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A Fundamental Theorem on Particle Acceleration

Description: A fundamental theorem on particle acceleration is derived from the reciprocity principle of electromagnetism and a rigorous proof of the theorem is presented. The theorem establishes a relation between acceleration and radiation, which is particularly useful for insightful understanding of and practical calculation about the first order acceleration in which energy gain of the accelerated particle is linearly proportional to the accelerating field.
Date: May 1, 2003
Creator: Xie, Ming
Partner: UNT Libraries Government Documents Department

Efficient electron injection into plasma waves using higher-orderlaser modes

Description: Using higher-order transverse laser modes as drivers forplasma wave excitation, and, in particular, using a ring laser beam withmaximum intensity off-axis, results in reversal of the focusinganddefocusing phase regions in a laser wakefield accelerator. Thisresults in improved performance of self-trapping and laser injectionschemes. Specifically, the trapping threshold required foropticalinjection is decreased and the maximum energy gain of the trappedelectrons is increased. This scheme could also be of interest for thegeneration of ring electron beams or for beam conditioning.
Date: August 2, 2006
Creator: Michel, P.; Esarey, E.; Schroeder, C.B.; Shadwick, B.A. & Leemans,W.P.
Partner: UNT Libraries Government Documents Department

Thermal effects in plasma-based accelerators

Description: Finite plasma temperature can modify the structure of thewake field, reduce the wave-breaking field, and lead to self-trappedelectrons, which can degrade the electron bunch quality in a plasma-basedaccelerator. A relativistic warm fluid theory is used to describe theplasma temperature evolution and alterations to the structure of anonlinear periodic wave exited in a warm plasma. The trapping thresholdfor a plasma electron and the fraction of electrons trapped from athermal distribution are examined using a single-particle model.Numerical artifacts in particle-in-cell models that can mimic the physicsassociated with finite momentum spread are discussed.
Date: January 9, 2007
Creator: Esarey, E.; Schroeder, C.B.; Michel, E.; Shadwick, B.A.; Geddes,C.G.R. & Leemans, W.P.
Partner: UNT Libraries Government Documents Department

Further measurements of normal accelerations on racing airplanes

Description: This report details the acceleration data collected from racing airplanes during actual races. The data was collected in order to make recommendations regarding the structural safety of racing airplanes and the methods of operating racing airplanes that reduces the probability of subjecting them to extreme air loads. The records do not lead to any conclusions regarding maximum air loads.
Date: February 1936
Creator: Kirschbaum, H. W. & Scudder, N. F.
Partner: UNT Libraries Government Documents Department

Particle Accelerator Division Summary Report: April Through September 1960

Description: Report issued by the Argonne National Laboratory discussing a summary report of the Particle Accelerator Division. As stated in the summary, "this report outlines two methods applicable respectively to longhand and computer calculations" (p. 4). This report includes tables, illustrations, and photographs.
Date: 1960
Creator: Crewe, Albert V.; FitzPatrick, John P.; Foss, Martyn H. & Manson, David S.
Partner: UNT Libraries Government Documents Department

An analysis of the normal accelerations and airspeeds of a four-engine airplane type in postwar commercial transport operations on trans-Pacific and Caribbean-South American routes

Description: Report presenting an analysis of normal-acceleration and airspeed data on several transport airplanes of a four-engine type during postwar commerical operations on trans-Pacific and Caribbean-South American routes of the same airlines. The results indicate that the acceleration increment corresponding to the limit-gust-load-factor increment may be exceed about twice in all of the flight miles for each route. Results regarding accelerations, flight loads, gust encounters, and speeds are provided.
Date: August 1950
Creator: Coleman, Thomas L. & Schumacher, Paul W. J.
Partner: UNT Libraries Government Documents Department

Flight investigation of the effect of transient wing response on measured accelerations of a modern transport airplane in rough air

Description: Report presenting a flight investigation on a transport airplane to determine the effect of transient wing response in rough air on acceleration measurements at the center of gravity of the airplane. Flights were made in clear-air turbulence over a range of altitudes for two speed conditions and different wing weights. Results indicate that the peak recorded center-of-gravity acceleration increments were over 20 percent higher than the true airplane acceleration increments.
Date: August 1950
Creator: Schufflebarger, C. C. & Mickleboro, Harry C.
Partner: UNT Libraries Government Documents Department

