WorldWideScience

Sample records for artillery guns

  1. South African Artillery in the Eighties

    OpenAIRE

    A. C. Lillie

    2012-01-01

    Emerging from the Second World War armed with the then completely adequate 25 pounder and BL 5.5" guns, the South African Field Artillery continued to use the same guns operationally over thirty years later.When the armed forces of South Africa were thrown into a conventional conflict during the Angolan Civil War in 1975, the gunners found their equipment to be woefully inadequate. Soviet made artillery systems in the hands of the Russian-backed forces possessed ranges far in excess of the Se...

  2. South African Artillery in the Eighties

    Directory of Open Access Journals (Sweden)

    A. C. Lillie

    2012-02-01

    Full Text Available Emerging from the Second World War armed with the then completely adequate 25 pounder and BL 5.5" guns, the South African Field Artillery continued to use the same guns operationally over thirty years later.When the armed forces of South Africa were thrown into a conventional conflict during the Angolan Civil War in 1975, the gunners found their equipment to be woefully inadequate. Soviet made artillery systems in the hands of the Russian-backed forces possessed ranges far in excess of the Second World War vintage South African systems and brought home in a very real way the need for drastic modernisation of the artillery branch of the South African Army.

  3. 利用声学方法采集人工影响天气高射炮作业数据%Data Auto-collection Based on Sound Level Characteristics for Weather Modification Operation by Ground-based Artillery Gun Shooting

    Institute of Scientific and Technical Information of China (English)

    李宏宇; 王华; 贾丽佳; 胡向峰; 陶癑; 汪晓滨

    2015-01-01

    As an important task of weather service system,improving information technology on weather modifi-cation aircraft and ground operations and accurately collecting basic data from all kinds of operating equip-ment is an important element for operation management and decision making,as well as the basis for the scientific assessment of operating results.Currently,ground information management of weather modifica-tion operation generally follows earlier national rules of information collection and reporting.On one side, the collected information includes operating equipment,operating time,dosage and other basic informa-tion.A simple assessment is needed to evaluate the operation by combining comprehensive meteorological observations,making it difficult to ensure the timeliness of information reporting.On the other side,the operating information collected at ground enters the system typically by oral reports and hand typing, which limits the accuracy of the reported information.Thus it is difficult for the managing departments to know in-situ operating conditions,which directly limits operations of other services including security man-agement.Improved data collecting methods are needed to overcome the bottleneck that data collection dur-ing weather modification operation relies on hand typing and the associated data security issues,and to im-prove the timeliness and accuracy of data collection.Based on mature technology,it is an effective way to collect operational data automatically through rebuilding operating instruments,and using in-situ operating sound,light or vibration features to trigger automatic responses of ground data operations.The way of u-sing in-situ sound characteristics to trigger automatic responses to identify operating data from common-used artillery guns and rocket launchers also has a low cost and no security risk.In order to overcome the bottleneck,a new ground-level data acquisition and transmission device based on the acoustic technology are

  4. Analysis of the design concept of 'Nora' family artillery weapons

    Directory of Open Access Journals (Sweden)

    Anastas L. Paligorić

    2011-10-01

    Full Text Available The development of the NORA family started as far as back to 1976 at the Military Technical Institute of the Yugoslav's People's Army. The programme covered development of several types of the main artillery weapon: the 152 mm NORA-A towed gun-howitzer, the 152 mm NORA-B self-propelled gun-howitzer and the 152 mm gun-howitzer with APU. Under the same programme, the conversion of the Russian 130 mm towed gun M46 into the 155 mm M46/84 gun (for export needs and the 152 mm M46/86 gun respectively (for the needs of the YPA was completed. Only the 152 mm M84 (NORA-A towed howitzer was introduced in service, while the development of the NORA-B and NORA-C weapons was carried on until 1992. After it had been suspended for many years, the development of the NORAB weapon was continued in 2003, followed by serial production of the 155 mm NORA-B52 self-propelled system for the export needs.

  5. A model for optimizing field artillery fire

    OpenAIRE

    Marin, John A.

    1989-01-01

    A microcomputer-based optimization model for short-term allocation of field artillery fire is developed and evaluated. The Artillery Optimization Model utilizes a mixed integer linear program that takes available targets, weights the targets by performing Target Value Analysis, and assigns firing units specific amounts and types of ammunition to fire at designated targets. In determining the optimal near-term allocation of artillery resources the model considers the target's intrinsic value, ...

  6. Analysis and control of error on two theodolite intersection measurement for gun rotated accuracy of artillery%双经纬仪交会测量火炮调炮精度的误差分析与抑制

    Institute of Scientific and Technical Information of China (English)

    孙泽林; 王昭; 翟唤春

    2011-01-01

    为了改进调炮精度测量方法,对双经纬仪交会测量火炮调炮精度的测量误差和误差抑制方法进行了研究.首先,根据双经纬仪交会测量原理,建立了测量调炮精度的空间解算模型.接着,以DT202C电子经纬仪为例,对影响其测量精度的各项因素进行了系统的定量分析,并建立了测量误差模型.最后,在预先确定炮管上两标记点的前提下,研究了经纬仪最佳布站方式以抑制其测量误差,并采用遗传算法进行了寻优解算.理论计算和试验结果表明,通过经纬仪合理布站,可以使调炮精度的测量误差控制在0.20 mil以内.提出的方法满足了试验需求,消除了经纬仪随机布站引起的测量结果的不确定性.%To improve the measurement for gun rotated accuracy, the measurement error and the method to control the error for measuring the gun rotated accuracy by two theodolite intersection were researched. First, according to the principle of two theodolites intersection measurement, a space calculation model for measuring the gun rotated accuracy was established. Then the factors influencing the measurement error were quantitatively analyzed by the DT202C electronic theodolite, and the measurement error model was established. Finally, the idiographic realization method for the theodolite optimal disposition to control the measurement error was researched after predefining two markers on the gun tube, and the optimal disposition place was calculated by genetic algorithm. The theoretical calculation and the test results indicate that the measuring error of the gun rotated accuracy can be controlled within 0. 20 mil by the reasonable disposition of the theodolites. It can meet the test re-quirements and can remove the uncertainty brought by the stochastic disposition of the theodolite.

  7. Mechanical Self-shrinkage of Artillery Barrels

    Directory of Open Access Journals (Sweden)

    Ioan Ciorba

    2012-09-01

    Full Text Available Objective of this paper is to define what self-shrink artillery barrel is. She is considered to be a compound barrel like as a thick-walled tube (k>2, in his wall being introduced a state of stress and strain using specific technological proceeds. This type of treatment is aimed to increase the artillery barrel load capacity and wear resistance in operation. The experimental part was realized using an industrial plant at Mechanical Factory of Resita. This part presents a comparative study between mechanical self-shrinkage on artillery head barrel, first using a mandrel and seconds a ball.

  8. Artillery and Warfare 1945-2025

    OpenAIRE

    Bailey, J. P. A.

    2009-01-01

    For millennia battles were essentially affairs of linear encounter. From the 10th Century to the 20th Century, artillery generally fired directly in the two dimensional plane,limiting potential effects. The development of indirect fire changed this , two-dimensional model. Warfare became not so much a matter of linear encounter as one of engagement as cross and throughout an area; and artillery dominated land operations in both the First and Second World Wars as a result. Fi...

  9. Artillery Strike Effectiveness in the Virtual Battlefield

    Directory of Open Access Journals (Sweden)

    Shen Yiying

    2012-08-01

    Full Text Available Artillery plays an irreplaceable role in modern warfare. But due to its huge destructive power, artillery experiment is dangerous and costly. Computer simulation technology uses mathematical models to replace the missile systems and thus avoid accidents and save funds. Based on the trajectory equation model, this paper presents a computer simulation of the projectile distribution. Then, by the simulation results, this paper analyzes each factor’s influence on the fall point’s distribution, as well as the distribution type and distribution parameters. The damage probability and the average amount of ammunition are calculated to assess the strike effectiveness.

  10. Evaluation of gun propelling charge performance during the life cycle by statistical utilization of data collected in test and troop gun firings

    OpenAIRE

    Nyberg, Heli

    2009-01-01

    The dissertation was intended to improve the quality and safety of gun propelling charges during their life cycle. The approach in three case studies was the evaluation of gun propelling charge performance by the statistical utilization of the results collected in artillery gun test firings and conscript practice troop firings. The interior ballistics branch needs to adjust to the new demands for weapon systems. The literature review shows that the actual interdisciplinary challenges ent...

  11. Gun Play

    Science.gov (United States)

    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. Mystery of the First Russian Rifle Naval Guns

    OpenAIRE

    Nicholas W. Mitiukov; Kent Rand Crawford

    2015-01-01

    In 1859 France completed the first ocean-going ironclad warship, «La Gloire», and changed the definition of naval power completely. Russia, as all the other Powers, found that her most powerful naval gun, the 60-pdr, was insufficient for modern warfare, and realized the future naval armament relied on heavy rifled artillery. Both the Army and Navy began purchasing such cannon from foreign providers until a suitable domestic weapon could be produced. The relationship between the Russian milita...

  13. The selection of a Marine artillery battery fire direction computer system

    OpenAIRE

    Gido, Paul Andrew

    1982-01-01

    Approved for public release; distribution is unlimited The artillery fire direction systems currently used by the U.S. Marine Corps are inadequate to meet the demands of today's battlefield. The lack of a modern artillery fire direction computer system degrades the Marine Corps overall combat effectiveness. This thesis presents a cost effectiveness analysis of four fire direction computer systems which can significantly enhance an artillery battery's combat effectiveness. As a result of...

  14. Gun Safety

    Science.gov (United States)

    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 ...

  15. Mystery of the First Russian Rifle Naval Guns

    Directory of Open Access Journals (Sweden)

    Nicholas W. Mitiukov

    2015-09-01

    Full Text Available In 1859 France completed the first ocean-going ironclad warship, «La Gloire», and changed the definition of naval power completely. Russia, as all the other Powers, found that her most powerful naval gun, the 60-pdr, was insufficient for modern warfare, and realized the future naval armament relied on heavy rifled artillery. Both the Army and Navy began purchasing such cannon from foreign providers until a suitable domestic weapon could be produced. The relationship between the Russian military and Krupp is well known. But there was another provided, the Blakely Ordnance Company in England sold many guns to the Army and Navy, beginning with 8-inch MLR in early 1863 to a large number of 9- and 11-inch guns. Deliveries began in November 1863 and continued until mid-1866. But no sources on the armament of Russian ships and fortresses mentions these guns. What happened to them is a mystery.

  16. 32 CFR 644.523 - Restricting future of artillery and other ranges.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Restricting future of artillery and other ranges. 644.523 Section 644.523 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY... Contamination from Proposed Excess Land and Improvements § 644.523 Restricting future of artillery and...

  17. Gun Control

    OpenAIRE

    Moore, Mark; Cook, Phil; Braga, Anthony

    2001-01-01

    The purpose of this essay is to provide a foundation for understanding the "Great American Gun War," and to consider the next steps that could be taken in the search for an effective gun-control policy. We begin with a review of the more-or-less uncontroversial facts about trends in gun ownership and use, and the reasons why Americans are inclined to arm themselves. A discussion follows of the more contentious issues, whether and how guns influence levels or seriousness of crime. We then iden...

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

    Science.gov (United States)

    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)

  19. The Method of Analysis Derived Coefficients of Database as a New Method of Historical Research (for Example, a Database of Ballistic Parameters of Naval Artillery

    Directory of Open Access Journals (Sweden)

    Nicholas W. Mitiukov

    2015-12-01

    Full Text Available In paper there is proposed a new method of historical research, based on analysis of derivatives coefficients of database (for example, the form factor in the database of ballistic data. This method has a much greater protection from subjectivism and direct falsification, compared with the analysis obtained directly from the source of the numerical series, as any intentional or unintentional distortion of the raw data provides a significant contrast ratio derived from the average sample values. Application of this method to the analysis of ballistic data base of naval artillery allowed to find the facts, forcing a new look at some of the events in the history data on the German naval artillery before World War I, probably overpriced for disinformation opponents of the Entente; during the First World War, Spain, apparently held secret talks with the firm Bofors ended purchase of Swedish shells; the first Russian naval rifled guns were created obvious based on the project Blackly, not Krupp as traditionally considered.

  20. Mathematical Model to Simulate the Trajectory Elements ofan Artillery Projectile Proof Shot

    OpenAIRE

    K.K. Chand; H.S. Panda

    2007-01-01

    In external ballistics of a conventional spin-stabilised artillery projectile, there are a numberof trajectory models developed for computing trajectory elements having varying degrees ofcomplexity. The present study attempts to propose a single mathematical model, viz., simplifiedpoint-mass/simple particle trajectory model to simulate the trajectory elements of a typical spin-stabilised flat-head artillery projectile proof shot. Due to difficulties in the projectile shape andsize, and the co...

  1. Laser beam riding artillery missiles guidance device is designed

    Science.gov (United States)

    Yan, Mingliang; Huo, Zhicheng; Chen, Wei

    2014-09-01

    Laser driving gun missile guidance type beam of laser information field formed by any link failure or reduced stability will directly lead to ballistic or miss out of control, and based on this, this paper designed the driving beam of laser guided missile guidance beam type forming device modulation and zoom mechanism, in order to make the missile can recognize its position in the laser beam, laser beam gun missile, by means of spatial encoding of the laser beam laser beam into information after forming device, a surface to achieve the purpose of precision guidance.

  2. Spectrometer gun

    Science.gov (United States)

    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.

  3. Spectrometer gun

    International Nuclear Information System (INIS)

    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

  4. Measurement System of Uniformity between Breech Horizontal Platform and Datum Tube Axis of Rocket Artillery

    Institute of Scientific and Technical Information of China (English)

    GUO Rui; MA Hong; YAN Yu-feng; BAI Su-ping

    2007-01-01

    The purpose of this development is to detect the parallelism between the breech horizontal platform and the datum tube axis of the rocket artillery. The located aiming mechanism at the muzzle and located adjustment mechanism at the breech are designed in the system. Besides those, the system also uses an autocollimator with accuracy of 1" and a collimating mirror together to determine the axis of the datum tube. An electronic level with accuracy of 2" is employed to measure and display the value of the included angle and the parameter of the inclined direction. The entire accuracy of this system is σ≤±9.1". This paper describes the composition and the operating principle of the system and analyzes the accuracy. The development of this system supplies reliable measurement method for new rocket artilleries and artilleries, and this technology is of a good application prospect.

  5. New Image Operator and Its Application in the Inner Surface Detection of Artillery Pipe

    Institute of Scientific and Technical Information of China (English)

    郑军; 徐春广; 肖定国; 张建民

    2003-01-01

    Aimed at the image detection on the ablation wearing, scrape wearing and rifling angle of the artillery body pipe, the character of the inner surface image of the pipe is discussed, the model for rifling, ablation wearing and scrape wearing is brought up, and a new image operator is proposed for these detection. This operator can detect the rifling angle in a high precision, and tell the ablation wearing from scrape wearing in the image, therefore the degree of ablation wearing and scrape wearing can be detected efficiently. This is useful for the artillery body pipe's producing process and life evaluation.

  6. ELECTRON GUN

    Science.gov (United States)

    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.

  7. ION GUN

    Science.gov (United States)

    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)

  8. Neutron gun

    International Nuclear Information System (INIS)

    The neutron gun combines a new core ion source of the cold type based on X-ray ionization and new cold type of neutron source working with core ion generation. The neutrons are formed from the impact of core ions on the negatively charged anode. Based on a new conversion function, the function of the positive anode becomes analogous to the beta-unstable decomposition of a neutron. A core ion and neutron amplifier in the sense of amplifying the number is derived from the beta-unstable neutron decomposition, in order to raise the output of a gun in pulsed operation by using the number amplification in the intervals between the pulses. The method of construction is simple and cheap, the equipment has purely linear acceleration or operation with circular acceleration with linear pre-acceleration as an alternative. Purely linear operation should be sufficient for medical applications, e.g. for neutron photography to replay X-ray photography and particularly for neutron scalpels in the surgical treatment of tumours. (orig./HP)

  9. Encyclopedia of Gun Control and Gun Rights.

    Science.gov (United States)

    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…

  10. Gun ownership and social gun culture.

    Science.gov (United States)

    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

  11. Study of Phosphating Process for Artillery Pipes Subjected to Mechanical Self-shrinkage with Mandrel

    Directory of Open Access Journals (Sweden)

    Ioan Ciorba

    2013-05-01

    Full Text Available This paper present the results of a study that was made to establish the optimal parameters of phosphating process for artillery pipes. The optimal parameters that were determined after analysis are: the temperature of phosphating solution respectively the holding time in the phosphate bathroom to obtain a maximum thickness of phosphate layer.

  12. Determination of parameters for digital meter of doppler radars systems for the artillery systems

    OpenAIRE

    Kaninskiy, Valeriy; Budaretskiy, Yuriy; Grabchak, Volodymyr; Prokopenko, Vyacheslav

    2010-01-01

    analytical choice of the digital meter parameters based on digital systems of phase synchronization (DSPS) is considered, also the simulation model design in order to perform the optimization of its parameters and to determine the temporary characteristics and the accuracy of the motion parameters of objects estimating, for the systems with autonomous navigation and ballistic training artillery systems.

  13. The Gun Dispute.

    Science.gov (United States)

    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)

  14. More Guns, More Crime

    OpenAIRE

    Mark Duggan

    2000-01-01

    This paper examines the relationship between gun ownership and crime. Previous research has suffered from a lack of reliable data on gun ownership. I exploit a unique data set to reliably estimate annual gun ownership rates at both the state and the county level during the past two decades. My findings demonstrate that changes in gun ownership are significantly positively related to changes in the homicide rate, with this relationship driven entirely by the impact of gun ownership on murders ...

  15. Mathematical Model to Simulate the Trajectory Elements ofan Artillery Projectile Proof Shot

    Directory of Open Access Journals (Sweden)

    K.K. Chand

    2007-01-01

    Full Text Available In external ballistics of a conventional spin-stabilised artillery projectile, there are a numberof trajectory models developed for computing trajectory elements having varying degrees ofcomplexity. The present study attempts to propose a single mathematical model, viz., simplifiedpoint-mass/simple particle trajectory model to simulate the trajectory elements of a typical spin-stabilised flat-head artillery projectile proof shot. Due to difficulties in the projectile shape andsize, and the complicated nature of air resistance, an accurate mathematical prediction of thetrajectory is difficult. To simplify the computations, the governing equations of motion of theprojectile have been simplified and assumed that the projectile is a particle and the only forcesacting on the projectile are drag and gravity. With this model, trajectory elements have beengenerated and compared with experimental results obtained in the field test. The measuringinstrument used in this case is a Doppler radar.

  16. Guns and Violence. Current Controversies.

    Science.gov (United States)

    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)

    Science.gov (United States)

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

  18. Electron gun for SSRF

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A 100 kV triode-electron-gun has been designed and manufactured for the Linac of Shanghai Synchrotron Radiation Facility (SSRF). In this paper the performance of the gun and some key components are described.

  19. Women and Guns. Firearm Facts.

    Science.gov (United States)

    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,…

  20. Carbon Nanotube Electron Gun

    Science.gov (United States)

    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.

  1. RF guns: a review

    International Nuclear Information System (INIS)

    Free Electron Lasers and future linear colliders require very bright electron beams. Conventional injectors made of DC guns and RF bunchers have intrinsic limitations. The recently proposed RF guns have already proven their capability to produce bright beams. The necessary effort to improve further these performances and to gain reliability is now undertaken by many laboratories. More than twenty RF gun projects both thermionic and laser-driven are reviewed. Their specific characteristics are outlined and their nominal performances are given

  2. GUNS BEFORE POLITICS

    OpenAIRE

    P.L. Moorcroft

    2012-01-01

    'What we must stop is a situation where the gun is a means of promotion, a machine gun a way of applying pressure, a tank becomes government policy.' This was the despairing cry of an African lawyer during yet another recent military intervention in that most coup-ridden of African states, Dahomey.

  3. GUNS BEFORE POLITICS

    Directory of Open Access Journals (Sweden)

    P.L. Moorcroft

    2012-02-01

    Full Text Available 'What we must stop is a situation where the gun is a means of promotion, a machine gun a way of applying pressure, a tank becomes government policy.' This was the despairing cry of an African lawyer during yet another recent military intervention in that most coup-ridden of African states, Dahomey.

  4. 大口径舰炮多发同时弹着射击效力分析%Analysis of Time-on-Target Fire Effectiveness of Large Caliber Naval Gun

    Institute of Scientific and Technical Information of China (English)

    李开龙; 石章松; 龚驰; 王卓

    2011-01-01

    炮兵火力打击的强度对炮兵火力打击效果的影响呈指数函数递增,集中火力依然是炮兵战斗的首要原则,也是提高火力打击效果的重要手段。通过对多发同时弹着的发射序列及射弹量的研究,论证了单炮多发同时弹着的可行性,在此基础上重点讨论各因素对多发同时弹着射击效力计算的影响,并进行仿真计算,对大口径舰炮武器应用及武器系统的改进具有一定的指导意义。%In view of artillery fire against the intensity of the artillery firepower to combat the effect of exponentially increasing function, concentrated firepower is still artillery fighting the first principles, but also improving effectiveness of fire-power to combat. The primary means of artillery firepower against the speed and strength combined with create decisive effects. This article analyzes the firing data and amount of projectile of large caliber naval gun multiple round time-on-target, demonstrated the feasibility of large caliber naval gun multiple round time-on-target and emphatically discussed the effect of some guide lines to the calculation of time-on-target fire effectiveness. The results have reference value for the application and amelioration of large caliber naval gun weapon system.

  5. The Missing Gun The Missing Gun

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Ma Shan, a criminal poljceman in a remotesmall town in the southwestern Yunnan province,gets drunk at his sister’s wedding and has his three-bullet gun lost, He tries to find it stealthily but endsup in vain. He has tno choice but to report the

  6. Lake Wobegon's Guns: Overestimating Our Gun-Related Competences

    OpenAIRE

    Emily Stark; Daniel Sachau

    2016-01-01

    The Lake Wobegon Effect is a general tendency for people to overestimate their own abilities. In this study, the authors conducted a large, nationally-representative survey of U.S. citizens to test whether Americans overestimate their own gun-relevant personality traits, gun safety knowledge, and ability to use a gun in an emergency. The authors also tested how gun control attitudes, political identification, gender, and gun experience affect self-perceptions. Consistent with prior research o...

  7. Rarefaction wave gun propulsion

    Science.gov (United States)

    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.

  8. Rethinking Gun Violence

    OpenAIRE

    Greenberg, Mark; Litman, Harry

    2010-01-01

    This working paper develops the argument of "Gun Violence and Gun Control" (also posted on SSRN), a short piece commissioned by the London Review of Books. We decided not to publish either paper, in part because we felt there were empirical issues that we were not in a position to assess. We welcome comments on either paper. In this Article, we propose a new way of approaching the problem of gun violence, synthesizing features of a number of successful initiatives. We begin, in Pa...

  9. CNG7 Consolidated Nail Gun

    OpenAIRE

    DeSantis, Christopher Daniel

    2015-01-01

    The purpose of my study is to create a compact, portable nail gun. The nail gun is to be used in tight spaces where hammers, pneumatic nail guns, and portable nail guns will not fit. The intended market is for homeowners renovating their houses. The short length and lightweight, compact frame make the CNG7 ideal for this market. The CNG7 is designed with minimum material waste and fewer parts than other nail guns.

  10. Copter Gun Explorations.

    Science.gov (United States)

    Park, John C.

    1992-01-01

    Describes an investigation in which students predict and verify the effect that the number of clicks of a toy copter gun has on the height that the copter will attain. Provides follow-up questions for the students. (MDH)

  11. High Velocity Gas Gun

    Science.gov (United States)

    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. Gun Safety (For Parents)

    Science.gov (United States)

    ... Reports? What to Say Vaccines: Which Ones & When? Smart School Lunches Emmy-Nominated Video "Cerebral Palsy: Shannon's ... If you do keep a gun in the house, it's vital to keep it out of sight ...

  13. Teen Suicide and Guns

    Science.gov (United States)

    ... Health Issues Listen Text Size Email Print Share Teen Suicide and Guns Page Content Article Body Protect ... thinking of a passing problem, not the outcome! Teen Suicide—A Big Problem Suicide is one of ...

  14. Calculating effective gun policies

    OpenAIRE

    Wodarz, Dominik; Komarova, Natalia L.

    2013-01-01

    Following recent shootings in the USA, a debate has erupted, one side favoring stricter gun control, the other promoting protection through more weapons. We provide a scientific foundation to inform this debate, based on mathematical, epidemiological models that quantify the dependence of firearm-related death rates of people on gun policies. We assume a shooter attacking a single individual or a crowd. Two strategies can minimize deaths in the model, depending on parameters: either a ban of ...

  15. Air gun test facility

    International Nuclear Information System (INIS)

    This paper describes a facility that is potentially useful in providing data for models to predict the effects of nuclear explosions on cities. IIT Research Institute has a large air gun facility capable of launching heavy items of a wide variety of geometries to velocities ranging from about 80 fps to 1100 fps. The facility and its capabilities are described, and city model problem areas capable of investigation using the air gun are presented

  16. Electromagnetic Guns versus Conventional Guns - a performance comparison

    NARCIS (Netherlands)

    Reus, N.M. de; Weijden, J. van der

    1993-01-01

    Performance improvement is one of the key issues of Electromagnetic gun systems compared to conventional gun systems. Due to higher muzzle velocities, the gun's fire control computer will be able to predict the target's future position more accurately because prediction time will be smaller. In this

  17. Fueling by coaxial plasma guns

    International Nuclear Information System (INIS)

    The operating principles of pulsed coaxial guns are reviewed. Some problems involved with the injection of plasma beams from these guns into containment fields are described. The injection during reactor operating conditions is then discussed

  18. Ion plasma electron gun

    International Nuclear Information System (INIS)

    In the disclosed electron gun positive ions generated by a hollow cathode plasma discharge in a first chamber are accelerated through control and shield grids into a second chamber containing a high voltage cold cathode. These positive ions bombard a surface of the cathode causing the cathode to emit secondary electrons which form an electron beam having a distribution adjacent to the cathode emissive surface substantially the same as the distribution of the ion beam impinging upon the cathode. After passing through the grids and the plasma discharge chamber, the electron beam exits from the electron gun via a foil window. Control of the generated electron beam is achieved by applying a relatively low control voltage between the control grid and the electron gun housing (which resides at ground potential) to control the density of the positive ions bombarding the cathode

  19. PHERMEX electron gun development

    International Nuclear Information System (INIS)

    The PHERMEX facility is a 50-MHz standing-wave linear accelerator. Electrons are injected, accelerated, and transported to a tungsten target where bremsstrahlung x rays are generated for flash radiography of hydrodynamic systems. The purpose of this article is to describe the progress of PHERMEX electron gun development. The goal of this program is to generate and transport a 200-ns, 1-MV, 1-kA electron beam into the first PHERMEX accelerating cavity. The standard gun is operated at a pulse voltage of 550 kV, which is the limit determined by internal breakdown of the vacuum insulator. This insulator has been redesigned, and the gun has been pulsed at 750 kV without internal breakdown. At present, the current output is not limited by voltage but by a phenomenon called pulse shortening, which occurs at a pulse voltage of approximately 650 kV. The phenomenon has been investigated and the results are presented

  20. Unbalanced field RF electron gun

    Science.gov (United States)

    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.

