun injury in a young child. PMID:27018525

  13. Gun-Control Legislation and the Impact on Suicide.

    PubMed

    Leenaars, Antoon A

    2007-01-01

    Gun control is the prototypical example of controlling the environment for the means of suicide, an effective public health approach to suicide prevention. Canada's Criminal Law Amendment Act of 1977 (Bill C-51) provides an excellent opportunity to illustrate the effects of legislative gun-control laws and the impact on suicide. The research in Canada supports the significant effect of C-51 in reducing suicides and firearm suicides, even if one controls for socioeconomic factors, although not equally for all ages. The young, a high-risk group, show the most significant decrease, without significant substitution of other methods (displacement). Studies on gun-control laws from New Zealand, the United States, and Australia support the Canadian findings. It is concluded that, although not equally applicable in all countries, gun control may well have significant applications in reducing suicide worldwide. PMID:26212195

  14. Gun possession among Massachusetts batterer intervention program enrollees.

    PubMed

    Rothman, Emily F; Johnson, Renee M; Hemenway, David

    2006-06-01

    Batterers with access to firearms present a serious lethal threat to their partners. The purpose of this exploratory study is to estimate the prevalence of and risk markers for gun possession among Massachusetts men enrolled in batterer intervention programs. The authors found that 1.8% of the men reported having a gun in or around their home. Those most likely to report having a gun were White, earned 25,000 US dollars or more per year, had served in the military, engaged in problem gambling, and had attempted homicide or threatened their partner with a firearm. Recommendations for strengthening relevant gun laws both within and outside of Massachusetts are discussed. PMID:16679497

  15. 16. CONSTRUCTION PROGRESS PHOTO SHOWING SURPLUS GUN BARREL BEING LOWERED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. CONSTRUCTION PROGRESS PHOTO SHOWING SURPLUS GUN BARREL BEING LOWERED INTO PLACE FOR USE AS PIPE TUNNEL. INEEL PHOTO NUMBER NRTS-59-709. - Idaho National Engineering Laboratory, Old Waste Calcining Facility, Scoville, Butte County, ID

  16. 18. CONSTRUCTION PROGRESS PHOTO SHOWING SURPLUS GUN BARRELS IN PLACE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. CONSTRUCTION PROGRESS PHOTO SHOWING SURPLUS GUN BARRELS IN PLACE TO BE USED AS PIPE TUNNELS. INEEL PHOTO NUMBER NRTS-59-925. - Idaho National Engineering Laboratory, Old Waste Calcining Facility, Scoville, Butte County, ID

  17. 81. VIEW NORTH ON WEST SIDE OF GUN HILL PLATFORM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    81. VIEW NORTH ON WEST SIDE OF GUN HILL PLATFORM SHOWING LAMP STANDARDS FOR NIGHT LIGHTNING. - Interborough Rapid Transit Company, Third Avenue Elevated Line, Borough of the Bronx, New York County, NY

  18. 2 of 3 Americans OK with Doctors Discussing Gun Safety

    MedlinePlus

    ... medlineplus.gov/news/fullstory_160058.html 2 of 3 Americans OK With Doctors Discussing Gun Safety But ... study reveals. The online survey included more than 3,900 respondents. The researchers found that 66 percent ...

  19. Ten self-inflicted intracranial penetrating nail gun injuries

    PubMed Central

    Yuh, Sung-Joo; Alaqeel, Ahmed

    2015-01-01

    Penetrating craniocerebral injuries from nail gun use are rare. We describe a case of 10 self-inflicted nail gun injuries with intracranial penetrations. We also review the literature and discuss management strategies of such craniocerebral trauma. A 33-year-old male with a long-standing history of severe depression took a nail gun and sustained 10 penetrating intracranial injuries. Initial neuroimaging revealed 10 penetrating nails, all sparing the major cerebral vasculature. Immediate surgical removal was undertaken in the surgical suite using a combination of craniotomies, craniectomies, and blind removal. Intracranial injuries from self-inflicted nail gun misuse is becoming increasingly more frequent. Initial appropriate clinical decision-making are critical in preventing further cortical or vascular damage. PMID:26166596

  20. Combined oil gun and coal guide for power plant boilers

    SciTech Connect

    Wiest, M.R.

    1990-08-28

    This paper discusses apparatus for introducing fuel into the combustion chamber of a power plant boiler. It comprises a coal guide; a coal disperser; tubular disperser support means; an oil gun; first actuator means; and second actuator means.

  1. Miniature paint-spray gun for recessed areas

    NASA Technical Reports Server (NTRS)

    Vanasse, M. A.

    1968-01-01

    Miniature spray gun regulates paints and other liquids to spray at close range, facilitating spraying of remote or recessed areas. Individual valves for regulating air pressure and paint maximizes atomization for low pressure spraying.

  2. High voltage processing of the SLC polarized electron gun

    SciTech Connect

    Saez, P.; Clendenin, J.; Garden, C.; Hoyt, E.; Klaisner, L.; Prescott, C.; Schultz, D.; Tang, H.

    1993-04-01

    The SLC polarized electron gun operates at 120 kV with very low dark current to maintain the ultra high vacuum (UHV). This strict requirement protects the extremely sensitive photocathode from contaminants caused by high voltage (HV) activity. Thorough HV processing is thus required x-ray sensitive photographic film, a nanoammeter in series with gun power supply, a radiation meter, a sensitive residual gas analyzer and surface x-ray spectrometry were used to study areas in the gun where HV activity occurred. By reducing the electric field gradients, carefully preparing the HV surfaces and adhering to very strict clean assembly procedures, we found it possible to process the gun so as to reduce both the dark current at operating voltage and the probability of HV discharge. These HV preparation and processing techniques are described.

  3. Explosive flux compression generators for rail gun power sources

    SciTech Connect

    Fowler, C.M.; Peterson, D.R.; Caird, R.S.; Erickson, D.J.; Freeman, B.L.; King, J.C.

    1980-01-01

    A class of explosive magnetic flux compression generators is described that has been used successfully to power rail guns. A program to increase current magnitudes and pulse lengths is outlined. Various generator loss terms are defined and plans to overcome some of them are discussed. Included are various modifications of the conventional strip generators that are more resistant to undesirable expansion of generator components from magnetic forces. Finally, an integral rail gun is discussed that has coaxial geometry. Integral rail guns utilize the rails themselves as flux compression generator elements and, under ideal conditions, are theoretically capable of driving projectiles to arbitrarily high velocities. Integral coaxial rail guns should be superior in some regards to their square bore counterparts.

  4. Finite element analyses of a linear-accelerator electron gun

    SciTech Connect

    Iqbal, M. E-mail: muniqbal@ihep.ac.cn; Wasy, A.; Islam, G. U.; Zhou, Z.

    2014-02-15

    Thermo-structural analyses of the Beijing Electron-Positron Collider (BEPCII) linear-accelerator, electron gun, were performed for the gun operating with the cathode at 1000 °C. The gun was modeled in computer aided three-dimensional interactive application for finite element analyses through ANSYS workbench. This was followed by simulations using the SLAC electron beam trajectory program EGUN for beam optics analyses. The simulations were compared with experimental results of the assembly to verify its beam parameters under the same boundary conditions. Simulation and test results were found to be in good agreement and hence confirmed the design parameters under the defined operating temperature. The gun is operating continuously since commissioning without any thermal induced failures for the BEPCII linear accelerator.

  5. Cold Test Measurements on the GTF Prototype RF Gun

    SciTech Connect

    Gierman, S.M.

    2010-12-03

    The SSRL Gun Test Facility (GTF) was built to develop a high brightness electron injector for the LCLS and has been operational since 1996. Based on longitudinal phase space measurements showing a correlated energy spread the gun was removed and re-characterized in 2002. The low power RF measurements performed on the gun are described below. Perturbative bead measurements were performed to determine the field ratio in the two-cell gun, and network analyzer measurements were made to characterize the mode structure. A second probe was installed to monitor the RF field in the first cell, and a diagnostic was developed to monitor the high-power field ratio. Calibration of the RF probes, a model for analyzing RF measurements, and Superfish simulations of bead and RF measurements are described.

  6. Operational Experience with the Nb/Pb SRF Photoelectron Gun

    SciTech Connect

    Kamps, T; Barday, R; Jankowiak, A; Knoblock, J; Kugeler, O; Matveenko, A N; Neumann, A; Quast, T; Rudolph, J; Schubert, S G; Volker, J; Kneisel, P; Nietubyc, R; Sekutowicz, J K; Smedley, J; Teichert, J; Volkov, V; Will, I

    2012-07-01

    SRF photoelectron guns offer the promise of high brightness, high average current beam production for the next generation of accelerator driven light sources such as free electron lasers, THz radiation sources or energy-recovery linac driven synchrotron radiation sources. In a first step a fully superconducting RF (SRF) photoelectron gun is under development by a collaboration between HZB, DESY, JLAB, BNL and NCBJ. The aim of the experiment is to understand and improve the performance of a Nb SRF gun cavity coated with a small metallic Pb cathode film on the cavity backplane. This paper describes the highlights from the commissioning and beam parameter measurements. The main focus is on lessons learned from operation of the SRF gun.

  7. Spot-Welding Gun With Adjustable Pneumatic Spring

    NASA Technical Reports Server (NTRS)

    Burley, Richard K.

    1990-01-01

    Proposed spot-welding gun equipped with pneumatic spring, which could be bellows or piston and cylinder, exerts force independent of position along stroke. Applies accurate controlled force to joint welded, without precise positioning at critical position within stroke.

  8. High-energy attosecond nanoplasmonic-based electron gun

    NASA Astrophysics Data System (ADS)

    Greig, S. R.; Elezzabi, A. Y.

    2016-03-01

    We present the design of an ultrafast conical lens based nanoplasmonic electron gun. Through excitation with a radially polarized laser pulse, and a combination of magnetostatic and spatial filtering, high energy electron packets with attosecond durations can be achieved.

  9. Mentally Ill Still Gain Illegal Possession of Guns, Study Shows

    MedlinePlus

    ... risk, added Swanson, a professor with Duke University School of Medicine's department of psychiatry and behavioral sciences. Mental illness causes only a small fraction of gun violence in the United States, around 3 to 5 ...

  10. More fun and curiosity with magnetic guns in the classroom

    NASA Astrophysics Data System (ADS)

    Chittasirinuwat, O.; Kruatong, T.; Paosawatyanyong, B.

    2011-05-01

    The magnetic gun was chosen as a hands-on activity for our high school students. When conducting this activity in the classroom, we found some interesting points were raised following difficulties encountered by the students. Some students proposed that during the collision, the magnet changed its pole then it pushed the last ball out of the apparatus, but some suggested that all the balls were attracted by magnetic forces, therefore the last ball could not shoot out. With a question to raise their curiosity, 'How do magnetic guns work?', our students explored notions of magnetic force, work, and conservation of energy and momentum through their own design of magnetic guns. This article describes a method for measuring the changes of kinetic energy and describes factors that students should consider for making magnetic guns more powerful and for having fun with the activity of building them.

  11. The Mystery of the Gun Turret in the Desert

    SciTech Connect

    Hoffman, R. D.

    2015-11-30

    The mystery of the gun turret in the desert began with an ingenious idea: to develop a reusable open-air line of sight diagnostic device to support LLNL’s early nuclear weapons development efforts. Obtained from the Mare Island Navy Shipyard (MINS) in January 1957, the gun turret traveled by ship to the Naval Construction Battalion base at Port Hueneme, California, and then by truck to Area 2 in the Yucca Flats valley at the Nevada Nuclear Security Site (NNSS).

  12. Plasma gun with coaxial powder feed and adjustable cathode

    NASA Technical Reports Server (NTRS)

    Zaplatynsky, Isidor (Inventor)

    1991-01-01

    An improved plasma gun coaxially injects particles of ceramic materials having high melting temperatures into the central portion of a plasma jet. This results in a more uniform and higher temperature and velocity distribution of the sprayed particles. The position of the cathode is adjustable to facilitate optimization of the performance of the gun wherein grains of the ceramic material are melted at lower power input levels.

  13. The development of a multi-cathode electron gun

    NASA Technical Reports Server (NTRS)

    Roberts, L. A.

    1973-01-01

    A multicathode electron gun, capable of automatically interchanging cathode structures of a microwave electron tube upon command was developed. This technique extends the life of a microwave electron tube into the range of fifty to one hundred years. The concept consists of mounting a number of cathode structures on a rotating platform. Rotation of the platform moves the different cathodes into operating position. The component tests, construction and operation of the gun are described.

  14. Model determines if falling, live TCP gun will detonate

    SciTech Connect

    Inayat-Hussain, A.A.; Owen, P.J. ); Nuttall, D.E. )

    1992-11-09

    BHP Research has developed a mathematical model to determine if a falling, live tubing-conveyed perforating (TCP) gun assembly will detonate upon impacting the bottom of a well. If the model finds that the falling fun exceeds the critical velocity, the gun assembly dimensions, fluid properties, or casing dimensions should be changed. BHP has successfully used the model to design downhole completions for the Challis oil field in the Timor Sea.

  15. A gun recoil system employing a magnetorheological fluid damper

    NASA Astrophysics Data System (ADS)

    Li, Z. C.; Wang, J.

    2012-10-01

    This research aims to design and control a full scale gun recoil buffering system which works under real firing impact loading conditions. A conventional gun recoil absorber is replaced with a controllable magnetorheological (MR) fluid damper. Through dynamic analysis of the gun recoil system, a theoretical model for optimal design and control of the MR fluid damper for impact loadings is derived. The optimal displacement, velocity and optimal design rules are obtained. By applying the optimal design theory to protect against impact loadings, an MR fluid damper for a full scale gun recoil system is designed and manufactured. An experimental study is carried out on a firing test rig which consists of a 30 mm caliber, multi-action automatic gun with an MR damper mounted to the fixed base through a sliding guide. Experimental buffering results under passive control and optimal control are obtained. By comparison, optimal control is better than passive control, because it produces smaller variation in the recoil force while achieving less displacement of the recoil body. The optimal control strategy presented in this paper is open-loop with no feedback system needed. This means that the control process is sensor-free. This is a great benefit for a buffering system under impact loading, especially for a gun recoil system which usually works in a harsh environment.

  16. Contoured-gap coaxial guns for imploding plasma liner experiments

    NASA Astrophysics Data System (ADS)

    Witherspoon, F. D.; Case, A.; Brockington, S.; Cassibry, J. T.; Hsu, S. C.

    2014-10-01

    Arrays of supersonic, high momentum flux plasma jets can be used as standoff compression drivers for generating spherically imploding plasma liners for driving magneto-inertial fusion, hence the name plasma-jet-driven MIF (PJMIF). HyperV developed linear plasma jets for the Plasma Liner Experiment (PLX) at LANL where two guns were successfully tested. Further development at HyperV resulted in achieving the PLX goal of 8000 μg at 50 km/s. Prior work on contoured-gap coaxial guns demonstrated an approach to control the blowby instability and achieved substantial performance improvements. For future plasma liner experiments we propose to use contoured-gap coaxial guns with small Minirailgun injectors. We will describe such a gun for a 60-gun plasma liner experiment. Discussion topics will include impurity control, plasma jet symmetry and topology (esp. related to uniformity and compactness), velocity capability, and techniques planned for achieving gun efficiency of >50% using tailored impedance matched pulse forming networks. Mach2 and UAH SPH code simulations will be included. Work supported by US DOE DE-FG02-05ER54810.