A preliminary determination of normal accelerations on racing airplanes

Description: "Rules and methods for insuring safe structural strength of racing airplanes used in the major air meets in this country have recently been considered. Acceleration records made in racing airplanes during actual air races were therefore considered desirable, and the NACA undertook the measurement of acceleration of loads on airplanes during all conditions of flight. Accelerations were measured on four airplanes at the Miami All-American Races in January 1934 and January 1935" (p. 1).
Date: August 1935
Creator: Scudder, N. F. & Kirschbaum, H. W.
Partner: UNT Libraries Government Documents Department

The effect of accelerating a hypothetical aircraft through the transonic range with controls fixed

Description: Memorandum presenting Mach number histories of the motion experienced by a hypothetical, small, straight-wing aircraft accelerating at various rates through an assumed controls-fixed pitch-down balance change in the transonic range. Two approximate analytical solutions of the longitudinal equations of motion are developed which are based on certain simplifying assumptions indicated by the differential-analyzer results.
Date: April 4, 1950
Creator: Matthews, Howard F.
Partner: UNT Libraries Government Documents Department

Acceleration of high-pressure-ratio single-spool turbojet engine as determined from component performance characteristics 3: effect of turbine stator adjustment

Description: From Summary: "An analytical investigation was made to determine from component performance the effect of turbine stator adjustment on the acceleration characteristics of a typical high-pressure-ratio single-spool turbojet engine. Turbine stator adjustment was adequate to permit engine operation in the intermediate-speed range, but was less satisfactory than the relatively simple schemes of compressor-interstage and -outlet bleed."
Date: August 2, 1954
Creator: Rohlik, Harold E. & Rebeske, John J.
Partner: UNT Libraries Government Documents Department

Acceleration characteristics of a turbojet engine with variable-position inlet guide vanes

Description: Report presenting a study of the acceleration characteristics of a turbojet engine equipped with variable-position inlet guide vanes in the altitude test chamber. Maximum acceleration values for 3 engines of the same model were also obtained during testing and were found to differ as much as 50 percent. Results regarding the effect of fuel step size and inlet guide vane on acceleration, effect of flight condition, reproducibility of engine acceleration, compressor pressure ratio in relation to acceleration, and acceleration with inlet air distortion are provided.
Date: July 7, 1955
Creator: Dobson, W. F. & Wallner, Lewis E.
Partner: UNT Libraries Government Documents Department

Theoretical analysis of an airplane acceleration restrictor controlled by normal acceleration, pitching acceleration, and pitching velocity

Description: Report presenting an analog computer analysis of an acceleration restrictor which limits the elevator motion of an airplane. The device applies a mechanical brake to the elevator control system in response to signals. Results for a restrictor sensitive to combined signal of normal and pitching acceleration and a restrictor sensitive to normal and pitching acceleration and pitching velocity are provided.
Date: September 1954
Creator: Kraft, Christopher C., Jr.
Partner: UNT Libraries Government Documents Department

An optimum switching criterion for a third-order contactor acceleration control system

Description: A switching criterion for optimum performance of a third-order contractor acceleration control system having complex roots is presented. Analytical and analog-computer methods are utilized to determine this criterion. The resulting optimum transient responses are presented and compared with those of an equivalent linear system.
Date: August 1956
Creator: Passera, Anthony L. & Willoh, Ross G., Jr.
Partner: UNT Libraries Government Documents Department

Flight investigation of transient wing response on a four-engine bomber airplane in rough air with respect to center-of-gravity accelerations

Description: Report presenting a flight investigation on a four-engine bomber to determine the effect of transient wing response in rough air on the acceleration measurements at the center of gravity of the airplane. Flights occurred in clear-air turbulence for two speed and two weight conditions. The results indicate that transient-response effects on total aerodynamic load are small for the test airplane.
Date: September 1952
Creator: Mickleboro, Harry C.; Fahrer, Richard B. & Shufflebarger, C. C.
Partner: UNT Libraries Government Documents Department

Operating Characteristics of an Acceleration Restrictor as Determined by Means of a Simulator

Description: Note presenting the operating characteristics of an acceleration restrictor which limits the normal acceleration of an airplane in maneuvers determined from tests on a simulator. The simulator consisted of a control stick geared to a magnetic brake unit and an analog computer which simulated the dynamic characteristics of the airplane.
Date: December 1954
Creator: Assadourian, Arthur
Partner: UNT Libraries Government Documents Department

High-brightness picosecond ion beam source based on BNL Terawatt CO2 laser: Proof-of-principle experiments