  1. Guns and sleep

    OpenAIRE

    Quan SF

    2015-01-01

    No abstract available. Article truncated at 150 words. Gun deaths are a problem in America. Irrespective of one’s position on gun control, the statistics do not lie. According to the Centers for Disease Control and Prevention (CDC), there were 11,208 deaths caused by firearms in 2013 (1). The recent high profile cases in Cincinnati, OH, Lafayette, LA and Memphis, TN further highlight the issue. Obviously, each case of death by a firearm had its own set of underlying factors that contributed t...

  2. Guns and votes

    OpenAIRE

    Bouton, Laurent; Conconi, Paola; Pino, Francisco; Zanardi, Maurizio

    2013-01-01

    Why are U.S. congressmen reluctant to support gun control regulations, despite the fact that most Americans are in favor of them? We argue that re-election motives can help explain why politicians often take a pro-gun stance against the interests of the majority of the electorate. We describe a model in which an incumbent politician must decide on a primary issue, which is more important to a majority of voters, and a secondary issue, which a minority cares more intensely about. We derive con...

  3. Glue Guns: Aiming for Safety

    Science.gov (United States)

    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…

  4. Look at nuclear artillery yield options using JANUS, a wargame simulation code

    International Nuclear Information System (INIS)

    JANUS, a two-sided, interactive wargame simulation code, was used to explore how using each of several different yield options in a nuclear artillery shell might affect a tactical battlefield simulation. In a general sense, the results or outcomes of these simulations support the results or outcomes of previous studies. In these simulations the Red player knew of the anticipated nuclear capability of the Blue player. Neither side experienced a decisive win over the other, and both continued fighting and experienced losses that, under most historical circumstances, would have been termed unacceptable - that is, something else would have happened (the attack would have been called off). During play, each side had only fragmentary knowledge of the remaining resources on the other side - thus each side desired to continue fighting on the basis of known information. We found that the anticipated use of nuclear weapons by either side affects the character of a game significantly and that, if the employment of nuclear weapons is to have a decided effect on the progress and outcome of a battle, each side will have to have an adequate number of nuclear weapons. In almost all the simulations we ran using JANUS, enhanced radiation (ER) weapons were more effective than 1-kt fission weapons in imposing overall losses on Red. The typical visibility in the JANUS simulation limited each side's ability to acquire units deep into enemy territory and so the 10-kt fission weapon was not useful against enemy tanks that were not engaged in battle

  5. Gun control saves lives.

    Science.gov (United States)

    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

  6. Gun Dealers, USA.

    Science.gov (United States)

    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…

  7. Serbian society and gun culture

    Directory of Open Access Journals (Sweden)

    Cvetković Vladimir

    2006-01-01

    Full Text Available This paper questions whether one characteristic of Serbian society is a gun culture. The first part of the paper deals with some theoretical concerns and closer explanation of what is understood by the term gun culture. Few different approaches to the issue are analyzed. The concept used has three main components of the gun culture: system of positive beliefs; social symbols embodied by the gun; agent "bearers" of gun culture. The second part of the paper presents results from Small Arms and Light Weapons survey conducted in 2004 in Serbia. The results were analyzed within the theoretical framework proposed in the first part of the paper.

  8. CAPE TOWN'S TIME-GUNS

    OpenAIRE

    Bisset, W. M.

    2012-01-01

    Although a great many articles have been written on the subject of Cape Town's noon gun (the. official terminology is 'time-gun') most of the writers have not had access to the Lion Battery Fort Record Book and the existance of more than one Cape Town time-gun has only recently been recorded. By 1807 a noon gun was fired regularly from the Imhoff Battery on the seaward side of the Castle.1 On 4 August 1902 the noon gun was fired from Lion Battery on Signal Hill for the first time.2 The batter...

  9. Electromagnetic Guns versus Conventional Guns - a performance comparison

    OpenAIRE

    Reus, N.M. de; Weijden, J. van der

    1993-01-01

    Performance improvement is one of the key issues of Electromagnetic gun systems compared to conventional gun systems. Due to higher muzzle velocities, the gun's fire control computer will be able to predict the target's future position more accurately because prediction time will be smaller. In this paper, an investigation is done for the expected performance increase due to the higher muzzle velocities in air defense applications using a parametric as well as a Monte-Carlo approach. The Mont...

  10. Prospects for deflagration guns

    International Nuclear Information System (INIS)

    Deflagration is a process of fluid expansion with energy addition. Its existence in plasma physics was first discovered in the back-strapped T-tube experiments. In the coaxial plasma gun configuration the operation can be simple and yet produce a clean, high density (5 x 1015 cm-3), and high kinetic energy (10 to 50 keV) collimated plasma beam. Plasma acceleration mechanism was thought to be driven by J x B force. Tapered electrodes have been used to obtain plasma beams. Scaling of the gun can be performed according to simple theory based on momentum and energy balance. Proposed plasma fueling and injection to magnetic fusion systems will be discussed

  11. Gun Attitudes and Fear of Crime.

    Science.gov (United States)

    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

    Science.gov (United States)

    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. CAPE TOWN'S TIME-GUNS

    Directory of Open Access Journals (Sweden)

    W.M. Bisset

    2012-02-01

    Full Text Available Although a great many articles have been written on the subject of Cape Town's noon gun (the. official terminology is 'time-gun' most of the writers have not had access to the Lion Battery Fort Record Book and the existance of more than one Cape Town time-gun has only recently been recorded. By 1807 a noon gun was fired regularly from the Imhoff Battery on the seaward side of the Castle.1 On 4 August 1902 the noon gun was fired from Lion Battery on Signal Hill for the first time.2 The battery was built because of fears of war with Russia and had been armed with two 9- inch Rifled Muzzle Loading guns by 1891. Lion Battery was remodelled in 1911.

  14. Study of Electro-Optical Measuring System for Measuring the Swaying of Rocket Launcher and Artillery Systems

    Institute of Scientific and Technical Information of China (English)

    LI Yang; YAN Yu-feng; CAI Li-juan; LIU Zhen-bo

    2008-01-01

    A scheme is proposed, of that the axis of directional barrel is simulated by a laser beam and an electro-optical axial angle encoder is using to measure the swaying of rocket Muncher or artillery. The measuring principle is stated, and an electro-optical measuring system is designed, including automatic force-applying device, angle-measurement device and photodetecting screen. The measurement accuracy of the system is analyzed. The measuring error of system is less then 17.3"(0.08 mil).

  15. Wisconsin SRF Electron Gun Commissioning

    Energy Technology Data Exchange (ETDEWEB)

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

    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.

  16. The ALS Gun Electronics system

    International Nuclear Information System (INIS)

    The ALS Gun Electronics system has been designed to accommodate gun with a custom made socket and high speed electronics circuit which is capable of producing single and multiple electron bunches with time jitters measured at better than 50 PS. The system generates the gated RF signal at ground level before sending it up to the 120 KV-biased gun deck via a fiber optic cable. The current pulse width as a function of grid bias, using an Eimac 8847A planar triode simulating an electron gun, was measured to show the relationship between the two parameters

  17. Public opinion about guns in the home

    OpenAIRE

    Kellermann, A.; Fuqua-Whitley, D.; Sampson, T.; Lindenmann, W.

    2000-01-01

    Objectives—(1) Determine the frequency of gun ownership, acquisition, and transfer; (2) assess gun storage practices; and (3) compare the views of firearm owning and non-owning adults regarding the protective value of keeping a gun in the home.

  18. Weight of RCL Guns in Comparison to Conventional Guns

    Directory of Open Access Journals (Sweden)

    J. P. Sirpal

    1956-07-01

    Full Text Available A study has been made of the weight of ordnance and equipment for a given performance. The comparative weights of the RCL and the orthodox equipments have been studied and it has been found that for the same muzzle energy the weight of RCL gun is 1/4th that of orthodox gun.

  19. Resonant optical gun.

    Science.gov (United States)

    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

  20. Gun Concerns Personal for Duncan

    Science.gov (United States)

    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…

  1. Preventing gun injuries in children.

    Science.gov (United States)

    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

  2. LCLS Gun Solenoid Design Considerations

    International Nuclear Information System (INIS)

    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.

  3. Guns and sleep

    Directory of Open Access Journals (Sweden)

    Quan SF

    2015-08-01

    Full Text Available No abstract available. Article truncated at 150 words. Gun deaths are a problem in America. Irrespective of one’s position on gun control, the statistics do not lie. According to the Centers for Disease Control and Prevention (CDC, there were 11,208 deaths caused by firearms in 2013 (1. The recent high profile cases in Cincinnati, OH, Lafayette, LA and Memphis, TN further highlight the issue. Obviously, each case of death by a firearm had its own set of underlying factors that contributed to the final fatal outcome, but one wonders whether sleep deprivation can be implicated in some of them. Sleep duration in adults over the past approximately 30 years has been declining in the United States (2. A variety of reasons can be cited as underlying causes such as greater use of artificial lighting, an expanding 24 hour non-stop society, promotion of a work ethic that values “burning the midnight oil”, and use of electronic devices before bedtime ...

  4. Electric arc welding gun

    Science.gov (United States)

    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.

  5. The Internal Ballistics of an Air Gun

    Science.gov (United States)

    Denny, Mark

    2011-01-01

    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…

  6. The Effects of Gun Ownership Rates and Gun Control Laws on Suicide Rates

    OpenAIRE

    Mark Gius

    2011-01-01

    The purpose of the present study is to determine the effects of gun control laws and gun ownership rates on state-level suicide rates. Using the most recent data on suicide rates, gun control measures, and gun ownership rates, the results of the present study suggest that states that require handgun permits have lower gun-related suicide rates, and states that have higher gun ownership rates have higher gun-related suicide rates. Regarding non-gun suicides, results suggest that stricter gun c...

  7. Calculating effective gun control policies

    CERN Document Server

    Wodarz, Dominik

    2013-01-01

    Following recent shootings in the USA, a debate has erupted, one side favoring stricter gun control, the other promoting protection through more weapons. We provide a scientific foundation to inform this debate, based on population dynamic models that quantify the dependence of firearm-related death rates of people on gun policies. We assume a shooter attacking a single individual or a crowd. Two strategies can minimize deaths in the model, depending on parameters: either a ban of private firearms possession, or a policy allowing the general population to carry guns. In particular, the outcome depends on the fraction of offenders that illegally possess a gun, on the degree of protection provided by gun ownership, and on the fraction of the population who take up their right to own a gun and carry it with them when attacked, parameters that can be estimated from statistical data. With the measured parameters, the model suggests that if the gun law is enforced at a level similar to that in the United Kingdom, g...

  8. Guns as a Symbol of American Individualism

    Institute of Scientific and Technical Information of China (English)

    许丹

    2011-01-01

    Due to continuous gun violence, Americans' crazy love for guns has always been attacked home and abroad. Americans' passion for guns derives from individualism through the development of American history. They consider guns as a means to guarantee independence and freedom, and therefore as a symbol of American individualism.

  9. Gun barrel erosion - Comparison of conventional and LOVA gun propellants

    NARCIS (Netherlands)

    Hordijk, A.C.; Leurs, O.

    2006-01-01

    The research department Energetic Materials within TNO Defence, Security and Safety is involved in the development and (safety and insensitive munitions) testing of conventional (nitro cellulose based) and thermoplastic elastomer (TPE) based gun propellants. Recently our testing capabilities have be

  10. Child Access Prevention Laws and Nonfatal Gun

    OpenAIRE

    Jeffrey DeSimone; Sara Markowitz

    2013-01-01

    Many states have passed child access prevention (CAP) laws, which hold the gun owner responsible if a child gains access to a gun that is not securely stored. Previous research on CAP laws has focused exclusively on gun-related deaths even though most gun injuries are not fatal. We use annual hospital discharge data to investigate whether CAP laws are associated with decreased nonfatal gun injuries. Results from Poisson regressions that control for various hospital, county, and state characte...

  11. Reverse Ballistic Air Gun Facility

    Data.gov (United States)

    Federal Laboratory Consortium — This custom-designed facility houses a suite of three air guns capable of generating accelerations up to 100,000 Gs and velocities up to 2,000 ft/s. In addition to...

  12. NASA-Ames vertical gun

    Science.gov (United States)

    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.

  13. State Gun Policy and Cross-State Externalities: Evidence from Crime Gun Tracing

    OpenAIRE

    Brian Knight

    2011-01-01

    This paper provides a theoretical and empirical analysis of cross-state externalities associated with gun regulations in the context of the gun trafficking market. Using gun tracing data, which identify the source state for crime guns recovered in destination states, we find that firearms in this market tend to flow from states with weak gun laws to states with strict gun laws, satisfying a necessary condition for the existence of cross-state externalities in the theoretical model. We also fi...

  14. Temporal Association between Federal Gun Laws and the Diversion of Guns to Criminals in Milwaukee

    OpenAIRE

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

    2012-01-01

    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 fol...

  15. The case for moderate gun control.

    Science.gov (United States)

    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

  16. Large Bore Powder Gun Qualification (U)

    Energy Technology Data Exchange (ETDEWEB)

    Rabern, Donald A. [Los Alamos National Laboratory; Valdiviez, Robert [Los Alamos National Laboratory

    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.

  17. Lake Wobegon’s Guns: Overestimating Our Gun-Related Competences

    Directory of Open Access Journals (Sweden)

    Emily Stark

    2016-02-01

    Full Text Available The Lake Wobegon Effect is a general tendency for people to overestimate their own abilities. In this study, the authors conducted a large, nationally-representative survey of U.S. citizens to test whether Americans overestimate their own gun-relevant personality traits, gun safety knowledge, and ability to use a gun in an emergency. The authors also tested how gun control attitudes, political identification, gender, and gun experience affect self-perceptions. Consistent with prior research on the Lake Wobegon Effect, participants overestimated their gun-related competencies. Conservatives, males, and pro-gun advocates self-enhanced somewhat more than their counterparts but this effect was primarily due to increased gun experience among these participants. These findings are important to policymakers in the area of gun use, because overconfidence in one’s gun-related abilities may lead to a reduced perceived need for gun training.

  18. [Suicide with home-made gun].

    Science.gov (United States)

    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

  19. The Social Costs of Gun Ownership

    OpenAIRE

    Phillip J. Cook; Jens Ludwig

    2004-01-01

    This paper provides new estimates of the effect of household gun prevalence on homicide rates, and infers the marginal external cost of handgun ownership. The estimates utilize a superior proxy for gun prevalence, the percentage of suicides committed with a gun, which we validate. Using county- and state-level panels for 20 years, we estimate the elasticity of homicide with respect to gun prevalence as between +.1 and +.3. All of the effect of gun prevalence is on gun homicide rates. Under ce...

  20. Streamlined approach for environmental restoration plan for corrective action unit 430, buried depleted uranium artillery round No. 1, Tonopah test range

    International Nuclear Information System (INIS)

    This plan addresses actions necessary for the restoration and closure of Corrective Action Unit (CAU) No. 430, Buried Depleted Uranium (DU) Artillery Round No. 1 (Corrective Action Site No. TA-55-003-0960), a buried and unexploded W-79 Joint Test Assembly (JTA) artillery test projectile with high explosives (HE), at the U.S. Department of Energy, Nevada Operations Office (DOE/NV) Tonopah Test Range (TTR) in south-central Nevada. It describes activities that will occur at the site as well as the steps that will be taken to gather adequate data to obtain a notice of completion from Nevada Division of Environmental Protection (NDEP). This plan was prepared under the Streamlined Approach for Environmental Restoration (SAFER) concept, and it will be implemented in accordance with the Federal Facility Agreement and Consent Order (FFACO) and the Resource Conservation and Recovery Act (RCRA) Industrial Sites Quality Assurance Project Plan

  1. Research on Artillery Fire Support Based on Queuing Theory%基于排队论的炮兵火力支援问题研究

    Institute of Scientific and Technical Information of China (English)

    蒋晓伟; 张亮; 魏巍

    2012-01-01

    针对当前战场上作战目标数量多,种类多样化的特点,运用排队论方法,建立一种基于排队论的炮兵火力支援模型.该模型综合考虑各种因素对炮兵火力支援的影响,最终给出了毁伤概率的参考公式.%According to the quantity of current combat targets on the battlefield is Urge and many fypes in diversity, using of queuing theory approach, we establish a queuing theory-based model for artillery fire support. The model considers the influence of various factors on the impact of artillery fire support, and gjyes the reference formula of kill probability ultimately.

  2. Streamlined approach for environmental restoration plan for corrective action unit 430, buried depleted uranium artillery round No. 1, Tonopah test range

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-09-01

    This plan addresses actions necessary for the restoration and closure of Corrective Action Unit (CAU) No. 430, Buried Depleted Uranium (DU) Artillery Round No. 1 (Corrective Action Site No. TA-55-003-0960), a buried and unexploded W-79 Joint Test Assembly (JTA) artillery test projectile with high explosives (HE), at the U.S. Department of Energy, Nevada Operations Office (DOE/NV) Tonopah Test Range (TTR) in south-central Nevada. It describes activities that will occur at the site as well as the steps that will be taken to gather adequate data to obtain a notice of completion from Nevada Division of Environmental Protection (NDEP). This plan was prepared under the Streamlined Approach for Environmental Restoration (SAFER) concept, and it will be implemented in accordance with the Federal Facility Agreement and Consent Order (FFACO) and the Resource Conservation and Recovery Act (RCRA) Industrial Sites Quality Assurance Project Plan.

  3. THE APPROACH TOWARDS THE ESTIMATION OF THE ARTILLERY AND ROCKET TROOPS “FIRE FOR EFFECT” ON ENEMY MODERN UNMANNED AIRCRAFT COMPLEX POSITIONS EFFECTIVENESS

    OpenAIRE

    Repilo, Yurii Y.; Riman, Oleksii O.; Demydko, Dmytro D.

    2015-01-01

    The approach towards the estimation of the artillery and rocket troops “fire for effect” on enemy modern unmanned aircraft complex positions, which, unlike the existing approach, takes into account main (reconnaissance) function of the complex in modern combat conditions. The features of such conflicts are distinct “fire nature” and integration of reconnaissance and “fire for effect” means into reconnaissance-fire system. The core function of this system is the implementation of the most appr...

  4. Foreign Artillery Suppressed Weapon Equipment Developing Situation Analysis%国外炮兵压制武器装备发展态势分析

    Institute of Scientific and Technical Information of China (English)

    琚章锋; 刘娟; 刘慧玲

    2013-01-01

    野战炮兵的压制火力作为战场综合火力体系中必不可少的部分,是整个陆军赖以生存的重要手段,为增强炮兵武器在现代信息化战场的作战能力,各国普遍对现役装备进行改造、更新,使其作战效能有突破性的提高。典型介绍了美、俄、英三国炮兵压制武器装备的发展现状,并说明在高新技术兴起的今天,世界各国军队的建设和炮兵压制武器装备的发展呈现出由数量规模型转向质量效益型、由人力密集型转向技术密集型的总体趋势。%The field artillery suppressed fire, as an essential part of integrated battlefield fire system, is an important survival means of the whole army, in order to enhance combat capability of artillery weapon in modern information battlefield, all countries generally modifies, updates the servicing equipment, and makes a breakthrough improvement in the operational effectiveness. This article typically describes the development situation of artillery suppression weapon in United States, Russia, Britain, and explains that the overall trend of world army building and artillery suppressed weapon development is from quantity-scale type to quality efficiency type, and from a manpower-intensive to technotogy-intensive as high-technology development in the world today.

  5. Development of coaxial rotating-plasma gun

    International Nuclear Information System (INIS)

    A rotating-plasma gun has been devised to produce plasma streams with higher rotational velocities. The working mechanism of the gun and the results of a preliminary experiment have been described. (author)

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

    Science.gov (United States)

    ... 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, ...

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

    Science.gov (United States)

    ... 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, ...

  8. Plasma focusing in coaxial gun

    International Nuclear Information System (INIS)

    A capacitor bank has been discharged between two coaxial electrodes of 6.6 cm outer diameter, 3.2 cm inner diameter and length of 31.5 cm. filled with hydrogen gas at pressure of 310 μHg. Results show that, the axial and radial plasma current reach a maximum value at a position adjacent to the gun muzzle, at which the plasma focus occurs. The measurement of the electron temperature and density and azimuthal electric field along the axis of the expansion chamber, gives a maximum value at z∼18 cm from the gun muzzle, while the axial plasma current and velocity has a minimum value at that position. These results indicate that a second point of a plasma focus has been formed at z∼18 cm from the gun muzzle, along the axis of the expansion chamber

  9. Automatic targeting of plasma spray gun

    International Nuclear Information System (INIS)

    A means for monitoring the material portion in the flame of a plasma spray gun during spraying operations is described. 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

  10. Automatic targeting of plasma spray gun

    Science.gov (United States)

    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.

  11. Liquid Propellants for Advanced Gun Ammunitions

    Directory of Open Access Journals (Sweden)

    K. P. Rao

    1987-01-01

    Full Text Available With constant improvements, the conventional solid propellants for guns have almost reached their limit in performance. Liquid gun propellants are promising new comers capable of surpassing these performance limits and have numerous advantages over solid propellants. A method has been worked out to predict the internal ballistics of a liquid propellant gun and illustrated in a typical application.

  12. Liquid Propellants for Advanced Gun Ammunitions

    OpenAIRE

    K. P. Rao; A. S. Bartakke; R.G.K. Nair

    1987-01-01

    With constant improvements, the conventional solid propellants for guns have almost reached their limit in performance. Liquid gun propellants are promising new comers capable of surpassing these performance limits and have numerous advantages over solid propellants. A method has been worked out to predict the internal ballistics of a liquid propellant gun and illustrated in a typical application.

  13. The supply and demand for guns to juveniles: Oakland’s gun tracing project

    OpenAIRE

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

    2005-01-01

    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...

  14. Modeling and Simulation of Information Influence on Artillery Combat Capability Based on System Dynamics%系统动力学信息对炮兵作战能力影响建模仿真*

    Institute of Scientific and Technical Information of China (English)

    李小全; 詹海洋; 程懿

    2013-01-01

    Information become an important element of system in system (SOS)combat artillery capability,to obtain infromation superiority is first requirement for artillery operation. According to artillery operation characteristics and doctrines,using index theory to construct artillery information combat capability model,using system dynamics to study information element influence on artillery combat capability,a combat case is taken for an example to simulate analysis information influence on artillery capability between traditional combat and SOS combat,This research can provide the good references for artillery information combat capability elements construction and development.%  信息成为体系作战炮兵作战能力的构成要素,夺取信息优势成为炮兵作战行动的前提。围绕炮兵信息化作战的特点规律,运用指数法建立信息化作战炮兵作战能力模型,运用系统动力学探究信息要素对炮兵作战能力生成的影响机制。依据设定作战背景,仿真分析了信息对炮兵在传统作战与体系作战不同条件下的作战能力影响问题,为优化炮兵信息化作战能力要素建设提供决策依据。

  15. The ELETTRA Gun Trigger module

    International Nuclear Information System (INIS)

    The ELETTRA injector is a full energy Linac. The Linac and the pulsed magnets need to be synchronized with the beam in the storage ring in order to fill it with the proper bunch pattern. Most of the triggers for the timing system are generated by a module which is named Gun Trigger module. The gun is triggered in synchronism with a reference bucket of the storage ring. It can be programmed with a delay between 2 and 864 ns, a range which covers one revolution period of the storage ring, so any arbitrary bucket of the ring can be filled. The module generates also the gun trigger for working in FEL mode, which needs a repetition from 30 to 50 ns in a 10 μs window. The jitter of all these triggers is less than 50 ps. The Gun Trigger module is developed in VMEbus standard, using TTL and ECL technology. It is remotely programmable through the ELETTRA control system. The general architecture of the ELETTRA timing system is also described in the paper

  16. Current controller for electron gun

    International Nuclear Information System (INIS)

    A beam-current controller for a triode electron gun is described that permits the voltage on the control electrode to be varied within 0-2.5 kV with 60-kV isolation of the output part of the circuit from the low-potential control-signal source. The carrier frequency for control-signal conversion is 32 khz

  17. Developments in electron gun simulation

    Energy Technology Data Exchange (ETDEWEB)

    Herrmannsfeldt, W.B.

    1994-05-01

    This paper will discuss the developments in the electron gun simulation programs that are based on EGUN and its derivatives and supporting programs. Much of the code development has been inspired by technology changes in computer hardware; the implications on EGN2 of this evolution will be discussed. Some examples and a review of the capabilities of the EGUN family will be described.

  18. Developments in electron gun simulation

    International Nuclear Information System (INIS)

    This paper will discuss the developments in the electron gun simulation programs that are based on EGUN and its derivatives and supporting programs. Much of the code development has been inspired by technology changes in computer hardware; the implications on EGN2 of this evolution will be discussed. Some examples and a review of the capabilities of the EGUN family will be described

  19. Electric rail gun application to space propulsion

    International Nuclear Information System (INIS)

    The paper examines the possibility of using the DC electric gun principles as a space vehicle propulsion system, capable of producing intermediate thrust levels. The application of an electromagnetic launch technique, called the DC electric rail gun, to the space propulsion concept of O'Neill, is examined. It is determined that the DC electric rail gun offers very high projectile accelerations and a very significant potential for reducing the size and mass of a reaction motor for space application. A detailed description of rail gun principles is given and some simple expressions for the accelerating force, gun impedance, power supply requirements, and system performance are discussed

  20. Electron gun for technological linear accelerator

    International Nuclear Information System (INIS)

    The work is purposed to the design of diode electron gun for powerful technologic electron linac and to experimental investigations of the beam parameters at the gun exit.The gun feature is the quick cathode replacement.This is very impotent for operating of the accelerator.The gun optics and beam parameters were calculated using the EGUN code.Beam parameters were investigated as at the special test stand so as component of the linac injector.The gun produces the beam current of 2 A at the anode voltage 25 kV.Measured beam parameters correspond to calculated results

  1. Revisiting Pneumatic Nail Gun Trigger Recommendations

    OpenAIRE

    Albers, James; Lowe, Brian; Lipscomb, Hester; Hudock, Stephen; Dement, John; Evanoff, Bradley; Fullen, Mark; Gillen, Matt; Kaskutas, Vicki; Nolan, James; Patterson, Dennis; Platner, James; Pompeii, Lisa; Schoenfisch, Ashley

    2015-01-01

    Use of a pneumatic nail gun with a sequential actuation trigger (SAT) significantly diminishes the risk for acute traumatic injury compared to use of a contact actuation trigger (CAT) nail gun. A theoretically-based increased risk of work-related musculoskeletal disorders from use of a SAT nail gun, relative to CAT, appears unlikely and remains unproven. Based on current knowledge, the use of CAT nail guns cannot be justified as a safe alternative to SAT nail guns. This letter provides a pers...

