451 Matching Results

Search Results

Advanced search parameters have been applied.

[The Old Hard Sell]

Description: Narrative by Junebug Clark: Photograph of a moonshiner's back pocket holding a pistol. Joe documented many moonshine stills. Some of which are in his mini-book "White Lightning." Photo by: Joe Clark, HBSS. Signed by: Joe Clark, HBSS Clark PhotoFile: 0001-87
Date: 19uu
Creator: Clark, Joe
Partner: UNT Libraries Special Collections

[News Script: News Briefs - Guns]

Description: Script from the WBAP-TV station in Fort Worth, Texas, covering a news story about Tarrant County sheriffs finding an arsenal of weapons in an overturned stolen car near Hurst, Texas.
Date: August 17, 1955
Creator: WBAP-TV (Television station : Fort Worth, Tex.)
Partner: UNT Libraries Special Collections

RTA gun performance

Description: The technical challenge for making two-beam accelerators into realizable power sources for high-energy colliders lie in the creation of the drive beam and in its propagation over long distances through multiple extraction sections. This year we have constructed a 1.2-kA, 1-MeV, electron induction injector for the RTA accelerator. The electron source will be a 8.9 cm diameter, thermionic, flat-surface cathode with a maximum shroud field stress of approximately 165 kV/cm. The injector� s pulse length should be over 120-ns flat top (1% energy variation) with a normalized edge emittance of less than 200 (small pi)-mm-mr. Details of the design and performance of the injector, beam line, and diagnostics will be presented.
Date: August 10, 1998
Creator: Andersen, D E; Eylon, S; Henestroza, E; Houck, T L; Lidia, S M; Vanecek, D L et al.
Partner: UNT Libraries Government Documents Department

Metallurgical examination of gun barrel screws

Description: The examination was conducted to determine the extent of degradation that had occurred after a series of firings; these screws prevent live rounds of ammunition from being loaded into the firing chamber. One concern is that if the screw tip fails and a live round is accidentally loaded into the chamber, a live round could be fired. Another concern is that if the blunt end of the screw begins to degrade by cracking, pieces could become small projectiles during firing. All screws used in firing 100 rounds or more exhibited some degree degradation, which progressively worsened as the number of rounds fired increased. (SEM, metallography, x-ray analysis, and microhardness were used.) Presence of cracks in these screws after 100 fired rounds is a serious concern that warrants the discontinued use of these screws. The screw could be improved by selecting an alloy more resistant to thermal and chemical degradation.
Date: June 1, 1996
Creator: Bird, E.L. & Clift, T.L.
Partner: UNT Libraries Government Documents Department

Electromagnetic targeting of guns

Description: This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Electromagnetic pulse (EMP) signals produced from explosives being fired have been reported in the literature for fifty years. When a gun is fired it produces an EMP muzzle blast signal. The strength and nature of these signals was first analyzed in the early 1970s, while the results were interesting, no follow-up studies were conducted. With modern detection and signal processing technology, we believe that these signals could be used to instantaneously locate guns of virtually all calibers as they fire. The objective of our one-year project was to establish the basic nature of these signals and their utility in the concept of electromagnetic targeting of guns.
Date: October 1, 1996
Creator: Pogue, E.W.; Boat, R.M.; Holden, D.N. & Lopez, J.R.
Partner: UNT Libraries Government Documents Department

PPM focused X-band klystron development at the Stanford Linear Accelerator Center

Description: X-band klystrons capable of 50 MW and utilizing Periodic Permanent Magnet (PPM) focusing are undergoing design and fabrication at the Stanford Linear Accelerator Center (SLAC). The klystron development is part of an effort to realize components necessary for the construction of the Next Linear Collider (NLC). The first klystron to be tested this year has a 0.6 microK beam at 465 kV, a 5 cells traveling wave output structure and a predicted efficiency of 63%. A 465 kV, 190 A beam stick with 12 periods of PPM focusing has recently operated to verify the gun optics and transmission of the beam in the absence of rf bunching. Beam transmission greater than 99.8% has been measured. Design and simulation of the beam stick and klystron are discussed, along with performance of the beam stick under confined flow and shielded conditions.
Date: July 1, 1996
Creator: Sprehn, D.; Caryotakis, G.; Eppley, K. & Phillips, R.M.
Partner: UNT Libraries Government Documents Department