Description: Under the continuing DOE support, we have: o assembled the basic experiment setup and then continued expanding it to include diverse diagnostics and to accommodate gas jet targets in addition to metal foils; o conducted an extensive study of our novel laser, significantly enhanced laser beam diagnostics, and improved relevant laser parameters; o turned our experiments into a truly international endeavor with active collaboration of close to 20 researchers in US, UK, and Germany; o conducted the first ever experiments with proton and ion acceleration by lasers interacting with overcritical plasma of gas jets; o for the first time directly observed radiation pressure acceleration of protons, including quasi-monoenergetic spectra promising for future applications; o for the first time directly observed quasi-stable, bubble-like plasma structures that likely evolved from relativistic laser-plasma solitons (post-solitons). Thus, we have confirmed a strong potential of a picosecond TW CO2 laser as a research tool in laser-plasma science and as a promising vehicle for future applications of laser ion acceleration. This has led to apparent increase of the interest in mid-IR laser ion acceleration. In particular, another major research group began extensive proton acceleration experiments with their own CO2 laser at UCLA. As a result, the mechanisms responsible for laser proton acceleration in gas jets have become somewhat clearer. It is also important to note that modest DOE funding played the role of a seed support ensuring the formation of a multinational research team, whose members contributed its time and equipment with value well in excess of that seed amount.
Date: October 4, 2012
Creator: Shkolnikov, Peter
Partner: UNT Libraries Government Documents Department

Temporal Characterization of Femtosecond Laser-Plasma-AcceleratedElectron Bunches using THz Radiation

Description: The temporal pro le of relativistic laser-plasma-acceleratedelectron bunches has been characterized. Coherent transition radiation atTHz frequencies, emitted at the plasma-vacuum boundary, is measuredthrough electro-optic sampling. The data indicates that THz radiation isemitted by a skewed bunch with a sub-50 fs rise time and a ~; 600 fs tail(half-width-at-half-maximum), consistent with ballistic debunching of 100percent-energy-spread beams. The measurement demonstrates bothshot-to-shot stability of the laser-plasma accelerator and femtosecondsynchronization between bunch and probe beam.
Date: July 12, 2005
Creator: van Tilborg, J.; Schroeder, C.B.; Filip, C.V.; Toth, Cs.; Geddes,C.G.R.; Fubiani, G. et al.
Partner: UNT Libraries Government Documents Department

The NACA impact basin and water landing tests of a float model at various velocities and weights

Description: The first data obtained in the United States under the controlled testing conditions necessary for establishing relationships among the numerous parameters involved when a float having both horizontal and vertical velocity contacts a water surface are presented. The data were obtained at the NACA impact basin. The report is confined to a presentation of the relationship between resultant velocity and impact normal acceleration for various float weights when all other parameters are constant. Analysis of the experimental results indicated that the maximum impact normal acceleration was proportional to the square of the resultant velocity, that increases in float weight resulted in decreases in the maximum impact normal acceleration, and that an increase in the flight-path angle caused increased impact normal acceleration.
Date: 1944
Creator: Batterson, Sidney A.
Partner: UNT Libraries Government Documents Department

The NACA impact basin and water landing tests of a float model at various velocities and weights

Description: Report presenting data obtained when a float with both horizontal and vertical velocity contact on a water surface. The report is confined to a presentation of the relationship between resultant velocity and impact normal acceleration for various float weights when all other parameters are constant.
Date: August 1944
Creator: Batterson, Sidney A.
Partner: UNT Libraries Government Documents Department

A method of analysis of V-G records from transport operations

Description: From Summary: "A method has been developed for interpreting v-g records taken during the course of commercial transport operation. This method involves the utilization of fairly simple statistical procedures to obtain "flight envelopes," which predict that, on the average, in a stated number of flight hours, one value of airspeed will exceed the envelope, and one positive and one negative acceleration increment will exceed the envelope with equal probability of being experienced at any airspeed. Comparison with the actual data obtained from various airplanes and from various airlines indicates that these envelopes predict the occurrences of large values of acceleration and airspeed with a high degree of accuracy."
Date: November 1945
Creator: Peiser, A. M. & Wilkerson, M.
Partner: UNT Libraries Government Documents Department

A method of analysis of V-G records from transport operations

Description: A method has been developed for interpreting v-g records taken during the course of commercial transport operation. This method involves the utilization of fairly simple statistical procedures to obtain "flight envelopes," which predict that, on the average, in a stated number of flight hours, one value of airspeed will exceed the envelope, and one positive and one negative acceleration increment will exceed the envelope with equal probability of being experienced at any airspeed. Comparison with the actual data obtained from various airplanes and from various airlines indicates that these envelopes predict the occurrences of large values of acceleration and airspeed with a high degree of accuracy.
Date: August 31, 1945
Creator: Peiser, A. M. & Wilkerson, M.
Partner: UNT Libraries Government Documents Department