  2. RF Design of the LCLS Gun

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    OpenAIRE

    Webster, Daniel W.; 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 interrupt...

  4. The Effect of Gun Shows on Gun-Related Deaths: Evidence from California and Texas

    OpenAIRE

    Mark Duggan; Randi Hjalmarsson; Brian A. Jacob

    2008-01-01

    Thousands of gun shows take place in the U.S. each year. Gun control advocates argue that because sales at gun shows are much less regulated than other sales, such shows make it easier for potential criminals to obtain a gun. Similarly, one might be concerned that gun shows would exacerbate suicide rates by providing individuals considering suicide with a more lethal means of ending their lives. On the other hand, proponents argue that gun shows are innocuous since potential criminals can acq...

  5. A gasdynamic gun driven by gaseous detonation.

    Science.gov (United States)

    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

  6. A gasdynamic gun driven by gaseous detonation

    Science.gov (United States)

    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.

  7. Self-bunching electron guns

    International Nuclear Information System (INIS)

    We report on three electron gun projects that are aimed at power tube and injector applications. The purpose of the work is to develop robust electron guns which produce self-bunched, high-current-density beams. We have demonstrated cold emission, long life, and tolerance to contamination. The cold emission process is based on secondary electron emission. FMT has studied this resonant bunching process which gives rise to high current densities (0.01-5 kA/cm2), high charge bunches (up to 100 nC/bunch), and short pulses (1-100 ps) for frequencies from 1 to 12 GHz. The beam pulse width is nominally ∼5% of the rf period. The first project is the L-Band Micro-Pulse Gun (MPG). Measurements show ∼40 ps long micro-bunches at ∼20 A/cm2 without contamination due to air exposure. Lifetime testing has been carried out for about 18 months operating at 1.25 GHz for almost 24 hours per day at a repetition rate of 300 Hz and 5 μs-long macro-pulses. About 5.8x1013 micro-bunches or ∼62,000 coulombs have passed through this gun and it is still working fine. The second project, the S-Band MPG†, is now operational. It is functioning at a frequency of 2.85 GHz, a repetition rate of 30 Hz, with a 2 μs-long macro-pulse. It produces about 150 A/cm2. The third project involves the construction of a 34.2 GHz frequency-multiplied source driven by an X-Band MPG. Analytical work has been carried out on this device, and we are ready to proceed with design, fabrication, and testing

  8. Internal Ballistics of Recoilless Guns

    Directory of Open Access Journals (Sweden)

    Asim Ray

    1967-01-01

    Full Text Available A new method for calculating the ballistics of recoilless guns during the period of burning of the propellant has been obtained. Ballistics have also been calculated by exact numerical integration in a few cases and these results have been compared with those obtained by the method described in this paper. It has been found that the results obtained by these two methods agree satisfactorily.

  9. A Supersonic Ping Pong Gun

    CERN Document Server

    French, Mark; Stratton, Jim

    2013-01-01

    The Ping Pong gun or Ping Pong bazooka has been a popular and compelling tool for physics education. However, the design necessarily means the ball emerges at subsonic speed. The design has been modified to include a pressure chamber and a convergent-divergent nozzle, similar to the design of some supersonic wind tunnels. This modification results in supersonic speeds. The current design has achieved a launch speed of 406 m/sec, about Mach 1.23.

  10. Self-bunching electron guns

    CERN Document Server

    Mako, F; Weilhammer, Peter

    1999-01-01

    We report on three electron gun projects that are aimed at power tube and injector applications. The purpose of the work is to develop robust electron guns which produce self-bunched, high-current-density beams. We have demonstrated cold emission, long life, and tolerance to contamination. The cold emission process is based on secondary electron emission. FMT has studied this resonant bunching process which gives rise to high current densities (0.01-5 kA/cm/sup 2/), high charge bunches (up to 100 nC/bunch), and short pulses (1-100 ps) for frequencies from 1 to 12 GHz. The beam pulse width is nominally ~5% of the RF period. The first project is the L-Band Micro-Pulse Gun (MPG). Measurements show ~40 ps long microbunches at ~20 A/cm/sup 2/ without contamination due to air exposure. Lifetime testing has been carried out for about 18 months operating at 1.25 GHz for almost 24 hours per day at a repetition rate of 300 Hz and 5 mu s-long macro- pulses. About 5.8*10/sup 13/ micro-bunches or 62,000 coulombs have pass...

  11. X-Band RF Gun Development

    International Nuclear Information System (INIS)

    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.

  12. X-Band RF Gun Development

    Energy Technology Data Exchange (ETDEWEB)

    Vlieks, Arnold; Dolgashev, Valery; Tantawi, Sami; /SLAC; 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.

  13. Racism, gun ownership and gun control: biased attitudes in US whites may influence policy decisions.

    Directory of Open Access Journals (Sweden)

    Kerry O'Brien

    Full Text Available 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.

  14. Racism, gun ownership and gun control:biased attitudes in US whites may influence policy decisions

    OpenAIRE

    Kerry O'Brien; Walter Forrest; Dermot Lynott; Michael Daly

    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 wh...

  15. Guns, Crime, and Academics: Some Reflections on the Gun Control Debate.

    OpenAIRE

    Parker, Jeffrey S

    2001-01-01

    This comment on Thomas Marvell's "The Impact of Banning Juvenile Gun Possession" analyzes Marvell's empirical findings and their policy implications for gun control legislation. While Marvell's article stresses the absence of any finding favorable to juvenile gun bans, this comment points out that the statistical results actually support the stronger finding that some of the juvenile gun bans are associated with a statistically significant increase in homicides nationwide. Under either findin...

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

    OpenAIRE

    O'Brien, Kerry S.; 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 whit...

  17. Gun Control in Australia: A Criminological Perspective

    Directory of Open Access Journals (Sweden)

    Rick Sarre

    2015-11-01

    Full Text Available In recent months there has been an upsurge in contributions to the popular press from social commentators insisting that guns make our nation safer. This essay questions these assertions. The paper provides evidence to support a contrary affirmation: that is, in order to have a reduction in gun violence, there needs to be a reduction in the number of guns generally, and a continuation of the legal controls that currently shape firearms policy in Australia.

  18. Nail-Gun Injuries to the Hand

    OpenAIRE

    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 ...

  19. Research on Hot Gunning Repairing in Laboratory

    Institute of Scientific and Technical Information of China (English)

    CAO Feng; LONG Shigang; MENG Qingmin; SUN Jialin; HONG Yanruo

    2003-01-01

    The lining of blast furnace may be damaged partly,so that gunning repair is needed. The bonding strength of boundary surface between the repairing layer and remained lining of blast furnace has been studied by thermal simulation.The factors influencing the bonding strength are the ingredient gunning repair temperature,remained lining condition and water content of gunning refractory.The bonding strength decreases with the increases of remained lining temperature.

  20. Gun Control in Australia: A Criminological Perspective

    OpenAIRE

    Rick Sarre

    2015-01-01

    In recent months there has been an upsurge in contributions to the popular press from social commentators insisting that guns make our nation safer. This essay questions these assertions. The paper provides evidence to support a contrary affirmation: that is, in order to have a reduction in gun violence, there needs to be a reduction in the number of guns generally, and a continuation of the legal controls that currently shape firearms policy in Australia.

  1. Rate control for electron gun evaporation

    International Nuclear Information System (INIS)

    Principles for obtaining high-quality rate control for electron gun evaporation are discussed. The design criteria for rate controllers are derived from this analysis. Results are presented which have been obtained with e-guns whose evaporation rate is controlled by a Wehnelt electrode or by sweeping of the electron beam. Further improvements of rate stability can be obtained by improved design of e-guns and power supplies

  2. Conceptual Design for CLIC Gun Pulser

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Tao [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2016-01-08

    The Compact Linear Collider (CLIC) is a proposed future electron-positron collider, designed to perform collisions at energies from 0.5 to 5 TeV, with a nominal design optimized for 3 TeV (Dannheim, 2012). The Drive Beam Accelerator consists of a thermionic DC gun, bunching section and an accelerating section. The thermionic gun needs deliver a long (~143us) pulse of current into the buncher. A pulser is needed to drive grid of the gun to generate a stable current output. This report explores the requirements of the gun pulser and potential solutions to regulate grid current.

  3. Hard-driven rail-gun tests

    International Nuclear Information System (INIS)

    A number of prototype rail-gun designs have been tested, powered by explosive magnetic flux compression generators. Peak currents as high as 1.3 MA were delivered. Rail guns with 50-mm-thick Kevlar fiberwound structural shells were able to survive these high currents with minimum mechanical damage and were refired after enlarging the bores 0.2 to 0.4 mm to remove arc damage. In some tests, mechanical damage occurred that was apparently caused by the rebound of the gun after firing. Although the Kevlar shells had more than adequate strength, they appeared to lack sufficient stiffness, allowing excessive deflections. The use of a steel structural shell with a Kevlar sleeve was an improvement. Intrusion into the seams of the rail guns and condensation of material from the plasma armature were observed. Improved sealing of seams is indicated. In some cases, we suspect maldistribution of current within the gun; that is, not all the current delivered to the breech of the gun seemed to reach the plasma armature. Experiments are being designed to quantify the effects discussed. Rail guns of advanced design are being fabricated. An 18-g titanium projectile was accelerated to 2.4 km/s in a 16-mm-round-bore, 0.6-m-long gun, 4-6 g polycarbonate projectiles were accelerated to 3.5 km/s in 13-mm-square-bore, 1.2-m-long rail guns. All tests were conducted at atmospheric pressure

  4. Optimization Analysis of Artillery Forces Distribution Based on Functioned Modularity%基于功能“模块化”炮兵兵力区分优化分析

    Institute of Scientific and Technical Information of China (English)

    尚保禄; 秦喜庆

    2011-01-01

    It expatiates the advantages of artillery forces distribution based on functional modularity with qualitative a nalysis method, establishes a artillery forces distribution model based on functional modularity, demonstrates what the ad vantages are with quantitative analysis method.%定性地阐述了基于功能“模块化”炮兵兵力区分的优势,构建了基于功能“模块化”炮兵兵力区分模型,利用定量分析的方法论证了其优势所在。

  5. Experimental studies of coaxial plasma gun current

    International Nuclear Information System (INIS)

    In this investigation of a coaxial plasma gun, plasma sheath currents and related behavior are examined. Plasma behavior in the gun affects gun characteristics. Plasma gun applications are determined by the plasma behavior. The AFWL PUFF capacitor bank (72 μF, 29 nH, 120 kV) drives the plasma gun using a deuterium fill gas. The gas breakdown site is isolated from the dielectric/vacuum interface in the AFWL system. Two gas values deliver gas in the system. The first delivers gas from the gun breech and the second optional valve delivers gas to the gun muzzle. Currents and voltages are measured by Rogowski coils, B probes and capacitive voltage probes. A O-D slug model is used to predict the current, inductance, gun voltage and plasma sheath velocity. The slug model assumes the sheath transits the gun with all mass in the sheath. In the snowplow mode, the plasma sheath is thin with a sharp current rise and drop. Our system operated in a transition mode between the snowplow and deflagration modes with early snowplow behavior and late deflagration behavior. Neutrons are produced in a plasma pinch at the gun muzzle, indicating snowplow behavior. The slug theory models overall gun behavior to experimental accuracy. Experimental results are compared to four theories for plasma sheath velocities: the Alfven collisionally limited model, the Rosenbluth model, the Fishbine saturated model and a single particle drift model. Experimental velocities vary from 105 to 106 m/s. Only the single particle drift and the slug model calculations are of the right magnitude (8 x 105 m/s). The Fishbine and the Rosenbluth models predict slower velocities (2 x 105 m/s). The Alfven model is not applicable to this system

  6. Genomic insights into strategies used by Xanthomonas albilineans with its reduced artillery to spread within sugarcane xylem vessels

    Directory of Open Access Journals (Sweden)

    Pieretti Isabelle

    2012-11-01

    specific to X. albilineans were identified, supposing that X. albilineans has a reduced artillery compared to other pathogenic Xanthomonas species. Particular attention has therefore been given to genomic features specific to X. albilineans making it more capable of evading sugarcane surveillance systems or resisting sugarcane defense systems. Conclusions This study confirms that X. albilineans is a highly distinctive species within the genus Xanthomonas, and opens new perpectives towards a greater understanding of the pathogenicity of this destructive sugarcane pathogen.

  7. Crafting a Gauss Gun Demonstration

    Science.gov (United States)

    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.

  8. Gun Control: The Debate and Public Policy.

    Science.gov (United States)

    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)

  9. Youth Homicide and Guns. Firearm Facts.

    Science.gov (United States)

    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…

  10. Plasma-gun fueling for tokamak reactors

    International Nuclear Information System (INIS)

    In light of the uncertain extrapolation of gas puffing for reactor fueling and certain limitations to pellet injection, the snowplow plasma gun has been studied as a fueling device. Based on current understanding of gun and plasma behavior a design is proposed, and its performance is predicted in a tokamak reactor environment

  11. On the theory of photocathode rf guns

    Institute of Scientific and Technical Information of China (English)

    GAO Jie

    2009-01-01

    In this paper we give a set of analytical formulae to describe the characteristics of photocathode rf guns at any rf frequencies, such as energy, energy spread, bunch length, out going current, and emittance etc.as functions of the laser injection phase, which are useful in the design and practical operation of rf guns.

  12. Pyrotechnic Igniters for Liquid Propellant Gun .

    OpenAIRE

    D. K. Kharat; K. J. Daniel; K. R. Rao; A. A. Ghosh; Shah, S.T.; S. C. Mitra

    1997-01-01

    The results of a preliminary investigation on the use of liquid propellant for gun application are presented. Both regenerative and bulk loaded liquid propellant guns were used in the study.Pyrotechnic igniters were tried out for igniting the liquid propellant. Existing pyrotechnic igniters were suitably modified to obtain pressure beyond 20 MPa in less than 3 ms in the combustion chamber.

  13. Superconducting 112 MHz QWR electron gun

    Energy Technology Data Exchange (ETDEWEB)

    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.

  14. Long pulse electron gun for laser applications

    International Nuclear Information System (INIS)

    This paper reports on large-area electron guns that are critical components in many high-energy gas laser systems. The secondary emission electron (SEE) gun offers an attractive option for pulsed laser applications. With this type of cold cathode gun, a dc voltage is applied to the cathode and the electron beam is generated by secondary emission due to ion bombardment processes. The gun is controlled by modulating the source of ions which resides at ground potential. This design greatly simplifies the electron gun power system. SEE-gun systems have been developed which provide 150-220 keV beams at current densities exceeding 25 mA/cm2 with current density uniformities of approximately ±10% over areas of up to 5 x 150 cm2. Pulse lengths have ranged from 30 μs to 20 ms at repetition rates from single-pulse to 30 Hz. It is expected that the SEE-gun can be scaled to beam voltages of greater than 300 kV, beam areas greater than 1 m2, peak current densities exceeding 1 A/cm2, time-averaged current densities approx-gt 0.5 mA/cm2, pulse lengths of 0.1 μs to dc, and pulse repetition rates >1 kHz with good uniformity, high reliability and long life. Furthermore, the inherent simplicity of the SEE-gun results in low cost and a compact, light-weight system

  15. New Electron Gun System for BEPCII

    CERN Document Server

    Liu, Bo; Long Chi, Yun; Zhang, Chuang

    2005-01-01

    The new electron gun system for BEPCII has been put into operation since Nov. 2004. The article describes the design, experiment and operation of this new system. The design current of the gun is 10 A for the pulse lengths of 1 ns, 2.5 ns and 1 μs with repetition rate of 50 Hz. The gun is operated with a pulsed high voltage power supply which can provide up to 200 kV high voltage. Computer simulations have been carried out in the design stage, including simulation of the gun geometry and beam transportation. Some important relation curves are obtained during the experiment. Two-bunch operation is available and some elementary tests have been performed. New scheme of the gun control system based on EPICS is also presented. The real operation shows that the design and manufacturing is basically successful.

  16. Sequential injection gas guns for accelerating projectiles

    Science.gov (United States)

    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.

  17. Beam dynamics studies for photocathode RF gun

    International Nuclear Information System (INIS)

    Photocathode RF guns are very popular choice as injector for low emittance beams especially to light sources world wide. In demand for these gun is increasing steadily and efforts are on to make 2.6 cell RF Gun as SAMEER as proto type for future use at various laboratories. The base design of this 2.6 cell RF Gun is ready and fabrication is planned in near future. In this paper, we present beam dynamic study results of the gun and methodology to arrive at the operating point. Simulation results for Gaussian with nano-second pulse length will be discussed in detail and proposal for generation of few MeV beam will be presented. (author)

  18. The Ames Vertical Gun Range

    Science.gov (United States)

    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.

  19. Top-down Structural Design Method of Large-caliber Naval Gun Based on UG/WAVE%基于UG/WAVE的大口径舰炮结构自顶向下设计方法

    Institute of Scientific and Technical Information of China (English)

    姚忠; 夏方超

    2016-01-01

    A top-down design method was applied to design the structure of large-caliber naval gun in accordance with the structural feature of large-caliber naval gun. Based on the analysis of structure differences,large-caliber naval guns were classified according to ammunition loading paths and laun-ching-feeding. Taken the complex loading large-caliber naval gun for example,the skeleton and para-metric solid models were established according to the top-down design method. The method can effec-tively achieve quantitative,parametric design of large-caliber naval gun,and also has a measure of reference value in improving the efficiency of artillery engineering design.%针对大口径舰炮结构特点,将自顶向下设计方法应用于大口径舰炮的结构设计中。按大口径舰炮弹药装填路径和扬供弹方式的不同,对大口径舰炮进行了类别划分。以复合装填大口径舰炮为设计实例,进行大口径舰炮结构自顶向下设计研究。建立了某复合装填大口径舰炮的顶层骨架模型和参数化实体模型。该设计方法能够有效实现大口径舰炮定量化、参数化设计,对提高火炮工程设计效率有一定的参考价值。

  20. 基于UG/WAVE的大口径舰炮结构自顶向下设计方法%Top-down Structural Design Method of Large-caliber Naval Gun Based on UG/WAVE

    Institute of Scientific and Technical Information of China (English)

    姚忠; 夏方超

    2016-01-01

    针对大口径舰炮结构特点,将自顶向下设计方法应用于大口径舰炮的结构设计中。按大口径舰炮弹药装填路径和扬供弹方式的不同,对大口径舰炮进行了类别划分。以复合装填大口径舰炮为设计实例,进行大口径舰炮结构自顶向下设计研究。建立了某复合装填大口径舰炮的顶层骨架模型和参数化实体模型。该设计方法能够有效实现大口径舰炮定量化、参数化设计,对提高火炮工程设计效率有一定的参考价值。%A top-down design method was applied to design the structure of large-caliber naval gun in accordance with the structural feature of large-caliber naval gun. Based on the analysis of structure differences,large-caliber naval guns were classified according to ammunition loading paths and laun-ching-feeding. Taken the complex loading large-caliber naval gun for example,the skeleton and para-metric solid models were established according to the top-down design method. The method can effec-tively achieve quantitative,parametric design of large-caliber naval gun,and also has a measure of reference value in improving the efficiency of artillery engineering design.

  1. 基于动态贝叶斯网的炮兵战斗效果评估建模仿真%Modeling and Simulation of Artillery Combat Effectiveness Assessment Based on Dynamic Bayesian Networks

    Institute of Scientific and Technical Information of China (English)

    李小全; 石高峰; 程懿

    2012-01-01

    依据炮兵火力作战的特点规律,分析炮兵战斗效果评估的内容、程序、建模过程和影响因素,运用动态Bayesian网建立炮兵战斗效果评估模型,运用主成分分析方法确定评估专家权重,运用Poly Tree的消息传递算法进行评估网络推理分析,最后结合案例仿真验证.结果表明,该研究解决了情报信息不确定性、模糊性和动态性等影响战斗效果精确评估问题.%According to artillery fire combat characteristics and pattern, artillery combat effectiveness assessment content, procedure, modeling mechanism and its effect factors is analyzed, artillery combat effectiveness assessment dynamics bayesian networks model is constructed, using principal component analysis to ascertain assessment factor weight, using Poly Tress message delivery algorithm to make bayesian networks reason. At last, a combat example is taken to be simulated and verified, some good results are gained. This research can resolve the problem affected artillery combat effectiveness exact assessment because of combat field intelligence uncertainty, obscure and developments.

  2. SEA-based dynamic assessment of artillery air power scout efficiency%基于SEA的炮兵空中力量侦察效能动态评估

    Institute of Scientific and Technical Information of China (English)

    薛向锋; 侯智斌; 孙彦飞

    2012-01-01

    With status continuous promotion of the air scout force applied to Artillery, the real-time, scientificalness and rationality of scout efficiency assessment will affect war course directly. Based on the SEA method, the calibration for three main performances of artillery air-power scout efficiency are proposed. The SEA model for evaluating the dynamic efficiency of artillery air-power system is established under the war conditions. The foundation for the reasonable application of the artillery air-power scout and for commander to make decision timely and right was established.%随着空中侦察力量在炮兵侦察中的地位不断提升,其效能评估的实时性、科学性以及合理性将直接影响到战争进程.基于SEA方法,提出了针对炮兵空中力量侦察效能的三个主要性能度量,结合具体战场环境的军事想定,建立了炮兵空中力量侦察效能的动态评估模型,为炮兵空中侦察力量的合理运用、指挥员做出正确决策指挥奠定了坚实的基础.

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

    Science.gov (United States)

    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

  4. Simulation of Gun Magneto-rheoloical Recoil System%火炮磁流变后坐系统仿真

    Institute of Scientific and Technical Information of China (English)

    朱超; 李赵春; 杨哲; 王炅

    2012-01-01

    Applying MR technology to gun recoil device is a new developing technology, which can reduce gun re coil force. A MR recoil system was designed according to a type of gun based on its dynamic model and electromag netic model. PID and fuzzy control algorithm was proposed to achieve the ideal recoil law. The result of ADAMS and MATLAB co-simulation shows that under the range of recoil stroke, the maximum recoil force is 3. 53×105N,3. 71 × 105N, reduced by 13% and 17% compared to traditional artillery. Recoil force curve under the fuzzy control has a good " platform effect" to achieve the control target, indicating that the MR damper has good controllability and feasi bility used in gun recoil system.%将磁流变技术应用于火炮反后坐装置是目前正在发展的一种降低火炮后坐力的新技术,优化火炮反后坐装置控制,达到实时调节阻力.针对某型号火炮,在建立动力学模型和电磁模型的基础上设计了磁流变反后坐系统.为实现理想的后坐控制规律,提出了PID和模糊控制算法.利用ADAMS和MATLAB进行联合仿真,仿真结果表明,在后坐行程范围内,最大后坐阻力分别为3.71×105N,3.53×105N,相比传统火炮减小了13%和17%,并且模糊控制的后坐阻力曲线具有良好的“平台效应”,实现了控制目标,表明磁流变阻尼器良好的可控性和应用于火炮后坐系统中的可行性.

  5. Simple light gas guns for hypervelocity studies

    International Nuclear Information System (INIS)

    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 ∼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

  6. Correlates of Gun Involvement and Aggressiveness among Adolescents.

    Science.gov (United States)

    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…

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

    Science.gov (United States)

    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…

  8. Gun Safety Management with Patients at Risk for Suicide

    Science.gov (United States)

    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…

  9. Texas youth stage rally against guns

    Institute of Scientific and Technical Information of China (English)

    Mary; Alice; Robbins; 李小平

    2000-01-01

    Young Texans Against Gun Violence rallied atthe State Capitol on Monday and called for the Legisla-ture to pass laws that would make it more difficult toget guns.“It is time for our state Legislature to pass laws tohelp protect us,”Marianne Moreno,a high school se-nior from the Dallas area,told a crowd of about 125students who attended the“Packing Peace Rally.”“As Texas law stands today,anyone—even acriminal—can walk into a gun show and purchase asemi-automatic weapon or any other type of firearm,...

  10. Advances in DC photocathode electron guns

    International Nuclear Information System (INIS)

    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 back-bombardment, 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

  11. Advances in DC photocathode electron guns

    International Nuclear Information System (INIS)

    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 throughput. 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, we will review recent results and discuss implications for future photocathode guns. copyright 1999 American Institute of Physics

  12. Field reversal produced by a plasma gun

    International Nuclear Information System (INIS)

    Experimental results are presented of the production of Field-Reversed Plasma with a high energy coaxial plasma gun. The gun is magnetized with solenoids inside the center electrode and outside the outer electrode so that plasma emerging from the gun entrains the radial fringer field at the muzzle. The plasma flow extends field lines propagating a high electrical conductivity, the flux inside the center electrode should be preserved. However, for low flux, the trapped flux exceeds by 2 or more the initial flux, possibly because of helical deformation of the current channel extending from the center electrode

  13. Evaluation of Smart Gun Technologies preliminary report

    Energy Technology Data Exchange (ETDEWEB)

    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.

  14. The internal ballistics of a leaking gun

    Directory of Open Access Journals (Sweden)

    D. S. Kothari

    1952-09-01

    Full Text Available The dynamical problem of the motion of the shot in the gun, which is rendered complicated as it has to take account of  the irreversible processes in the gun such as the physical shot-start pressure, the bore resistance and the heat-loss to the barrel, and the flow of the gas behind the shot. In the theory of an orthodox gun, the effect of the gas-flow is taken, account of by the so-called ‘Lagrange corrections.  

  15. Serious childhood injuries caused by air guns.

    OpenAIRE

    Shanon, A; Feldman, W.

    1991-01-01

    OBJECTIVE: To determine the severity of nonfatal injuries to children caused by air guns and pellet guns. DESIGN: Case series (hospital chart review). SETTING: Inpatient wards of the Children's Hospital of Eastern Ontario. PATIENTS: All children under 18 years of age admitted to the hospital from Jan. 1, 1979, to Dec. 31, 1989, under ICD code E917, E922, E955, E965, E970 or E985 who had suffered air gun injuries. MAIN OUTCOME MEASURES: Personal data, circumstances of event and clinical data. ...

  16. Advances in DC photocathode electron guns

    International Nuclear Information System (INIS)

    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 throughput. 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, we will review recent results and discuss implications for future photocathode guns

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

    Science.gov (United States)

    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

  18. Rail gun powered by an integral explosive generator

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, D.R.; Fowler, C.M.

    1979-01-01

    We propose the use of a rail gun powered by an explosive magnetic flux compression generator built into the rail gun itself in which the rails of the gun are driven together behind the projectile by explosives. The magnetic field established between the rails by an initial current supplied by an external source at the breech of the gun is trapped and compressed by the collapsing rails to accelerate the projectile down the bore of the gun.

  19. Waterfowl habitat survey : Canvasback Gun Club : 1965

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes a survey of the submergent and emergent aquatics growing in the marsh on the Canvasback Gun Club in Nevada. As stated in previous years of...

  20. Waterfowl habitat survey : Canvasback Gun Club : 1963

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes a survey of the submergent and emergent aquatics growing in the marsh on the Canvasback Gun Club in Nevada. The marsh portion of the...