  17. Money for guns: evaluation of the Seattle Gun Buy-Back Program.

    PubMed Central

    Callahan, C M; Rivara, F P; Koepsell, T D

    1994-01-01

    Community involvement in local firearms policy is advocated to be an important component of efforts to curtail violence. This report describes the first evaluation of one such effort, a gun buy-back program conducted in Seattle, WA, during the fall of 1992. The evaluation included (a) surveys of 500 participants and a description of the firearms exchanged; (b) monitoring police reports, trauma center admissions, and medical examiners' data to assess short-term effects on the frequency of firearm-related events; and (c) an assessment of community beliefs by random-digit dialing telephone interviews of 1,000 residents. Of the 1,172 firearms relinquished, 95 percent were handguns, 83 percent were operational, and 67 percent were owned for more than 5 years. Twenty-five percent were exchanged by women. The mean age of participants in the exchange program was 51 years. Females and persons in older age groups were more likely than males (83 percent versus 70 percent, P < 0.01) and minors (88 percent versus 55 percent, P < 0.05) to select safe disposal as motivation to participate. Comparing firearm-related events per month before and after the program, crimes and deaths increased, and injuries decreased, but the changes were not statistically significant. Telephone interviews revealed broad support for publicly funded gun buy-back programs even among households (61 percent) with firearms. Gun buy-back programs are a broadly supported means to decrease voluntarily the prevalence of handguns within a community, but their effect on decreasing violent crime and reducing firearm mortality is unknown. PMID:8041845

  18. Simulation of electron beam from two strip electron guns and control of power density by rotation of gun

    NASA Astrophysics Data System (ADS)

    Sahu, G. K.; Baruah, S.; Thakur, K. B.

    2012-11-01

    Electron beam is preferably used for large scale evaporation of refractory materials. Material evaporation from a long and narrow source providing a well collimated wedge shaped atomic beam has applications in isotopic purification of metals relevant to nuclear industry. The electron beam from an electron gun with strip type filament provides a linear heating source. However, the high power density of the electron beam can lead to turbulence of the melt pool and undesirable splashing of molten metal. For obtaining quiet surface evaporation, the linear electron beam is generally scanned along its length. To further reduce the power density to maintain quiet evaporation the width of the vapour source can be controlled by rotating the electron gun on its plane, thereby scanning an inclined beam over the molten pool. The rotation of gun has further advantages. When multiple strip type electron guns are used for scaling up evaporation length, a dark zone appears between two beams due to physical separation of adjacent guns. This dark zone can be reduced by rotating the gun and thereby bringing two adjacent beams closer. The paper presented here provides the simulation results of the electron beam trajectory and incident power density originating from two strip electron guns by using in-house developed code. The effect of electron gun rotation on the electron beam trajectory and power density is studied. The simulation result is experimentally verified with the image of molten pool and heat affected zone taken after experiment. This technique can be gainfully utilized in controlling the time averaged power density of the electron beam and obtaining quiet evaporation from the metal molten pool.

  19. Temperature Controller System for Gas Gun Targets

    NASA Astrophysics Data System (ADS)

    Bucholtz, Scott; Sheffield, Stephen

    2005-07-01

    A temperature controller system capable of heating and cooling gas gun targets over the range -75 C to +200 C was designed and tested. The system uses cold nitrogen gas from a liquid nitrogen Dewar for cooling and compressed air for heating. Two gas flow heaters control the gas temperature for both heating and cooling. One heater controls the temperature of the target mounting plate and the other the temperature of a copper tubing coil surrounding the target. Each heater is separately adjustable, so the target material will achieve a uniform temperature throughout its volume. A magnetic gauge with integrated thermocouples was developed to measure the internal temperature of the target. Using this system shock experiments, including equation-of-state measurements and shock initiation of high explosives, can be performed over a range of initial temperatures. Successful tests were completed on Teflon samples. This work was supported by the NNSA Enhanced Surveillance Campaign through contract DE-ACO4-01AL66850.

  20. Controlled expedient disposal of excess gun propellant.

    PubMed

    Walsh, M R; Thiboutot, S; Walsh, M E; Ampleman, G

    2012-06-15

    The expedient field disposal of excess gun propellants on the ground is an integral part of live-fire training in many countries. However, burning excess propellant in the field will leave significant quantities of energetic residues and heavy metals in the environment. Compounds such as dinitrotoluene and nitroglycerin and metals such as lead will leach into the soil column, eventually migrating to groundwater. Contamination of the environment will lead to high remediation costs and the possible loss of the training facility. After investigating the contamination at several propellant disposal sites, a portable propellant burn pan was developed and tested. The pan was transported to training sites where excess propellant was loaded and burned in a controlled manner. Up to 120 kg of excess single-base propellant charges have been burned during two series of tests at a consumption rate of greater than 99.9%. Less than 0.03% of the energetic material was recovered outside the burn pan. Recovered lead is largely contained within the pan. The turnover rate for burns is 15 min. The residues can be collected following cool-down for proper disposal. PMID:22503215

  1. Air pollution: a smoking gun for cancer

    PubMed Central

    Zhang, Wei; Qian, Chao-Nan; Zeng, Yi-Xin

    2014-01-01

    Once considered a taboo topic or stigma, cancer is the number one public health enemy in the world. Once a product of an almost untouchable industry, tobacco is indisputably recognized as a major cause of cancer and a target for anticancer efforts. With the emergence of new economic powers in the world, especially in highly populated countries such as China, air pollution has rapidly emerged as a smoking gun for cancer and has become a hot topic for public health debate because of the complex political, economic, scientific, and technologic issues surrounding the air pollution problem. This editorial and the referred articles published in this special issue of the Chinese Journal of Cancer discuss these fundamental questions. Does air pollution cause a wide spectrum of cancers? Should air pollution be considered a necessary evil accompanying economic transformation in developing countries? Is an explosion of cancer incidence coming to China and how soon will it arrive? What must be done to prevent this possible human catastrophe? Finally, the approaches for air pollution control are also discussed. PMID:24636233

  2. Spindt cold cathode electron gun development program

    NASA Technical Reports Server (NTRS)

    Spindt, C. A.

    1983-01-01

    A thin film field emission cathode array and an electron gun based on this emitter array are summarized. Fabricating state of the art cathodes for testing at NASA and NRL, advancing the fabrication technology, developing wedge shaped emitters, and performing emission tests are covered. An anistropic dry etching process (reactive ion beam etching) developed that leads to increasing the packing density of the emitter tips to about 5 x 10 to the 6th power/square cm. Tests with small arrays of emitter tips having about 10 tips has demonstrated current densities of over 100 A/sq cm. Several times using cathodes having a packing density of 1.25 x 10 to the 6th power tips/sq cm. Indications are that the higher packing density achievable with the dry etch process may extend this capability to the 500 A/sq cm range and beyond. The wedge emitter geometry was developed and shown to produce emission. This geometry can (in principle) extend the current density capability of the cathodes beyond the 500 A/sq cm level. An emission microscope was built and tested for use with the cathodes.

  3. A novel electron gun for inline MRI-linac configurations

    SciTech Connect

    Constantin, Dragoş E. Fahrig, Rebecca; Holloway, Lois; Keall, Paul J.

    2014-02-15

    Purpose: This work introduces a new electron gun geometry capable of robust functioning in the presence of a high strength external magnetic field for axisymmetric magnetic resonance imaging (MRI)-linac configurations. This allows an inline MRI-linac to operate without the need to isolate the linear accelerator (linac) using a magnetic shield. This MRI-linac integration approach not only leaves the magnet homogeneity unchanged but also provides the linac flexibility to move along the magnet axis of symmetry if the source to target distance needs to be adjusted. Methods: Simple electron gun geometry modifications of a Varian 600C electron gun are considered and solved in the presence of an external magnetic field in order to determine a set of design principles for the new geometry. Based on these results, a new gun geometry is proposed and optimized in the fringe field of a 0.5 T open bore MRI magnet (GE Signa SP). A computer model for the 6 MeV Varian 600C linac is used to determine the capture efficiency of the new electron gun-linac system in the presence of the fringe field of the same MRI scanner. The behavior of the new electron gun plus the linac system is also studied in the fringe fields of two other magnets, a 1.0 T prototype open bore magnet and a 1.5 T GE Conquest scanner. Results: Simple geometrical modifications of the original electron gun geometry do not provide feasible solutions. However, these tests show that a smaller transverse cathode diameter with a flat surface and a slightly larger anode diameter could alleviate the current loss due to beam interactions with the anode in the presence of magnetic fields. Based on these findings, an initial geometry resembling a parallel plate capacitor with a hole in the anode is proposed. The optimization procedure finds a cathode-anode distance of 5 mm, a focusing electrode angle of 5°, and an anode drift tube length of 17.1 mm. Also, the linac can be displaced with ±15 cm along the axis of the 0.5 T

  4. A novel electron gun for inline MRI-linac configurations

    PubMed Central

    Constantin, Dragoş E.; Holloway, Lois; Keall, Paul J.; Fahrig, Rebecca

    2014-01-01

    Purpose: This work introduces a new electron gun geometry capable of robust functioning in the presence of a high strength external magnetic field for axisymmetric magnetic resonance imaging (MRI)-linac configurations. This allows an inline MRI-linac to operate without the need to isolate the linear accelerator (linac) using a magnetic shield. This MRI-linac integration approach not only leaves the magnet homogeneity unchanged but also provides the linac flexibility to move along the magnet axis of symmetry if the source to target distance needs to be adjusted. Methods: Simple electron gun geometry modifications of a Varian 600C electron gun are considered and solved in the presence of an external magnetic field in order to determine a set of design principles for the new geometry. Based on these results, a new gun geometry is proposed and optimized in the fringe field of a 0.5 T open bore MRI magnet (GE Signa SP). A computer model for the 6 MeV Varian 600C linac is used to determine the capture efficiency of the new electron gun-linac system in the presence of the fringe field of the same MRI scanner. The behavior of the new electron gun plus the linac system is also studied in the fringe fields of two other magnets, a 1.0 T prototype open bore magnet and a 1.5 T GE Conquest scanner. Results: Simple geometrical modifications of the original electron gun geometry do not provide feasible solutions. However, these tests show that a smaller transverse cathode diameter with a flat surface and a slightly larger anode diameter could alleviate the current loss due to beam interactions with the anode in the presence of magnetic fields. Based on these findings, an initial geometry resembling a parallel plate capacitor with a hole in the anode is proposed. The optimization procedure finds a cathode-anode distance of 5 mm, a focusing electrode angle of 5°, and an anode drift tube length of 17.1 mm. Also, the linac can be displaced with ±15 cm along the axis of the 0.5 T

  5. Optimization of a two stage light gas gun. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Rynearson, R. J.; Rand, J. L.

    1972-01-01

    Performance characteristics of the Texas A&M University light gas gun are presented along with a review of basic gun theory and popular prediction methods. A computer routine based on the simple isentropic compression method is discussed. Results from over 60 test shots are given which demonstrate an increase in gun muzzle velocity from 9.100 ft/sec. to 19,000 ft/sec. The data gathered indicated the Texas A&M light gas gun more closely resembles an isentropic compression gun rather than a shock compression gun.

  6. A high voltage test stand for electron gun qualification for LINACs

    SciTech Connect

    Wanmode, Yashwant D.; Mulchandani, J.; Acharya, M.; Bhisikar, A.; Singh, H.G.; Shrivastava, Purushottam

    2011-07-01

    An electron gun lest stand has been developed at RRCAT. The test stand consists of a high voltage pulsed power supply, electron gun filament supply, grid supply, UHV system and electron gun current measurement system. Several electron guns developed indigenously were evaluated on this test stand. The shielding is provided for the electron gun set up. Electron gun tests can be tested upto 55 kV with pulse width of 15 microsecs and pulse repetition rates up to 200 Hz. The technical details of the subsystems are furnished and results of performance of the test stand have been reported in this paper. (author)

  7. A 3 Ghz photoelectron gun for high beam intensity

    SciTech Connect

    Bossart, R.; Braun, H.; Dehler, M.

    1995-12-31

    The CLIC Test Facility (CTF) for new accelerator structures of the proposed Compact Linear Collider (CLIC) is to be equipped with a new RF gun containing a laser driven photocathode. The new 3 GHz gun with photocathode shall produce a bunch train of 48 electron bunches of 25 nC charge each with a bunch length of 8 - 15 ps fwhm. The new RF gun consists of 2{1/2} cells and accelerates the beam to an energy of 7 MeV with a peak field gradient Ez = 100 MV/m. The strong space charge forces at low beam energy caused by the high charge density of the electron bunches must be contained by radial and longitudinal RF focusing in the RF gun. Radial RF focusing is applied by a conical backplane around the photocathode in the first cell where the electrons have a low energy. Longitudinal RF focusing is obtained by varying the length of each of the three cells of the gun. The total electric charge of the bunch train exceeds 1{mu}C and causes strong beam loading to the RF structures so that the stored energy is reduced to half of the unloaded RF energy. The RF gun under construction is being optimized by MAFIA beam simulations for an injector assembly comprising a second accelerating RF structure of 4 cells and an intermediate solenoid magnet correcting the beam divergence of the 2{1/2} cell gun. The scheme with two accelerating RF sections will provide a linear energy increase along the bunch suitable for further compression of the bunch length in a magnetic chicane.

  8. RF Processing Experience with the GTF Prototype RF Gun

    SciTech Connect

    Schmerge, J.F.

    2010-11-24

    The SSRL Gun Test Facility (GTF) was built to develop a high brightness electron injector for the LCLS and has been operational since 1996. A total of five different metal cathodes (4 Cu and 1 Mg) have been installed on the GTF gun. The rf processing history with the different cathodes will be presented including peak field achieved at the cathode. The LCLS gun is intended to operate at 120 MV/m and fields up to 140 MV/m have been achieved in the GTF gun. After installing a new cathode the number of rf pulses required to reach 120 MV/m is approximately 5-10 million. Total emitted dark current and Fowler Nordheim plots are also shown over the life of the cathode. The GTF photo-injector gun is an S-band standing-wave structure, with two resonant cavities and an intervening thick washer (Figure 1). The flat, back wall of the first cavity is a copper plate that serves as photocathode when illuminated with ultraviolet light from a pulsed, high-power laser. RF power enters the gun through an iris on the outer wall of the second cavity, and is coupled to the first through the axial opening of the washer. The first cavity is often referred to as a half cell, because its full-cell length has been truncated by the cathode plate and the second cavity is called the full cell. The gun is designed to operate in a {pi} mode, with the peak field on axis in each cell approximately equal. The maximum in the half cell occurs at the cathode, and in the full cell near the center of the cavity. The field profile and tuning procedures are discussed in a separate tech note [1].

  9. Compact Electron Gun Based on Secondary Emission Through Ionic Bombardment

    PubMed Central

    Diop, Babacar; Bonnet, Jean; Schmid, Thomas; Mohamed, Ajmal

    2011-01-01

    We present a new compact electron gun based on the secondary emission through ionic bombardment principle. The driving parameters to develop such a gun are to obtain a quite small electron gun for an in-flight instrument performing Electron Beam Fluorescence measurements (EBF) on board of a reentry vehicle in the upper atmosphere. These measurements are useful to characterize the gas flow around the vehicle in terms of gas chemical composition, temperatures and velocity of the flow which usually presents thermo-chemical non-equilibrium. Such an instrument can also be employed to characterize the upper atmosphere if placed on another carrier like a balloon. In ground facilities, it appears as a more practical tool to characterize flows in wind tunnel studies or as an alternative to complex electron guns in industrial processes requiring an electron beam. We describe in this paper the gun which has been developed as well as its different features which have been characterized in the laboratory. PMID:22163896

  10. The Hobart Time Ball and Time Gun: a Critical Review

    NASA Astrophysics Data System (ADS)

    Kinns, Roger

    2011-07-01

    Discussion at the Royal Society in Hobart in 1865 and acoustic experiments in 1868 led to a combined time ball and time gun service in Hobart from March 1875. Complaints from residents led to relocation of the gun a month later, but it was then fired from Queen's Battery in the Domain for half a century. The drop of the ball at Battery Point was always the master signal; the gun was fired when the ball was seen to drop. During the early years, private citizens in Hobart provided the time reference. From September 1886, an electric telegraph signal from Hobart Observatory was used to provide correct time to the ball operator, but signals were of questionable accuracy. During February 1910, the source of the telegraph signal was changed from Hobart Observatory to Melbourne Observatory, but the service was still unreliable and there was pressure to re-equip Hobart Observatory. Finally, automatic dropping of the time ball by telegraph from Melbourne was introduced in November 1910. The time ball service ended in February 1927. The time gun had probably ceased to operate by the end of 1923, but before that date there were sometimes long gaps in the time gun service, particularly on Sundays.