Air-Gun Studies of Ferroelectric Materials (Second Printing)

Description: Specimens of two ferroelectric materials, barium titanate and lead-zirconate titanate, have been subjected to high dynamic stresses by impacting them with a projectile accelerated by an air gun. The purpose of these tests was to supplement information previously obtained using high explosives to stress the ferromagnetic materials.
Date: February 6, 1958
Creator: Ripperger, E. A. & Beck, A. F.
Partner: UNT Libraries Government Documents Department

Engineering Design and Fabrication of an Ampere-Class Superconducting Photocathode Electron Gun

Description: Over the past three years, Advanced Energy Systems and Brookhaven National Laboratory (BNL) have been collaborating on the design of an Ampere- class superconducting photocathode electron gun. BNL performed the physics design of the overall system and RF cavity under prior programs. Advanced Energy Systems (AES) is currently responsible for the engineering design and fabrication of the electron gun under contract to BNL. We will report on the engineering design and fabrication status of the superconducting photocathode electron gun. The overall configuration of the cryomodule will be reviewed. The layout of the hermitic string, space frame, shielding package, and cold mass will be discussed. The engineering design of the gun cavity and removable cathode will be presented in detail and areas of technical risk will be highlighted. Finally, the fabrication sequence and fabrication status of the gun cavity will be discussed.
Date: November 17, 2008
Creator: Ben-Zvi,I.
Partner: UNT Libraries Government Documents Department

Experience at Fermilab with high quantum efficiency photo-cathodes for rf electron guns

Description: As part of the A0 Photo-injector collaboration at Fermi-lab [1, 2] and the TeSLA collaboration [3], a high bright-ness, low emittance electron source has been developed. In the process, a system was constructed for coating molybde-num cathodes with a layer of cæsium telluride (Cs2 Te), a photo-emissive material of high quantum efficiency (QE). The use of Cs2 Te was first investigated at CERN [4] and LANL [5]. The development of the systems for the TeSLA Test Facility Linac and the Fermilab Photo-injector was done in Milano [6]. The system at Fermilab incorporates manipulator arms to transfer a cathode from the preparation chamber into a 1.3 GHz photo-electron RF gun while it re-mains in an ultra-high vacuum (UHV) environment, in or-der to avoid the deleterious effects of residual gases on the QE. A first prototype electron gun has been operated with a photo-cathode for several months [1]. This paper describes preliminary results obtained with the first 2 photo-cathodes and the first gun. Some of the desired parameters for the TeSLA Test Fa-cility beam are given in Table 1. The desired characteristics for the photo-cathodes include (i) high QE, (ii) high current density (>500 A/cm{sup 2} ), (iii) long lifetime, and (iv) low field emission. The choice of Cs2 Te is a compromise between long lifetime, rugged metal cathodes with low QE (typi-cally between 10{sup -6} and 10{sup -4} and semiconductor cathodes with high QE (>10%), which generally have a short life-time because of their sensitivity to contamination.
Date: October 1998
Creator: Fry, A.; Hahn, E.; Hartung, W.; Kuchnir, M.; Michelato, P. & Sertore, D.
Partner: UNT Libraries Government Documents Department

Electromagnetically Induced Guiding of Counter-propagating Lasers in Plasmas

Description: The interaction of counter-propagating laser pulses in a plasma is considered. When the frequencies of the two lasers are close, nonlinear modification of the refraction index results in the mutual focusing of the two beams. A short (of order the plasma period) laser pulse can also be nonlinearly focused by a long counter-propagating beam which extends over the entire guiding length. This phenomenon of electromagnetically induced guiding can be utilized in laser-driven plasma accelerators.
Date: May 1998
Creator: Shvets, G. & Pukhov, A.
Partner: UNT Libraries Government Documents Department