  1. Ballistic Rail Gun Soft Recovery Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Ballistic Rail Gun Soft Recovery Facility accommodates a 155mm Howitzer, fired horizontally into a 104-foot long water trough to slow the projectile and recover...

  2. Waterfowl habitat survey : Canvasback Gun Club : 1964

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes a survey of the submergent and emergent aquatics growing in the marsh on the Canvasback Gun Club in Nevada. The marsh portion of the...

  3. Waterfowl habitat survey : Canvasback Gun Club : 1972

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Since the last vegetative survey in 1965, the marsh at Canvasback Gun Club has remained virtually unchanged. The ArthurJohnson Ponds produced most of the waterfowl...

  4. Uudised : Guns N' Roses Soomes. Valmis ulmeraadio

    Index Scriptorium Estoniae

    2006-01-01

    Ameerika hard-rock-bändi Guns N' Roses kontserdist 5. juulil Hartwall Areenal Soomes. Kord kuus on Ulmeplaatide kodulehekülel www. ulmeplaadid.ee võimalus kuulata ulmeraadiot, kus esitusel eesti kergemuusika

  5. RF Electron Gun with Driven Plasma Cathode

    CERN Document Server

    Khodak, Igor

    2005-01-01

    It's known that RF guns with plasma cathodes based on solid-state dielectrics are able to generate an intense electron beam. In this paper we describe results of experimental investigation of the single cavity S-band RF gun with driven plasma cathode. The experimental sample of the cathode based on ferroelectric ceramics has been designed. Special design of the cathode permits to separate spatially processes of plasma development and electron acceleration. It has been obtained at RF gun output electron beam with particle energy ~500 keV, pulse current of 4 A and pulse duration of 80 ns. Results of experimental study of beam parameters are referred in. The gun is purposed to be applied as the intense electron beam source for electron linacs.

  6. Arc Plasma Gun With Coaxial Powder Feed

    Science.gov (United States)

    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.

  7. Waterfowl habitat survey : Canvasback Gun Club : 1962

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report is about an investigation that was done to determine the quantity and species of submergent vegetation in the marsh area on the Canvasback Gun Club in...

  8. Conference on electromagnetic guns and launchers, 1980

    International Nuclear Information System (INIS)

    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. All papers are abstracted and indexed separately

  9. The Impact of Banning Juvenile Gun Possession.

    OpenAIRE

    Thomas B. Marvell

    2001-01-01

    A 1994 federal law bans possession of handguns by persons under 18 years of age. Also in 1994, 11 states passed their own juvenile gun possession bans. Eighteen states had previously passed bans, 15 of them between 1975 and 1993. These laws were intended to reduce homicides, but arguments can be made that they have no effect on or that they even increase the homicide rate. This paper estimates the laws' impacts on various crime measures, primarily juvenile gun homicide victimizations and suic...

  10. Pyrotechnic Igniters for Liquid Propellant Gun .

    Directory of Open Access Journals (Sweden)

    D. K. Kharat

    1997-04-01

    Full Text Available The results of a preliminary investigation on the use of liquid propellant for gun application are presented. Both regenerative and bulk loaded liquid propellant guns were used in the study.Pyrotechnic igniters were tried out for igniting the liquid propellant. Existing pyrotechnic igniters were suitably modified to obtain pressure beyond 20 MPa in less than 3 ms in the combustion chamber.

  11. Anti-aircraft Missiles and Gun Control

    OpenAIRE

    BLOCK, Walter

    2016-01-01

    Abstract. Gun control is a highly debatable topic both in the popular and scholarly media. But what about anti-aircraft missiles? Should they be banned? On the one hand, there are fewer of them around, so their challenge is more tractable. On the other hand, they can do far more damage than handguns. The present paper is an attempt to wrestle with this challenge.Keywords. Gun control, Second amendment, Libertarianism, Anti-aircraft missiles.JEL. K15.

  12. Research Status of Gun Barrel Erosion and Inhibitor Mitigation Mechanism%身管烧蚀及缓蚀剂作用机理研究现状

    Institute of Scientific and Technical Information of China (English)

    林少森; 闫军; 俞卫博; 李洪广; 杜仕国

    2016-01-01

    身管烧蚀磨损严重限制了火炮性能的提高和服役年限的延长。为延长身管寿命、发展高威力火炮,需增强火炮身管的抗烧蚀磨损能力。从热冲击、化学侵蚀、机械磨损三方面综述国内外身管烧蚀机理的研究现状,分析认为烧蚀磨损的发生与加剧主要归结于热-化学-机械复合作用。在此基础上梳理缓蚀剂技术抑制身管烧蚀磨损的机理,指出纳米材料在缓蚀剂研制中的意义,无机氧化物和含氮有机材料在发射环境下可对身管内壁形成保护。对缓蚀剂的设计作出展望,为新型缓蚀剂设计提供有益思考。%Serious wear and erosion of barrel has limited the improvement of artillery performance and the extension of service life. In order to extend the life of barrel and increase gun performance,it is necessary to enhance anti-erosion endurance and resistance to attrition of artillery barrel. It summarized the domestic and international research status of wear and erosion mechanism of barrel in terms of ther-mal damage,chemical corrosion and mechanical wear. It was analyzed that the occurrence and aggra-vation of wear and erosion was primarily attributed to thermal-chemical-mechanical effects. Based on this,an analysis is made of the mitigation mechanism of the erosion inhibiting agent. The significance of nanometer materials in producing inhibitor is pointed out. And it is also pointed out that inorganic oxide and nitrogenous organic materials could protect gun bore under firing condition. Moreover,pros-pects in the future are envisioned in the design of inhibitor and provided thought-provoking ideas for the design of new type of inhibitor.

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

    Science.gov (United States)

    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…

  14. 基于DoDAF的舰载弹炮结合防空武器系统模型%Shipboard Missile Gun Integrated Air-Defense Weapon System Model Based on DoDAF

    Institute of Scientific and Technical Information of China (English)

    王洪胜; 禹大勇; 曲延明

    2014-01-01

    In current sea battle, aiming at the point-defense ship-to-air missile and small caliber shipboard artillery can’t realize reserving battle task independently, establish shipboard missile-gun integrated air-defense weapon system based on DoDAF. Analyze design process of shipboard missile-gun integrated air-defense weapon system, combining with military requirement and battle flow to establish part of battle model, then describe operation process of shipboard missile-gun integrated air-defense weapon system in water surface ship terminal defense. It promotes the top layer design of shipboard missile-gun integrated air-defense weapon system and gives technology support for danger control.%针对现代海战中点防御舰空导弹和小口径舰炮难以独立完成预定作战任务的问题,构建一种基于DoDAF的舰载弹炮结合防空武器系统模型。分析了舰载弹炮结合防空武器系统设计步骤,结合军事需求、作战流程构建了部分作战模型,并阐述了舰载弹炮结合防空武器系统在水面舰艇末端防御作战中的活动过程。目的是推动舰载弹炮结合防空武器系统顶层设计和风险控制提供技术支撑。

  15. Modeling internal ballistics of gas combustion guns.

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

  17. A high-brightness thermionic microwave electron gun

    International Nuclear Information System (INIS)

    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 ec · μm for a beam consisting of approximately 50% of the particles emitted from the gun, and having a momentum spread ±10%. These emittances are for up to 5 x 109e- per bunch. Chromatic aberrations in the transport line between the gun and linear accelerator increase this to typically e · μm

  18. Higher-order mode rf guns

    Science.gov (United States)

    Lewellen, John W.

    2001-04-01

    Traditional photocathode rf gun design is based around the use of TM0,1,0-mode cavities. This is typically done in the interest of obtaining the highest possible gradient per unit supplied rf power and for historical reasons. In a multicell, aperture-coupled photoinjector, however, the gun as a whole is produced from strongly coupled cavities oscillating in a π mode. This design requires very careful preparation and tuning, as the field balance and resonant frequencies are easily disturbed. Side-coupled designs are often avoided because of the dipole modes introduced into the cavity fields. This paper proposes the use of a single higher-order mode rf cavity in order to generate the desired on-axis fields. It is shown that the field experienced by a beam in a higher-order mode rf gun is initially very similar to traditional 1.5- or 2.5-cell π-mode gun fields, and projected performance in terms of beam quality is also comparable. The new design has the advantages of much greater ease of fabrication, immunity from coupled-cell effects, and simpler tuning procedures. Because of the gun geometry, the possibility also exists for improved temperature stabilization and cooling for high duty-cycle applications.

  19. ECR ion source with electron gun

    Science.gov (United States)

    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.

  20. Progress of the Rossendorf SRF Gun Project

    CERN Document Server

    Teichert, J; Büttig, H; Janssen, D; Lehnert, U; Michel, P; Möller, K; Murcek, P; Schneider, C; Schurig, R; Staufenbiel, F; Xiang, R

    2005-01-01

    A superconducting rf photo electron injector (SRF gun) is under development at the Forschungszentrum Rossendorf. The project aims at several issues: improvement of the beam quality for the ELBE superconducting electron linac, demonstration of feasibility of this gun type, investigation of critical components, and parameter studies for future application (BESSY-FEL, 4GLS). In 2005, a substantial progress has been made. The two 3.5-cell niobium cavities for the gun have been delivered from the company ACCEL. The main parts for gun cryostat like vacuum vessel, cryogenic and magnetic shields are ready. Test benches for the cathode cooling system and the cavity tuner are being assembled. The photo cathode preparation lab has been arranged, and the diagnostic beam line has been designed (see T. Kamps et al., this conference). After delivering the gun cavities, their rf properties are being measured at room temperature and the warm tuning is being carried out. The set-up for this treatment and measurement as well as...

  1. Development of plasma cathode electron guns

    Science.gov (United States)

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

    Science.gov (United States)

    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

  3. Gun Injuries More Often Fatal Now, Study Finds

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_159357.html Gun Injuries More Often Fatal Now, Study Finds ERs ... June 14, 2016 (HealthDay News) -- Injuries from senseless gun violence -- like those witnessed in Orlando on Sunday ...

  4. Gun Injuries More Often Fatal Now, Study Finds

    Science.gov (United States)

    ... nlm.nih.gov/medlineplus/news/fullstory_159357.html Gun Injuries More Often Fatal Now, Study Finds ERs ... June 14, 2016 (HealthDay News) -- Injuries from senseless gun violence -- like those witnessed in Orlando on Sunday ...

  5. The Adhesion and Formation Mechanism of Blast Furnace Gunning Layer

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Basing on the study of the equilibrium relationship of interfacial tension among gunning particles, repaired surface and atmosphere, this test is in a position to draw a conclusion concerning the adhesion mechanism of the gunning refractory and the repaired surface, which illustrates the formation of the bottom gunning layer by moist fine gunning particles on the repaired surface. Also involved within the scope of discussion and probe are the patterns formed under this contacting effect and the formation mechanism of gunning layer. The analytic research regarding the behavior of gunning interface has ascribed the influence upon adhesion intensity to the quality of furnace gunning refractory, the state of the repaired surface and the gunning techniques.

  6. The Real Costs of Gun Violence

    Energy Technology Data Exchange (ETDEWEB)

    Cook, Philip J. (Duke University)

    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.

  7. Secondary emission electron gun using external primaries

    Science.gov (United States)

    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.

  8. Improved DC Gun and Insulator Assembly

    Energy Technology Data Exchange (ETDEWEB)

    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.

  9. The interaction between potential criminals' and victims' demands for guns

    OpenAIRE

    Baç, Mehmet; Bac, Mehmet

    2009-01-01

    I develop a model with endogenous gun ownership and study the interaction between the demands for guns by heterogeneous potential offenders and victims. I show that the interaction depends on pervasiveness of guns, injury probabilities and, in particular, the impact of the gun on the probability of success against armed relative to unarmed adversaries. While the sanction on armed offense is maximal under plausible conditions, the sanction on unarmed offense balances direct deterrence benef...

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

    OpenAIRE

    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 m...

  11. Development of Electron Guns for Linacs and DC Accelerator

    International Nuclear Information System (INIS)

    Electrons guns for RF linacs and DC Accelerators are designed and developed at Electron Beam Centre (EBC)/APPD/BARC. Planar geometry grid and Pierce geometry grid configuration diode and triode guns with LaB6 cathode are developed. The cathode assembly consists of cups and heat shields made out of Tantalum and Rhenium sheets. The cathode assembly and the electron guns are tested on a test bench for beam characterization. The paper presents the development of the electron guns.

  12. Interpreting the Empirical Evidence on Illegal Gun Market Dynamics

    OpenAIRE

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

    2012-01-01

    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 ad...

  13. Dynamic Simulation of the Tank Gun Recoil Response

    Institute of Scientific and Technical Information of China (English)

    XING Jun-wen; WANG Liang-xi; SHI Yan; CHEN Chun-liang

    2005-01-01

    By using the ATV module of MSC. ADAMS, the dynamic simulation of recoil response of tank gun is analyzed.How the recoil force affects the bodywork and the suspension during gun firing, as well as the changing status of the gun muzzle's velocity are gained. All results and analyzing methods are offered for the designing basis of optimizing tank vehicle-gun match. The constructive exploration is beneficial to improving the general capability of tank.

  14. Simulations of Gaussian electron guns for RHIC electron lens

    Energy Technology Data Exchange (ETDEWEB)

    Pikin, A. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.

    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.

  15. Simulations of Gaussian electron guns for RHIC electron lens

    International Nuclear Information System (INIS)

    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.

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

    OpenAIRE

    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 incurr...

  17. Cellulose Acetate Binder-Based LOVA Gun Propellant for Tank Guns.

    Directory of Open Access Journals (Sweden)

    A.G.S. Pillai

    1999-04-01

    Full Text Available Cellulose acetate (CA binder-based low vulnerability ammunition (LOYA gun propellant formulations with varying percentages of fine RDX as energetic ingredient have been studied. RDX percentage varied from 76 to 80 in these formulations. An optimised composition with 78 per cent RDX was then studied exhaustively. Ballistic data determined by closed vessel (CV evaluation and vulnerability aspects obtained by safety tests were then compared vis-a-vis the properties of standard triple base NQ composition. Theoretical prediction and CV test results indicated that the CA binder-based LOVA gun propellant Could satisfactorily meet the ballistic requirements for gun application.

  18. OCULAR INJURIES CAUSED BY BB GUN

    Directory of Open Access Journals (Sweden)

    M.S. Farahvash

    1999-08-01

    Full Text Available in ordere to determine the prognosis of perforating eye injuries caused hy BB guns in our patients, the"nvisual and anatomic results of 14 patients with gun injuries seen between September 1996 and February 1998 in Farafti Hospital and private office in Tehran were reviewed. Five patients liad nonn erf orating eye injuries. All perforated eyes underwent scleral buckling, tenseclomy, vitrectomy ami silicone injection. All injured iyes had a visual acuity of light perception or better at presentation. Among 9 cases of perforating injuries. 7 had doable and 2 had single perforation. All patients had a final.

  19. Guns N’ Arenas黑枪事件

    Institute of Scientific and Technical Information of China (English)

    狄艾

    2010-01-01

    奇才队"零号探员"阿里纳斯(Gilbert Arenas)和知名摇滚乐团"枪和玫瑰(Guns N’Roses)"同样发迹于美国加州,但当"枪和阿里纳斯(Guns N’Are nas)"连结在一起时,代志就大条了!先前名气直逼摇滚巨星的阿里纳斯,恐怕将因去年12月的"黑枪事件"身败名裂!

  20. Dynamics modelling of biolistic gene guns

    International Nuclear Information System (INIS)

    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

  1. Electron trapping mechanisms in magnetron injection guns

    Science.gov (United States)

    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.

  2. Study of Control Grid Thermionic Cathode RF Gun

    CERN Document Server

    Xiao, Jin; Ming, Li; Xinfan, Yang; Xumin, Shen; Yanan, Chen; Zhou, Xu

    2004-01-01

    In this paper, the beam loading effect of RF Gun was analyzed. To minimize the energy spread, the grid control RF Gun was introduced. The result shows that the grid congrol RF Gun can increase electron beam within 1% energy spread.

  3. 78 FR 11902 - Review of Gun Safety Technologies

    Science.gov (United States)

    2013-02-20

    ... of Justice Programs Review of Gun Safety Technologies AGENCY: National Institute of Justice, JPO, DOJ. ACTION: Notice. SUMMARY: Following the President's Plan to reduce gun violence released on January 16...) is conducting a review of existing and emerging gun safety technologies and plans to issue a...

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

    Science.gov (United States)

    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…

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

    Science.gov (United States)

    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…

  6. Economic Analysis of a Traveling Gun for Feedyard Dust Suppression

    OpenAIRE

    Amosson, Stephen H.; Bretz, Fran E.; New, Leon L.; Almas, Lal K.

    2007-01-01

    Dust created in feedyards can adversely affect cattle performance. Dust suppression can be accomplished by moistening pen surfaces with traveling gun(s) sprinklers, solid-set sprinklers, and water trucks. This study specifically addresses the fixed and operational costs associated with a traveling gun sprinkler system for various sized feedyards.

  7. Numerical Modelling of Regenerative Liquid Propellant Guns with Annular Piston

    OpenAIRE

    K. J. Daniel; D. K. Kharat; K.R. Rao; Shah, S.T.; S. C. Mitra

    1997-01-01

    The development of regenerative liquid propellant guns (RLPGs) needs due consideration of numerous interdependent parameters that affect its performance. To help in this task, computer simulation was undertaken to predict internal ballistics of a conceptual liquid propellant gun. The expected pressure and other important parameters are documented which serve as an aid to the hardware, design of the regenerative liquid propellant guns.

  8. Klystron - Space-charge limited flow, guns, Perveance

    International Nuclear Information System (INIS)

    This paper treats Thermionic emission, Cathode as an e- emitter, Space-charge limited effect and 3/2 power law, Perveance, Beam spread due to space charge, Pierce guns, Magnetically immersed guns, Method of gun design including simulations, and Examples, mainly treating E3786, which attendees will operate above 1 MW-CW in a practical exercise course at KEK. (author). 74 refs

  9. Pulsed electron gun and linear accelerator fitted with such a gun

    International Nuclear Information System (INIS)

    This invention relates to a pulsed electron gun comprising a leak-tight insulating tube closed at one end. A voltage of several tens of kilovolts is applied by cables to the ends of the tube. Among its other features this gun includes a conducting tube fitted inside an insulating tube on the same centre line, in a leak-tight manner to it. This conducting tube forms the grid support, and the bottom of the well so formed being closed by a conducting plate insulated from the conducting tube by an insulating ring, this plate becomes the support of the gun cathode. The grid support is part of the vacuum containment so formed. The electron linear accelerator comprising such a pulsed electron gun is also described

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

    OpenAIRE

    Kelly V Ruggles; Sonali Rajan

    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 cal...

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

    OpenAIRE

    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 calcu...

  12. Internal ballistics of guns and rockets

    Directory of Open Access Journals (Sweden)

    Asim Ray

    1964-07-01

    Full Text Available An exact analytical solutions of the equations relating to the internals ballistics of guns and rockets in the non-isothermal model using tubular propellants which burns according to the pressure-index law has been obtained. An approximate solution to a pre-assigned level of accuracy has been presented.

  13. Collapsible pistons for light-gas guns

    Science.gov (United States)

    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%.

  14. Effective launch package integration for electromagnetic guns

    Energy Technology Data Exchange (ETDEWEB)

    Hayden, T.E. [Kaman Sciences Corp., Colorado Springs, CO (United States); Dethlefsen, R. [Maxwell Labs., Inc., San Diego, CA (United States); Price, J.H. [Univ. of Texas, Austin, TX (United States). Center for Electromechanics

    1995-01-01

    Many engineering disciplines must be considered when designing launch packages for electromagnetic guns. These include electromechanics, plasma physics, fluid dynamics, structures, materials science, aerodynamics, thermodynamics, flight dynamics, and terminal effects. Often, the requirements of one discipline will be in direct conflict with the requirements of another. Each discipline can claim to be of overriding importance, but all aspects of launch package design must be considered if the gun system is to succeed in its mission. Choices must be made regarding launch package configuration. Base-pushing or mid-riding solutions are possible with solid, hybrid or plasma armatures. Fully optimized launch package designs must be used in comparisons to find the actual optimal design point. The most effective design for one gun system will not necessarily be the most effective for another. This paper discusses the interplay among the various engineering disciplines involved in launch package design. Successful testing of integrated projectile/armature/sabot configurations from 90 mm EM guns is reviewed.

  15. How Sociology Texts Address Gun Control

    Science.gov (United States)

    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…

  16. College Students Opinions on Gun Violence.

    Science.gov (United States)

    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 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

  17. Development of the Antares electron gun

    International Nuclear Information System (INIS)

    Antares is the Los Alamos National Laboratory 40-kJ, 1-ns, CO2 laser system that is now operational. This laser system was developed for the Intertial Confinement Fusion (ICF) program and is beginning target experiments. The distributed circuit modeling, design and operation of the large electron gun developed for the final laser power amplifier are reviewed. This gun is significant because of the large electron current area, 9 m2; the number of emitter blades, 48; the dual cathode current return; and the coaxial geometry and grid control. The gun components and their development are discussed. These include the emitter blades, the coaxial grid (to maintain constant electron current during the 5-μs pulse), the bonded stacked-ring insulator (to electrically insulate the grid/cathode), the Kapton/aluminum electron transmission windows (to provide an interface between gun vacuum and laser gas) and the vacuum shell (operated at a vacuum of 10-6 torr). A unique pressure diagnostic is also discussed

  18. Nerf Guns Strike a Nerve on Campuses

    Science.gov (United States)

    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…

  19. Guns on Campus: A Chilling Effect

    Science.gov (United States)

    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. Reconnection conditions for a coaxial plasma gun

    International Nuclear Information System (INIS)

    A fluid model for the flow conditions necessary to form a compact torus from the plasma ejected by a coaxial plasma gun is developed. This is done by finding the conditions for which the steady-flow equations break down. Results are found for two cases; variable external flux and variable outer-wall radius

  1. Magnetic guns with cylindrical permanent magnets

    DEFF Research Database (Denmark)

    Vokoun, David; Beleggia, Marco; Heller, Luděk

    2012-01-01

    The motion of a cylindrical permanent magnet (projectile) inside a tubular permanent magnet, with both magnets magnetized axially, illustrates nicely the physical principles behind the operation of magnetic guns. The force acting upon the projectile is expressed semi-analytically as derivative of...... the generated forces and motion of the inner cylindrical magnet....

  2. Green plasticizers for multibase gun propellants (Lecture)

    NARCIS (Netherlands)

    Schoolderman, C.; Driel, C.A. van; Zebregs, M.

    2007-01-01

    TNO Defence, Security and Safety has a long history of research on gun propellants. Areas investigated are formulating (new ingredients, optimization), manufacturing, charge design and lifetime assessment [1,2,3,4,5]. In conventional propellants inert plasticizers are used to alter performance, proc

  3. Safety Plan for Schools: No Guns

    Science.gov (United States)

    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…

  4. Simulation of an rf thermionic gun

    Science.gov (United States)

    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. Youth Suicide and Guns. Firearm Facts.

    Science.gov (United States)

    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…

  6. Capital Punishment, Gun Ownership, and Homicide.

    Science.gov (United States)

    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)

  7. The important relationship between socioeconomic decline, masculinity, and guns

    OpenAIRE

    Carlson, Jennifer

    2015-01-01

    Recent events have reopened the debate over the role of guns in U.S. society, at a time when many states are expanding gun laws through open and concealed carry measures. How can we account for the popularity of guns in America, especially among men? Jennifer Carlson investigated this question by interviewing, and spending time with, gun-owning men in Michigan. She found that for these men, protecting their family and community was an important part of their gun ownership, a role which is has...

  8. Child Access Prevention Laws, Youth Gun Carrying, and School Shootings

    OpenAIRE

    Anderson, D. Mark; SABIA, JOSEPH J.

    2016-01-01

    Despite intense public interest in keeping guns out of schools, next to nothing is known about the effects of gun control policies on youth gun carrying or school violence. Using data from the Youth Risk Behavior Surveys (YRBS) for the period 1993-2013, this study is the first to examine the relationship between child access prevention (CAP) gun controls laws and gun carrying among high school students. Our results suggest that CAP laws are associated with a 13 percent decrease in the rate of...

  9. Development of the electron gun control system of SSRF

    International Nuclear Information System (INIS)

    An electron gun is the key part of a linac, the beam quality of which depends on beam quality of the electron gun, hence the need of a stable control system of the electron gun to ensure its safe operation.In this paper, we report our progresses in developing the linac's electron gun control system of Shanghai Synchrotron Radiation Facility (SSRF). It uses PLC as the device controllers, with the monitoring software developed on EPICS. The whole system is connected by Ethernet. The PLC and Ethernet technology ensures good reliability and easy maintenance of the electron gun control system. (authors)

  10. Fired Models of Air-gun Source and Its Application

    Institute of Scientific and Technical Information of China (English)

    Luo Guichun; Ge Hongkui; Wang Baoshan; Hu Ping; Mu Hongwang; Chen Yong

    2008-01-01

    Air-gun is an important active seismic source. With the development of the theory about air-gun array, the technique for air-gun array design becomes mature and is widely used in petroleum exploration and geophysics. In order to adapt it to different research domains,different combination and fired models are needed. At the present time, there are two firedmodels of air-gun source, namely, reinforced initial pulse and reinforced first bubble pulse.The fired time, space between single guns, frequency and resolution of the two models are different. This comparison can supply the basis for its extensive application.

  11. Elusive Facts About Gun Violence: Where Good Surveys Go Bad

    OpenAIRE

    Cook, Philip J.; Jens Ludwig

    2014-01-01

    The evidence base for the study of guns and violence begins with data on such fundamental issues as the number and distribution of guns, the number of people shot each year in criminal assaults, and the frequency of gun use in self-defense. It seems that these simple descriptive statistics should be readily available, and in fact the rhetoric of the debate over gun control in the United States routinely includes reference to 300 million guns, or 100,000 people who are shot each year, or 2.5 m...

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

    Science.gov (United States)

    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

  13. Improved DC Gun Insulator Assembly

    Energy Technology Data Exchange (ETDEWEB)

    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

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

    Science.gov (United States)

    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

  15. Advanced Concepts of the Propulsion System for the Futuristic Gun Ammunition

    OpenAIRE

    R.S. Darnse; Amarjit Singh

    2003-01-01

    This review paper reports various concepts of the gun propulsion system to meet the goal of the futuristic hypervelocity projectiles. The nonconventional concepts, such as liquid gun propellant, rail gun, coil gun, electrothermal gun, electrothermal chemical gun along with conventional energetic solid gun propellant have been discussed. Even though muzzle velocity around 2000 m/s has been claimed to be achieved using such nonconventional propulsion systems, it will take quite some time before...