  11. RF Guns for Generation of Polarized Electron Beams

    SciTech Connect

    Clendenin, J.E.; Brachmann, A.; Dowell, D.H.; Garwin, E.L.; Ioakeimidi, K.; Kirby, R.E.; Maruyama, T.; Prescott, C.Y.; Prepost, R.; /Wisconsin U., Madison

    2005-11-09

    Several accelerators, including the SLC, JLAB, Mainz, Bates/MIT, and Bonn have successfully operated for medium and high energy physics experiments using polarized electron beams generated by dc-biased guns employing GaAs photocathodes. Since these guns have all used a bias on the order of 100 kV, the longitudinal emittance of the extracted bunch is rather poor. Downstream rf bunching systems increase the transverse emittance. An rf gun with a GaAs photocathode would eliminate the need for separate rf bunchers, resulting in a simpler injection system. In addition, the thermal emittance of GaAs-type cathodes is significantly lower than for other photocathode materials. The environmental requirements for operating activated GaAs photocathodes cannot be met by rf guns as currently designed and operated. These requirements, including limits on vacuum and electron back bombardment, are discussed in some detail. Modifications to actual and proposed rf gun designs that would allow these requirements to be met are presented.

  12. New Gas Gun Helping Scientists Better Understand Plutonium Behavior

    SciTech Connect

    Hazi, A

    2005-09-20

    One of the most daunting scientific and engineering challenges today is ensuring the safety and reliability of the nation's nuclear arsenal. To effectively meet that challenge, scientists need better data showing how plutonium, a key component of nuclear warheads, behaves under extreme pressures and temperatures. On July 8, 2003, Lawrence Livermore researchers performed the inaugural experiment of a 30-meter-long, two-stage gas gun designed to obtain those data. The results from a continuing stream of successful experiments on the gas gun are strengthening scientists' ability to ensure that the nation's nuclear stockpile is safe and reliable. The JASPER (Joint Actinide Shock Physics Experimental Research) Facility at the Department of Energy's (DOE's) Nevada Test Site (NTS) is home to the two-stage gas gun. In the gun's first test, an unqualified success, Livermore scientists fired a projectile weighing 28.6 grams and traveling about 5.21 kilometers per second when it impacted an extremely small (about 30-gram) plutonium target. This experiment marked the culmination of years of effort in facility construction, gun installation, system integration, design reviews, and federal authorizations required to bring the experimental facility online. Ongoing experiments have drawn enthusiastic praise from throughout DOE, the National Nuclear Security Administration (NNSA), and the scientific community. NNSA Administrator Linton Brooks said, ''Our national laboratories now have at their disposal a valuable asset that enhances our due diligence to certify the nuclear weapons stockpile in the absence of underground nuclear weapons testing.''

  13. rf traveling-wave electron gun for photoinjectors

    NASA Astrophysics Data System (ADS)

    Schaer, Mattia; Citterio, Alessandro; Craievich, Paolo; Reiche, Sven; Stingelin, Lukas; Zennaro, Riccardo

    2016-07-01

    The design of a photoinjector, in particular that of the electron source, is of central importance for free electron laser (FEL) machines where a high beam brightness is required. In comparison to standard designs, an rf traveling-wave photocathode gun can provide a more rigid beam with a higher brightness and a shorter pulse. This is illustrated by applying a specific optimization procedure to the SwissFEL photoinjector, for which a brightness improvement up to a factor 3 could be achieved together with a double gun output energy compared to the reference setup foreseeing a state-of-the-art S-band rf standing-wave gun. The higher brightness is mainly given by a (at least) double peak current at the exit of the gun which brings benefits for both the beam dynamics in the linac and the efficiency of the FEL process. The gun design foresees an innovative coaxial rf coupling at both ends of the structure which allows a solenoid with integrated bucking coil to be placed around the cathode in order to provide the necessary focusing right after emission.

  14. ER Docs Only Ask Half of Suicidal Patients about Guns, Study Shows

    MedlinePlus

    ... Docs Only Ask Half of Suicidal Patients About Guns, Study Shows Finding points to missed chances to ... EDs) are asked if they have access to guns, a new study finds. National guidelines say doctors ...

  15. The SHARP Gas Gun: Shooting payloads into space Juels Verne's way

    SciTech Connect

    Hunter, J.W.

    1993-07-01

    A light-gas gun that could replace all but the final stage of today's rocket launchers and would be ideal for advanced hypersonic research has been designed, built, and tested. The development and performances of the gun are described.

  16. Cerenkov Radiator Driven by a Superconducting RF Electron Gun

    SciTech Connect

    Poole, B R; Harris, J R

    2011-03-07

    The Naval Postgraduate School (NPS), Niowave, Inc., and Boeing have recently demonstrated operation of the first superconducting RF electron gun based on a quarter wave resonator structure. In preliminary tests, this gun has produced 10 ps long bunches with charge in excess of 78 pC, and with beam energy up to 396 keV. Initial testing occurred at Niowave's Lansing, MI facility, but the gun and diagnostic beam line are planned for installation in California in the near future. The design of the diagnostic beam line is conducive to the addition of a Cerenkov radiator without interfering with other beam line operations. Design and simulations of a Cerenkov radiator, consisting of a dielectric lined waveguide will be presented. The dispersion relation for the structure is determined and the beam interaction is studied using numerical simulations. The characteristics of the microwave radiation produced in both the short and long bunch regimes will be presented.

  17. The challenge of gun control for mental health advocates.

    PubMed

    Pandya, Anand

    2013-09-01

    Mass shootings, such as the 2012 Newtown massacre, have repeatedly led to political discourse about limiting access to guns for individuals with serious mental illness. Although the political climate after such tragic events poses a considerable challenge to mental health advocates who wish to minimize unsympathetic portrayals of those with mental illness, such media attention may be a rare opportunity to focus attention on risks of victimization of those with serious mental illness and barriers to obtaining psychiatric care. Current federal gun control laws may discourage individuals from seeking psychiatric treatment and describe individuals with mental illness using anachronistic, imprecise, and gratuitously stigmatizing language. This article lays out potential talking points that may be useful after future gun violence. PMID:24042247

  18. An active expriments with electron gun on the microsatellite

    NASA Astrophysics Data System (ADS)

    Dokukin, V.; Ruzhin, Yu.

    Plasma radio emission in the presence of energetic particle fluxes is a very informative source of knowledge about plasma processes and its parameters in the interaction region. Now there is a big experience of work with election beams in the Earth ionosphere. The new generation of spacecrafts- micro and small satellites give us rather chip possibilities to carry out space orbital experiments. But there is an obstacle to do an active experiments at microsatellite with injection of electron beam-the limited onboard power source. Typically it requires at least tens of Watts to heat the cathode of electron gun and to accelerate the electrons of the beam. The proposal is made to apply ``solar'' electron gun with ``zero'' consumption from satellite powersuppliment. Such type of electron gun could be applied for space experiments at near Earth orbits and for solar or planetary missions.

  19. Los Alamos Guns Take Aim at Material's Mysteries

    ScienceCinema

    Byers, Mark; Moore, David; Dimarino, Steve

    2014-05-30

    Los Alamos National Laboratory scientists and technicians conduct thousands of experiments a year, delving into the fundamental nature of everything from supernovas to subatomic particles. One set of instruments used to better understand the fundamental nature of various materials are 10 scientific gun systems that fire various projectiles at high-tech targets to create enormous velocities, pressures, and temperatures - and using laser, x-ray, and other diagnostics - explore the very nature of metals and other materials. The hundreds of gun-based experiments conducted every year at the Laboratory require a highly-skilled staff of scientists and technicians, and has given rise to a special organization called the "gun working group" to foster open communications, cooperation, problem-solving, and a healthy safety culture.

  20. Carrying guns in public: legal and public health implications.

    PubMed

    Vernick, Jon S

    2013-03-01

    In District of Columbia v. Heller, the U.S. Supreme Court ruled that the Second Amendment protects an individual's right to own handguns in the home for protection, invalidating a Washington, D.C. law banning most handgun possession. The Heller decision, however, provided lower courts with little guidance regarding how to judge the constitutionality of gun laws other than handgun bans. Nevertheless, lower courts have upheld the vast majority of federal, state, and local gun laws challenged since Heller. One area in which some lower courts have disagreed has been the constitutionality of laws regulating the ability to carry firearms in public. This issue may be the next to be addressed by the Supreme Court under its evolving Second Amendment jurisprudence. Courts should carefully consider the negative public health and safety implications of gun carrying in public as they weigh the constitutionality of these laws. PMID:23590749

  1. Modelling and simulation of beam formation in electron guns

    NASA Astrophysics Data System (ADS)

    Sabchevski, S.; Mladenov, G.; Titov, A.; Barbarich, I.

    1996-02-01

    This paper describes a new PC version of the software package GUN-EBT for computer simulation of beam formation in rotationally symmetric electron guns with thermionic cathodes. It is based on a self-consistent physical model which takes into account the beam space charge and the initial velocities effects. The theoretical framework used for both the formulation of the model and for the interpretation of the results of numerical experiments is the formalism of the charged particle dynamics in phase space. This enables not only a trajectory analysis (ray tracing) but also a phase-space analysis of beams to be performed. The package can be used as an effective tool for computer aided design and optimization of electron guns in various electron-optical systems. The operation of the package is illustrated with a typical example.

  2. Design and performance of high uniformity linear filament electron gun

    NASA Astrophysics Data System (ADS)

    Iqbal, Munawar; Fazal-e-Aleem

    2006-10-01

    We describe new features and results from the previously reported [M. Iqbal et al., Rev. Sci. Instrum. 74, 4616 (2003)] thermionic long (up to 140mm) cathode, electromagnetically focused electron beam gun. The gun which was tested up to 50kW (5000mA×10kV) achieves power density of 33kW/cm2 at the target. The cathode temperature and emission current was uniform over a length of 100mm of the cathode. The beam density profile along the line cathode strongly relates to the temperature distribution along the line cathode. The gun has a remarkable application in heat treatment of large surface area and to coat large substrate surfaces at much faster evaporation rates with lower cost.

  3. Nail-gun injuries. Accident, homicide, or suicide?

    PubMed

    McCorkell, S J; Harley, J D; Cummings, D

    1986-09-01

    It may be difficult to distinguish industrial accidents from suicide attempts or even assaults or homicide. Nail guns are relatively new industrial tools that can produce severe or fatal injuries. The configuration of the nail on patients' radiographs after such injuries can be helpful in determining the cause of injury. Steel nails that are bent are due to a ricochet and thus indicate accidental injury. Straight-nail injuries to the co-workers of nail-gun users are most likely due to over-penetration of the substance being nailed or accidental mid-air firing; however, intentional injury cannot be ruled out. Extremity injuries caused by straight steel nails in nail gun users are the result of carelessness or poor technique, but suicide should be considered when straight nails cause wounds to the chest, head, or abdomen. PMID:3788906

  4. Rf Gun with High-Current Density Field Emission Cathode

    SciTech Connect

    Jay L. Hirshfield

    2005-12-19

    High current-density field emission from an array of carbon nanotubes, with field-emission-transistor control, and with secondary electron channel multiplication in a ceramic facing structure, have been combined in a cold cathode for rf guns and diode guns. Electrodynamic and space-charge flow simulations were conducted to specify the cathode configuration and range of emission current density from the field emission cold cathode. Design of this cathode has been made for installation and testing in an existing S-band 2-1/2 cell rf gun. With emission control and modulation, and with current density in the range of 0.1-1 kA/cm2, this cathode could provide performance and long-life not enjoyed by other currently-available cathodes

  5. Firearm retailers' willingness to participate in an illegal gun purchase.

    PubMed

    Wintemute, Garen

    2010-09-01

    Firearm-related violence is a significant public health and public safety problem for cities in the USA, and licensed firearm retailers are an important source of the guns used in that violence. Using a scripted telephone interview, we screened a sample of licensed retailers in California to assess their willingness to participate in the surrogate or "straw" purchase of a handgun; such purchases are illegal under federal law. Of 149 retailers who provided a response, 30 (20.1%) agreed to participate. In multivariate analysis, pawnbrokers were more likely to agree than were gun dealers (odds ratio 6.58, 95% confidence interval 1.99-21.71). Sales of handguns that were later subjected to ownership tracing (a proxy measure for a gun's use in crime) were not more frequent among retailers who agreed to participate than among others, and other findings were unexpected as well. PMID:20803095

  6. Los Alamos Guns Take Aim at Material's Mysteries

    SciTech Connect

    Byers, Mark; Moore, David; Dimarino, Steve

    2014-04-14

    Los Alamos National Laboratory scientists and technicians conduct thousands of experiments a year, delving into the fundamental nature of everything from supernovas to subatomic particles. One set of instruments used to better understand the fundamental nature of various materials are 10 scientific gun systems that fire various projectiles at high-tech targets to create enormous velocities, pressures, and temperatures - and using laser, x-ray, and other diagnostics - explore the very nature of metals and other materials. The hundreds of gun-based experiments conducted every year at the Laboratory require a highly-skilled staff of scientists and technicians, and has given rise to a special organization called the "gun working group" to foster open communications, cooperation, problem-solving, and a healthy safety culture.

  7. ELECTROSTATIC MODELING OF THE JEFFERSON LABORATORY INVERTED CERAMIC GUN

    SciTech Connect

    P. Evtushenko ,F.E. Hannon, C. Hernandez-Garcia

    2010-05-01

    Jefferson Laboratory (JLab) is currently developing a new 500kV DC electron gun for future use with the FEL. The design consists of two inverted ceramics which support a central cathode electrode. This layout allows for a load-lock system to be located behind the gun chamber. The electrostatic geometry of the gun has been designed to minimize surface electric field gradients and also to provide some transverse focusing to the electron beam during transit between the cathode and anode. This paper discusses the electrode design philosophy and presents the results of electrostatic simulations. The electric field information obtained through modeling was used with particle tracking codes to predict the effects on the electron beam.

  8. Emittance Measurements of the SSRL Gun Test Facility

    SciTech Connect

    Hernandez, Michael; Clendenin, James; Fisher, Alan; Miller, Roger; Palmer, Dennis; Park, Sam; Schmerge, John; Weaver, Jim; Wiedemann, Helmut; Winick, Herman; Yeremian, Dian; Meyerhofer, David; Reis, David; /Rochester U.

    2011-09-01

    A photocathode RF gun test stand is under construction in the injector vault of the Stanford Synchrotron Radiation Laboratory at SLAC. The goal of this facility is to produce an electron beam with a normalized emittance of 1-3[mm-mr], a longitudinal bunch duration of the order of 10[ps] FWHM and approximately 1[nC] of charge per bunch. The beam will be generated from a laser driven copper photocathode RF gun developed in collaboration with BNL, LBL and UCLA. The 3-5[MeV] beam from the gun will be accelerated using a SLAC three meter S-band accelerator section. The emittance of the electron beam will be measured through the use of quadrupole scans with phosphor screens and also a wire scanner. The details of the experimental setup will be discussed, and first measurements will be presented and compared with results from PARMELA simulations.

  9. [Wounds caused by projectiles of pressure guns in children].