Active plasma source formation in the MAP diode

Description: The Ion Beam Surface Treatment (IBEST) program is exploring using ion beams to treat the surface of a wide variety of materials. These experiments have shown that improved corrosion resistance, surface hardening, grain size modification, polishing and surface cleaning can all be achieved using a pulsed 0.4-0.8 MeV ion beam delivering 1-10 J/cm{sup 2}. The Magnetically-confined Anode Plasma (MAP) diode, developed at Cornell University, produces an active plasma which can be used to treat the surfaces of materials. The diode consists of a fast puff valve as the source of gas to produce the desired ions and two capacitively driven B-fields. A slow magnetic field is used for electron insulation and a fast field is used to both ionize the puffed gas and to position the plasma in the proper spatial location in the anode prior to the accelerator pulse. The relative timing between subsystems is an important factor in the effective production of the active plasma source for the MAP diode system. The MAP diode has been characterized using a Langmuir probe to measure plasma arrival times at the anode annulus for hydrogen gas. This data was then used to determine the optimum operating point for the MAP diode on RHEPP-1 accelerator shots. Operation of the MAP diode system to produce an ion beam of 500 kV, 12 kA with 40% efficiency (measured at the diode) has been demonstrated.
Date: July 1, 1995
Creator: Lamppa, K.P.; Stinnett, R.W. & Renk, T.J.
Partner: UNT Libraries Government Documents Department

''Smart Gun'' Technology Update

Description: This report is an update to previous ''smart gun'' work and the corresponding report that were completed in 1996. It incorporates some new terminology and expanded definitions. This effort is the product of an open source look at what has happened to the ''smart gun'' technology landscape since the 1996 report was published.
Date: November 1, 2001
Creator: WIRSBINSKI, JOHN W.
Partner: UNT Libraries Government Documents Department

Proof-of-principle Experiment of a Ferroelectric Tuner for the 1.3 GHz Cavity

Description: A novel tuner has been developed by the Omega-P company to achieve fast control of the accelerator RF cavity frequency. The tuner is based on the ferroelectric property which has a variable dielectric constant as function of applied voltage. Tests using a Brookhaven National Laboratory (BNL) 1.3 GHz electron gun cavity have been carried out for a proof-of-principle experiment of the ferroelectric tuner. Two different methods were used to determine the frequency change achieved with the ferroelectric tuner (FT). The first method is based on a S11 measurement at the tuner port to find the reactive impedance change when the voltage is applied. The reactive impedance change then is used to estimate the cavity frequency shift. The second method is a direct S21 measurement of the frequency shift in the cavity with the tuner connected. The estimated frequency change from the reactive impedance measurement due to 5 kV is in the range between 3.2 kHz and 14 kHz, while 9 kHz is the result from the direct measurement. The two methods are in reasonable agreement. The detail description of the experiment and the analysis are discussed in the paper.
Date: January 1, 2009
Creator: Choi,E.M.; Hahn, H.; Shchelkunov, S. V.; Hirshfield, J. & Kazakov, S.
Partner: UNT Libraries Government Documents Department

Development of hollow electron beams for proton and ion collimation

Description: Magnetically confined hollow electron beams for controlled halo removal in high-energy colliders such as the Tevatron or the LHC may extend traditional collimation systems beyond the intensity limits imposed by tolerable material damage. They may also improve collimation performance by suppressing loss spikes due to beam jitter and by increasing capture efficiency. A hollow electron gun was designed and built. Its performance and stability were measured at the Fermilab test stand. The gun will be installed in one of the existing Tevatron electron lenses for preliminary tests of the hollow-beam collimator concept, addressing critical issues such as alignment and instabilities of the overlapping proton and electron beams.
Date: June 1, 2010
Creator: Stancari, G.; Drozhdin, A.I.; Kuznetsov, G.; Shiltsev, V.; Still, D.A.; Valishev, A. et al.
Partner: UNT Libraries Government Documents Department