  16. Fast Plasma from a Coaxial Gun

    International Nuclear Information System (INIS)

    The coaxial gun in use here is a source or two different plasmas produced by separate mechanisms. Abundant slow (∼107 cm/sec) deuterium plasma is produced directly by the j x B interaction of the radial plasma current and the magnetic field of the feed current along the centre electrode. The current disturbance moves through the injected gas toward the gun muzzle at ∼2.5 x 107 cm/sec, storing energy behind it in magnetic field and plasma motion. The gun, with its stored energy, functions as a high power low impedance electrical generator to drive into the vacuum beyond the gun muzzle a jet of current which is the source of the fast plasma (∼5 x 1017 deuterons, ∼108 cm/sec). The current jet and the plasma it produces are the subjects of these experiments. The mechanism of acceleration is complicated and imperfectly understood, but considerable insight has been gained by an extensive series of experiments, using as diagnostics the following: external diamagnetic pickup loops, intra vacuo Rogowsky loops, electric probes, external capacitive pickup electrodes, magnetic and electrostatic particle deflection analysis, spectroscopy, target light photography, time of flight with and without a guide field, d-d neutrons from the plasma volume and other methods. The picture which emerges is one of a complicated magneto-electric process taking place in front of the gun muzzle. The acceleration process depends on low gas density there as contrasted'with high density inside the gun. The fast plasma is largely derived from gas adsorbed on the electrodes. This makes necessary a clean vacuum so as to avoid contamination with highly ionized fast impurity ions (C5+, 108 cm/sec). Electrode material evaporates but appears not to be a serious contaminant because it comes late. The high voltage actually accelerating the ions is associated with the rapid expansion into vacuum of a magnetic flux volume around the jet. Fast plasma is emitted in a narrow conical distribution with an

  17. Field Test Kit for Gun Residue Detection

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. High Impetus Cool Burning Gun Propellants

    Directory of Open Access Journals (Sweden)

    R.S. Dames

    2000-07-01

    Full Text Available This study explores the possibility of reducing the flame temperature (Tf without decrease in impetus of RDX-NC matrix-based high energy gun propellants by partial replacement of RDX with triaminoguanidine nitrate (TAGN. Compositions containing TAGN as an energetic oxidiser with varying percentage of RDX have been formulated. Glycidyl azide polymer was incorporated as an energetic plasticiser to achieve the higher level of impetus. Performance in terms of ballistic parameters (theoretical/experimental sensitivity, thermal characteristics, stability and mechanical properties was evaluated and compared with the basic composition containing RDX as a single oxidiser. Experimental data indicates that the partial replacement of RDX by TAGN in gun propellant compositions decreases Tf significantly with only marginal decrease in impetus. "

  19. Femtosecond electron microscopy using photocathode RF gun

    International Nuclear Information System (INIS)

    The revealing and understanding of ultrafast structural-change induced dynamics are essential not only in physics, chemistry and biology, but also are indispensable for the development of new materials, new devices and applications. Both new RF gun based ultrafast relativistic electron diffraction and microscopy (UED and UEM) have being developed in Osaka University to probe directly structural changes at the atomic scale with sub-100 fs temporal resolution in materials. The first prototype of relativistic-energy UEM using a femtosecond photocathode RF gun has been developed. Both ultrafast diffraction and image measurements have been succeeded using a femtosecond electron beam. In this paper, the development of the UEM prototype and the first experiments of relativistic-energy electron imaging will be reported. (author)

  20. Development of L-band RF gun

    International Nuclear Information System (INIS)

    Continuing from the report at the previous annual meeting, we show the present status about the development of the L-band photocathode RF gun which is conducted by the collaborations with the groups of Osaka University, KEK, and Hiroshima University. At the last summary, we carried out the high power test and RF processing of the RF-gun cavity at KEK's Superconducting radiofrequency Test Facility (STF). Comparing with the predecessor working at STF, we find that the RF process of this cavity make faster progress. In this report, we show the result of this high power RF processing of the cavity and the present problems found out after that. We also show the development of the laser system as the cathode driver. (author)

  1. Current diffusion in rail-gun conductors

    International Nuclear Information System (INIS)

    A method has been developed to analyze one- and two-dimensional, nonlinear current diffusion in rail-gun conductors. A nonlinear current-diffusion equation that accounts for the temperature dependence of electrical conductivity has been developed from Maxwell's equations. A finite-difference heat-transfer computer program was adapted to solve the current-diffusion and thermal-diffusion problems for rail-gun conductors in one and two dimensions. The nonlinear current-diffusion equation was also extended to account for the magnetic-field dependence of the magnetic permeability, thus allowing ferromagnetic materials to be considered. A one-dimensional finite-difference technique was developed for ferromagnetic materials. Two one-dimensional test problems that compare results with other analyses are discussed. A series of calculations of current density and rail temperature was done for various size rectangular rails. One analysis of current diffusion in a ferromagnetic material was also performed

  2. 46 CFR 160.031-4 - Equipment for shoulder gun type line-throwing appliance.

    Science.gov (United States)

    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)...

  3. Gun Laws and Crime: An Empirical Assessment

    OpenAIRE

    Matti Viren

    2013-01-01

    This paper deals with the effect of gun laws on crime. Several empirical analyses are carried to investigate the relationship between five different crime rates and alternative law variables. The tests are based on cross-section data from US sates. Three different law variables are used in the analysis, together with a set of control variables for income, poverty, unemployment and ethnic background of the population. Empirical analysis does not lend support to the notion that crime laws would...

  4. Statistics tolerances on built up guns.

    Directory of Open Access Journals (Sweden)

    J. P. Sirpal

    1962-07-01

    Full Text Available The strength of built up guns depends on the shrinkages allowed between cylinders and therefore for a given strength, the assembly is either selective or the nominal sizes are so chosen as to give the required shrinkage for a worst combination, it can be seen from the analysis that with little disadvantage tolerances can be greatly increased assuming random assemblies of parts whose sizes follow a normal pattern. This can bring down production costs considerably.

  5. Accurate calculations of thermionic electron gun properties

    Czech Academy of Sciences Publication Activity Database

    Jánský, Pavel; Lencová, Bohumila; Zlámal, J.

    Berlin: Springer, 2008 - (Luysberg, M.; Tillmann, K.; Weirich, T.), s. 557-558 ISBN 978-3-540-85154-7. [EMC 2008 - European Microscopy Congress /14./. Aachen (DE), 01.09.2008-05.09.2008] R&D Projects: GA AV ČR IAA100650805 Institutional research plan: CEZ:AV0Z20650511 Keywords : electron emission * electron gun * space charge Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  6. Magnetic guns with cylindrical permanent magnets

    Czech Academy of Sciences Publication Activity Database

    Vokoun, David; Beleggia, M.; Heller, Luděk

    2012-01-01

    Roč. 324, č. 9 (2012), s. 1715-1719. ISSN 0304-8853 R&D Projects: GA ČR(CZ) GAP107/11/0391; GA AV ČR IAA100100920 Institutional research plan: CEZ:AV0Z10100520 Keywords : permanent magnet * cylindrical magnet * Earnshaw's theorem * magnetic gun * magnetostatic interaction Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.826, year: 2012 http://www.sciencedirect.com/science/article/pii/S0304885311008997

  7. Gun Laws and Crime: An Empirical Assessment

    OpenAIRE

    Matti Viren

    2012-01-01

    This paper deals with the effect of gun laws on crime. Several empirical analyses are carried to investigate the relationship between five different crime rates and alternative law variables. The tests are based on cross-section data from US sates. Three different law variables are used in the analysis together with a set of control variables for income, poverty, unemployment and ethnic background of the population. Empirical analysis does not lend support to the notion that crime laws would ...

  8. Cylinder fragmentation using gas gun techniques

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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

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

    International Nuclear Information System (INIS)

    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

  11. Diagnostics Beamline for the SRF Gun Project

    CERN Document Server

    Kamps, T; Goldammer, K; Krämer, Dietrich; Kuske, P; Kuszynski, J; Lipka, D; Marhauser, F; Quast, T; Richter, R

    2005-01-01

    A superconducting rf photo electron injector (SRF gun) is currently under construction by a collaboration between BESSY, DESY, FZR and MBI. The project aims at the design and setup of an 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 pi 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 be...

  12. Beam-Based Procedures for RF Guns

    CERN Document Server

    Krasilnikov, Mikhail; Grabosch, H J; Hartrott, Michael; Hui Han, Jang; Miltchev, Velizar; Oppelt, Anne; Petrosyan, Bagrat; Staykov, Lazar; Stephan, Frank

    2005-01-01

    A wide range of rf photo injector parameters has to be optimized in order to achieve an electron source performance as required for linac based high gain FELs. Some of the machine parameters can not be precisely controlled by direct measurements, whereas the tolerance on them is extremely tight. Therefore, this should be met with beam-based techniques. Procedures for beam-based alignment (BBA) of the laser on the photo cathode as well as solenoid alignment have been developed. They were applied at the Photo Injector Test facility at DESY Zeuthen (PITZ) and at the photo injector of the VUV-FEL at DESY Hamburg. A field balance of the accelerating mode in the 1 ½ cell gun cavity is one of the key beam dynamics issues of the rf gun. Since no direct field measurement in the half and full cell of the cavity is available for the PITZ gun, a beam-based technique to determine the field balance has been proposed. A beam-based rf phase monitoring procedure has been developed as well.

  13. A Robust High Current Density Electron Gun

    Science.gov (United States)

    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.

  14. Diagnostics Beamline for the SRF Gun Project

    Energy Technology Data Exchange (ETDEWEB)

    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.

  15. Overview of Plasma Guns for PLX

    Science.gov (United States)

    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.

  16. Experimental Studies of Electrothermal Plasma Gun

    International Nuclear Information System (INIS)

    The aim of the present work is to study the capillary plasma discharge dynamics and characteristics. The capillary plasma device is a new technology for producing high density plasma after ablating the capillary wall using a pulsed electric power. An Electrothermal Plasma Gun (ETG) is composed of a capillary discharge tube made of Teflon operated with simple RLC circuit. The device called Electrothermal Gun (ETG) which is composed of 4 capacitors (70 μF, 10 kV, 1.28 μH) connected in parallel to a plasma source by means of one high power supply. The gun was operated in open air at discharge energies between 35 J - 3.5 kJ according to charging voltage. The work presented in this thesis covers the following items, 1- Measurements of the basic parameters and characterizations of the pretest results of the electrical circuits and capillary plasma discharge using Rogowski coil, voltage probe and Photomultiplier. 2- Material processing including (physics of the surface modifications, the morphology of the surface by using Scanning Electron Microscope (SEM) at different conditions, compositions of the materials by using X-ray Fluorescence (XRF), Micro hardness test and material particle deposition.

  17. Gas Gun Studies of Interface Wear Effects

    Science.gov (United States)

    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.

  18. Design of an electron gun for terahertz radiation source

    International Nuclear Information System (INIS)

    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. (authors)

  19. Design of an electron gun for terahertz radiation source

    CERN Document Server

    Li, Ji; Hu, Tongning; Chen, Qushan; Feng, Guangyao; Shang, Lei; Li, Chenglong

    2013-01-01

    With the aim to obtain short-pulse bunches with high peak current for a terahertz radiation source, an EC-ITC (External-Cathode Independently Tunable Cells) RF gun was employed. As the external injecting electron source of the ITC RF gun, a gridded DC gun plays a key role, 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 is shown to overcome the strong space- charge force on the cathode, which is able to generate 6 {\\mu}s beam with 4.5A current successfully.

  20. 多 Agent的聚合级炮兵营 CGF 设计与实现%Design and realization of aggregated artillery battalion CGF based on Multi-Agent

    Institute of Scientific and Technical Information of China (English)

    康春农; 王永良; 张春娣

    2013-01-01

    Centered on the artillery battalion Computer Generated Forces(CGF), this paper devises a simulation system which is based on High Level Architecture(HLA). The system, consisting of six communicative parts, analyzes the workflow and com-munication among the federal members. By defining the artillery battalion CGF as a simulation entity of multi-Agent and poly-meric level, the paper provides the categories and components of Agent. Besides, modeling on different battle units of artillery battalion, it works out the ways of depolymerization on the basis of object-oriented technology. The focus of the study is to find out the communicative contents, means, and functions among the Agents. The simulation results verify the validity of CGF sys-tem for artillery battalion of multi-Agent and polymeric level, which can serve as a platform for further simulation research.%  以炮兵营 CGF 为中心设计了一套基于 HLA 的仿真体系结构,分析了各联邦成员的工作流程和之间的通信类别;分析了炮兵营 CGF 是多 Agent 的聚合级仿真实体,给出了 Agent 的划分和组成,以6部分的通信关系为主给出了体系结构图;以面向对象技术组织炮兵营各作战单位模型,并依此设计了解聚方法;重点讨论了 Agent间的通信内容、通信方式和通信所实现的功能。采用多种技术实现了系统仿真,仿真结果验证了多 Agent 的聚合级炮兵营 CGF 体系结构设计合理且有效,能够作为平台进行进一步的仿真开发。

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

    Science.gov (United States)

    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.

  2. Continuity and Change in the American Gun Debate

    OpenAIRE

    Zimring, Franklin

    2001-01-01

    My paper traces the debates about firearms control over the three decades since I became involved in gun research in the late 1960s. The circumstances of public discourse about guns in the late 1960s were rich in sentiment and almost completely lacking in empirical data. Questions of firearms control were only episodically important at the national level, and the administration of federal gun laws was of minuscule importance prior to 1968.

  3. Guns, Grass, and God's Wrath, Colorado's Budget, Politics, and Elections

    OpenAIRE

    Berry, Michael J.

    2016-01-01

    The legalization of recreational marijuana and the fight over gun control grabbed the lion’s share of headlines in the state over the past year. With respect to the state budget, the tax revenue from marijuana sales should soon have significant budgetary implications. Though not as substantial, new gun control laws also have budgetary consequences since gun purchasers must now pay for the cost of background checks, where previously public funds were allocated for this purpose.

  4. America, guns and freedom: Part II — An international perspective

    OpenAIRE

    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 d...

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

    OpenAIRE

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

    2014-01-01

    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.

  6. Design and manufacture of electron guns for welding

    International Nuclear Information System (INIS)

    In order to select the perveance and aperture of an electron beam for welding, a method has been developed. It allows a high power density, a low probability of breakdown occurence during the welding process. It has been applied to design and realize three EB guns: an early 100kW prototype gun, two guns for tube to plate welding in the horizontal vertical mode: on thick sections, for heat exchanger assemblies

  7. Structural Optimization of Machine Gun Based on Dynamic Stability Concept

    Institute of Scientific and Technical Information of China (English)

    LI Yong-jian; WANG Rui-lin; ZHANG Ben-jun

    2008-01-01

    Improving the firing accuracy is a final goal of structural optimization of machine guns. The main factors which affect the dispersion accuracy of machine gun are analyzed. Based on the concept of dynamic stability, a structural optimization model is built up, and the sensitivity of dispersion accuracy to design variables is analyzed. The optimization results of a type of machine gun show that the method is valid, feasible, and can be used as a guide to the structural optimization of other automatic weapons.

  8. Alternating Current All-electrical Gun Control System in Tanks

    OpenAIRE

    Zang Kemao; Ma Xiaojun; Li Changbing

    2004-01-01

    The ac all-electrical gun control system is composed of permanent magnetic synchronous machine-drive control systems and the ball-screw by replacing the complicated electrohydraulic systems. At the same time, the variable-structure system with sliding modes makes the gun control systems to have higher performances using the only rate flexure gyroscope. Thereby, vehicle hull gyroscope and angular gyroscope are left out.The new ac all-electrical gun control systems developed are reduced by 40 p...

  9. Violence, Guns, and Drugs: A Cross-Country Analysis.

    OpenAIRE

    Jeffrey A. Miron

    2001-01-01

    Violence rates differ dramatically across countries. A widely held view is that these differences reflect differences in gun control and/or gun availability, and certain pieces of evidence appear consistent with this hypothesis. A more detailed examination of this evidence suggests that the role of gun control/availability is not compelling. This more detailed examination, however, does not provide an alternative explanation for cross-country differences in violence. This paper suggests that ...

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

    Science.gov (United States)

    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

  11. The bird in hand: A feasible strategy for gun control

    OpenAIRE

    Moore, Mark H

    1982-01-01

    Policy analysis has failed to guide gun control policy away from its current impasse because analysts have avoided facing several crucially important features of the current reality: the existence of some widely held values in the United States public that favor the possession of guns; the limitations on the ability of public agencies in the United States to enforce restraints on the possession of handguns; and the implications of the fact that so many guns are already in the hands of the pub...

  12. The Effects of Gun Prevalence on Burglary: Deterrence vs Inducement

    OpenAIRE

    Cook, Philip J.; Jens Ludwig

    2002-01-01

    The proposition that widespread gun ownership serves as a deterrent to residential burglary is widely touted by advocates, but the evidence is weak, consisting of anecdotes, interviews with burglars, casual comparisons with other countries, and the like. A more systematic exploration requires data on local rates of gun ownership and of residential burglary, and such data have only recently become available. In this paper we exploit a new well-validated proxy for local gun-ownership prevalence...

  13. Numerical Modelling of Regenerative Liquid Propellant Guns with Annular Piston

    Directory of Open Access Journals (Sweden)

    K. J. Daniel

    1997-01-01

    Full Text Available The development of regenerative liquid propellant guns (RLPGs needs due consideration of numerous interdependent parameters that affect its performance. To help in this task, computer simulation was undertaken to predict internal ballistics of a conceptual liquid propellant gun. The expected pressure and other important parameters are documented which serve as an aid to the hardware, design of the regenerative liquid propellant guns.

  14. Evaluation of a Light Machine Gun Using Analytic Network Process

    OpenAIRE

    Emel Kizilkaya Aydogan; Cevriye Gencer; Saim Aytürk

    2009-01-01

    The light machine guns are among the significant fire support guns for the infantry. While the rapid advances in technology are improving the quality, these are also increasing the diversity, increasing the research carried out in the existing institutions and organisations.This is making the decision problem faced during the process complicated as well. To solve such problems, multiple criteria decision making methods are used. In this study, the selection of the light machine guns has been ...

  15. Gun Buybacks and Firm Behavior: Do Buyback Programs Really Reduce the Number of Guns?

    OpenAIRE

    Gregory E. Goering

    2011-01-01

    We suppose that guns or firearms are subject to an anticipated future buyback program undertaken by the government. A simple linear demand durable-goods monopoly model is then analyzed where the durable-good manufactured is a firearm that lasts for two-periods. The model is calibrated so that buyers are indifferent between selling (participating in the buyback program) or holding the gun in the future period. This allows us to focus solely on the firm¡¯s behavior. We find, among other things,...

  16. A flow cryostat for cooling of eight independent pipe guns

    DEFF Research Database (Denmark)

    Sørensen, H.; Hansen, J.E.; Sass, B.

    1991-01-01

    A flow cryostat allowing independent cooling of eight pipe guns in a multishot deuterium pellet injector is described. The pipe guns are placed symmetrically around the flow cryostat and with a liquid helium consumption of 4-5 l/h the cooling is sufficient for simultaneous formation of eight...... pellets at 8-9 K with a diameter of 2.1 mm containing up to 8 x 10(20) atoms/pellet. The thermal interaction between the eight pipe guns is sufficiently low to allow successive firing of the guns with time intervals of up to 1 s....

  17. Development of beam diagnostic devices for characterizing electron guns

    International Nuclear Information System (INIS)

    The electron guns for the DC accelerators and RF Linacs are designed and developed at EBC/APPD/BARC, Kharghar. These electron guns need to be characterized for its design and performance. Two test benches were developed for characterizing the electron guns. Various beam diagnostic devices for measuring beam currents and beam sizes were developed. Conical faraday cup, segmented faraday cup, slit scanning bellows movement arrangement, multi-plate beam size measurement setup, multi- wire beam size measurement setup, Aluminum foil puncture assembly etc. were developed and used. The paper presents the in-house development of various beam diagnostics for characterizing electron guns and their use. (author)

  18. Development of an electron gun for the KEK positron generator

    International Nuclear Information System (INIS)

    In the KEK Positron Generator, a semi-long pulsed beam (∼40ns) has turned out to be suitable for effective positron injection into the PF storage ring. However, to use the semi-long pulsed beam, there was a problem concerning the cathode lifetime of the gun. Thus, a new gun has been developed with a dispenser cathode, Y-796(EIMAC); the characteristics of this gun have been investigated. This new gun has been used since October 1988 and has continued to produce constant current of about 12A without having to exchange its cathode. Thus, the cathode lifetime has been remarkably improved. (author) 6 refs., 7 figs

  19. Coaxial plasma guns as injectors of high beta linear theta pinches

    International Nuclear Information System (INIS)

    A brief review of research on coaxial plasma guns and their use is given. Some problems and possibilities of using this gun for beam injection experiments are pointed out. Some scaling laws for gun energy are described

  20. Prevalence of youth access to alcohol or a gun in the home

    OpenAIRE

    Swahn, M; Hammig, B; Ikeda, R

    2002-01-01

    Objectives: To estimate the national prevalence of youth access to alcohol, a gun, or both alcohol and a gun, in their home and to describe the demographic characteristics associated with access to either alcohol or a gun.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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…

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

    Science.gov (United States)

    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…

  4. Testing a GaAs cathode in SRF gun

    Energy Technology Data Exchange (ETDEWEB)

    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

  5. Filament free electron gun and ISU generator

    International Nuclear Information System (INIS)

    Electron Beam Curing consists of the use of accelerated electrons for the creation of chemical reactions such as polymerisation cross linking or grafting. Electron guns use thermal emission to produce electrons before accelerating them towards the products to be cured. In the range of energy from 150 kV to 300 kV, A.I.D. has developed a new machine that is more adapted to industrial uses. A filament free system that is more reliable, tougher and easier to maintain than conventional systems, is described. The ISU (Induction Spire Unique) high voltage generator is also described briefly. (U.K.)

  6. Pulse shaper for electron gun control

    International Nuclear Information System (INIS)

    Modulation of electron gun of spectrometer for surface diagnostics allows to proceed to recording of N(E) from recording of the first derivative of secondary-emitted electron energy redistribution, dN/dE(E) with minimal modernization of the available modernization of the available receiving channel of spectrometer. Circuit with inductive bond ensures galvanic decoupling of the former by inlet and outlet. Irial spectra of characteristical losses in N(E) form obtained at modulation of the electron primary beam using the developed pulse former, and in dN/dE(E) form-using modulation of braking potential, are presented. 9 refs.; 2 figs

  7. Gas powered fluid gun with recoil mitigation

    Science.gov (United States)

    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.

  8. Smart gun technology requirements preliminary report

    Energy Technology Data Exchange (ETDEWEB)

    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.

  9. Nanosecond modulator of an electron gun

    International Nuclear Information System (INIS)

    The nanosecond modulator of an electron gun is developed for forming an electron beam with small emittance, necessary for generating the laser on free electrons. The block-diagram of the modulator is presented. The modulator consists of an optical receiver, two formers, two high-frequency power keys, diode with the DNZ charge storage and storage line. The modulator is positioned inside the timer container in the SF6 insulating gas medium under the 300 kV potential. The measured pulsation of the modulator output pulses is below 50 ps. The modulator operates reliably by the high-voltage breakdowns in the system

  10. Gas powered fluid gun with recoil mitigation

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Numerical Simulations of Thermionic Electron Guns

    Czech Academy of Sciences Publication Activity Database

    Jánský, Pavel; Lencová, Bohumila; Zlámal, J.

    Brno: Institute of Scientific Instruments AS CR, v.v.i, 2008 - (Mika, F.), s. 51-52 ISBN 978-80-254-0905-3. [International Seminar on Recent Trends in Charged Particle Optics and Surface Physics Instrumentation /11./. Skalský dvůr (CZ), 14.07.2008-18.07.2008] R&D Projects: GA AV ČR IAA100650805 Institutional research plan: CEZ:AV0Z20650511 Keywords : electron emission * electron gun * space charge * numerical simulations Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  12. Air pollution: a smoking gun for cancer

    OpenAIRE

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

    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...

  13. Ion gun operations at high altitudes

    OpenAIRE

    Werner, Paul W.

    1988-01-01

    Experiments in charge control were conducted on the P78-2 (SCATHA) satellite as part of a program on spacecraft charging at high altitudes. Experiments with the SCATHA ion gun were monitored by charged particle detectors and the electric field experiment. It was found that the electric field experiment could be used to measure satellite potential during ion beam emission in sunlight and eclipse. Unneutralized ion beam emission in high energy (1-2 KeV) and high current (1-2 mA) modes resulted ...

  14. Gun possession among American youth: a discovery-based approach to understand gun violence.

    Directory of Open Access Journals (Sweden)

    Kelly V Ruggles

    Full Text Available 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.

  15. Gun Access and Safety Practices among Older Adults

    Directory of Open Access Journals (Sweden)

    Hillary D. Lum

    2016-01-01

    Full Text Available 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.

  16. Gun Access and Safety Practices among Older Adults.

    Science.gov (United States)

    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

  17. The gun control system of the IFUSP microtron

    International Nuclear Information System (INIS)

    A thermionic gun control system has been developed for the IFUSP microtron. The control system, which is composed of a dedicated microcomputer, A/D converter, grid pulser, filament and grid power supplies, is kept at a high voltage potential. The gun parameters are handled through a PC computer at ground potential via fiber-optic link. (orig.)

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

    Science.gov (United States)

    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…

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

    Science.gov (United States)

    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…

  20. What we know about gun use among adolescents.

    Science.gov (United States)

    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

  1. The breakdown phase in a coaxial plasma gun

    International Nuclear Information System (INIS)

    The electrical breakdown in a coaxial plasma gun was investigated by means of optical and electrical measurements. The optimum start and operation conditions of the gun turned out to be strongly dependent on material and length of the cylindrical insulator. (orig.)

  2. Gun Possession among Massachusetts Batterer Intervention Program Enrollees

    Science.gov (United States)

    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.…

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

    Science.gov (United States)

    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.

  4. Gun Access and Safety Practices among Older Adults

    Science.gov (United States)

    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. Gunning Mix or Converter and Electric Arc Furnace in China

    Institute of Scientific and Technical Information of China (English)

    LIUJie-hua; ZHANGYong-fang

    1996-01-01

    The increase of steel output by converter and electric are furnace has imposed a critical demand in quality and quantity on gunning mix in functioning a longer life of those de-vices linings.The paoer describes the consump-tion of gunning mix for converter and EAF and its recent development in variety and quality in China.

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

    Science.gov (United States)

    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…

  7. A Gridded Electron Gun for a Sheet Beam Klystron

    Energy Technology Data Exchange (ETDEWEB)

    Read, M.E.; Miram, G.; Ives, R.L.; /Calabazas Creek Res., Saratoga; 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.

  8. Multikiloampere magnetron gun with secondary emission at relativistic voltage

    International Nuclear Information System (INIS)

    Magnetron gun for voltage up 1000 kV and current more 1 kA was tested in pulse mode. The secondary emission nature of the cathode current was established. The identification was held basing on considered features of the exciting and on the maintenance of the secondary emission current. The gun may be used for charge particle accelerators and RF power sources

  9. Plasma wave observations during electron gun experiments on ISEE-1

    OpenAIRE

    Olsen, R. C.; F. S. Mozer; Anderson, R. R.