    PubMed

    Barreras-Salcedo, J I; Avila-Vergara, M A

    1993-05-01

    The present study is a survey to analyze the actual situation of the wounds produced by bibi-guns, concerning the damage produced, kind of surgical procedure, clinical evolution, and some general characteristics of the population on study. During a period of two years from May 1990 to May 1992 at the General Hospital of Culiacan, Sin. Six patients from the Pediatric Surgery Department with a diagnosis of wound produced by bibi-guns were studied. All patients required surgical treatment with general anesthesia. The average age of patients was 5.8 +/- 1.5 years, five male and one female; wounds were produced accidentally in four cases and two in a guns-game. The severity of the injury was evaluated, and in two cases their internal injury laid in danger the life of patient. No deaths occurred. PMID:8504003

  10. Design and performance of high uniformity linear filament electron gun

    SciTech Connect

    Iqbal, Munawar; Fazal-e-Aleem

    2006-10-15

    We describe new features and results from the previously reported [M. Iqbal et al., Rev. Sci. Instrum. 74, 4616 (2003)] thermionic long (up to 140 mm) cathode, electromagnetically focused electron beam gun. The gun which was tested up to 50 kW (5000 mAx10 kV) achieves power density of 33 kW/cm{sup 2} at the target. The cathode temperature and emission current was uniform over a length of 100 mm of the cathode. The beam density profile along the line cathode strongly relates to the temperature distribution along the line cathode. The gun has a remarkable application in heat treatment of large surface area and to coat large substrate surfaces at much faster evaporation rates with lower cost.

  11. FEMTO SECOND ELECTRON BEAM DIFFRACTION USING A PHOTOCATHODE RF GUN.

    SciTech Connect

    WANG,X.J.WU,Z.IHEE,H.

    2003-05-12

    One of the 21st century scientific frontiers is to explore the molecule structure transition on the femtosecond time scale. X-ray free electron laser (XFEL) is one of the tools now under development for investigating femto-second structure transition. We are proposing an alternative technique--femto-second electron diffraction based on a photocathode RF gun. We will present a design of a kHz femto-seconds electron diffraction system based on a photocathode RF gun. Our simulation shows that, the photocathode RF gun can produce 100 fs (FWHM) electron bunch with millions electrons at about 2 MeV. This is at least one order of magnitude reduction in bunch length, and two orders of magnitude increase in number of electrons comparing to present time-resolved electron diffraction system. We will also discuss various issues and limitations related to MeV electron diffraction.

  12. Simulation of the velocity spread in magnetron injection guns

    SciTech Connect

    Liu, C.; Antonsen, T.M. Jr.; Levush, B.

    1996-06-01

    The velocity spread associated with phase mixing due to dc space charge in a magnetron injection gun (MIG) is investigated. A simple model is introduced to describe the mixing process. Simulations are performed by using the results of the EGUN trajectory calculation for initial conditions at the entrance of the drift region. Results for a 170 GHz gun are obtained and compared with EGUN simulations. This new model provides a more accurate and efficient approach for analyzing the velocity spread due to mixing in MIG`s.

  13. Plasma-filled diode based on the coaxial gun.

    PubMed

    Zherlitsyn, A A; Kovalchuk, B M; Pedin, N N

    2012-10-01

    The paper presents the results of studies of a coaxial gun for a plasma-filled electron diode. Effects of the discharge channel diameter and gun current on characteristics of the plasma and pulse generated in the diode were investigated. The electron beam with maximum energy of ≥1 MeV at the current of ≈100 kA was obtained in the experiments with a plasma-filled diode. The energy of ≈5 kJ with the peak power of ≥100 GW dissipated in the diode. PMID:23126788

  14. Finite-element simulation of thermoemission electron guns

    NASA Astrophysics Data System (ADS)

    Greenfield, D.

    2006-05-01

    The peculiarity of the numeric simulation of the thermoemission electron guns consists in the principal necessity of taking into account the contribution of the electrons' charge into the potential distribution in the beam formation region. Ths fact makes the mathematical model essentially nonlinear especially in the high-perveance operation mode. Moreover, the charge density is extremely high in the vicinity of emitting surfaces, rising infinitely in the limit of zero initial velocities. A special semi-analytical approach has been applied to deal with the charge singularity. Being combined with traditional finite-element numerical techniques, this approach provides an efficient way to simulate thermoemission electron guns.

  15. Unloading the hired gun: Inoculation effects in expert witness testimony.

    PubMed

    Ziemke, Mitchell H; Brodsky, Stanley L

    2015-01-01

    The current study investigated the efficacy of inoculation as a trial strategy designed to counter mock jurors' perceptions that an expert is a hired gun in a criminal trial. The effect of narrative and fragmented expert responses to cross-examination questions was also examined. The significant results were that not using inoculation led to higher ratings of expert knowledge compared to other conditions. Response style did not make a difference in the criminal setting. Implications of these results regarding "hired gun" expert witnesses and courtroom persuasion are discussed. PMID:26299600

  16. A new chemical analysis system using a photocathode RF gun

    NASA Astrophysics Data System (ADS)

    Aoki, Yasushi; Yang, Jinfeng; Hirose, Masafumi; Sakai, Fumio; Tsunemi, Akira; Yorozu, Masafumi; Okada, Yasuhiro; Endo, Akira; Wang, Xijie; Ben-Zvi, Ilan

    2000-11-01

    A compact chemical analysis (pulse radiolysis) apparatus using a BNL-type s-band photocathode RF gun (GUN-IV) is now under development at Sumitomo Heavy Industries (SHI). Using the apparatus, fast chemical reactions induced by 3.5 ps pulse of electron beam can be analyzed by means of time-resolved photo-absorption spectroscopy with 10 ps laser pulses in the wavelength range of 210-2000 nm. The high-precision control of RF phase makes 10 ps of time-resolution possible for the analysis.

  17. Observation of a charge limit for photocathode electron guns

    SciTech Connect

    Woods, M.; Clendenin, J.; Frisch, J.; Kulikov, A.; Saez, P.; Schultz, D.; Turner, J.; Witte, K.; Zolotorev, M.

    1992-12-01

    The Photocathode Electron Gun (PEG) at SLAC is required to produce bunch intensities of up to 10{sup 11} electrons within 2 ns (8 Amps). Operation of PEG has demonstrated a `Charge Limit` phenomenon, whereby the charge that can be extracted from the gun with an intense laser beam saturates at significantly less than 10{sup 11} electrons (the expected `Space Charge Limited` charge) when the photocathode Quantum Efficiency is low. We report studies of this Charge Limit phenomenon observed with a GaAs photocathode.

  18. Observation of a charge limit for photocathode electron guns

    SciTech Connect

    Woods, M.; Clendenin, J.; Frisch, J.; Kulikov, A.; Saez, P.; Schultz, D.; Turner, J.; Witte, K.; Zolotorev, M.

    1992-12-01

    The Photocathode Electron Gun (PEG) at SLAC is required to produce bunch intensities of up to 10[sup 11] electrons within 2 ns (8 Amps). Operation of PEG has demonstrated a 'Charge Limit' phenomenon, whereby the charge that can be extracted from the gun with an intense laser beam saturates at significantly less than 10[sup 11] electrons (the expected Space Charge Limited' charge) when the photocathode Quantum Efficiency is low. We report studies of this Charge Limit phenomenon observed with a GaAs photocathode.

  19. Gridded Electron Guns and Modulation of Intense Beams

    SciTech Connect

    Harris, J R; O'Shea, P G

    2006-05-02

    Gridded guns are useful for producing modulated electron beams. This modulation is generally limited to simple gating of the beam, but may be used to apply structure to the beam pulse shape. In intense beams, this structure spawns space charge waves whose dynamics depend in part on the relative strengths of the velocity and density variations which comprise the initial current modulation. In this paper, we calculate the strengths of beam current and velocity modulation produced in a gridded electron gun, and show that under normal conditions the initial modulation is dominated by density variation rather than velocity variation.

  20. The system of RF beam control for electron gun

    NASA Astrophysics Data System (ADS)

    Barnyakov, A. M.; Chernousov, Yu. D.; Ivannikov, V. I.; Levichev, A. E.; Shebolaev, I. V.

    2015-06-01

    The system of RF control of three-electrode electron gun current is described. It consists of a source of microwave signal, coaxial line, coaxial RF switch and RF antenna lead. The system allows one to get the electron beam in the form of bunches with the frequency of the accelerating section to achieve the capture of particles in the acceleration mode close to 100%. The results of calculation and analysis of the elements of the system are presented. Characteristics of the devices are obtained experimentally. The results of using RF control in three-electrode electron gun at electron linear accelerator are described.

  1. L-band RF gun with a thermionic cathode

    SciTech Connect

    Nagaitsev, S.; Andrews, R.; Church, M.; Lunin, A.; Nezhevenko, O.; Solyak, N.; Sun, D.; Yakovlev, V.; /Fermilab

    2008-06-01

    We present a conceptual design for an L-band (1.3 GHz) rf gun with a two-grid thermionic cathode assembly. The rf gun is designed to provide a 9 mA average beam current for 1 ms pulses at a 5 Hz rate. These parameters match the beam requirements for both the ILC and the Fermilab Project X test facilities. In our simulations we are able to attain a full bunch length of 20-30 degrees, while the output energy can vary from 2 to 4 MeV. Simulations as well as a preliminary design will be presented.

  2. Development program on a Spindt cold-cathode electron gun

    NASA Technical Reports Server (NTRS)

    Spindt, C. A.

    1982-01-01

    A thin film field emission cathode (TFFEC) array and a cold cathode electron gun based on the emitter were developed. A microwave tube gun that uses the thin film field emission cathode as an electron source is produced. State-of-the-art cathodes were fabricated and tested. The tip-packing density of the arrays were increased thereby increasing the cathode's current density capability. The TFFEC is based on the well known field emission effect and was conceived to exploit the advantages of that phenomenon while minimizing the difficulties associated with conventional field emission structures, e.g. limited life and high voltage requirements. Field emission follows the Fowler-Nordheim equation.

  3. Plasma-filled diode based on the coaxial gun

    SciTech Connect

    Zherlitsyn, A. A.; Kovalchuk, B. M.; Pedin, N. N.

    2012-10-15

    The paper presents the results of studies of a coaxial gun for a plasma-filled electron diode. Effects of the discharge channel diameter and gun current on characteristics of the plasma and pulse generated in the diode were investigated. The electron beam with maximum energy of {>=}1 MeV at the current of Almost-Equal-To 100 kA was obtained in the experiments with a plasma-filled diode. The energy of Almost-Equal-To 5 kJ with the peak power of {>=}100 GW dissipated in the diode.

  4. Plasma-filled diode based on the coaxial gun

    NASA Astrophysics Data System (ADS)

    Zherlitsyn, A. A.; Kovalchuk, B. M.; Pedin, N. N.

    2012-10-01

    The paper presents the results of studies of a coaxial gun for a plasma-filled electron diode. Effects of the discharge channel diameter and gun current on characteristics of the plasma and pulse generated in the diode were investigated. The electron beam with maximum energy of ≥1 MeV at the current of ≈100 kA was obtained in the experiments with a plasma-filled diode. The energy of ≈5 kJ with the peak power of ≥100 GW dissipated in the diode.

  5. Surface Characterization of the LCLS RF Gun Cathode

    SciTech Connect

    Brachmann, Axel; Decker, Franz-Josef; Ding, Yuantao; Dowell, David; Emma, Paul; Frisch, Josef; Gilevich, Sasha; Hays, Gregory; Hering, Philippe; Huang, Zhirong; Iverson, Richard; Loos, Henrik; Miahnahri, Alan; Nordlund, Dennis; Nuhn, Heinz-Dieter; Pianetta, Piero; Turner, James; Welch, James; White, William; Wu, Juhao; Xiang, Dao; /SLAC

    2012-06-25

    The first copper cathode installed in the LCLS RF gun was used during LCLS commissioning for more than a year. However, after high charge operation (> 500 pC), the cathode showed a decline of quantum efficiency within the area of drive laser illumination. They report results of SEM, XPS and XAS studies that were carried out on this cathode after it was removed from the gun. X-ray absorption and X-ray photoelectron spectroscopy reveal surface contamination by various hydrocarbon compounds. In addition they report on the performance of the second installed cathode with emphasis on the spatial distribution of electron emission.

  6. Sources of guns to dangerous people: what we learn by asking them.

    PubMed

    Cook, Philip J; Parker, Susan T; Pollack, Harold A

    2015-10-01

    Gun violence exacts a lethal toll on public health. This paper focuses on reducing access to firearms by dangerous offenders, contributing original empirical data on the gun transactions that arm offenders in Chicago. Conducted in the fall of 2013, analysis of an open-ended survey of 99 inmates of Cook County Jail focuses on a subset of violence-prone individuals with the goal of improving law enforcement actions. Among our principal findings: *Our respondents (adult offenders living in Chicago or nearby) obtain most of their guns from their social network of personal connections. Rarely is the proximate source either direct purchase from a gun store, or theft. *Only about 60% of guns in the possession of respondents were obtained by purchase or trade. Other common arrangements include sharing guns and holding guns for others. *About one in seven respondents report selling guns, but in only a few cases as a regular source of income. *Gangs continue to play some role in Chicago in organizing gun buys and in distributing guns to members as needed. *The Chicago Police Department has a considerable effect on the workings of the underground gun market through deterrence. Transactions with strangers and less-trusted associates are limited by concerns over arrest risk (if the buyer should happen to be an undercover officer or a snitch), and about being caught with a "dirty" gun (one that has been fired in a crime). PMID:25937592

  7. Employment of Second Order Ruled Surfaces in Design of Sheet Beam Guns

    SciTech Connect

    Krasnykh, Anatoly; /SLAC

    2007-03-05

    A novel 3D method of sheet beam gun design has recently been developed. Second order ruled surfaces (SORS) can be used to define the geometry of the gun electrodes. The gun design process is made simpler if SORS are derived from analytical formulas. A proposed method is discussed and illustrated.

  8. To Keep and Bear Arms: Gun Control and the Second Amendment. Teacher's Guide.

    ERIC Educational Resources Information Center

    Edwards, Amy N.; Walker, Tim

    This teacher's guide is designed to accompany the two-part videotape "To Keep and Bear Arms: Gun Control and the Second Amendment." The videotape and teacher's guide should help students to: (1) understand the history of the Second Amendment; (2) examine how guns and gun control laws affect people's lives; (3) compare and contrast the many…

  9. Crime, Culture Conflict, and the Sources of Support for Gun Control.

    ERIC Educational Resources Information Center

    Kleck, Gary

    1996-01-01

    Questions whether attitudes towards gun control are influenced primarily by exposure to high crime rates, prior victimization, and fear of crime, or result from membership in social groups hostile to gun ownership. Maintains that support for gun control is more a product of culture conflict than a response to crime. (MJP)

  10. 27 CFR 70.442 - Taxes relating to machine guns, destructive devices, and certain other firearms.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... relating to machine guns, destructive devices, and certain other firearms. Part 479 of title 27 CFR... guns, destructive devices, and certain other firearms. 70.442 Section 70.442 Alcohol, Tobacco Products... importers of and dealers in, machine guns, destructive devices, and certain other types of firearms,...

  11. 27 CFR 479.105 - Transfer and possession of machine guns.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... machine guns. 479.105 Section 479.105 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION MACHINE GUNS, DESTRUCTIVE DEVICES, AND CERTAIN OTHER FIREARMS Registration and Identification of Firearms Machine Guns § 479.105...

  12. 3 CFR - Engaging in Public Health Research on the Causes and Prevention of Gun Violence

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Prevention of Gun Violence Presidential Documents Other Presidential Documents Memorandum of January 16, 2013 Engaging in Public Health Research on the Causes and Prevention of Gun Violence Memorandum for the Secretary of Health and Human Services In addition to being a law enforcement challenge, gun violence...

  13. 27 CFR 70.442 - Taxes relating to machine guns, destructive devices, and certain other firearms.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... relating to machine guns, destructive devices, and certain other firearms. Part 479 of title 27 CFR... guns, destructive devices, and certain other firearms. 70.442 Section 70.442 Alcohol, Tobacco Products... importers of and dealers in, machine guns, destructive devices, and certain other types of firearms,...