Modelling multi-ion plasma gun simulations of Tokamak disruptions

Description: The effect of impurity ions in plasma gun ablation tests of various targets is considered. Inclusion of reasonable amounts of impurity ({approximately}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.
Date: August 1, 1995
Creator: Ehst, D.A.
Partner: UNT Libraries Government Documents Department

Advanced photon source low-energy undulator test line

Description: The injector system of the Advanced Photon Source (APS) consists of a linac capable of producing 450-MeV positrons or > 650-MeV electrons, a positron accumulator ring (PAR), and a booster synchrotron designed to accelerate particles to 7 GeV. There are long periods of time when these machines are not required for filling the main storage ring and instead can be used for synchrotron radiation research. We describe here an extension of the linac beam transport called the Low-Energy Undulator Test Line (LEUTL). The LEUTL will have a twofold purpose. The first is to fully characterize innovative, future generation undulators, some of which may prove difficult or impossible to measure by traditional techniques. These might include small-gap and superconducting undulators, very long undulators, undulators with designed-in internal focusing, and helical undulators. This technique also holds the promise of extending the magnetic measurement sensitivity beyond that presently attainable. This line will provide the capability to directly test undulators before their possible insertion into operating storage rings. A second use for the test line will be to investigate the generation of coherent radiation at wavelengths down to a few tens of nanometers.
Date: April 1, 1997
Creator: Milton, S.V.
Partner: UNT Libraries Government Documents Department

Experimental gun brightness measurements on a 300 kV CFEG

Description: Effective use of the ANL 300kV CFEG/AAEM requires a knowledge of the probe current and size distribution during operation. In most cases this can be calculated once basic parameters of the system are experimentally determined. Central to this is a determination of the source brightness of the Cold Field Emission Gun (CFEG) under standard operating conditions of the instrument. For the last ten years most probe calculations of CFEG`s have been done assuming a brightness parameter of {beta}{approximately}1{times}10{sup 9} A/cm{sup 2}/sterad{sup 2} at 100 kV, while few if any experimental values have been reported at 300 kV. In order to determine {beta}, and thus characterize the source, the authors have measured the probe size, current and convergence angles on the ANL AAEM and from this calculated the effective brightness as a function of operating conditions. They compute d{sub g} = 0.92 nm and effective source brightness for the system of {beta} = 8.6{times}10{sup 8} A/cm{sup 2}/sterad. A value which is within experimental errors of the commonly used parameter at 100 kV, but is less than the expected value of {approximately}4{times}10{sup 9} A/cm{sup 2}/sterad.
Date: January 1, 1998
Creator: Zaluzec, N.J. & Nicholls, A.
Partner: UNT Libraries Government Documents Department

Relativistic-klystron two-beam accelerator as a power source for future linear colliders

Description: The technical challenge for making two-beam accelerators into realizable power sources for high-energy colliders lies in the creation of the drive beam and in its propagation over long distances through multiple extraction sections. This year we have been constructing a 1.2&A, l-MeV, induction gun for a prototype relativistic klystron two-beam accelerator (RK-TBA). The electron source will be a 8.9 cm diameter, thermionic, flat-surface cathode with a maximum shroud field stress of approximately 165 kV/cm. Additional design parameters for the injector include a pulse length of over 150-ns flat top (1% energy variation), and a normalized edge emittance of less than 300 pi-mm-n-n. The prototype accelerator will be used to study physics, engineering, and costing issues involved in the application of the RK-TBA concept to linear colliders. We have also been studying optimization parameters, such as frequency, for the application of the RK-TBA concept to multi-TeV linear colliders. As an rf power source the RK-TBA scales favorably up to frequencies around 35 GHz. An overview of this work with details of the design and performance of the prototype injector, beam line, and diagnostics will be presented.
Date: October 5, 1998
Creator: Anderson, D E; Eylon, S; Henestroza, E; Houck, T L; Lidia, M; Vanecek, D L et al.
Partner: UNT Libraries Government Documents Department