    1992-01-01

    Advances in Space Research, 12, (12)29 The ISEE-1 electron guns were operated during the final orbits of ISEE-1 in 1987 in tests designed to study the stimulation of plasma waves. The guns were operated in modes which varied from ...

  10. Preventing Clogging In A Vacuum Plasma Spray Gun

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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…

  12. Modelling multi-ion plasma gun simulations of Tokamak disruptions

    International Nuclear Information System (INIS)

    The effect of impurity ions in plasma gun ablation tests of various targets is considered. Inclusion of reasonable amounts of impurity (∼10%) is adequate to explain observed energy transmission and erosion measurements. The gun tests and the computer code calculations are relevant to the parameter range expected for major disruptions on large tokamaks

  13. A 3 GHz photoelectron gun for high beam intensity

    CERN Document Server

    Bossart, Rudolf; Dehler, M; Godot, J C

    1996-01-01

    For the Compact Linear Collider Test Facility (CTF) at CERN a new rf gun with a laser driven photocathode is under construction. The new rf gun will replace the present 11/2 cell gun and will consist of 21/2 cells accelerating the beam to a momentum of 7.0 MeV/c with an electric field strength of 100 MV/m. The strong space-charge forces at low beam energy caused by the high charge density of the electron bunches are contained by radial and longitudinal rf focusing in the gun. The rf gun under construction has been optimized by MAFIA beam simulations for an injector assembly comprising a second accelerating rf structure and an intermediate solenoid magnet correcting the beam divergence of the 21/2 cell gun. The beam loading of the rf gun, by a train of 48 bunches with 21 nC charge each, causes a strong energy decay accompanied by an increase of the flight time for the bunches with lower energy. These effects can be corrected by slightly shifting the acceleration frequency of the gun. The experimental results...

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

    Science.gov (United States)

    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

  15. Polarized Electron Gun Development at the Brookhaven National Laboratory

    International Nuclear Information System (INIS)

    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.

  16. Therminoic gun control system for the CEBAF injector

    International Nuclear Information System (INIS)

    The injector for the CEBAF accelerator must produce a high-quality electron beam to meet the overall accelerator specifications. A Hermosa electron gun with a 2 mm-diameter cathode and a control aperture has been chosen as the electron source. This must be controlled over a wide range of operating conditions to meet the beam specifications and to provide flexibility for accelerator commissioning. The gun is controlled using Computer Automated Measurement and Control (CAMAC IEEE-583) technology. The system employs the CAMAC-based control architecture developed at CEBAF. The control system has been tested, and early operating data on the electron gun and the injector beam transport system has been obtained. This system also allows gun parameters to be stored at the operator location, without paralyzing operation. This paper describes the use of this computer system in the control of the CEBAF electron gun. 2 refs., 6 figs., 1 tab

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

    Science.gov (United States)

    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

  18. 77 FR 37834 - Revocation of Certain Requirements Pertaining to Caps Intended for Use With Toy Guns and Toy Guns...

    Science.gov (United States)

    2012-06-25

    ... CPSC. See 38 FR 27012 (September 27, 1973). One of the transferred regulations includes a ban on caps... COMMISSION 16 CFR Part 1500 Revocation of Certain Requirements Pertaining to Caps Intended for Use With Toy Guns and Toy Guns Not Intended for Use With Caps AGENCY: Consumer Product Safety Commission....

  19. Pelapisan Alloy FeNiAl Menggunakan Metode Detonation Gun (D-Gun)

    OpenAIRE

    M.R.T. Siregar; F.W. Machmud; Muchiar Muchiar; G.E. Timuda; Cece Cece

    2012-01-01

    Pelapisan material alloy Fe38Ni10Al dilakukan dengan metode D-Gun untuk meningkatkan kekerasan material Stainless Steel AISI 316 L. Analisis parameter proses dilakukan dengan perangkat statistik ANOVA (Analysis of Variance) – Taguchi untuk memperoleh ukuran kristal, ketebalan dan tingkat kekerasan yang optimum. Lapisan paling tebal dimiliki oleh sampel SS03 sebesar 280 mikron, sedangkan sampel SS02 memiliki ketebalan paling rendah, 97 mikron. Ketebalan lapisan sangat dipengaruhi oleh laju a...

  20. Beliefs about the risks of guns in the home: analysis of a national survey

    OpenAIRE

    Howard, K. A.; Webster, D.; Vernick, J.

    1999-01-01

    Objectives—While epidemiological evidence suggests homes with guns are more likely to be the site of a suicide or homicide than homes without guns, the public's perception of these risks remains unknown. This study assesses the prevalence of the belief that homes with guns are safer than homes without guns, and factors associated with this belief.

  1. Law enforcement officers' opinions about gun locks: anchors on life jackets?

    OpenAIRE

    Coyne-Beasley, T; Johnson, R

    2001-01-01

    Objectives—One way law enforcement officers support firearm safety is by promoting the use of gun locks. This investigation examined law enforcement officers' willingness to use gun locks on their own guns, as well as their opinions regarding gun locks in general.

  2. Analysis of Simi-Swaying Phenomenon During Gun Pitching Process%炮身俯仰过程中的类摇摆现象分析

    Institute of Scientific and Technical Information of China (English)

    霍李; 王媛; 刘景江; 江明义

    2016-01-01

    The simi-swaying phenomenon is first discovered during the gun pitching process. Through the coupling model of barrel-trunnion system,the influence of trunnion axis inclination, verticality of trunnion and barrel axis upon the direction error is quantitatively analyzed. The conditions for the occurrence of simi-swaying phenomenon are derived. Points out independently considered the trunnion axis inclination or the verticality of trunnion and barrel axis are a special case of the coupling model. The discovery of the simi-swaying phenomenon helps to explain the abnormal phenomena in artillery testing reasonably,and the coupling model can provide certain theoretical foundation for further improve the barrel pointing accuracy.%在火炮俯仰过程中发现了炮身的类摇摆现象,通过对炮身轴线-炮耳轴系统耦合建模,揭示了炮耳轴倾斜度、炮耳轴与炮身轴线不垂直度共同作用对方向偏差的影响规律,并推导出了类摇摆现象发生的条件。指出了单独考虑炮耳轴的倾斜或炮身轴线与炮耳轴的不垂直度都是耦合模型的特例。类摇摆现象的发现有助于合理解释火炮试验中出现的异常现象,耦合模型可为进一步提高身管指向精度提供一定的理论依据。

  3. Pelapisan Alloy FeNiAl Menggunakan Metode Detonation Gun (D-Gun

    Directory of Open Access Journals (Sweden)

    M.R.T. Siregar

    2012-02-01

    Full Text Available Pelapisan material alloy Fe38Ni10Al dilakukan dengan metode D-Gun untuk meningkatkan kekerasan material Stainless Steel AISI 316 L. Analisis parameter proses dilakukan dengan perangkat statistik ANOVA (Analysis of Variance – Taguchi untuk memperoleh ukuran kristal, ketebalan dan tingkat kekerasan yang optimum. Lapisan paling tebal dimiliki oleh sampel SS03 sebesar 280 mikron, sedangkan sampel SS02 memiliki ketebalan paling rendah, 97 mikron. Ketebalan lapisan sangat dipengaruhi oleh laju aliran gas pembawa serbuk dengan rasio kontribusi sebesar 82, 7%. Kekerasan optimum diperoleh sampel SS08 dengan tingkat kekerasan sebesar 281,6 HV yang jauh lebih besar dari tingkat kekerasan Stainless Steel tanpa lapisan (195,0 HV. Analisis struktur dan ukuran kristal dilakukan dengan menggunakan XRD dan Metode Scherrer yang menghasilkan struktur kristal Taenite (γ-(Fe,Ni dengan ukuran kristal pada orde nanometer (nanokristal pada kisaran 27,5 hingga 37,7 nm. Ukuran kristal sangat dipengaruhi oleh parameter rasio gas asetilene – oksigen dengan rasio kontribusi 60,4 %. Kata kunci: Detonation Gun (D-Gun, ANOVA –Taguchi, XRD, Nanokristal, Metode Scherer, Tingkat Kekerasan (Hardness

  4. Dynamics of a coaxial plasma gun

    International Nuclear Information System (INIS)

    The dynamics of an ionizing wave in a coaxial plasma gun with an azimuthal bias magnetic field is analysed in a theoretical model. Only the radial dependence is treated and instead of including a treatment of the energy balance two separate physical assumptions are made. In the first case it is assumed that the total internal electric field is given by the critical ionization velocity condition and in the second that the ionization rate is constant. For consistency wall sheaths are assumed to match the internal plasma potential to that of the walls. On the basis of momentum and particle balance the radial dependence of the electron density, current density, electric field and drift velocity are found. An electron source is required at the cathode and the relative contribution from ionization within the plasma is deduced. The assumption that there are no ion sources at the electrodes leads to a restriction on the possible values of the axial electric field. (Auth.)

  5. Projectile Balloting Attributable to Gun Tube Curvature

    Directory of Open Access Journals (Sweden)

    Michael M. Chen

    2010-01-01

    Full Text Available Transverse motion of a projectile during launch is detrimental to firing accuracy, structural integrity, and/or on-board electronics performance of the projectile. One manifest contributing factor to the undesired motion is imperfect bore centerline straightness. This paper starts with the presentation of a deterministic barrel model that possesses both vertical and lateral deviations from centerline in accordance with measurement data, followed by a novel approach to simulating comprehensive barrel centerline variations for the investigation of projectile balloting^1 motions. A modern projectile was adopted for this study. In-bore projectile responses at various locations of the projectile while traveling through the simulated gun tubes were obtained. The balloting was evaluated in both time and frequency domains. Some statistical quantities and the significance were outlined.

  6. Smart Gun Technology project. Final report

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. TRAIL - a tokamak rail gun limiter

    International Nuclear Information System (INIS)

    An attractive new limiter concept is investigated. The TRAIL (Tokamak Rail Gun Limiter) system impacts a stream of moderate velocity pellets (100 to 200 m/sec) through the plasma edge region to absorb energy and define the plasma boundary. The pellets are recycled after cooling, to the injector of an E-M mass accelerator. Heat fluxes of approx. 30,000 W/cm2 can be readily accommodated by the pellets, with very low recirculating power requirements (approx. 0.1%) for the accelerator. The mass accelerator velocity requirements are well within the present state of the art (several Km/sec). Accelerators injecting pellets at approx. 1 Km/sec can be used to control local plasma temperature and current profiles and to act as energy absorbers to shut down the plasma without damage to the first wall if a plasma disruption occurs. (author)

  8. Trail-A Tokamak RAIL Gun Limiter

    International Nuclear Information System (INIS)

    An attractive new limiter concept is investigated. The Tokamak RAIl Gun Limiter (TRAIL) system directs a stream of moderate velocity pellets (100 to 200 m/s) through the plasma edge region to absorb energy and define the plasma boundary. The pellets are recycled, after cooling, to the injector in an electromagnetic mass accelerator. Heat fluxes of about30000 W/cm2 can be readily accommodated by the pellets, with very low recirculating power requirements ( about0.1%) for the accelerator. The mass accelerator velocity requirements are well within the present state of the art (several kilometres per second). Accelerators injecting pellets at about1 km/s can be used to control local plasma temperature and current profiles and to act as energy absorbers to shut down the plasma without damage to the first wall if a plasma disruption occurs

  9. Six beam spherical compression of plasma focus guns

    International Nuclear Information System (INIS)

    A preliminary experiment with a one beam plasma focus is carried out to confirm plasma formation with the lowest input energy of 0.2 kJ for six beam spherical compression of plasma focus guns. The plasma front of this cableless gun can be used for compression and for the coupling of six guns situated along three rectangular axes, providing a good plasma focus pinch instantaneously or many plasma focus pinches continuously. The whole device with the energy bank is mounted on a sphere, and the minimum requirement for the plasma chamber of this sphere is a diameter of ∼ 22 cm. (author). 4 refs, 3 figs

  10. Method of electron emission control in RF guns

    CERN Document Server

    Khodak, I V

    2001-01-01

    The electron emission control method for a RF gun is considered.According to the main idea of the method,the additional resonance system is created in a cathode region where the RF field strength could be varied using the external pulse equipment. The additional resonance system is composed of a coaxial cavity coupled with a RF gun cylindrical cavity via an axial hole. Computed results of radiofrequency and electrodynamic performances of such a two-cavity system and results of the RF gun model pilot study are presented in. Results of particle dynamics simulation are described.

  11. The internal ballistics of a high: low pressure gun

    Directory of Open Access Journals (Sweden)

    J. N. Kapur

    1957-04-01

    Full Text Available In the present paper the system of equations for the Non-Isothermal Model for a H/L gun has been developed and from this, the systems of equations for Isothermal and Non-isothermal models for orthodox gun and solid fuel rockets have been deduced. The Non-Isothermal Model for H/L gun has been integrated for a tubular charge. For isothermal model, reduction to an equivalent non-leaking problem has been discussed and the partially non-isothermal model has been integrated for the linear law. After all-burnt modification needed in Corner's energy equation is obtained.

  12. Analysis on a electron gun for metal fusion

    International Nuclear Information System (INIS)

    The characteristics of the electron beam of the HK-011600 Δ, electron gun for metal fusion at the 'Divisao de Materiais do Instituto de Pesquisa e Desenvolvimento do CTA (PMR/IPD/CTA)', is analyzed. In this analysis, the Pierce gun model and the SLAC computational code for electron optics are used. The electron beam R and Z profiles are obtained in the gun region and in the magnetic lenses region. The behaviour of the electron beam in the prism region is also discussed using a simple model. (author)

  13. Study on ion induced secondary emission electron gun

    International Nuclear Information System (INIS)

    A low energy (2 is obtained in pulse width duration of 20 μs over an area of 64.5 cm2 at cathode voltage of 100 kV. The achieved combination of parameters (effective secondary emission coefficient γ' = 6.36, foil window transparency τ = 0.49, gun efficiency η = 33% and average power Pav = 230 W) are attractive to use the gun in various applications requiring a large cross-section electron beam. The utilization of the gun in the electron beam induced flue gas (NOx) treatment is underway. (author)

  14. Design studies on high current and grid control electron gun

    International Nuclear Information System (INIS)

    Electron gun, the source of electrons, is a kind of ultrahigh vacuum device and plays an important role in different kind of accelerators. With the irradiation accelerator demands, describes the design studies on beam optics optimization. The simulation result shows that the beam current is above 5 A with cathode voltage of 80 kV and beam emittance, gun electric field and beam waist radius meet the accelerator needs. The electron gun manufactured and installed in the test stand, the conditioning and test will be done in the near future. (authors)

  15. Method of electron emission control in RF guns

    International Nuclear Information System (INIS)

    The electron emission control method for a RF gun is considered.According to the main idea of the method,the additional resonance system is created in a cathode region where the RF field strength could be varied using the external pulse equipment. The additional resonance system is composed of a coaxial cavity coupled with a RF gun cylindrical cavity via an axial hole. Computed results of radiofrequency and electrodynamic performances of such a two-cavity system and results of the RF gun model pilot study are presented in. Results of particle dynamics simulation are described

  16. Analytical solution for a coaxial plasma gun: Weak coupling limit

    International Nuclear Information System (INIS)

    The analytical solution of the system of coupled ODE's which describes the time evolution of an ideal (i.e., zero resistance) coaxial plasma gun operating in the snowplow mode is obtained in the weak coupling limit, i.e, when the gun is fully influenced by the driving (RLC) circuit in which it resides but the circuit is negligibly influenced by the gun. Criteria for the validity of this limit are derived and numerical examples are presented. Although others have obtained approximate, asymptotic and numerical solutions of the equations, the present analytical results seem not to have appeared previously in the literature

  17. Ultra-low emittance X-band photocathode RF gun

    Institute of Scientific and Technical Information of China (English)

    TANG Chuan-Xiang; LIU Xiao-Han

    2009-01-01

    In this paper,we present the simulation results of a 1.6 cell X-band photocathode RF gun for ultra-low emittance electron beams.It will work at 9.3 GHz.The emittance,bunch length,electron energy and energy spread at the gun exit are optimized at bunch charge of 1pC using PARMELA.Electron bunches type coupler is adopted in this gun and an initial simulation by MAFIA is also given in this paper.

  18. Multipacting analysis in micro-pulse electron gun

    International Nuclear Information System (INIS)

    Modeling multipacting to steady state saturation is of interest in determining the performance of the micro-pulse electron gun. In this paper, a novel method is proposed to calculate the multipacting resonance parameters for the gun. This method works well, and the 2-D simulation results suggest that steady state saturation can be achieved in the gun. After saturation the transition from two-surface multipacting to single-surface multipacting occurred, and an extensive range of electron emission time is a suggested way to avoid this kind of transition. (authors)

  19. DAN PIENAAR GUN PARK LAUNCHES MUSEUM INTO 21ST CENTURY

    Directory of Open Access Journals (Sweden)

    C. Monick

    2012-02-01

    Full Text Available On 14 February 1992 there occurred the official opening of the Dan Pienaar Gun Park at the South African National Museum of Military History. The Gun Park is a newly completed exhibition area created by roofing and repairing the central courtyard between the exhibition's main halls. Lt Gen G L Meiring, SSA, SO, officially opened the Dan Pienaar Gun Park. The statue of Maj Gen D H ('Dan' Pienaar was officially unveiled by his widow (now Mrs Norma Seuffert. Maj Gen Pienaar's children, Fay, Barry and Nelia, were also present, in addition to a very wide representation of the Pienaar family.

  20. The Effect of Child Access Prevention Laws on Non-Fatal Gun Injuries

    OpenAIRE

    Jeff DeSimone; Sara Markowitz

    2005-01-01

    Many states have passed child access prevention (CAP) laws, which hold the gun owner responsible if a child gains access to a gun that is not securely stored. Previous CAP law research has focused exclusively on gun-related deaths even though most gun injuries are not fatal. We use annual hospital discharge data from 1988-2001 to investigate whether CAP laws decrease non-fatal gun injuries. Results from Poisson regressions that control for various hospital, county and state characteristics, i...

  1. Revisiting the Gun Ownership and Violence Link; a multi- level analysis of victimisation survey data.

    OpenAIRE

    van Kesteren, J.N.

    2014-01-01

    The link between gun ownership victimisation by violent crime remains one of the most contested issues in criminology. Some authors claim that high gun availability facilitates serious violence. Others claim that gun ownership prevents crime. This article revisits these issues using individual and aggregate data on gun ownership and victimisation from the ICVS. Analysis at country level shows that the level of hand gun ownership is positively related to serious violence but not for lesser ser...

  2. Model input and output files for the simulation of time of arrival of landfill leachate at the water table, Municipal Solid Waste Landfill Facility, U.S. Army Air Defense Artillery Center and Fort Bliss, El Paso County, Texas

    Science.gov (United States)

    Abeyta, Cynthia G.; Frenzel, Peter F.

    1999-01-01

    This report contains listings of model input and output files for the simulation of the time of arrival of landfill leachate at the water table from the Municipal Solid Waste Landfill Facility (MSWLF), about 10 miles northeast of downtown El Paso, Texas. This simulation was done by the U.S. Geological Survey in cooperation with the U.S. Department of the Army, U.S. Army Air Defense Artillery Center and Fort Bliss, El Paso, Texas. The U.S. Environmental Protection Agency-developed Hydrologic Evaluation of Landfill Performance (HELP) and Multimedia Exposure Assessment (MULTIMED) computer models were used to simulate the production of leachate by a landfill and transport of landfill leachate to the water table. Model input data files used with and output files generated by the HELP and MULTIMED models are provided in ASCII format on a 3.5-inch 1.44-megabyte IBM-PC compatible floppy disk.

  3. Alternating Current All-electrical Gun Control System in Tanks

    Directory of Open Access Journals (Sweden)

    Zang Kemao

    2004-07-01

    Full Text Available The ac all-electrical gun control system is composed of permanent magnetic synchronous machine-drive control systems and the ball-screw by replacing the complicated electrohydraulic systems. At the same time, the variable-structure system with sliding modes makes the gun control systems to have higher performances using the only rate flexure gyroscope. Thereby, vehicle hull gyroscope and angular gyroscope are left out.The new ac all-electrical gun control systems developed are reduced by 40 per cent in weight, decreased by 30 per cent in volume, increased by 35 per cent in efficiency, and enhanced by three times in service life as compared to the current gun control systems.

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

    Science.gov (United States)

    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

  5. Recent developments of low-emittance electron gun for accelerator

    International Nuclear Information System (INIS)

    Recent developments of low-emittance electron guns for accelerator are reviewed. In the accelerator field, DC biased triode thermionic gun (Pierce type gun) has been widely used and is still conventional. On the other hand, because of strong demands on the high brightness electron beam by FEL and other advanced accelerator concepts based on linear accelerator, the low emittance beam generation becomes one of the most important issue in the accelerator science. The R and D effort is 'accelerated' by two technological innovations, photo-cathode and RF gun. They made a large improvement on the beam emittance. After the explanations on the technical and physical aspects of the low emittance electron beam generation, advanced electron sources for accelerators are reviewed. (author)

  6. High-energy attosecond nanoplasmonic-based electron gun

    Science.gov (United States)

    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.

  7. Penetrating Cardiac Nail Gun Injury in a Child.

    Science.gov (United States)

    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

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

    Science.gov (United States)

    ... 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 ...

  9. Refractory Gunning Material for Inner Lining Maintenance of Blast Furnace

    Institute of Scientific and Technical Information of China (English)

    Yu Lingyan; Peng Xigao

    2010-01-01

    @@ 1 Scope This standard specifies the term and definition,classification, technical requirements, test methods,quality appraisal procedures, packing, marking, transportation, storage, and quality certificate of refractory gunning material for inner lining maintenance of blast furnace .

  10. Finite element analyses for RF photoinjector gun cavities

    International Nuclear Information System (INIS)

    This paper details electromagnetical, thermal and structural 3D Finite Element Analyses (FEA) for normal conducting RF photoinjector gun cavities. The simulation methods are described extensively. Achieved results are presented. (orig.)

  11. Feasibility Study of Processing Estane-based LOVA Gun Propellant

    Directory of Open Access Journals (Sweden)

    M.A.R. Shaikh

    2007-07-01

    Full Text Available Low vulnerability ammunition (LOVA propellant are currently being developed globally toreplace all types of single-base, double-base and triple-base gun propellants, because LOVApropellants possess advantage like low vulnerability without compromising on ballistic properties.The objective of present study is to establish processing of thermoplastic elastomer (TPE;estane-based LOVA gun propellant in cord/heptatubular geometry.  Keeping in view variousadvantages of TPE such as simple processing, greater dimensional stability, lower productionlosses, superior insensitivity, and mechanical properties of the propellants, estane 5731(polyurethane-ester-MDI, aromatic polyester is selected for feasibility study as a binder inLOVA-based gun propellant composition, processed by solvent and semi-solvent methods andcompared feasibility of processing as well as their evaluation wrt ballistics, vulnerability, andmechanical properties. The results indicate that gun propellants processed by semi-solventmethod and extruded at elevated temperatures exhibit better ballistics, mechanical, andvulnerability properties.

  12. Cold Test Measurements on the GTF Prototype RF Gun

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

  14. Canvasback Gun Club : Submerged aquatic plant survey : 1986

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Flood waters which impacted the Stillwater Wildlife Management Area for the past several years also had their effect on the northern portions of the Canvasback Gun...

  15. The Mystery of the Gun Turret in the Desert

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, R. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    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).

  16. Recent developments in high voltage photocathode DC gun for accelerator

    International Nuclear Information System (INIS)

    A photoinjector which can generate a high brightness, low emittance and short duration electron bunches is required for future light source accelerators and applications such as electron microscopes. A DC high voltage gun which has a semiconductor photocathode in a high DC electric field is one of the technology choices for the generation of high quality electron beam. Many techniques to the development of semiconductor based photoemission gun are introduced in briefly. (author)

  17. Cardiac stimulation with high voltage discharge from stun guns

    OpenAIRE

    Nanthakumar, Kumaraswamy; Massé, Stephane; Umapathy, Karthikeyan; Dorian, Paul; Sevaptsidis, Elias; Waxman, Menashe

    2008-01-01

    The ability of an electrical discharge to stimulate the heart depends on the duration of the pulse, the voltage and the current density that reaches the heart. Stun guns deliver very short electrical pulses with minimal amount of current at high voltages. We discuss external stimulation of the heart by high voltage discharges and review studies that have evaluated the potential of stun guns to stimulate cardiac muscle. Despite theoretical analyses and animal studies which suggest that stun gu...

  18. Resistance Spot Welding with Middelfrequency-Inverter Weling Gun

    DEFF Research Database (Denmark)

    Rasmussen, Mogens H.

    The paper presents the results of investigations concerning the process stability and weldability lobes for uncoated sheets of 1.0 mm thickness when performing resistance spot welding with a middlefrequency-inverter welding gun......The paper presents the results of investigations concerning the process stability and weldability lobes for uncoated sheets of 1.0 mm thickness when performing resistance spot welding with a middlefrequency-inverter welding gun...

  19. RF gun for an intense THz radiation source

    Institute of Scientific and Technical Information of China (English)

    GU Qiang; ZHAO Zhen-Tang; TONG De-Chun; CHEN Li-Fang; XU Xiu-Min

    2008-01-01

    A new facility is under construction at the Shanghai Institute of Applied Physics,to generate femto-second electron bunches and intense coherent THz radiation pulses.A thermionic RF-gun is used to be the electron source of the linac,which is 1.6 cell,π/2,side coupled in design.In the following of this paper,the design,manufacture and beam operation of this gun are presented.

  20. Efficiency of guns from the technical point of view

    Directory of Open Access Journals (Sweden)

    G. Baranski

    1953-01-01

    Full Text Available From the engineering point of view, a gun or machine gun is a heat engine very similar to a Diesel or petrol engine. It has to do work when-operated by a soldier. A fuel is burnt, namely the propellant, and certain power (energy per unit time is obtained, namely the kinetic energy of the projectile for each interval of rounds fired.

  1. Feasibility Study of Processing Estane-based LOVA Gun Propellant

    OpenAIRE

    M.A.R. Shaikh; R. R. Sanghavi; S. D. Shelar; T. K. Chakraborthy; Amarjit Singh

    2007-01-01

    Low vulnerability ammunition (LOVA) propellant are currently being developed globally toreplace all types of single-base, double-base and triple-base gun propellants, because LOVApropellants possess advantage like low vulnerability without compromising on ballistic properties.The objective of present study is to establish processing of thermoplastic elastomer (TPE);estane-based LOVA gun propellant in cord/heptatubular geometry.  Keeping in view variousadvantages of TPE such as simple processi...

  2. Microcomputer based ship-board gun control system.

    OpenAIRE

    Erdogan, Ahmet

    1981-01-01

    Approved for public release; distribution is unlimited This study was undertaken to design and implement a microcomputer based gun control and interactive display system which is suitable as a model of a shipboard Gun Fire Control System and Tactical-Situation display. The stand-alone system includes two plasma display scopes, a microcomputer, a cathode ray tube (CRT), an analog-to-digital, digital-to-analog (ADC/DAC) board and a servo unit. The scope of the effort includes, calculation ...