  14. 27 CFR 478.36 - Transfer or possession of machine guns.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... machine guns. 478.36 Section 478.36 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO... Administrative and Miscellaneous Provisions § 478.36 Transfer or possession of machine guns. No person shall transfer or possess a machine gun except: (a) A transfer to or by, or possession by or under the...

  15. Individual-Level Risk Factors for Gun Victimization in a Sample of Probationers

    ERIC Educational Resources Information Center

    Wells, William; Chermak, Steven

    2011-01-01

    Interventions aimed at preventing the important problem of gun injuries could be improved with an understanding of whether there are unique factors that place individuals at an increased risk of gun victimization. Much remains to be known about the victims of gun violence. The purpose of this article is to assess whether there are individual-level…

  16. 75 FR 41518 - Match-E-Be-Nash-She-Wish (Gun Lake) Tribe Liquor Control Ordinance

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-16

    ... Bureau of Indian Affairs Match-E-Be-Nash-She-Wish (Gun Lake) Tribe Liquor Control Ordinance AGENCY... certification of the Match-E-Be-Nash-She-Wish Band of Pottawatomi Indians (Gun Lake) Liquor Control Ordinance... purpose of regulating liquor transactions in Indian Country. The Tribal Council of the Gun Lake...

  17. 27 CFR 478.36 - Transfer or possession of machine guns.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... machine guns. 478.36 Section 478.36 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO... Administrative and Miscellaneous Provisions § 478.36 Transfer or possession of machine guns. No person shall transfer or possess a machine gun except: (a) A transfer to or by, or possession by or under the...

  18. 27 CFR 479.105 - Transfer and possession of machine guns.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... machine guns. 479.105 Section 479.105 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION MACHINE GUNS, DESTRUCTIVE DEVICES, AND CERTAIN OTHER FIREARMS Registration and Identification of Firearms Machine Guns § 479.105...

  19. 27 CFR 479.105 - Transfer and possession of machine guns.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... machine guns. 479.105 Section 479.105 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION MACHINE GUNS, DESTRUCTIVE DEVICES, AND CERTAIN OTHER FIREARMS Registration and Identification of Firearms Machine Guns § 479.105...

  20. 27 CFR 70.442 - Taxes relating to machine guns, destructive devices, and certain other firearms.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... relating to machine guns, destructive devices, and certain other firearms. Part 479 of title 27 CFR... guns, destructive devices, and certain other firearms. 70.442 Section 70.442 Alcohol, Tobacco Products... importers of and dealers in, machine guns, destructive devices, and certain other types of firearms,...

  1. 27 CFR 478.36 - Transfer or possession of machine guns.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... machine guns. 478.36 Section 478.36 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO... Administrative and Miscellaneous Provisions § 478.36 Transfer or possession of machine guns. No person shall transfer or possess a machine gun except: (a) A transfer to or by, or possession by or under the...

  2. 27 CFR 478.36 - Transfer or possession of machine guns.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... machine guns. 478.36 Section 478.36 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO... Administrative and Miscellaneous Provisions § 478.36 Transfer or possession of machine guns. No person shall transfer or possess a machine gun except: (a) A transfer to or by, or possession by or under the...

  3. 27 CFR 479.105 - Transfer and possession of machine guns.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... machine guns. 479.105 Section 479.105 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION MACHINE GUNS, DESTRUCTIVE DEVICES, AND CERTAIN OTHER FIREARMS Registration and Identification of Firearms Machine Guns § 479.105...

  4. 27 CFR 479.105 - Transfer and possession of machine guns.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... machine guns. 479.105 Section 479.105 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION MACHINE GUNS, DESTRUCTIVE DEVICES, AND CERTAIN OTHER FIREARMS Registration and Identification of Firearms Machine Guns § 479.105...

  5. 27 CFR 70.442 - Taxes relating to machine guns, destructive devices, and certain other firearms.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... relating to machine guns, destructive devices, and certain other firearms. Part 479 of title 27 CFR... guns, destructive devices, and certain other firearms. 70.442 Section 70.442 Alcohol, Tobacco Products... importers of and dealers in, machine guns, destructive devices, and certain other types of firearms,...

  6. 27 CFR 478.36 - Transfer or possession of machine guns.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... machine guns. 478.36 Section 478.36 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO... Administrative and Miscellaneous Provisions § 478.36 Transfer or possession of machine guns. No person shall transfer or possess a machine gun except: (a) A transfer to or by, or possession by or under the...

  7. 27 CFR 70.442 - Taxes relating to machine guns, destructive devices, and certain other firearms.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... relating to machine guns, destructive devices, and certain other firearms. Part 179 of title 27 CFR... guns, destructive devices, and certain other firearms. 70.442 Section 70.442 Alcohol, Tobacco Products... importers of and dealers in, machine guns, destructive devices, and certain other types of firearms,...

  8. The Origins of Gun Culture in the United States, 1760-1865.

    ERIC Educational Resources Information Center

    Bellesiles, Michael A.

    1996-01-01

    Maintains that, counter to popular opinion, guns played no significant role in U.S. frontier life until the Civil War era. Evidence from probate and militia records reveal a consistent lack of gun ownership while magazine articles painted unflattering portraits of gun ownership and hunting. Discusses reasons for the change. (MJP)

  9. Comparison of a laboratory and a production coating spray gun with respect to scale-up.

    PubMed

    Mueller, Ronny; Kleinebudde, Peter

    2007-01-01

    A laboratory spray gun and a production spray gun were investigated in a scale-up study. Two Schlick spray guns, which are equipped with a new antibearding cap, were used in this study. The influence of the atomization air pressure, spray gun-to tablet bed distance, polymer solution viscosity, and spray rate were analyzed in a statistical design of experiments. The 2 spray guns were compared with respect to the spray width and height, droplet size, droplet velocity, and spray density. The droplet size, velocity, and spray density were measured with a Phase Doppler Particle Analyzer. A successful scale-up of the atomization is accomplished if similar droplet sizes, droplet velocities, and spray densities are achieved in the production scale as in the laboratory scale. This study gives basic information for the scale-up of the settings from the laboratory spray gun to the production spray gun. Both spray guns are highly comparable with respect to the droplet size and velocity. The scale-up of the droplet size should be performed by an adjustment of the atomization air pressure. The scale-up of the droplet velocity should be performed by an adjustment of the spray gun to tablet bed distance. The presented statistical model and surface plots are convenient and powerful tools for scaling up the spray settings if the spray gun is changed from laboratory spray gun to the production spray gun. PMID:17408226

  10. 10. Emplacement no. 2, view to west from gun platform ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. Emplacement no. 2, view to west from gun platform showing a portion of the counterweight well, steps up to the loading platform, stair (at center rear) to top of center tranverse - Fort Wadsworth Battery Romeyn B. Ayers, South side of Ayers Road, Staten Island, Rosebank, Richmond County, NY

  11. Modified faceplate assembly for stud-welding gun

    NASA Technical Reports Server (NTRS)

    Johnson, R. E.

    1970-01-01

    Ventilated barrel assembly aids installation of studs on narrow uneven weld lands. The modified faceplate permits proper aligning of the percussion stud-welding gun in any position and on a smaller surface, and it maintains gap setting without any other adjustment.

  12. A magnetron injection gun with extraction of reflected electrons

    NASA Astrophysics Data System (ADS)

    Vilkov, M. V.; Glyavin, M. Yu.; Goldenberg, A. L.; Petelin, M. I.

    2012-07-01

    Using irreversibility of electron drift in crossed axisymmetric electric and magnetic fields, it is possible to ensure the extraction of electrons reflected from a magnetic mirror, provided that one electrode possesses a helical symmetry. Electron guns of this type may be recommended for use in moderate-power subterahertz gyrotrons.

  13. Kids and Guns. 1999 National Report Series. Juvenile Justice Bulletin.

    ERIC Educational Resources Information Center

    Department of Justice, Washington, DC. Office of Juvenile Justice and Delinquency Prevention.

    This report provides information about the use of guns by children and adolescents, with related information on juvenile homicides and suicides. The annual number of juveniles killed with a firearm increased substantially between 1987 and 1993 as occurrences of other types of homicide remained constant. Since 1980, one in four murders of juveniles…

  14. Firearm Advertising: Product Depiction in Consumer Gun Magazines

    ERIC Educational Resources Information Center

    Saylor, Elizabeth A.; Vittes, Katherine A.; Sorenson, Susan B.

    2004-01-01

    In contrast to tobacco, alcohol, and other consumer products associated with health risks, we know very little about how firearm manufacturers advertise their products. The authors examined advertisements for firearms in all 27 ad-accepting magazines listed in "Bacon's Magazine Directory" "guns and shooting" category. Sixty-three manufacturers…

  15. Magnetron Driven L Band RF Gun using a Photocathode Emitter

    NASA Astrophysics Data System (ADS)

    Evans, Kirk; Fisher, Amnon; Friedman, Moshe

    1996-11-01

    Magnetron Driven L Band RF Gun using a Photocathode Emitter A tunable 5 megawatt L-Band injection locked magnetron amplifier is used to drive a 1-1/2 cell RF cavity gun, to produce a 2.5 megavolt electron beam. A tunable RF source relaxes the precision of the cavity gun construction, and therefore simplifies the design and reduces the overall cost. The design of the L-Band ( 1.3 GHz) RF cavity linear accelerator is presented, along with Superfish, SOS computer simulations, and calculations of beam energy and temporal qualities. Measurements of a few robust photocathode materials as well as measurements of the beam qualities of the final accelerator are presented. Future work will utilize new semiconductor laser diodes that can be electrically driven in the gigahertz range. This makes possible an electron gun system which can run at the RF frequency used to accelerate the electron beam. Such a system produces a "lock to clock" and synchronized RF and electron beam source which can be run single shot or any rep rate up to the RF frequency.

  16. Hartford's gun buy-back program: are we on target?

    PubMed

    Marinelli, Laura W; Thaker, Shefali; Borrup, Kevin; Shapiro, David S; Bentley, George C; Saleheen, Hassan; Lapidus, Garry; Campbell, Brendan T

    2013-09-01

    Gunbuy-backprograms have been proposed as away to remove unwanted firearms from circulation, but remain controversial because their ability to prevent firearm injuries remains unproven. The purpose of this study is to describe the demographics of individuals participating in Connecticut's gun buy-backprogram in the context of annual gun sales and the epidemiology of firearm violence in the state. Over four years the buy-back program collected 464 firearms, including 232 handguns. In contrast, 91,602 firearms were sold in Connecticut during 2009 alone. The incidence of gun-related deaths was unchanged in the two years following the inception of the buy-back program. Suicide was associated with older age (mean = 51 +/- 18years) and Caucasian race (n = 539, 90%). Homicide was associated with younger age (mean = 30 +/- 12 years) and minority race (n = 425, 81%). A gun buy-back program alone is not likely to produce a measurable decrease in firearm injuries and deaths. PMID:24156172

  17. "Fist, Stick, Knife, Gun": Getting Real in Upward Bound.

    ERIC Educational Resources Information Center

    Pace, Barbara G.; Adkins, Theresa A.

    2002-01-01

    Describes how a teacher found literature for Upward Bound students. Presents Geoffrey Canada's "Fist, Stick, Knife, Gun: A Personal History of Violence in America" as a nonfiction work to provide clarity and connections that might not have been available in a fictional work, yet it had elements of literary fiction that made the text engaging. (SG)

  18. New LANL gas-driven two-stage gun

    SciTech Connect

    Martinez, A.R.; Sheffield, S.A.; Whitehead, M.C.; Olivas, H.D.; Dick, J.J.

    1993-08-01

    A new compressed-helium driven two-stage light gas gun has been installed at LANL to study shock initiated reaction in insensitive high explosives. The gun (based on a design at Ernst Mach Institute) has a 100-mm diameter by 7.6 long pump tube and a 50-mm diameter by 7.6-m long launch tube. The gas breech, capable of pressures up to 15.000 psi, has a volume of 42.5 liters and can be used in either a wrap-around or double-diaphragm mode. This breech was designed so we could use helium rather than powder combustion gases to drive the pump piston, eliminating the safety and cleanup problems associated with gun powder. Large hydraulic clamps (pressurized to 10,000 psi) are used to clamp the breech to the pump tube, the pump tube to the transition section, and the transition section to the launch tube. The target chamber was designed to allow the necessary room to do multiple magnetic gauging experiments. Gun control is accomplished using a MAC computer and LabVIEW control software.

  19. New LANL gas driven two-stage gun

    SciTech Connect

    Martinez, A.R.; Sheffied, S.A.; Whitehead, M.C.; Olivas, H.D.; Dick, J.J. )

    1994-07-10

    A new compressed-helium driven two-stage light gas gun has been installed at LANL to study shock initiated reaction in insensitive high explosives. The gun (based on a design at Ernst Mach Institute) has a 100-mm diameter by 7.6 long pump tube and a 50-mm diameter by 7.6-m long launch tube. The gas breech, capable of pressures up to 15,000 psi, has a volume of 42.5 liters and can be used in either a wrap-around or double-diaphragm mode. This breech was designed so we could use helium rather than powder combustion gases to drive the pump piston, eliminating the safety and cleanup problems assoicated with gun powder. Large hydraulic clamps (pressurized to 10,000 psi) are used to clamp the breech to the pump tube, the pump tube to the transition section, and the transition section to the launch tube. The target chamber was designed to allow the necessary room to do multiple magnetic gauging experiments. Gun control is accomplished using a MAC computer and LabVIEW control software. [copyright]American Institute of Physics

  20. New LANL gas driven two-stage gun

    NASA Astrophysics Data System (ADS)

    Martinez, A. R.; Sheffied, S. A.; Whitehead, M. C.; Olivas, H. D.; Dick, J. J.

    1994-07-01

    A new compressed-helium driven two-stage light gas gun has been installed at LANL to study shock initiated reaction in insensitive high explosives. The gun (based on a design at Ernst Mach Institute) has a 100-mm diameter by 7.6 long pump tube and a 50-mm diameter by 7.6-m long launch tube. The gas breech, capable of pressures up to 15,000 psi, has a volume of 42.5 liters and can be used in either a wrap-around or double-diaphragm mode. This breech was designed so we could use helium rather than powder combustion gases to drive the pump piston, eliminating the safety and cleanup problems assoicated with gun powder. Large hydraulic clamps (pressurized to 10,000 psi) are used to clamp the breech to the pump tube, the pump tube to the transition section, and the transition section to the launch tube. The target chamber was designed to allow the necessary room to do multiple magnetic gauging experiments. Gun control is accomplished using a MAC computer and LabVIEW control software.

  1. Validity of a household gun question in a telephone survey.

    PubMed Central

    Rafferty, A P; Thrush, J C; Smith, P K; McGee, H B

    1995-01-01

    The validity of self-reported data on the presence of guns in the home obtained in a telephone survey was assessed in samples of households where a hunting license had been purchased or a handgun registered. The survey was conducted among a random sample of Ingham County, MI, residents who had purchased a hunting license between April 1990 and March 1991 and among those registering a handgun during 1990. A third study sample was selected from the county's general adult population using a random digit dialing method. The interviews were conducted between November 1991 and January 1992. The proportion of respondents who reported that at least one gun was kept in their household was 87.3 percent among handgun registration households and 89.7 percent among hunting license households. In the survey of the general population of the county, approximately one-third of the respondents reported keeping a gun in the household, 67 percent of them for hunting and 23 percent for safety. Despite some limitations, the data indicate that a question on gun presence in a household can be used in a in a telephone survey. PMID:7610216

  2. Electron gun test report. [shock and vibration tests

    NASA Technical Reports Server (NTRS)

    1974-01-01

    Shock and vibration tests were performed to determine the electron optical properties of the electron gun. The test procedure included complete mechanical inspection including a dimensional check of all critical parts. Electrical inspection involved tests for dielectric strengths and element to element leakage resistance. All test circuits and equipment for each test are specified in the test plan.

  3. Repetitive, small-bore two-stage light gas gun

    SciTech Connect

    Combs, S.K.; Foust, C.R.; Fehling, D.T.; Gouge, M.J.; Milora, S.L.