  3. UPAYA POLRI DALAM MEMINIMALISIR KEJAHATAN PENYALAHGUNAAN AIRSOFT GUN

    OpenAIRE

    Priyambodo, Tito Dwi Yudo

    2014-01-01

    Indonesian National Police have limitations, both in terms of availability of personnel, equipment and operational budgets. Lately violent crimes by using increasingly widespread. The perpetrators are not only using sharp weapons, but also many who use firearms, firearms both organic and homemade firearms. In addition to these, there are among the criminals who use guns airsoft gun type commonly used for sports games. The purpose of this study is to identify and analyze the Indonesian Nat...

  4. The politics of gun control: comparing Canadian and American patterns

    OpenAIRE

    G A Mauser; Margolis, M.

    1992-01-01

    In this paper two questions are asked: to what extent do the Canadian and US publics differ in their beliefs about firearms-control legislation, and to what extent do these differences help to account for the stricter firearms legislation found in Canada? Surveys indicate that Canadians and Americans have remarkably similar attitudes towards firearms and gun control. Linear regression is used to analyze the factors that underlie the popular support for (or opposition to) stricter gun-control ...

  5. Plasma gun with coaxial powder feed and adjustable cathode

    Science.gov (United States)

    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.

  6. Low friction coatings prepared by high performance type spray gun

    OpenAIRE

    Fukumasa, O.; Osaki, K.; Fujimoto, S; Lungu, C. P.; Lungu, Ana Mihaela

    2003-01-01

    To produce low friction coatings to be used as overlays for automobile journal bearings and to perform depositions with high rate, we prepared composite coatings of Ag and graphite by using the new-type spray gun based on the forced constricted type plasma jet generator (i.e. the high performance type spray gun). Characterization of the films showed the graphite phase dispersed into the Ag matrix, analyzed by optical microscopy, electron probe microanalysis and X-ray diffraction. The coeffici...

  7. Cylinder expansion test and gas gun experiment comparison

    Energy Technology Data Exchange (ETDEWEB)

    Harrier, Danielle [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-06-30

    This is a summer internship presentation by the Hydro Working Group at Los Alamos National Laboratory (LANL) and goes into detail about their cylinder expansion test and gas gun experiment comparison. Specifically, the gas gun experiment is detailed along with applications, the cylinder expansion test is detailed along with applications, there is a comparison of the methods with pros and cons and limitations listed, the summer project is detailed, and future work is talked about.

  8. Design of S-band RF photocathode gun

    International Nuclear Information System (INIS)

    A linear electron accelerator used for medical or industrial applications needs moderate beam currents of about 120 mA (peak). In such cases the emittance or the energy spread are not very critical parameters. The Pierce type gun with the standing wave linac is suitable for such applications where emittance of the order of 15 π-mm-mrad or more is acceptable. In contrast, the RF photo cathode gun can be used to achieve emittance of the order of 3 to 5 π-mm-mrad at a charge of about 1 nC. In an RF photo cathode gun, laser pulses will strike the photo cathode to produce electron bunches. This paper presents the basic technologies needed for successful implementation of RF gun mainly for an activity like the inverse Compton source. The proposed design is presented with detailed calculations and simulations for operating the RF gun in multi bunch mode. The gun will be operating at 2998 MHz frequency and the expected energy gain is a 5 MeV using a 10 MW Klystron. A multi bunch train with 1 nC charge per bunch and 100 bunches per train will be accelerated such that the peak to peak energy difference is less than 1%. (author)

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

    Science.gov (United States)

    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.

  10. Development of laser heated high current DC electron gun

    International Nuclear Information System (INIS)

    The paper deals with the development of a Laser heated cathode for Electron Accelerator. The electron gun is meant for Megawatt-class DC Accelerator for Electron Beam Flue Gas Treatment applications. Conventionally, LaB6 cathode is indirectly heated by tungsten filaments whereas in the newly proposed gun, Laser is utilized for heating. A Nd:YAG Laser is used to heat the LaB6 cathode to emission temperatures. The characterization of cathode heating at various Laser powers has been carried out. In initial trials, it has been observed that with 125 W of Laser power, the LaB6 pellet was heated to 1315 ° C. Based on these experimental results, an electron gun rated for 30 kV, 350 mA CW has been designed. The optimization of gun electrode geometry has been done using CST Particle Studio in order to tune the various electron gun parameters. The beam diameter obtained in simulation is 8 mm at 100 mm from the LaB6 cathode. The perveance obtained is 7.1 x 10-8 A/V3/2 . The Laser heated cathode has the advantages of eliminating the magnetic field effects of filament on the electron beam, electrical isolation needed for gun filament power supplies and better electron beam emittances. (author)

  11. A gun recoil system employing a magnetorheological fluid damper

    International Nuclear Information System (INIS)

    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. (paper)

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

    International Nuclear Information System (INIS)

    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.

  13. Advanced Concepts of the Propulsion System for the Futuristic Gun Ammunition

    Directory of Open Access Journals (Sweden)

    R.S. Darnse

    2003-10-01

    Full Text Available This review paper reports various concepts of the gun propulsion system to meet the goal of the futuristic hypervelocity projectiles. The nonconventional concepts, such as liquid gun propellant, rail gun, coil gun, electrothermal gun, electrothermal chemical gun along with conventional energetic solid gun propellant have been discussed. Even though muzzle velocity around 2000 m/s has been claimed to be achieved using such nonconventional propulsion systems, it will take quite some time before such systems are in regular use in the battlefield. Hence, solid gun propellants containing novel energetic ingredients (binders, plasticisers, and oxidisers would continue to be used in the near future and are expected to meet the requirements of the futuristic gun ammunition.

  14. Air pollution: a smoking gun for cancer

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    2014-04-01

    Full Text Available 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

  15. Rail gun type two stage accelerator

    International Nuclear Information System (INIS)

    In a rail gun type two stage accelerator, a cavity resonator which resonates microwaves to once convert gases behind a fuel pellet into plasmas is disposed to a transport pipe between a gas injector and rail electrodes. When gases reach a fuel pellet to push it, the gases are once converted into plasmas by microwaves, pass through the cavity resonator to be gradually decayed, in which an ionization rate is decreased, and returned to neutral particles. Gas constituent particles flow between the rail electrodes while keeping a highly excited state, and the fuel pellet reaches a detection axial line of a pass detector. In this case, a pulse laser oscillator and a pulse current power source are operated to convert gases again into plasmas by a pulse laser restricted by a focusing lens, to which electric current is supplied to accelerate the fuel pellet. With such procedures, plasmas in an initial stage upon re-acceleration can be generated easily, as well as an optical axis can easily be controlled. (N.H.)

  16. Geohydrologic site characterization of the municipal solid waste landfill facility, US Army Air Defense Artillery Center and Fort Bliss, El Paso County, Texas

    Science.gov (United States)

    Abeyta, Cynthia G.

    1996-01-01

    Geohydrologic conditions of the Municipal Solid Waste Landfill Facility (MSWLF) on the U.S. Army Air Defense Artillery Center and Fort Bliss, El Paso County, Texas, were evaluated by the U.S. Geological Survey in cooperation with the U.S. Army. The 106.03-acre MSWLF has been in operation since January 1974. The landfill contains household refuse, Post solid wastes, bulky items, grass and tree trimmings from family housing, refuse from litter cans, construction debris, classified waste (dry), dead animals, asbestos, and empty oil cans. The MSWLF, located about 1,200 feet east of the nearest occupied structure, is estimated to receive an average of approximately 56 tons of municipal solid waste per day and, at a fill rate of 1-4 acres per year, is expected to reach its capacity by the year 2004. The MSWLF is located in the Hueco Bolson, 4 miles east of the Franklin Mountains. Elevations at the MSWLF range from 3,907 to 3,937 feet above sea level. The climate at the MSWLF and vicinity is arid continental, characterized by an abundance of sunny days, high summer temperatures, relatively cool winters typical of arid areas, scanty rainfall, and very low humidity throughout the year. Average annual temperature near the MSWLF and vicinity is 63.3 degrees Fahrenheit and annual precipitation is 7.8 inches. Potential evaporation in the El Paso area was estimated to be 65 inches per year. Soils at and adjacent to the MSWLF are nearly level to gently sloping, have a fine sandy loam subsoil, and are moderately deep over caliche. The MSWLF is underlain by Hueco Bolson deposits of Tertiary age and typically are composed of unconsolidated to slightly consolidated interbedded sands, clay, silt, gravel, and caliche. Individual beds are not well defined and range in thickness from a fraction of an inch to about 100 feet. The primary source of ground water in the MSWLF area is in the deposits of the Hueco Bolson. A relatively thick vadose zone of approximately 300 feet overlies the

  17. Study on Gathering and Production Structure of Pine Nuts in Korea : Centering on Gapyeong-gun, Gyeonggi-do and Hongcheon-gun, Gangwon-do

    OpenAIRE

    Kang, Hag Mo; Lee, Sang Hyun; Kim, Hyun; Sato, Noriko

    2010-01-01

    In the results of survey against households engaging in gathering and producing pine nuts in Gapyeong-gun, Gyeonggido and Hongcheon-gun, Gangwon-do, the representative pine nuts producing region in Korea, it was found that average household managing land were relatively smaller as 1.5 ha and 0.9 ha in Gapyeong-gun and Hongcheon-gun. Among 20 households having forest in Gapyeong-gun, only 3 households conducted thinning practice during the last 5 years and any positive forest management such a...

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

    International Nuclear Information System (INIS)

    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)

  19. Rheological and Adhesive Behavior of Gunning Mix for Blast Furnace Repair

    Institute of Scientific and Technical Information of China (English)

    CAO Feng; LONG Shigang; WU Xingrong; SUN Jialin; HONG Yanruo

    2003-01-01

    The aim of this experimental work was to investigate the rheological and adhesive performance of gunning mix suspensions. The results of rheological tests indicate that:the rheological curve of gunning mix bonded by high-alumina cement (HACG) is Bingham type; the rheological curve of low cement gunning mix (LCG) bonded by microsilica is characterized by pseudo-plasticity fluid with yielding stress; and the rheological property of low-cement gunning mix bonded by microsilica is proved to be better than that of gunning mix bonded by cement. Meanwhile as indicated by the adhesive tests: the better the rheological properties of gunning mix suspension, the better the repair effect would be.

  20. Rural and suburban 5-8 year old children: Gun-injury risks and crisis responses.

    OpenAIRE

    Bradbury, Kirsten

    2005-01-01

    Recent research has provided empirical support for counseling guidelines for pediatric gun safety and has demonstrated that some parental behaviors increase children's risk of gun injury. However, few data exist on patterns of gun-injury risks, especially for children younger than age 10, children from middle-class and non-urban families, and children of non-gun-owning vs. gun-owning parents. Part I of the study presents data on gun injury risks in a middle-SES sample of rural and suburban gu...

  1. Why are there more and more guns in America? Blame Fox News

    OpenAIRE

    Cassino, Dan

    2016-01-01

    Dan Cassion 80x108Why do Americans buy guns? For many, it’s because they are worried that new gun control measures may stop them from buying guns in the future. Dan Cassino examines the role of the news media – specifically Fox and network news, in driving Americans’ fears about gun control. He finds that while mass shootings do lead to an increase in gun sales – as measured by the number of background checks – coverage of gun control measures by Fox leads to far more. He writes that in the w...

  2. Development of a photo-cathode rf electron gun for ultra-short bunch generation

    International Nuclear Information System (INIS)

    The photocathode rf electron gun is a high brightness electron source because the initial electron bunch shape can be controlled by the cathode illuminating laser pulse and then the bunch is rapidly accelerated by the high gradient electric field in the rf gun cavity. The rf guns are widely used not only as a injector for large facility but also application researches. At Waseda University, I and collaborators have been developing an rf electron gun since 1999. We performed optimization of cavity structure, improvement of rf tuner and development of photocathode material, then we succeeded in operating 3.6 cell rf gun. In these backgrounds, I conceived a new type rf gun cavity structure for ultra-short electron bunch generation, named Energy-Chirping-Cell attached rf gun (ECC rf gun). Less than 100 fs (rms) bunch can be produced with 100 pC charge by this ECC rf gun in the simulation. Such a high peak current bunch has a possibility to apply for the coherent THz radiation source and single shot electron diffraction microscope. Encouraged by this successful simulation results, we manufactured an ECC rf gun and measured the bunch length at Waseda University. The experimental results showed a good agreement with simulation and we found that the bunch length from ECC rf gun was less than 500 fs (rms). In this paper, the introduction of the photocathode rf gun, principle and experimental results of ECC rf gun, and future prospective will be described. (author)

  3. Polarized RF guns for linear colliders: An ICFA Workshop

    Energy Technology Data Exchange (ETDEWEB)

    D.A. Edwards

    2002-01-31

    The ICFA Workshop on Polarized RF Guns for Linear Colliders was held at Fermilab during April 18-20, 2001. It was attended by 37 scientists from 14 institutions. A list of participants is appended. An RF photoemission gun that delivers polarized electrons at low emittance would be an attractive electron source for a linear collider. Moreover, recently it has been demonstrated that an RF gun in conjunction with nearby injection system optics can deliver a beam with a high ratio of transverse emittances; a simplification of a linear collider's damping system could result. However, at present RF electron gun technology has not developed sufficiently to assure that such a source is feasible. The purpose of the workshop was to review the status of polarized RF gun development with linear collider application in mind, and outline a possible program for the future. A table lists the requirements for the electron injector for proposed linear colliders. The specifications are given for the beam before and after the electron damping ring.

  4. rf traveling-wave electron gun for photoinjectors

    Science.gov (United States)

    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.

  5. Operation of the superconducting RF photo gun at ELBE

    CERN Document Server

    Teichert, J; Buettig, H; Janssen, D; Justus, M; Lehnert, U; Michel, P; Murcek, P; Schneider, Ch; Schurig, R; Staufenbiel, F; Xiang, R; Kamps, T; Rudolph, J; Schenk, M; Klemz, G; Will, I

    2012-01-01

    As the first superconducting RF photo-injector (SRF gun) in practical operation, the SRF gun has been successfully connected to the superconducting linac ELBE at Forschungzentrum Dresden-Rossendorf. The injection with this new gun will improve the beam quality for the users of the radiation source. The SRF gun contains a 3½ cell superconducting accelerating cavity with a frequency of 1.3 GHz. The design is for use of normal conducting photocathodes. At present, caesium telluride photocathodes are applied which are illuminated by an ultraviolet laser beam. The kinetic energy of the produced electron beam is 3 MeV which belongs to a peak electric field of 16 MV/m in the cavity. The maximum bunch charge which is obtained and measured in a Faraday cup is about 400 pC (20 μA average current at a repetition rate of 50 kHz). The SRF gun injector is connected to the ELBE accelerator via a dogleg with two 45° deflection magnets. This connection beam line was commissioned in January 2010. A first beam injection into...

  6. Operation of the superconducting RF photo gun at ELBE

    CERN Document Server

    Teichert, J; Buettig, H; Janssen, D; Justus, M; Lehnert, U; Michel, P; Murcek, P; Schneider, C; Schurig, R; Staufenbiel, F; Xiang, R; Kamps, T; Rudolph, J; Schenk, M; Klemz, G; Will, I

    2011-01-01

    As the first superconducting RF photo-injector (SRF gun) in practical operation, the SRF gun has been successfully connected to the superconducting linac ELBE at Forschungzentrum Dresden-Rossendorf. The injection with this new gun will improve the beam quality for the users of the radiation source. The SRF gun contains a 3½ cell superconducting accelerating cavity with a frequency of 1.3 GHz. The design is for use of normal conducting photocathodes. At present, caesium telluride photocathodes are applied which are illuminated by an ultraviolet laser beam. The kinetic energy of the produced electron beam is 3 MeV which belongs to a peak electric field of 16 MV/m in the cavity. The maximum bunch charge which is obtained and measured in a Faraday cup is about 400 pC (20 µA average current at a repetition rate of 50 kHz). The SRF gun injector is connected to the ELBE accelerator via a dogleg with two 45° deflection magnets. This connection beam line was commissioned in January 2010. A first beam injection into...

  7. Evaluation of a Light Machine Gun Using Analytic Network Process

    Directory of Open Access Journals (Sweden)

    Emel Kizilkaya Aydogan

    2009-05-01

    Full Text Available The light machine guns are among the significant fire support guns for the infantry. While the rapid advances in technology are improving the quality, these are also increasing the diversity, increasing the research carried out in the existing institutions and organisations.This is making the decision problem faced during the process complicated as well. To solve such problems, multiple criteria decision making methods are used. In this study, the selection of the light machine guns has been dealt as a multiple criteria decision making problem. To decide about the best machine gun, selection criteria of the best light machine gun is evaluated within a systematic feedback and a model pertaining to using Analytical Network Process (ANP in the selection of the weapons has been developed. The criteria pertaining to the alternative weapons have been determined, the necessary polls have been prepared and applied, and the results have been achieved using the Super Decisions 1.6.0 package program.Defence Science Journal, 2009, 59(3, pp.273-283, DOI:http://dx.doi.org/10.14429/dsj.59.1521

  8. Numerical design of electron guns and space charge limited transport systems

    International Nuclear Information System (INIS)

    This paper describes the capabilities and limitations of computer programs used to design electron guns and similarly space-charge limited transport systems. Examples of computer generated plots from several different types of gun problems are included

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

    Science.gov (United States)

    ... 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 ...

  10. Gun use in the United States: results from two national surveys

    OpenAIRE

    Hemenway, D; Azrael, D; Miller, M

    2000-01-01

    Objectives—To determine the relative incidence of gun victimization versus self defense gun use by civilians in the United States, and the circumstances and probable legality of the self defense uses.

  11. Development of an Energy Chirp Cell attached rf electron gun and its prospective applications

    International Nuclear Information System (INIS)

    We have been developing an Energy-Chirping-Cell attached rf electron gun (ECC rf gun) for ultra-short bunch generation with enough charge of more than 100 pC. ECC rf gun has an extra cell for energy chirping, then the energy chirped bunch is gradually compressed by the velocity bunching. We estimated the bunch length by coherent radiation spectrum that the bunch length will be less than 500 fs (rms). The important point of this rf gun is the gun itself has an abilities of acceleration and compression, thus ECC rf gun is the compact ultra-short electron source. Such a gun, we think, can be applied to a coherent THz source and dynamic electron diffraction microscope. In this presentation, the introduction of our ECC rf gun, recent experimental results, and future prospective applications will be discussed. (author)

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

    Science.gov (United States)

    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

  13. Cerenkov Radiator Driven by a Superconducting RF Electron Gun

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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

  15. Longitudinal jitter analysis of linear accelerator electron gun

    CERN Document Server

    Mingshan, Liu; Iqbal, Munawar

    2015-01-01

    We present measurement and analyses of longitudinal timing jitter of Beijing Electron Positron Collider (BEPCII) linear accelerator electron gun. We simulated longitudinal jitter effect of the gun using PARMELA about beam performance including beam profile, average energy, energy spread, longitudinal phase of reference particle and XY emittance. The maximum percentage difference of the beam parameters are calculated to be; 100%, 13.27%, 42.24%, 7.79% and 65.01%, 86.81%, respectively due to which the bunching efficiency is reduced to 54%. The simulation results are in agreement with test and are helpful to optimize the beam parameters by tuning the trigger timing of the gun during the bunching process.

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

    Science.gov (United States)

    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.

  17. Emittance compensation of CW DC-gun photoinjector

    International Nuclear Information System (INIS)

    Emittance growth induced by space charge effect is very important, especially for CW DC-gun photoinjector. In this work, the linear space charge force and its effect on electron beam transverse emittance are studied, and the principle and properties of emittance compensation by solenoid are analyzed. The CAEP DC-gun photoinjector with a solenoid is also simulated by code Parmela. Simulated results indicate that the normalized transverse emittance of an 80 pC bunch at the 350 keV DC-gun ex-it is 5.14 mm · mrad. And after compensated by a solenoid, it becomes 1.27 mm · mrad. The emittance of beam is well compensated. (authors)

  18. Spectral diagnostic of plasma in the coaxial gun

    International Nuclear Information System (INIS)

    Plasma ejected from a coaxial plasma gun was investigated spectroscopically. The coaxial gun consisted of two copper coaxial electrodes 57 and 100 mm in diameter, the length of the central electrode being 67 mm. The gun was fed by a 11 μF capacitor bank of 16 kV operating voltage. Hydrogen, helium and air were used as working gases. The emission spectra were recorded with spectrograph ISP-51 and with a monochromator-photomultiplier system. The plasma density reached its maximum of 4x1015 cm-3 with the ejecting voltage applied some 20 to 30 μs after the gas injection. At this moment also the spectral lines of electrode material were most intensive. The electron temperature calculated from the presence of spectral lines of OII, CII and NII was about 2 eV. The velocity of fast hydrogen ions was 4x107 cmsec-1 calculated from the Hsub(β) line. (J.U.)

  19. ELECTROSTATIC MODELING OF THE JEFFERSON LABORATORY INVERTED CERAMIC GUN

    Energy Technology Data Exchange (ETDEWEB)

    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.

  20. Modelling and simulation of beam formation in electron guns

    International Nuclear Information System (INIS)

    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 velocity 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. (orig.)

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

    Science.gov (United States)

    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

  2. High quality flux control system for electron gun evaporation

    International Nuclear Information System (INIS)

    This paper reports on a high quality flux control system for electron gun evaporation developed and tested for the MBE growth of high temperature superconductors. The system can be applied to any electron gun without altering the electron gun itself. Essential elements of the system are a high bandwidth mass spectrometer, control electronics and a high voltage modulator to sweep the electron beam over the melt at high frequencies. the sweep amplitude of the electron beam is used to control the evaporation flux at high frequencies. The feedback loop of the system has a bandwidth of over 100 Hz, which makes it possible to grow superlattices and layered structures in a fast and precisely controlled manner

  3. Characterization of a Dielectric Barrier Plasma Gun Discharging at Atmospheric Pressure

    Institute of Scientific and Technical Information of China (English)

    ZHANG Guang-Qiu; GE Yuan-Jing; ZHANG Yue-Fei; CHEN Guang-Liang

    2004-01-01

    @@ We develop a plasma gun based on dielectric barrier discharge and working at atmospheric pressure. A theoretical model to predict the gun discharge voltage is built, which is in agreement with the experimental results. After investigating the characterization of discharging gun and utilizing it for polymerization, we find that the gun can be used as a source to generate a stable uniform plasma for different plasma-processing technologies.

  4. American preferences for “smart” guns versus traditional weapons: Results from a nationwide survey

    OpenAIRE

    Wallace, Lacey Nicole

    2016-01-01

    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 at...

  5. Gun Prevalence, Homicide Rates and Causality: A GMM Approach to Endogeneity Bias

    OpenAIRE

    Kleck, Gary; Kovandzic, Tomislav; Schaffer, Mark E.

    2005-01-01

    The positive correlation between gun prevalence and homicide rates has been widely documented. But does this correlation reflect a causal relationship? This study seeks to answer the question of whether more guns cause more crime, and unlike nearly all previous such studies, we properly account for the endogeneity of gun ownership levels. We discuss the three main sources of endogeneity bias - reverse causality (higher crime rates lead people to acquire guns for self-protection), mismeasureme...

  6. The system of RF beam control for electron gun

    Science.gov (United States)

    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.

  7. Surface Characterization of the LCLS RF Gun Cathode

    Energy Technology Data Exchange (ETDEWEB)

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

  8. POSTSCRIPT ON SOUTH AFRRICA'S FIRST ANTI-AIRCRAFT GUNS

    OpenAIRE

    W.M. Bisset

    2012-01-01

    One of the most fascinating things about South Africa's military history is the often surprising nature of some of its sources. In a short article on South Africa's first anti-aircraft guns which appeared in Militaria 8/1, 1978 pages 22-23 the present writer mentioned that he was unable to explain why the fact that two 15-pounder BlC's had been converted to anti-aircraft guns had been given wide publicity or why it had been necessary to undertake their conversion when the Cape Peninsula seeme...

  9. Description of Idiomatic Expression Found in Guns N’ Roses songs

    OpenAIRE

    Hutabarat, Chandra Xaverius Putra

    2011-01-01

    A paper with title “ Description of Idiomatic Expression Found in Guns N’ Roses Songs. Describing idiomatic expression in three songs of Guns N’ Roses, which are chosen randomly in Use Your Illusion I album. The method of reseach applies in this study is library reseach, and method of analysis the data is descriptive method. This study is analyzed because most of people can sing a English song, but most of them can not understand the meaning of the song. Describing idiomatic expression in a ...

  10. The system of RF beam control for electron gun

    International Nuclear Information System (INIS)

    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

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

    Science.gov (United States)

    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

  12. Electron gun operating by secondary emission under ionic bombardment

    International Nuclear Information System (INIS)

    The electron gun includes an ionization chamber adjacent to the high voltage chamber. In the common wall to the two chambers there is an extraction grid. Facing it, the ionization chamber includes a window, with a same form as the extraction grid, and with a thin metal film. High voltage chamber includes a cathode. In giving to the two grids the form of parallel homologous thin sheet, a masking effect and a focusing effect are got, which allow to increase the electron gun efficiency

  13. Beta II plasma-gun mechanical design and construction

    Energy Technology Data Exchange (ETDEWEB)

    Pedrotti, L.; Deis, G.; Wong, R.; Calderon, M.; Chargin, A.; Garner, D.

    1979-11-12

    The magnetized coaxial plasma gun (located on the east end of the Beta II facility at the Lawrence Livermore Laboratory) will be used to test a new method of initiating a field reversed mirror plasma. The field-reversed mirror is expected to improve the mirror-fusion reactor by enhancing the ratio of fusion power to injected power. This paper concentrates on the mechanical design and construction of the magnetized coaxial plasma gun and also discusses the diagnostic devices necessary to demonstrate the formation of field-reversed rings.

  14. Plasma-filled diode based on the coaxial gun

    Energy Technology Data Exchange (ETDEWEB)

    Zherlitsyn, A. A.; Kovalchuk, B. M.; Pedin, N. N. [Institute of High Current Electronics, 2/3 Academichesky Avenue, 634055 Tomsk (Russian Federation)

    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.

  15. Plasma-filled diode based on the coaxial gun

    Science.gov (United States)

    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.

  16. Finite-element simulation of thermoemission electron guns

    Science.gov (United States)

    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.

  17. Plasma-filled diode based on the coaxial gun

    International Nuclear Information System (INIS)

    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.

  18. Development of pierce type high-brightness electron gun

    International Nuclear Information System (INIS)

    A Pierce type electron gun has been developed. High voltage of 200kV DC is effective for the purpose of high brightness. A compact insulation gas tank of 600mmx600mmφ, and a very simple structure of high voltage feeding is realized by insulation designing using an electric field analysis. At the test bench experiments, high voltage of 200kV was achieved, which justifies our design. After a measurement of electron beam characteristics, the gun has been installed into linac system and operated stably. (author)

  19. POSTSCRIPT ON SOUTH AFRRICA'S FIRST ANTI-AIRCRAFT GUNS

    Directory of Open Access Journals (Sweden)

    W.M. Bisset

    2012-02-01

    Full Text Available One of the most fascinating things about South Africa's military history is the often surprising nature of some of its sources. In a short article on South Africa's first anti-aircraft guns which appeared in Militaria 8/1, 1978 pages 22-23 the present writer mentioned that he was unable to explain why the fact that two 15-pounder BlC's had been converted to anti-aircraft guns had been given wide publicity or why it had been necessary to undertake their conversion when the Cape Peninsula seemed beyond the range of enemy aircraft.