    1991-01-01

    A repetitive two-stage light gas gun for high-speed pellet injection has been developed at Oak Ridge National Laboratory. In general, applications of the two-stage light gas gun have been limited to only single shots, with a finite time (at least minutes) needed for recovery and preparation for the next shot. The new device overcomes problems associated with repetitive operation, including rapidly evacuating the propellant gases, reloading the gun breech with a new projectile, returning the piston to its initial position, and refilling the first- and second-stage gas volumes to the appropriate pressure levels. In addition, some components are subjected to and must survive severe operating conditions, which include rapid cycling to high pressures and temperatures (up to thousands of bars and thousands of kelvins) and significant mechanical shocks. Small plastic projectiles (4-mm nominal size) and helium gas have been used in the prototype device, which was equipped with a 1-m-long pump tube and a 1-m-long gun barrel, to demonstrate repetitive operation (up to 1 Hz) at relatively high pellet velocities (up to 3000 m/s). The equipment is described, and experimental results are presented. 124 refs., 6 figs., 5 tabs.

  4. 14. GENERAL VIEW OF D BAY; LOOKING S. GUN TUBE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. GENERAL VIEW OF D BAY; LOOKING S. GUN TUBE STOCK CAN BE SEEN IN THE FOREGROUND & ELECTRIC FURNACE EQUIPMENT BEYOND. TWO SHEPARD NILES 10 TON CRANES CAN BE SEEN ON THE CRANEWAY. (Ryan) - Watervliet Arsenal, Building No. 135, Gillespie Road, South of Parker Road, Watervliet, Albany County, NY

  5. Drugs and Guns among Inner-City High School Students.

    ERIC Educational Resources Information Center

    Sheley, Joseph F.

    1994-01-01

    Reports the results of an analysis of survey data collected from male inner-city high school students pertaining to firearms possession, use of heroin, cocaine, and crack, drug selling, and commission of crimes with weapons. No evidence of a progressive, linear relationship between level of drug use and gun possession was found. (JPS)

  6. 63. SIXTEEN INCH GUN MACHINING LATHE; LOOKING ESE. THE CUTTING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    63. SIXTEEN INCH GUN MACHINING LATHE; LOOKING ESE. THE CUTTING HEAD AND THE W WALL OF THE MAIN AISLE CAN BE SEEN IN THE RIGHT FOREGROUND. THE LATHE CHUCK AND THE ARCHED E WALL OF THE MAIN AISLE SHOP FLOOR ARE IN THE BACKGROUND. (Ryan) - Watervliet Arsenal, Building No. 110, Hagner Road between Schull & Whittemore Roads, Watervliet, Albany County, NY

  7. Note: Thermal analysis of the long line source electron gun

    NASA Astrophysics Data System (ADS)

    Iqbal, M.; Wasy, A.; Lodhi, M. A. K.

    2013-05-01

    We performed thermal analysis for our previously reported [M. Iqbal, K. Masood, M. Rafiq, M. A. Chaudhry, and F. Aleem, Rev. Sci. Instrum. 74, 4616 (2003), 10.1063/1.1614852], long linear filament electron gun assembly using ANSYS software. The source was set under a thermal load of 3000 °C, to evaluate temperature distribution, thermal strain, and heat flux at various components of the gun. We calculated the maximum heat flux (9.0 W/mm2) that produced a thermal strain of 0.05 at the focusing electrodes. However, the minimum value of the heat flux (0.3 W/mm2) was at the anode electrodes which correspond to a negligible thermal strain. The gun was validated experimentally showing a uniform cross section of the beam at the molybdenum work plate comparable to the size of the filament. Our experimental and theoretical results are in agreement. The gun had been in continuous operation for several hours at high temperatures without any thermal run-out.

  8. Analytical methods of electrode design for a relativistic electron gun

    SciTech Connect

    Caporaso, G.J.; Cole, A.G.; Boyd, J.K.

    1985-05-09

    The standard paraxial ray equation method for the design of electrodes for an electrostatically focused gun is extended to include relativistic effects and the effects of the beam's azimuthal magnetic field. Solutions for parallel and converging beams are obtained and the predicted currents are compared against those measured on the High Brightness Test Stand. 4 refs., 2 figs.

  9. America, guns and freedom: Part II - An international perspective.

    PubMed

    Faria, Miguel A

    2012-01-01

    The need for reducing gun violence is discussed along with the necessity for citizens to assume some responsibility for protecting themselves, their families, and their property from criminal elements because the police cannot physically be everywhere to protect us all of the time. The problem of sensationalization of gun crimes by the media, multiple shootings by deranged individuals, accidents with firearms, suicide rates, and children with guns are discussed.The relationship of civilian disarmament in the context of tyrannical governments and genocide are also explored. Incidents in which liberty has been extinguished because firearms have been banned and citizens have been disarmed by increasingly oppressive governments, and the converse, countries where freedom has been preserved by armed citizens are also described. We conclude that guns in the hands of law-abiding citizens deter crimes, and nations that trust their citizens with firearms have governments that sustain liberty and affirm individual freedom. Governments that do not trust their citizens with firearms tend to be despotic and tyrannical, and are a potential danger to good citizens - and a peril to humanity. PMID:23227440

  10. Gas loading system for LANL two-stage gas guns

    NASA Astrophysics Data System (ADS)

    Gibson, Lee; Bartram, Brian; Dattelbaum, Dana; Lang, John; Morris, John

    2015-06-01

    A novel gas loading system was designed for the specific application of remotely loading high purity gases into targets for gas-gun driven plate impact experiments. The high purity gases are loaded into well-defined target configurations to obtain Hugoniot states in the gas phase at greater than ambient pressures. The small volume of the gas samples is challenging, as slight changing in the ambient temperature result in measurable pressure changes. Therefore, the ability to load a gas gun target and continually monitor the sample pressure prior to firing provides the most stable and reliable target fielding approach. We present the design and evaluation of a gas loading system built for the LANL 50 mm bore two-stage light gas gun. Targets for the gun are made of 6061 Al or OFHC Cu, and assembled to form a gas containment cell with a volume of approximately 1.38 cc. The compatibility of materials was a major consideration in the design of the system, particularly for its use with corrosive gases. Piping and valves are stainless steel with wetted seals made from Kalrez and Teflon. Preliminary testing was completed to ensure proper flow rate and that the proper safety controls were in place. The system has been used to successfully load Ar, Kr, Xe, and anhydrous ammonia with purities of up to 99.999 percent. The design of the system, and example data from the plate impact experiments will be shown. LA-UR-15-20521

  11. Proposed Federal Gun-Control Amendment. Student Forum.

    ERIC Educational Resources Information Center

    Mertz, Gayle; Mertz, David

    1995-01-01

    Presents an outline for a student-run forum on a proposed federal gun control amendment. Procedures include mandatory reading assignments and researching the issue. Students role-play fictional representative characters and later facilitate discussions. Concludes with a vote on the amendment. (MJP)

  12. Optimizing SRF Gun Cavity Profiles in a Genetic Algorithm Framework

    SciTech Connect

    Alicia Hofler, Pavel Evtushenko, Frank Marhauser

    2009-09-01

    Automation of DC photoinjector designs using a genetic algorithm (GA) based optimization is an accepted practice in accelerator physics. Allowing the gun cavity field profile shape to be varied can extend the utility of this optimization methodology to superconducting and normal conducting radio frequency (SRF/RF) gun based injectors. Finding optimal field and cavity geometry configurations can provide guidance for cavity design choices and verify existing designs. We have considered two approaches for varying the electric field profile. The first is to determine the optimal field profile shape that should be used independent of the cavity geometry, and the other is to vary the geometry of the gun cavity structure to produce an optimal field profile. The first method can provide a theoretical optimal and can illuminate where possible gains can be made in field shaping. The second method can produce more realistically achievable designs that can be compared to existing designs. In this paper, we discuss the design and implementation for these two methods for generating field profiles for SRF/RF guns in a GA based injector optimization scheme and provide preliminary results.

  13. Promising Strategies To Reduce Gun Violence. OJJDP Report.

    ERIC Educational Resources Information Center

    Office of Juvenile Justice and Delinquent Prevention (Dept. of Justice), Washington, DC.

    In recent years, communities across the country have struggled to develop effective solutions to the problem of gun violence. Many have approached the United States Department of Justice for help in identifying solutions. This publication was developed in response to these requests. It is designed to provide state and local elected officials,…

  14. America, guns and freedom: Part II — An international perspective

    PubMed Central

    Faria, Miguel A.

    2012-01-01

    The need for reducing gun violence is discussed along with the necessity for citizens to assume some responsibility for protecting themselves, their families, and their property from criminal elements because the police cannot physically be everywhere to protect us all of the time. The problem of sensationalization of gun crimes by the media, multiple shootings by deranged individuals, accidents with firearms, suicide rates, and children with guns are discussed. The relationship of civilian disarmament in the context of tyrannical governments and genocide are also explored. Incidents in which liberty has been extinguished because firearms have been banned and citizens have been disarmed by increasingly oppressive governments, and the converse, countries where freedom has been preserved by armed citizens are also described. We conclude that guns in the hands of law-abiding citizens deter crimes, and nations that trust their citizens with firearms have governments that sustain liberty and affirm individual freedom. Governments that do not trust their citizens with firearms tend to be despotic and tyrannical, and are a potential danger to good citizens — and a peril to humanity. PMID:23227440

  15. Implications of Gun Launch to Space for Nanosatellite Architectures

    NASA Technical Reports Server (NTRS)

    Palmer, Miles R.

    1995-01-01

    Engineering and economic scaling factors for gun launch to space (GLTS) systems are compared to conventional rocket launch systems. It is argued that GLTS might reduce the cost of small satellite development and launch in the mid to far term, thereby inducing a shift away from large centralized geosynchronous communications satellites to small proliferated low earth orbit systems.

  16. Long-Life/Low-Power Ion-Gun Cathode

    NASA Technical Reports Server (NTRS)

    Fitzgerald, D. J.

    1982-01-01

    New cathode has form of hollow tube through which gas enters region of high electron density, produced by electric discharge with auxiliary electrode referred to as "keeper." Ion-gun cathode emits electrons that bombard gas in chamber. Ions accelerated out of source are used to dope semiconductor material.

  17. Adolescents' Views of Guns in a High-Violence Community

    ERIC Educational Resources Information Center

    Black, Sally; Hausman, Alice

    2008-01-01

    Firearms account for the majority of deaths among young Black men in America. This article presents a qualitative investigation of youth temptations, emotional reactions, and subsequent behavior with respect to guns. Twenty-three youth enrolled in a community-based firearm reduction program have participated in interviews on retrospective…

  18. Guns on Campus: A Current Debate. E-Fact Sheet

    ERIC Educational Resources Information Center

    Higher Education Center for Alcohol, Drug Abuse, and Violence Prevention, 2010

    2010-01-01

    Almost all U.S. college campuses ban concealed weapons. But in the aftermath of the tragic shooting deaths at Virginia Tech in 2007, the debate on whether guns should be permitted at colleges and universities has intensified. Dozens of states have considered proposals to lift bans on concealed weapons at colleges and universities, but so far none…

  19. More Fun and Curiosity with Magnetic Guns in the Classroom

    ERIC Educational Resources Information Center

    Chittasirinuwat, O.; Kruatong, T.; Paosawatyanyong, B.

    2011-01-01

    The magnetic gun was chosen as a hands-on activity for our high school students. When conducting this activity in the classroom, we found some interesting points were raised following difficulties encountered by the students. Some students proposed that during the collision, the magnet changed its pole then it pushed the last ball out of the…

  20. First beam commissioning at BNL ERL SRF Gun

    SciTech Connect

    Xu, W.; Altinbas, Z.; Belomestnykh, S.; Ben-Zvi, I.; Deonarine, S.; DeSanto, L.; Gassner, D.; Gupta, R. C.; Hahn, H.; Hammons, L.; Ho, C.; Jamilkoski, J.; Kankiya, P.; Kayran, D.; Kellerman, R.; Laloudakis, N.; Lambiase, R.; Liaw, C.; Litvinenko, V.; Mahler, G.; Masi, L.; McIntyre, G.; Miller, T.; Philips, D.; Ptitsyn, V.; Seda, T.; Sheehy, B.; Smith, K.; Rao, T.; Steszyn, A.; Tallerico, T.; Than, R.; Tuozollo, J.; Wang, E.; Weiss, D.; Wiliniski, M.; Zaltsman, A.

    2015-05-03

    The 704 MHz SRF gun successfully generated the first photoemission beam in November of 2014. The configurations of the test and the sub-systems are described.The latest results of SRF commissioning, including the cavity performance, cathode QE measurements, beam current/energy measurements, are presented in the paper.

  1. Spot-Welding Gun With Pivoting Twin-Collet Assembly

    NASA Technical Reports Server (NTRS)

    Nguyen, Francis; Simpson, Gareth; Hoult, William S.

    1996-01-01

    Modified spot-welding gun includes pivoting twin-collet assembly that holds two spot-welding electrodes. Designed to weld highly conductive (30 percent gold) brazing-alloy foils to thin nickel alloy workpieces; also suitable for other spot-welding applications compatible with two-electrode configuration.

  2. Community College Faculty: Attitudes toward Guns on Campus

    ERIC Educational Resources Information Center

    Dahl, Patricia P.; Bonham, Gene, Jr.; Reddington, Frances P.

    2016-01-01

    This exploratory research surveyed faculty who instruct in community colleges from 18 states about their attitudes toward the concealed carry gun policies that allow appropriately licensed citizens to carry a handgun in public places such as college campuses. Building upon previous research involving 4-year institutions, we surveyed 1,889…

  3. TESLA FEL Gun simulations with PARMELA and MAFIA

    NASA Astrophysics Data System (ADS)

    Zhang, Min; Schuett, Petra

    1997-02-01

    The most recent simulation results of the DESY TESLA FEL gun are presented. Two codes are used: PARMELA and MAFIA. Since the two use different schemes in particle simulations, we will address their differences and try to give an explanation for them.

  4. Serious air gun injuries in children: update of injury statistics and presentation of five cases.

    PubMed

    Myre, L E; Black, R E

    1987-09-01

    There were over 70,000 injuries to children caused by air guns reported from 1981 to 1984. The majority of these injuries were minor; however, serious injury resulted in eight deaths. Reported injuries include corneal perforation, liver laceration, stomach and intestinal perforation, intracranial bleeding, cardiac perforation, and hemopneumothorax. Primary care physicians must be aware of the potentially serious or lethal nature of air gun injury and educate their patients accordingly. Legislation is also needed to restrict the sale of these guns, or increase the safety of air gun use. We report five cases of potentially life-threatening injury caused by air guns, three of which required emergency laparotomy. PMID:3313302

  5. Design of a high repetition rate S-band photocathode gun

    NASA Astrophysics Data System (ADS)

    Han, Jang-Hui; Cox, Matthew; Huang, Houcheng; Pande, Shivaji

    2011-08-01

    Photocathode RF guns have been developed in many laboratories for generating high quality electron beams for free-electron lasers based on linear accelerators. Such guns can generate electron beams with an exceptionally high peak current as well as a small transverse emittance. Their applications have been recently expanded for ultrafast electron diffraction, coherent terahertz radiation, and X-ray or γ-ray radiation by Compton scattering. In this paper, we design an S-band normal-conducting gun with capabilities of high quality beam generation and high repetition rate operation. The RF design and thermal analysis of the gun cavity and coupler are introduced. Optimal position of the gun focusing solenoid for low emittance beam generation is found by performing particle tracking simulations. Then, the gun system is designed to be able to afford the optimal solenoid position. The cooling-water channel surrounding the gun cavity and coupler is designed and analyzed numerically. The pressure in the gun is simulated with a vacuum model containing the detailed inner structure of the gun. An injector for a free-electron laser application is designed by using this gun and the beam dynamics simulation is shown. A cold test with a prototype gun for confirmation of the RF design is reported.