  20. Analysis on Venting Time of Rarefaction Wave Gun

    Institute of Scientific and Technical Information of China (English)

    WANG Ying-ze; ZHANG Xiao-bing; YUAN Yax-iong

    2008-01-01

    Based on the operation principle of rarefaction wave gun, the selection and calculation methods for venting opportune moment are invastigated. Considering property of the rarefaction wave, taking the center of muzzle section as initial calculation point, supposing that at the moment projectile arrives to the muzzle, the rarefaction wave arrives to the base of projectile, the rarefaction wave velocity along the barrel can be obtained by fitting calculation of the interior ballis-tic data of the same closed gun and reverse deduction. And then, the optimal venting time can be found out correctly based on the rarefaction wave velocity.

  1. Internal Ballistics of High Velocity Special Purpose Guns

    Directory of Open Access Journals (Sweden)

    V. K. Gupta

    1976-07-01

    Full Text Available More and more conventional guns are being utilized as special purpose guns to achieve very high velocity by using unconventionally high C/W ratios. The existing methods of internal ballistics give satisfactory results only for low (less than one C/W ratios. In the present paper the basic internal ballistic equations have been modified to cater for non-linear rate of burning, cubical form function and a realistic pressure gradient between breech face and the projectile base. The equations have been numerically solved. The results for low and high C/W ratios have been compared with those obtained by using conventional methods.

  2. High-voltage pulse generator for electron gun power supply

    International Nuclear Information System (INIS)

    High-voltage pulse generator with combined capacitive and inductive energy storages for electron gun power supply is described. Hydrogen thyratron set in a short magnetic lense is a current breaker. Times of current interruption in thyratrons are in the range from 100 to 300 ns. With 1 kV charging voltage of capacitive energy storage 25 kV voltage pulse is obtained in the load. The given high-voltage pulse generator was used for supply of an electron gun generating 10-30 keV low-energy electron beam

  3. Gun Access and Safety Practices among Older Adults

    OpenAIRE

    Lum, Hillary D.; Hanna K. Flaten; 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 ...

  4. An RF excited plasma cathode electron beam gun design

    OpenAIRE

    Del Pozo, S.; Ribton, C; Smith, DR

    2014-01-01

    A plasma cathode electron beam (EB) gun is presented in this work. A radio frequency (RF) excited plasma at 84 MHz was used as the electron source to produce a beam power of up to 3.2 kW at -60 kV accelerating voltage. The pressure in the plasma chamber is approximately 1 mbar. The electrons are extracted from the plasma chamber to the vacuum chamber (at 10-5 mbar) through a diaphragm with a 0.5 mm diameter nozzle. Advantages over thermionic cathode guns were demonstrated empirically. Mainten...

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

    Science.gov (United States)

    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

  6. The Origins of Gun Culture in the United States, 1760-1865.

    Science.gov (United States)

    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)

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

    Science.gov (United States)

    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)

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

    Science.gov (United States)

    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. Revisiting the Gun Ownership and Violence Link; a multi- level analysis of victimisation survey data.

    NARCIS (Netherlands)

    van Kesteren, J.N.

    2014-01-01

    The link between gun ownership victimisation by violent crime remains one of the most contested issues in criminology. Some authors claim that high gun availability facilitates serious violence. Others claim that gun ownership prevents crime. This article revisits these issues using individual and a

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

    Science.gov (United States)

    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…

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

    Science.gov (United States)

    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...

  12. 27 CFR 70.442 - Taxes relating to machine guns, destructive devices, and certain other firearms.

    Science.gov (United States)

    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,...

  13. 27 CFR 478.36 - Transfer or possession of machine guns.

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    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

  15. Du Style pour dire non, ou l’artillerie d’une poétique de combat dans Cahier d’un Retour au Pays Natal d’Aimé Césaire

    Directory of Open Access Journals (Sweden)

    Clotaire Saah Nengou

    2013-05-01

    Full Text Available Malgré les divers thèmes étudiés par des générations d’écrivains d’Afrique et de la diaspora noire francophone, la plupart de leurs œuvres ne reflète souvent que très timidement une forme esthétique hardie; serait-ce par peur de faire la différence? Par contre le poète Aimé Césaire ose. Dans son poème Cahier d’un Retour au Pays Natal, Césaire fait du signe une arme stylistique et insurrectionnelle pour combattre la norme culturelle tyrannique imposée à sa conscience, combattre les oppresseurs d’hommes et les larbins de la révolte. Soit le “style pour dire non!” La présente étude voudrait montrer que l’expressivité chez Césaire dans cet inusable, long et délirant texte poétique, c’est de l’artillerie lourde qui se caractérise par l’usage quantitatif, qualitatif et volumique d’éléments linguistiques, sortes d’obus donnant vitalité aux idées et violence aux signifiants.

  16. Proposed Federal Gun-Control Amendment. Student Forum.

    Science.gov (United States)

    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)

  17. High perveance electron gun for the electron cooling system

    CERN Document Server

    Korotaev, Yu V; Petrov, A; Sidorin, A; Smirnov, A; Syresin, E M; Titkova, I

    2000-01-01

    The cooling time in the electron cooling system is inversely proportional to the beam current. To obtain high current of the electron beam the control electrode of the gun is provided with a positive potential and an electrostatic trap for secondary electrons appears inside the electron gun. This leads to a decrease in the gun perveance. To avoid this problem, the adiabatic high perveance electron gun with the clearing control electrode is designed in JINR (J. Bosser, Y. Korotaev, I. Meshkov, E. Syresin et al., Nucl. Instr. and Meth. A 391 (1996) 103. Yu. Korotaev, I. Meshkov, A. Sidorin, A. Smirnov, E. Syresin, The generation of electron beams with perveance of 3-6 mu A/V sup 3 sup / sup 2 , Proceedings of SCHEF'99). The clearing control electrode has a transverse electric field, which clears secondary electrons. Computer simulations of the potential map were made with RELAX3D computer code (C.J. Kost, F.W. Jones, RELAX3D User's Guide and References Manual).

  18. Modified faceplate assembly for stud-welding gun

    Science.gov (United States)

    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.

  19. TESLA FEL Gun simulations with PARMELA and MAFIA

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, M. [Deutches Elektronen Synchrotron (DESY)-MPY-, Notkestr. 85, D-22603 Hamburg (Germany); Schuett, P. [FB 18, Fachgebiet Theorie Elektromagnetischer Felder, TH Darmstadt, Schlossgartenstr. 8, D-64289 Darmstadt (Germany)

    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. {copyright} {ital 1997 American Institute of Physics.}

  20. TESLA FEL Gun simulations with PARMELA and MAFIA

    Science.gov (United States)

    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.

  1. Temperature controlled cathode heating in the electron gun

    Czech Academy of Sciences Publication Activity Database

    Horáček, Miroslav

    Brno: CSMS, 2002 - (Frank, L.), s. 69 - 70 ISBN 80-238-8749-1. [CSEM. Vranovská Ves (CZ), 08.02.2002-09.02.2002] Institutional research plan: CEZ:AV0Z2065902 Keywords : directly heated tungsten cathode * electron gun * temperature controlled cathode heating Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  2. Development of the electron gun control system for LEBRA

    International Nuclear Information System (INIS)

    The control system of the electron gun was replaced at LEBRA. This system was developed using EPICS. EPICS is de-fact standard control framework. Device Support for the high voltage station controller and high frequency grid pulser was developed. (author)

  3. Gas-gun facility for shock wave research at BARC

    International Nuclear Information System (INIS)

    For carrying out shock-wave experiments on materials, we have built a 63 mm diameter gas-gun facility at our laboratory. It is capable of accelerating projectiles (about half kg in weight) to velocities up to 1 km/s using N2 and He gases. These on impacting a target generate shock pressures up to 40 GPa, depending upon the impedance of the impactor and the target. The barrel of the gun is slotted so that a keyed projectile can be fired for combined compression- shear studies. Large samples can be shocked (about 60 mm diameter and 5-10 mm thick), with pressures lasting for a few microseconds. The gun is similar in design to the one at Washington State University. A number of diagnostic techniques have also been developed. These include measurement of projectile velocity, tilt between the impactor and the target, shock velocity in the target, and time resolved in-material stress wave histories in the shock loaded samples. Recovery capsules have also been made to retrieve shocked samples on unloading, which are then analysed using microscopic techniques like x-ray diffraction, Raman and electron microscopy. The gun has been performing well and has already been used for a few phase transition studies. (author). 73 refs., 42 figs

  4. Update on photo cathodes for RF-Guns at DESY

    OpenAIRE

    Schreiber, Siegfried; Hansen, Ingo; Lederer, Sven; Michelato, Paolo; Monaco, Laura; Sertore, Daniele

    2013-01-01

    At DESY, caesium telluride photocathodes are successfully used for the RF Guns at DESY,namely FLASH, PITZ, and REGAE. Their high quantum efficiency and long lifetime allow toproduce routinely thousands of bunches per second with a single bunch charge in the nCrange. We report on the status of the preparation system and updates on lifetime, quantumefficiency, darkcurrent, and operating experience.

  5. High perveance electron gun for the electron cooling system

    International Nuclear Information System (INIS)

    The cooling time in the electron cooling system is inversely proportional to the beam current. To obtain high current of the electron beam the control electrode of the gun is provided with a positive potential and an electrostatic trap for secondary electrons appears inside the electron gun. This leads to a decrease in the gun perveance. To avoid this problem, the adiabatic high perveance electron gun with the clearing control electrode is designed in JINR (J. Bosser, Y. Korotaev, I. Meshkov, E. Syresin et al., Nucl. Instr. and Meth. A 391 (1996) 103. Yu. Korotaev, I. Meshkov, A. Sidorin, A. Smirnov, E. Syresin, The generation of electron beams with perveance of 3-6 μA/V3/2, Proceedings of SCHEF'99). The clearing control electrode has a transverse electric field, which clears secondary electrons. Computer simulations of the potential map were made with RELAX3D computer code (C.J. Kost, F.W. Jones, RELAX3D User's Guide and References Manual)

  6. Community College Faculty: Attitudes toward Guns on Campus

    Science.gov (United States)

    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…

  7. Electrical properties of a co-axial plasma gun

    International Nuclear Information System (INIS)

    The main interest of this work is to study the power discharge of capacitor bank through a coaxial electrodes system. Such arrangement is called the coaxial gun or coaxial accelerator. It is used in jet propulsion and in triggering of discharge in turbo engines or in plasma combustion arrangement. The main goal is to find out the efficiency of the system in both cases. coaxial plasma gun system has been constructed for this course of study. The plasma gun system consists of the plasma gun tube and the discharge chamber, the capacitor bank, the triggering system the vacuum system, the power supply, and safety and dumping system. Simple and efficient diagnostic techniques were used to measure the different parameters concerning the coaxial discharge system such as the Rogowski loop, the voltage divider, the magnetic probes, the double electric probe. Results were obtained using argon gas with an operating pressure ranging from 0.1 torr to 1 torr. The peak discharge current in the first half cycle was 44 K A with rise time of 6.25 μs for a bank charging voltage of 10 kv and gas pressure of 0.9 torr. 4-26 figs., 4-8 tabs., 33 refs

  8. Decay of plasma cluster accelerated by coaxial gun

    International Nuclear Information System (INIS)

    The decay of an air cluster accelerated in a vacuum tube is studied. The time dependence of electron density and electron temperature is introduced and the effect of different recombination processes is discussed. The observed plasma decay shows an exponential law, is independent of the gun regime and may be explained by ambipolar diffusion to the tube walls. (author)

  9. Guns on Campus: A Current Debate. E-Fact Sheet

    Science.gov (United States)

    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…

  10. Adolescents' Views of Guns in a High-Violence Community

    Science.gov (United States)

    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…

  11. More Fun and Curiosity with Magnetic Guns in the Classroom

    Science.gov (United States)

    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…

  12. Configuration optimization of high velocity arc spraying gun

    Institute of Scientific and Technical Information of China (English)

    CHEN Yong-xiong; ZHU Zi-xin; LIU Yan; XU Bin-shi

    2004-01-01

    In order to improve the in-flight characteristics of the atomizing droplets during high velocity wire arc spraying (HVAS), some changes have been operated on the original design of the HVAS gun configuration. A comparative study was carried out to investigate the microstructure and properties of the coatings produced by the original design spraying gun and the modified one, using 3Cr13 wires of 3 mm in diameter. The characteristics of their jets were examined during spraying. The results indicate that, the included angle between the two wires and the distance from the nozzle to the meeting point of the two vires may have a strong influence on the characteristics of the in-flight droplets and then the coatings. The jet divergence is found to be lower than that of the original one (about 12° against 25°). By modified gun, the adhesion strength, the microhardness and porosity of the coating deposited by modified gun are increased by 39% and 9% respectively. And the porosity of the coatings is decreased by 57%.

  13. Emissions of gun propellant compositions with added urea

    NARCIS (Netherlands)

    Driel, C.A. van; Hulst, M. van; Meuken, D.

    2011-01-01

    Addition of certain components to gun propellants may lead to a reduction of the NOx content in combustion gases. This is escribed in the literature based on small scale laboratory research. One of these components is urea. In the investigation described here, propellants have been studied which con

  14. Firearm Advertising: Product Depiction in Consumer Gun Magazines

    Science.gov (United States)

    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

    Science.gov (United States)

    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. Design and construction a full copper photocathode RF gun

    International Nuclear Information System (INIS)

    The design and construction of an all copper S-band one-and-half cell photocathode electron gun without a choke joint is described. The methods utilized to determine the field balance at the operational frequency without usage of the bead pulling perturbation measurement is given together wit the computational data

  17. Optimizing SRF Gun Cavity Profiles in a Genetic Algorithm Framework

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. Repetitive, small-bore two-stage light gas gun

    International Nuclear Information System (INIS)

    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

  19. First beam commissioning at BNL ERL SRF Gun

    Energy Technology Data Exchange (ETDEWEB)

    Xu, W. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Altinbas, Z. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Belomestnykh, S. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Stony Brook Univ., NY (United States). Dept. of Physics and Astronomy; Ben-Zvi, I. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Stony Brook Univ., NY (United States). Dept. of Physics and Astronomy; Deonarine, S. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; DeSanto, L. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Gassner, D. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Gupta, R. C. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Hahn, H. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Hammons, L. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Ho, C. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Jamilkoski, J. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Kankiya, P. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Kayran, D. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Kellerman, R. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Laloudakis, N. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Lambiase, R. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Liaw, C. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Litvinenko, V. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Stony Brook Univ., NY (United States). Dept. of Physics and Astronomy; Mahler, G. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Masi, L. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; McIntyre, G. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Miller, T. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Philips, D. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Ptitsyn, V. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Seda, T. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Sheehy, B. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Smith, K. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Rao, T. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Steszyn, A. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Tallerico, T. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Than, R. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Tuozollo, J. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Wang, E. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Weiss, D. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Wiliniski, M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Zaltsman, A. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.

    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.

  20. Gas loading system for LANL two-stage gas guns

    Science.gov (United States)

    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

  1. People and guns involved in denied and completed handgun sales

    OpenAIRE

    Wright, M.; Wintemute, G; Claire, B

    2005-01-01

    Objective: Denial of handgun purchases by prohibited people and knowledge of the structure of gun commerce have helped to deter and prevent firearm violence. The authors hypothesize that handguns involved in a denied purchase would more closely resemble those used in crime compared with handguns sold.

  2. Development of a 500kV photoemission gun

    International Nuclear Information System (INIS)

    A high-brightness, high-current electron gun for energy recovery linac light sources, high repetition rate X-ray FEL and high power EUV FEL requires an exit beam energy of ≥ 500 keV to reduce space-charge induced emittance growth in the drift space from the gun exit to the following accelerator entrance. We demonstrated generation of a 500-keV electron beam. This demonstration was achieved by addressing two discharge problems that lead to vacuum breakdown in the dc gun. One is field emission generated from a central stem electrode. We employed a segmented insulator to protect the ceramic insulator surface from the field emission. The other is microdischarge at an anode electrode or a vacuum chamber, which is triggered by microparticle transfer or field emission from a cathode electrode. An experimental investigation revealed that a larger acceleration gap, optimized mainly to reduce the surface electric field of the anode electrode, suppresses the microdischarge events that accompany gas desorption. It was also found that nonevaporable getter pumps placed around the acceleration gap greatly help to suppress those microdischarge events. The gun has provided stable beam for commissioning of the compact ERL at KEK since April 2013. (author)

  3. Development of superconducting RF electron gun in KEK

    International Nuclear Information System (INIS)

    A high-intensity electron gun is required for the next generation ERL or a high power FEL system. KEK started development of a superconducting RF electron gun in addition to the conventional DC electron gun. 1.3 GHz of the resonant frequency, 100 mA of the beam current, and 2 MeV of the energy in the exit of gun are made into the precondition. By combining electromagnetic field analysis and charged particle dynamics analysis, the optimal design of the cavity shape, where the maximum surface electric field of less than 50 MV/m, a low emittance of less than 1 mm mrad, and a low energy spread of less than 0.1% (2 keV)) can be filled with this precondition, was tried. The designed elliptical cavity is a 1.5-cell structure made of Nb material, and the three half cells are manufactured from one common die. Thermo-structural analysis under cryogenic temperature and vacuum environment was also carried out, and the resonance frequency change would be evaluated. (author)

  4. Gridded gun test results for dual mode medical Linac

    International Nuclear Information System (INIS)

    As an advancement in the current low energy (6 MV) radiotherapy linac technology, SAMEER is developing a dual photon energy linac capable of giving 6 and 15 MV photons and multiple electron energies (6, 8, 10, 12, 14, 16 and 18 MeV) for electron treatment. The main feature of this development is to produce clinically acceptable quality electron beam and photon beam. The gridded gun development is a crucial part of this project because of the electron beam current requirement which ranges from milliampere to nanoampere level from photon mode to electron mode. Therefore, precise control on the beam current is key feature in linac operation. The gridded gun design specifications is given. The gun assembly was successfully carried out. The gridded gun was assembled in a test jig and baked at 100 °C. The vacuum achieved after baking was ∼10-9 mbar. The cathode activation results and DC test results were obtained. The high voltage test results in pulsed mode is discussed in this paper along with its supply. (author)

  5. X-Band Thermionic Cathode RF Gun at UTNL

    CERN Document Server

    Fukasawa, Atsushi; Dobashi, Katsuhiro; Ebina, Futaro; Hayano, Hitoshi; Higo, Toshiyasu; Kaneyasu, Tatsuo; Matsuo, Kennichi; Ogino, Haruyuki; Sakae, Hisaharu; Sakamoto, Fumito; Uesaka, Mitsuru; Urakawa, Junji

    2005-01-01

    The X-band (11.424 GHz) linac for compact Compton scattering hard X-ray source are under construction at Nuclear Engineering Research Laboratory, University of Tokyo. This linac designed to accelerate up to 35 MeV, and this electron beam will be used to produce hard X-ray by colliding with laser. It consists of a thermionic cathode RF gun, an alpha magnet, and a traveling wave tube. The gun has 3.5 cells (unloaded Q is 8250) and will be operated at pi-mode. A dispenser cathode is introduced. Since the energy spread of the beam from the gun is predicted to be broad due to the continuous emission from the thermionic cathode, a slit is placed in the alpha magnet to eliminate low energy electrons. The simulation on the injector shows the beam energy 2.9 MeV, the charge 23 pC/bunch, and the emittance less than 10 mm.mrad. The experiment on the gun is planed in the beginning of 2005, and the details will be discussed on the spot.

  6. Enhancing the brightness of high current electron guns

    International Nuclear Information System (INIS)

    Concepts such as the two-beam accelerator offer the possibility of translating pulsed power technology into a form useful to the design of high luminosity accelerators for high-energy physics applications. Realization of the promise of these concepts will require the design of electron guns which are optimized with respect to beam brightness at current levels of approximately 1 kA. Because high luminosity implies accelerator operation at high repetition rates, the high-current beam source must be designed so that the beam does not intercept the electrodes. In our investigations of electron gun configurations, we have found that the brightness of a given source is set by practical design choices such as peak voltage, cathode type, gun electrode geometry, and focusing field topology. To investigate the sensitivity of beam brightness to these factors in a manner suitable for modelling transient phenomena at the beam head, we have developed a Darwin approximation particle code, DPC. The main component in our experimental program is a readily modified electron gun that allows us to test many candidate cathode materials, types, and electrode geometries at field stresses up to 1 MW/cm. We have also developed several diagnostics suitable for measuring the brightness of intense, low-emittance beams

  7. Terahertz-driven, all-optical electron gun

    CERN Document Server

    Huang, W Ronny; Wu, Xiaojun; Cankaya, Huseyin; Calendron, Anne-Laure; Ravi, Koustuban; Zhang, Dongfang; Nanni, Emilio A; Hong, Kyung-Han; Kärtner, Franz X

    2016-01-01

    Ultrashort electron beams with narrow energy spread, high charge, and low jitter are essential for resolving phase transitions in metals, semiconductors, and molecular crystals. These semirelativistic beams, produced by phototriggered electron guns, are also injected into accelerators for x-ray light sources. The achievable resolution of these time-resolved electron diffraction or x-ray experiments has been hindered by surface field and timing jitter limitations in conventional RF guns, which thus far are 96 fs, respectively. A gun driven by optically-generated single-cycle THz pulses provides a practical solution to enable not only GV/m surface fields but also absolute timing stability, since the pulses are generated by the same laser as the phototrigger. Here, we demonstrate an all-optical THz gun yielding peak electron energies approaching 1 keV, accelerated by 300 MV/m THz fields in a novel micron-scale waveguide structure. We also achieve quasimonoenergetic, sub-keV bunches with 32 fC of charge, which ca...

  8. Electron Gun for Computer-controlled Welding of Small Components

    Czech Academy of Sciences Publication Activity Database

    Dupák, Jan; Vlček, Ivan; Zobač, Martin

    2001-01-01

    Roč. 62, 2-3 (2001), s. 159-164. ISSN 0042-207X R&D Projects: GA AV ČR IBS2065015 Institutional research plan: CEZ:AV0Z2065902 Keywords : Electron beam-welding machine * Electron gun * Computer- control led beam Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.541, year: 2001

  9. Numerical modelling of the CEBAF electron gun with EGUN

    International Nuclear Information System (INIS)

    The electron source used in the injector for the CEBAF accelerator is a Hermosa electron gun with a 2 mm diameter cathode and a control electrode. It produces a 100 keV electron beam to be focused on the first of two apertures which comprise an emittance filter. A normalized emittance of less than π mm mrad at 1.2 mA is set by the requirements of the final beam from the CEBAF linac, since downstream of the filter, a system of two choppers and a third aperture removes 5/6 of the current. In addition, for RF test purposes a higher current of about 5 mA is needed, possibly at higher emittance. This paper presents a way of calculating the characteristics of the CEBAF electron gun with the gun design code EGUN, and the accuracy of the results is discussed. The transverse shape of the beam delivered by the gun has been observed, and its current measured. A halo around the beam has been seen, and the calculations can reproduce this effect

  10. Magnetic-gun igniter for controlled thermonuclear fusion

    International Nuclear Information System (INIS)

    A conceptual design for the magnetic gun is given in order to show that the various parameters required turn out to be reasonable (in an engineering sense). An engineering design will necessarily turn out to be far more complex; the purpose of the following calculations is merely to show that the basic idea looks sufficiently good to warrant further work

  11. Control led electron gun with a plasma cathode

    International Nuclear Information System (INIS)

    A description of a power electron gun with a plasma cathode is given. Its design is the development of gas-discharge sources of the duaplasmatron type. The basic elements of the gas-discharge source- the gun anode, the gun plasma cathode, the intermediate electrode of the source, and the tungsten thermocathode- are placed in side a high-voltage insulator. The diameter of the plasma cathode can be up to 2 cm, and the length of the accelerating gap- up to 0.3 cm. The discharge chamber is filled with Ar under 0.3 torr pressure. The electron beam focusing is carried out by means of two magnetic lenses, and displacement of the electron beam - by means of a deflecting coil. Experimental data are given on beam current control by modulating the discharge current and also by means of the electromagnetic system of the plasma gas-discharge source. The electron gun described shapes electron beams with a current up to 4.5 A under stationary operating conditions

  12. The analysis of random effects regression model for predicting the shelf-life of gun propellant

    OpenAIRE

    Chang, Wei-Te

    1995-01-01

    Most gun propellant is stored at depots for a long time before it is used. While being stored, the quality of the gun propellant may deteriorate and become unstable. In an attempt to avoid disaster due to use of unstable gun propellant, accurate prediction of the safe shelf-life of gun propellant is necessary. The shelf-life estimation methods used currently for a group of similar gun propellant lots are based on a fixed effects regression model. This does not take into consideration the fact...

  13. Comparison of a laboratory and a production coating spray gun with respect to scale-up

    OpenAIRE

    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 dro...

  14. Media portrayals of gun violence depend on race, leading to often very disparate policy responses

    OpenAIRE

    Parham-Payne, Wanda V.

    2014-01-01

    Far more Blacks than Whites are killed because of gun violence in the U.S. Despite this fact, when arguing for greater gun control, politicians tend to respond to gun violence involving whites, such as the 2012 Sandy Hook shootings. Wanda V. Parham-Payne argues that much of this difference in policy response is down to how the media portrays gun violence. She writes that the inner city gun violence that disproportionately affects Blacks is portrayed by the media as a manifestation of immorali...

  15. Serious air gun injuries in children: update of injury statistics and presentation of five cases.

    Science.gov (United States)

    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

  16. American preferences for "smart" guns versus traditional weapons: Results from a nationwide survey.

    Science.gov (United States)

    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

  17. Design of a high repetition rate S-band photocathode gun

    Science.gov (United States)

    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.

  18. New Gas Gun Helping Scientists Better Understand Plutonium Behavior

    Energy Technology Data Exchange (ETDEWEB)

    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.''

  19. Gun violence among youth and the pediatrician's role in primary prevention.

    Science.gov (United States)

    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

  20. Does the Declining Lethality of Gunshot Injuries Mask a Rising Epidemic of Gun Violence in the United States?

    OpenAIRE

    Jena, Anupam B.; Eric C. Sun; Prasad, Vinay

    2014-01-01

    Recent mass shootings in the U.S. have reignited the important public health debate concerning measures to decrease the epidemic of gun violence. Editorialists and gun lobbyists have criticized the recent focus on gun violence, arguing that gun-related homicide rates have been stable in the last decade. While true, data from the U.S. Centers for Disease Control and Prevention also demonstrate that although gun-related homicide rates were stable between 2002 and 2011, rates of violent gunshot ...