  6. American preferences for "smart" guns versus traditional weapons: Results from a nationwide survey.

    PubMed

    Wallace, Lacey Nicole

    2016-12-01

    This study examines Americans' preferences regarding smart guns. The study builds on prior research by including previously unexamined factors, specifically victimization and comfort sharing gun ownership status with a doctor. Further, this study examines differences in preference patterns among gun owners and non-owners. Data were obtained from a nationwide online survey with 524 respondents in February 2016. The study finds that, among non-owners, older respondents and those with pro-gun attitudes are less likely to prefer smart guns to traditional firearms. Among gun owners, those with moderate political views, those with a history of victimization, and those residing in the Northeast are all more likely to prefer smart guns. Males and those with pro-gun attitudes are less likely to prefer smart guns. Education, income, race, marital status, presence of children in the home, and comfort discussing gun ownership with a doctor had no significant association with smart gun preference. Practical implications of these findings are discussed. PMID:27413655

  7. Development of spray guns for the application of rigid foam insulation

    NASA Technical Reports Server (NTRS)

    Allen, Peter B.

    1993-01-01

    The paper describes the activities initiated to improve the existing spray gun system used for spraying insulating foam on the External Tank of the Space Shuttle, due to the quality variations of the applied foam noted in the past. Consideration is given to the two tasks of the project: (1) investigations of possible improvements, as an interim measure, to the spray gun currently used to apply the large acreage spray-on-foam insulation and the evaluation of other commercial equipment; and (2) the design and fabrication of a new automatic spray gun. The design and operation of the currently used Binks 43 PA spray gun are described together with several new breadboard spray guns designed and fabricated and the testing procedures developed. These new guns include the Modular Automatic Foam spray gun, the Ball Valve spray gun, and the Tapered Plug Valve (TPV) gun. As a result of tests, the TPV spray gun is recommended to replace the currently used automatic spray gun.

  8. Gun violence among youth and the pediatrician's role in primary prevention.

    PubMed

    Webster, D W; Wilson, M E

    1994-10-01

    Adolescence is a developmental stage characterized by high rates of violent behavior. Increasingly, violent injury is involving preadolescent children. Evidence suggests that the availability of guns increases the lethality of violent acts. Because guns are ubiquitous in the United States and integral to the current epidemic of youth violence, pediatricians should participate in primary prevention of firearm injuries. Efforts should begin long before children reach adolescence. Pediatricians should: (1) Encourage parents to remove guns from the home, or at a minimum to keep guns unloaded and locked up; (2) Advise parents to limit viewing of gun violence in the media, and playing with toy guns and video games that involve shooting; (3) Be alert for early indicators of aggressive behavior; and (4) Become outspoken advocates for laws that restrict gun availability. PMID:7936887

  9. Evaluation of biological and male reproductive-function responses to potential lead exposures in 155-mm-howitzer crewmen. Technical report, Jul 90-Dec 91

    SciTech Connect

    Weyandt, T.B.

    1992-01-01

    A collaborative pilot study between the U.S. Army Biomedical Research and Development Laboratory and the National Institute for Occupational Safety and Health was designed to assess the fecundity of male artillery soldiers with potential exposures to airborne lead aerosols. Many soldiers in the initial control population reported possible job-related microwave exposure as radar equipment operators. As a result, a third group of soldiers without potential for lead or microwave exposure, but with similar duty-associated environmental exposure conditions, was selected as a comparison population. Blood hormone levels and semen analyses were conducted on artillerymen (n=30), radar equipment operators (n=20), and the comparison group (n=31). Analysis of the questionnaire information revealed that concern about fertility problems motivated participation of some soldiers with potential artillery or microwave exposures. Data analysis was complicated by the small study population size and the confounding variable of perceived infertility. Although the small number of subjects and infertility concerns somewhat compromise the statistical power and general applicability of the study, several statistically significant findings were identified.

  10. Factors influencing the sustained-performance capabilities of 155-mm howitzer sections in simulated conventional and chemical warfare environments. Technical report

    SciTech Connect

    Rauch, T.M.; Banderet, L.E.; Tharion, W.J.; Munro, I.; Lussier, A.R.

    1986-04-01

    Factors that limit the performance capabilities of sustained artillery operations in simulated conventional and chemical warfare environments were studied. The results show that perceptions of psychological (mental) fatigue, rather than perceptions of muscular fatigue, were primary factors affecting sustained artillery performance. Furthermore, variations in these psychological states were correlated with artillery task performance during the period. In the simulated chemical warfare environment, extreme symptom and mood changes resulted in medical casualties, combat ineffectiveness, and early termination of all testing. Significant perosnality differences existed between casualties and survivors. The majority of casualties voluntarily terminated operational duties because of intense symptoms associated with wearing the chemical protective mask and clothing system. These symptoms were manifestations of respiratory and thermal stress.

  11. Improving Firearm Storage in Alaska Native Villages: A Randomized Trial of Household Gun Cabinets

    PubMed Central

    Stafford, Helen A.; Koepsell, Thomas D.; Hill, Ryan; Retzer, Kyla D.; Jones, Ward

    2012-01-01

    Objectives. We determined if the installation of gun cabinets improved household firearm storage practices. Methods. We used a wait list, randomized trial design with 2 groups. The “early” group received the intervention at baseline, and the “late” group received it at 12 months. Up to 2 gun cabinets were installed in each enrolled home, along with safety messages. In-person surveys were conducted at 12 and 18 months to determine the proportion of households reporting unlocked guns or ammunition. Direct observations of unlocked guns were also compared. Results. At baseline, 93% of homes reported having at least 1 unlocked gun in the home, and 89% reported unlocked ammunition. At 12 months, 35% of homes in the early group reported unlocked guns compared with 89% in the late group (P < .001). Thirty-six percent of the early homes reported unlocked ammunition compared with 84% of late homes (P < .001). The prevalence of these storage practices was maintained at 18 months. Observations of unlocked guns decreased significantly (from 20% to 8%) between groups (P < .03). Conclusions. Gun cabinet installation in rural Alaskan households improved the storage of guns and ammunition. If these gains are sustained over time, it may lead to a reduction in gun-related injuries and deaths in this population. PMID:22401514

  12. Patterns and correlates of gun ownership among nonmetropolitan and rural middle school students.

    PubMed

    Cunningham, P B; Henggeler, S W; Limber, S P; Melton, G B; Nation, M A

    2000-09-01

    Examined prevalence of gun ownership and the links among gun ownership, reasons for gun ownership, and antisocial behavior in a sample of nonmetropolitan and rural middle school students. Participants completed the Questionnaire for Students (Olweus, 1995) and included 6,263 students from 36 elementary and middle schools, of whom most were African American (range = 46%-95% per school). Reasons for gun ownership were strongly associated with rates of antisocial behavior. Youths who owned guns for sporting reasons reported rates of antisocial behavior that were only slightly higher than those reported by youths who did not own guns. Youths who owned guns to gain respect or to frighten others reported extremely high rates of antisocial behavior. These high-risk adolescent gun owners were likely to come from families of high-risk gun owners, associate with friends who were high-risk gun owners, and engage in high rates of bullying behavior. Findings suggest that effective violence prevention programs must target high-risk youths, address risk factors that go beyond individual settings, and address a comprehensive array of risk factors. PMID:10969427

  13. Joe Camel with Feathers. How the NRA with Gun and Tobacco Industry Dollars Uses Its Eddie Eagle Program To Market Guns to Kids.

    ERIC Educational Resources Information Center

    Glick, Susan; Sugarmann, Josh

    The National Rifle Association (NRA) has developed its Eddie Eagle program as a school-based curriculum that claims to teach gun safety to children in preschool through grade six. The program uses a four-part message for children to follow when they see a gun, admonishing them to stop, not touch it, leave the area, and tell an adult. The NRA has…

  14. Firearm advertising: product depiction in consumer gun magazines.

    PubMed

    Saylor, Elizabeth A; Vittes, Katherine A; Sorenson, Susan B

    2004-10-01

    In contrast to tobacco, alcohol, and other consumer products associated with health risks, we know very little about how firearm manufacturers advertise their products. The authors examined advertisements for firearms in all 27 ad-accepting magazines listed in Bacon's Magazine Directory "guns and shooting" category. Sixty-three manufacturers spent an estimated $1,195,680 on firearm advertising during the month studied. Annual advertising costs ranged widely; manufacturers spent an estimated $28.16 in advertising per firearm produced. Firearms generally were presented as a part of a lifestyle. Self-protection was noted infrequently in the advertisements. By contrast, attributes of the gun, typically technological characteristics, were noted in almost every advertisement. PMID:15358905

  15. Relativistic Velocity Addition Law from Machine Gun Analogy

    NASA Astrophysics Data System (ADS)

    Rothenstein, Bernhard; Popescu, Stefan

    2009-01-01

    Many derivations of the relativistic addition law of parallel velocities without use of the Lorentz transformations (LT) are known.1-5 Some of them are based on thought experiments that require knowledge of the time dilation and the length contraction effects.1,4,5 Other derivations involve the Doppler effect in the optic domain considered from three inertial reference frames in relative motion.6 A few derivations simply involve only the principle of constancy of the light velocity.2 Such derivations are interesting for the teaching of special relativity theory since the relativistic addition of velocities leads directly to the LT.7 The derivation we propose is based on a machine gun-target analogy8 of the acoustic Doppler effect, considered from the rest frame of the machine gun and from the rest frame of the target.

  16. DESIGN OF A DC/RF PHOTOELECTRON GUN.

    SciTech Connect

    YU,D.NEWSHAM,Y.SMIRONOV,A.YU,J.SMEDLEY,J.SRINIVASAN RAU,T.LEWELLEN,J.ZHOLENTS,A.

    2003-05-12

    An integrated dc/rf photoelectron gun produces a low-emittance beam by first rapidly accelerating electrons at a high gradient during a short ({approx}1 ns), high-voltage pulse, and then injecting the electrons into an rf cavity for subsequent acceleration. Simulations show that significant improvement of the emittance appears when a high field ({approx} 0.5-1 GV/m) is applied to the cathode surface. An adjustable dc gap ({le} 1 mm) which can be integrated with an rf cavity is designed for initial testing at the Injector Test Stand at Argonne National Laboratory using an existing 70-kV pulse generator. Plans for additional experiments of an integrated dc/rf gun with a 250-kV pulse generator are being made.

  17. Note: O-ring stack system for electron gun alignment.

    PubMed

    Park, In-Yong; Cho, Boklae; Han, Cheolsu; Shin, Seungmin; Lee, Dongjun; Ahn, Sang Jung

    2015-01-01

    We present a reliable method for aligning an electron gun which consists of an electron source and lenses by controlling a stack of rubber O-rings in a vacuum condition. The beam direction angle is precisely tilted along two axes by adjusting the height difference of a stack of O-rings. In addition, the source position is shifted in each of three orthogonal directions. We show that the tilting angle and linear shift along the x and y axes as obtained from ten stacked O-rings are ±2.55° and ±2 mm, respectively. This study can easily be adapted to charged particle gun alignment and adjustments of the flange position in a vacuum, ensuring that its results can be useful with regard to electrical insulation between flanges with slight modifications. PMID:25638137

  18. Guns and blood alcohol levels among homicide victims.

    PubMed

    Abel, E L

    1986-11-01

    A retrospective study of homicide victims in Erie County, NY was conducted for 1973-1984 to determine the association of blood alcohol levels among homicide victims slain by guns and other weapons. Most victims of gunshot or beating had negative blood alcohol levels (BALs) at time of death whereas most stabbing victims had positive BALs, especially black victims. Gunshot victims were more likely to be killed in a private home compared to a street or building. Location of homicide did not relate significantly to BAL. Younger victims were less likely to be shot to death compared to middle-aged victims. These results do not support previous contentions that alcohol is a major contributor to gun-related homicides. PMID:3803196

  19. Limitations on area compression of beams from pierce guns

    SciTech Connect

    Yakovlev, V.P.; Nezhevenko, O.A.

    1999-05-01

    An important limitation for rf sources such as klystrons and magnicons, designed for 10{close_quote}s of MW power outputs at cm-wavelengths, is the transverse electron beam size. Cathode current density limits require high beam area compressions to obtain small transverse beam areas for fixed currents. This paper discusses the limitations to high beam area compression, namely geometrical aberrations and thermal spread in transverse velocities. Compensation can oftentimes be introduced for aberrations, but thermal velocity spread presents a fundamental limitation. Examples where subtle compensation strategies were employed are discussed for three guns with 100 MW beam power, and area compressions greater than 2000:1. Two of these guns have already been built. A clear determination of effective cathode temperature has yet to be found experimentally, but possible means to measure it are discussed. {copyright} {ital 1999 American Institute of Physics.}

  20. Air gun--a deadly toy?: A case report.

    PubMed

    Kuligod, F S; Jirli, Prasanna S; Kumar, Pradeep

    2006-04-01

    Air guns (air rifles) are used throughout the world as instruments of amusement such as toys in funfairs, for bird hunting and firearms training. In India and in many other countries, this instrument neither comes under the purview of the Arms Act, nor is there is any restriction on the user's age. This enables a person to gain access to this instrument quite easily. Sometimes serious and fatal injuries result when it is used by an ignorant person or by a criminal. There are reports which suggest that these 'toys' can cause painful injuries but only a few cases of death have been reported. There is no literature about the features of injuries that help to establish the range of fire by an air gun. Here we report a case where a boy was accidentally shot to death while watching bird shooting. We attempt to correlate the injury with the range of fire. PMID:16683474

  1. Note: O-ring stack system for electron gun alignment

    NASA Astrophysics Data System (ADS)

    Park, In-Yong; Cho, Boklae; Han, Cheolsu; Shin, Seungmin; Lee, Dongjun; Ahn, Sang Jung

    2015-01-01

    We present a reliable method for aligning an electron gun which consists of an electron source and lenses by controlling a stack of rubber O-rings in a vacuum condition. The beam direction angle is precisely tilted along two axes by adjusting the height difference of a stack of O-rings. In addition, the source position is shifted in each of three orthogonal directions. We show that the tilting angle and linear shift along the x and y axes as obtained from ten stacked O-rings are ±2.55° and ±2 mm, respectively. This study can easily be adapted to charged particle gun alignment and adjustments of the flange position in a vacuum, ensuring that its results can be useful with regard to electrical insulation between flanges with slight modifications.

  2. Toroid Joining Gun. [thermoplastic welding system using induction heating

    NASA Technical Reports Server (NTRS)

    Buckley, J. D.; Fox, R. L.; Swaim, R J.

    1985-01-01

    The Toroid Joining Gun is a low cost, self-contained, portable low powered (100-400 watts) thermoplastic welding system developed at Langley Research Center for joining plastic and composite parts using an induction heating technique. The device developed for use in the fabrication of large space sructures (LSST Program) can be used in any atmosphere or in a vacuum. Components can be joined in situ, whether on earth or on a space platform. The expanded application of this welding gun is in the joining of thermoplastic composites, thermosetting composites, metals, and combinations of these materials. Its low-power requirements, light weight, rapid response, low cost, portability, and effective joining make it a candidate for solving many varied and unique bonding tasks.

  3. An electrostatically and a magnetically confined electron gun lens system

    NASA Technical Reports Server (NTRS)

    Bernius, Mark T.; Man, Kin F.; Chutjian, Ara

    1988-01-01

    Focal properties, electron trajectory calculations, and geometries are given for two electron 'gun' lens systems that have a variety of applications in, for example, electron-neutral and electron-ion scattering experiments. One nine-lens system utilizes only electrostatic confinement and is capable of focusing electrons onto a fixed target with extremely small divergence angles, over a range of final energies 1-790 eV. The second gun lens system is a simpler three-lens system suitable for use in a uniform, solenoidal magnetic field. While the focusing properties of such a magnetically confined lens systenm are simpler to deal with, the system does illustrate features of electron extraction and Brillouin flow that have not been suitably emphasized in the literature.

  4. Note: Simulation and test of a strip source electron gun

    SciTech Connect

    Iqbal, Munawar; Islam, G. U.; Misbah, I.; Iqbal, O.; Zhou, Z.

    2014-06-15

    We present simulation and test of an indirectly heated strip source electron beam gun assembly using Stanford Linear Accelerator Center (SLAC) electron beam trajectory program. The beam is now sharply focused with 3.04 mm diameter in the post anode region at 15.9 mm. The measured emission current and emission density were 1.12 A and 1.15 A/cm{sup 2}, respectively, that corresponds to power density of 11.5 kW/cm{sup 2}, at 10 kV acceleration potential. The simulated results were compared with then and now experiments and found in agreement. The gun is without any biasing, electrostatic and magnetic fields; hence simple and inexpensive. Moreover, it is now more powerful and is useful for accelerators technology due to high emission and low emittance parameters.

  5. Magnetized Target Fusion Propulsion: Plasma Injectors for MTF Guns

    NASA Technical Reports Server (NTRS)

    Griffin, Steven T.

    2003-01-01

    To achieve increased payload size and decreased trip time for interplanetary travel, a low mass, high specific impulse, high thrust propulsion system is required. This suggests the need for research into fusion as a source of power and high temperature plasma. The plasma would be deflected by magnetic fields to provide thrust. Magnetized Target Fusion (MTF) research consists of several related investigations into these topics. These include the orientation and timing of the plasma guns and the convergence and interface development of the "pusher" plasma. Computer simulations of the gun as it relates to plasma initiation and repeatability are under investigation. One of the items under development is the plasma injector. This is a surface breakdown driven plasma generator designed to function at very low pressures. The performance, operating conditions and limitations of these injectors need to be determined.

  6. Inverse photoelectron spectrometer with magnetically focused electron gun

    NASA Technical Reports Server (NTRS)

    Krainsky, Isay L.

    1991-01-01

    An inverse photoelectron spectrometer is described which is based on the design of a magnetically focused low energy electron gun. The magnetic lens extends its field over a relatively large segment of the electron trajectory, which could provide a better focusing effect on a high-current-density low-velocity electron beam, providing the magnetic field in the vicinity of the target is reduced sufficiently to preserve the collinearity of the beam. In order to prove the concept, ray tracing is conducted using the Herrmannsfeldt program for solving electron trajectories in electrostatic and magnetostatic focusing systems. The program allows the calculation of the angles of the electron trajectories with the z axis, at the target location. The results of the ray-tracing procedure conducted for this gun are discussed. Some of the advantages of the magnetic focusing are also discussed.

  7. Note: O-ring stack system for electron gun alignment

    SciTech Connect

    Park, In-Yong; Cho, Boklae; Han, Cheolsu; Shin, Seungmin; Lee, Dongjun; Ahn, Sang Jung

    2015-01-15

    We present a reliable method for aligning an electron gun which consists of an electron source and lenses by controlling a stack of rubber O-rings in a vacuum condition. The beam direction angle is precisely tilted along two axes by adjusting the height difference of a stack of O-rings. In addition, the source position is shifted in each of three orthogonal directions. We show that the tilting angle and linear shift along the x and y axes as obtained from ten stacked O-rings are ±2.55° and ±2 mm, respectively. This study can easily be adapted to charged particle gun alignment and adjustments of the flange position in a vacuum, ensuring that its results can be useful with regard to electrical insulation between flanges with slight modifications.

  8. Informed Consent at Gunpoint: When Psychiatry Affects Gun Ownership.

    PubMed

    Candilis, Philip J; Khurana, Gagandeep; Leong, Gregory B; Weinstock, Robert

    2015-06-01

    As states take more steps to connect patients' gun ownership to their mental health, psychiatrists are being asked to provide mental health information after clinical interviews as well as after confiscation. This move into the patient-physician relationship raises new questions about how psychiatrists should obtain informed consent when interviews may result in reports to legal authorities. Consent warnings are already practiced more in the breach than in the observance and informed consent is imperfect at its best. In communities torn by controversies surrounding gun control, vehement political views will further influence these established themes to result in unprecedented pressures on patient confidentiality. This analysis draws on new movements in ethical theory and behavioral medicine that go beyond balancing principles to question the use of psychiatry in firearm reporting, and support a vigorous practice of informed consent to protect both individuals and the communities they live in. PMID:25640524

  9. Asian carp behavior in response to static water gun firing

    USGS Publications Warehouse

    Layhee, Megan J.; Gross, Jackson A.; Parsley, Michael J.; Romine, Jason G.; Glover, David C.; Suski, Cory D.; Wagner, Tristany L.; Sepulveda, Adam J.; Gresswell, Robert E.

    2013-01-01

    The potential for invasion of Asian carp into the Great Lakes has ecological and socio-economic implications. If they become established, Asian carp are predicted to alter lake ecosystems and impact commercial and recreational fisheries. The Chicago Sanitary and Shipping Canal is an important biological conduit between the Mississippi River Basin, where invasive Asian carp are abundant, and the Great Lakes. Millions of dollars have been spent to erect an electric barrier defense in the canal to prevent movement of Asian carp into the Great Lakes, but the need for additional fish deterrent technologies to supplement the existing barrier is warranted. Scientists with the U.S. Geological Survey Northern Rocky Mountain Science Center are examining seismic water gun technology, formerly used in oceanic oil exploration, as a fish deterrent. The goal of the current study is to employ telemetry and sonar monitoring equipment to assess the behavioral response of Asian carp to seismic water guns and the sound energy it generates.

  10. Preliminary Langmuir probe results on the CTX gun experiment

    SciTech Connect

    Tuszewski, M.

    1981-12-01

    Preliminary results obtained with a double Langmuir probe in the Compact Toroid experiment facility confirm the existence of a gun plasma of n approx. 5 x 10/sup 14/ cm/sup -3/ and T approx. 10 eV lasting for approx. 250 to 400 ..mu..s, which is consistent with interferometry and Thomson scattering data. The probe current characteristics as a function of voltage suggest non-Maxwellian features of the particles distribution functions.

  11. High gradient rf gun studies of CsBr photocathodes

    SciTech Connect

    Vecchione, Theodore; Maldonado, Juan R.; Gierman, Stephen; Corbett, Jeff; Hartmann, Nick; Pianetta, Piero A.; Hesselink, Lambertus; Schmerge, John F.

    2015-04-03

    CsBr photocathodes have 10 times higher quantum efficiency with only 3 times larger intrinsic transverse emittance than copper. They are robust and can withstand 80 MV/m fields without breaking down or emitting dark current. They can operate in 2×10⁻⁹ torr vacuum and survive exposure to air. They are well suited for generating high pulse charge in rf guns without a photocathode transfer system.

  12. Status of Nb-Pb Superconducting RF-Gun Cavities

    SciTech Connect

    Sekutowicz, J.; Iversen, J.; Klinke, D.; Kostin, D.; Moller, W.; Muhs, A.; Kneisel, P.; Smedley, J.; Rao, T.; Strzyzewski, P.; Li, Z.; Ko, K.; Xiao, L.; Lefferts, R.; Lipski, A.; Ferrario, M.; /Frascati

    2007-11-09

    We report on the progress and status of an electron RFgun made of two superconductors: niobium and lead [1]. The presented design combines the advantages of the RF performance of bulk niobium superconducting cavities and the reasonably high quantum efficiency of lead. The design of RF-gun and performance of 3 test cavities without and with the emitting lead spot are reported in this contribution. Measured quantum efficiency for lead at 2K is presented briefly. More details are reported in [9].

  13. Status of Nb-Pb superconducting RF-gun cavities

    SciTech Connect

    J. Sekutowicz; J. Iversen; D. Klinke; D. Kostin; W. Möller; A. Muhs; P. Kneisel; J. Smedley; T. Rao; P. Strzyżewski; Z. Li; K. Ko; L. Xiao; R. Lefferts; A. Lipski; M. Ferrario

    2007-06-01

    We report on the progress in the status of an electron RF-gun made of two superconductors: niobium and lead. The presented design combines the advantages of the RF performance of bulk niobium superconducting cavities and the reasonably high quantum efficiency of lead. Measured values of quantum efficiency for lead at 2K and the RF-performance of three half-cell niobium cavities with the lead spot exposed to high electric fields are reported in this contribution.

  14. The status of gallium arsenide photoemission guns at Jefferson Lab

    SciTech Connect

    M. Poelker; P. Adderley; M. Baylac; J. Brittian; D. Charles; J. Clark; J. Grames; J. Hansknecht; R. Kazimi; M. Stutzman; K. Surles-Law

    2004-10-07

    Highlights of the polarized beam program at CEBAF at Jefferson Lab will be presented. These include successful completion of portions of parity violation experiments G0 Forward Angle and HAPPex II. Experience with commercial modelocked Ti-Sapphire lasers and high polarization strained superlattice GaAs photocathodes will be discussed. Finally, gun charge lifetime measurements made over the course of many years following charge extraction of nearly 3000 C will be presented.

  15. High gradient rf gun studies of CsBr photocathodes

    NASA Astrophysics Data System (ADS)

    Vecchione, Theodore; Maldonado, Juan R.; Gierman, Stephen; Corbett, Jeff; Hartmann, Nick; Pianetta, Piero A.; Hesselink, Lambertus; Schmerge, John F.

    2015-04-01

    CsBr photocathodes have 10 times higher quantum efficiency with only 3 times larger intrinsic transverse emittance than copper. They are robust and can withstand 80 MV /m fields without breaking down or emitting dark current. They can operate in 2 ×10-9 torr vacuum and survive exposure to air. They are well suited for generating high pulse charge in rf guns without a photocathode transfer system.

  16. Momentum transfer to rotating magnetized plasma from gun plasma injection

    SciTech Connect

    Shamim, Imran; Hassam, A. B.; Ellis, R. F.; Witherspoon, F. D.; Phillips, M. W.

    2006-11-15

    Numerical simulations are carried out to investigate the penetration and momentum coupling of a gun-injected plasma slug into a rotating magnetized plasma. An experiment along these lines is envisioned for the Maryland Centrifugal Experiment (MCX) [R. F. Ellis et al., Phys. Plasmas 8, 2057 (2001)] using a coaxial plasma accelerator gun developed by HyperV Technologies Corp. [F. D. Witherspoon et al., Bull. Am. Phys. Soc. 50, LP1 87 (2005)]. The plasma gun would be located in the axial midplane and fired off-axis into the rotating MCX plasma annulus. The numerical simulation is set up so that the initial momentum in the injected plasma slug is of the order of the initial momentum of the target plasma. Several numerical firings are done into the cylindrical rotating plasma. Axial symmetry is assumed. The slug is seen to penetrate readily and deform into a mushroom, characteristic of interchange deformations. It is found that up to 25% of the momentum in the slug can be transferred to the background plasma in one pass across a cylindrical chord. For the same initial momentum, a high-speed low density slug gives more momentum transfer than a low-speed high density slug. Details of the numerical simulations and a scaling study are presented.

  17. A microwave plasma cathode electron gun for ion beam neutralization

    NASA Astrophysics Data System (ADS)

    Fusellier, C.; Wartski, L.; Aubert, J.; Schwebel, C.; Coste, Ph.; Chabrier, A.

    1998-02-01

    It is well known that there exist two distinct types of ion beam neutralization, viz., charge and current neutralization. We have designed and studied a versatile and compact microwave plasma (MP) cathode electron gun dedicated to charge as well as current neutralization. Unlike the conventional hot cathode neutralizer, this MP cathode allows operation of the electron gun in a reactive gaseous environment when it is eventually associated with an electron cyclotron resonance (ECR) ion gun. Charge neutralization can be easily carried out by extracting from the MP cathode through a 1 mm diameter hole, a 35 mA electron beam under a 20 V voltage; the MP cathode being fed with a 75 W microwave power at 2.45 GHz. Higher beam intensities could be obtained using a multiaperture thin plate. Electron beam intensities as high as 300 mA and energies of 2 keV needed for current neutralization, e.g., when an ion beam impinges onto a thick dielectric surface, are obtained via a two-stage arrangement including an anodic chamber associated with a set of three monoaperture plates for the electron beam extraction. Transport of 200-2000 eV electron beams is ensured using focusing optics composed of three aligned tubes 6 cm in diameter and unsymmetrically polarized.

  18. Wavefront conjugation using electron-gun-controlled piezoelectric materials

    NASA Astrophysics Data System (ADS)

    Nelson, George C.; Main, John A.; Martin, Jeffrey W.

    2000-07-01

    Current adaptive optics designs often rely upon multiple actuators to mechanically deform mirrored surfaces. The spatial resolution of control is dependent upon the physical size of these actuators and the number of actuators present. Piezoelectric materials may be used for actuation however the classical control methods of these materials also rely on discrete areas of actuation and require lead wiring for each electrode, patch, or stack utilized. Electron gun control of piezoelectric materials eliminates the need for discrete, segmented electrodes and their associated lead wiring. This method also holds the potential for much finer control resolution since the restraining parameter is beam size. Lightweight piezoelectric ceramics may possibly be used as wavefront conjugating mirrors. Piezo-ceramic plates can be actuated with an electron gun and a single distributed electrode of optical quality. The electron gun functions as a pointing device while varying the potential, referred to as backpressure, of the single electrode controls the magnitude of actuation. By using this method, future corrective optics may significantly surpass current design performance without significantly increasing system complexity.

  19. A double-frequency rf gun for field emission

    NASA Astrophysics Data System (ADS)

    Li, Xiangkun; Li, Ming; Dan, Lijun; He, Tianhui; Liu, Yu; Xu, Zhou; Tang, Chuanxiang

    2015-05-01

    Cold cathodes have attracted a lot of attention in the field of accelerators in recent years. While the development of suitable cold cathodes is in progress, attempts have been made to combine the cold cathode with a rf structure. Due to the strong dependence on the electric field, field emissions peak at the wave crest, which is not the best injection phase, during a rf cycle. To make the injection phase adjustable, a flexible double-frequency rf gun is designed. The addition of a 3rd-harmonic field to the fundamental one in the half cell will move the wave crest toward a better injection phase and make the initial bunch length shorter. The full cell is resonant at the fundamental frequency. Since only the half cell is resonant at two frequencies, the gun can be easily tuned. Simulations show that the time-dependent rf effects on the transverse and longitudinal phase spaces of the electron bunch can be reduced by choosing proper rf parameters and the space charge effects can be compensated for by using an external solenoid field. Therefore, the gun is able to provide low emittance, low energy spread and short electron bunches with high average current.

  20. Momentum transfer to rotating magnetized plasma from gun plasma injection

    NASA Astrophysics Data System (ADS)

    Shamim, Imran; Hassam, A. B.; Ellis, R. F.; Witherspoon, F. D.; Phillips, M. W.

    2006-11-01

    Numerical simulations are carried out to investigate the penetration and momentum coupling of a gun-injected plasma slug into a rotating magnetized plasma. An experiment along these lines is envisioned for the Maryland Centrifugal Experiment (MCX) [R. F. Ellis et al., Phys. Plasmas 8, 2057 (2001)] using a coaxial plasma accelerator gun developed by HyperV Technologies Corp. [F. D. Witherspoon et al., Bull. Am. Phys. Soc. 50, LP1-87 (2005)]. The plasma gun would be located in the axial midplane and fired off-axis into the rotating MCX plasma annulus. The numerical simulation is set up so that the initial momentum in the injected plasma slug is of the order of the initial momentum of the target plasma. Several numerical firings are done into the cylindrical rotating plasma. Axial symmetry is assumed. The slug is seen to penetrate readily and deform into a mushroom, characteristic of interchange deformations. It is found that up to 25% of the momentum in the slug can be transferred to the background plasma in one pass across a cylindrical chord. For the same initial momentum, a high-speed low density slug gives more momentum transfer than a low-speed high density slug. Details of the numerical simulations and a scaling study are presented.