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in subjects: "Rf Systems"

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Numerical simulation of a short RFQ resonator using the MAFIA codes

The electrical characteristics of a short (2{beta}{lambda}=0.4 m) resonator with large modulation (m=4) have been studied using the three dimensional codes, MAFIA. The complete resonator, including the modulated electrodes and a complex support structure, has been simulated using {approximately} 350,000 mesh points. Important characteristics studied include the resonant frequency, electric and magnetic fields distributions, quality factor and stored energy. The results of the numerical simulati… more

Date: January 1, 1991

Creator: Wang, H.; Ben-Zvi, Ilan; Jain, A.; Paul, P. (State Univ. of New York, Stony Brook, NY (United States). Dept. of Physics) & Lombardi, A. (Istituto Nazionale di Fisica Nucleare, Legnaro (Italy). Lab. Nazionale di Legnaro)

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Schemes for anti pp interactions at ISABELLE

Various schemes for obtaining anti pp interactions are outlined, and the luminosities obtainable for each case calculated. In the simplest realistic case, a luminosity of 1.3 x 10/sup 29/ is obtained with a 13 hour filling time. The addition of special rf systems in both the AGS and ISABELLE give a scheme with luminosity 8 x 10/sup 29/ in 6 hours. The use of stochastic cooling to stack raises the luminosity to as high as 10/sup 31/ but the filling time is then 68 hours. Finally a scheme is cons… more

Date: September 8, 1977

Creator: Palmer, Robert B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Power excitation by the use of a rf wiggler

It is well-known that there are difficulties to obtain rf power sources of significant amount for frequencies larger than 3 GHz. Yet, rf sources in the centimeter/millimeter wavelength range would be very useful to drive, for example, high-gradient accelerating linacs for electron-positron linear colliders. We would like to propose an alternative method to produce such radiation. It makes use of a short electron bunch traveling along the axis of a waveguide which is at the same time excited by … more

Date: January 1, 1992

Creator: Ruggiero, Alessandro G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Radio-frequency size effect and the Fermi surface of aluminum

No Description Available.

Date: May 1, 1975

Creator: Hartman, J.S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Error Analysis of Acceleration Control Loops of a Synchrotron

For beam control during acceleration, it is conventional to derive the frequency from an external reference, be it a field marker or an external oscillator, to provide phase and radius feedback loops to ensure the phase stability, radial position and emittance integrity of the beam. The open and closed loop behaviors of both feedback control and their response under the possible frequency, phase and radius errors are derived from fundamental principles and equations. The stability of the loops … more

Date: January 1, 1991

Creator: Zhang, S. Y. & Weng, W. T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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New newtron time-of-flight (NTOF) facilities at the Brookhaven 200-MeV Linac

The installation of a new beam chopper and radio-frequency quadrupole (RFQ) preinjector (750 keV) at the Brookhaven National Laboratory (BNL) 200-MeV Linac will enable single micropulse selection (pulse width <1 ns) with periods ranging from 400 ns to 10 ..mu..s. The standard micropulse intensity is 1.2 X 10/sup 9/ p..mu.. pulse with dc-average beam currents of 50 nA-1 ..mu..A routinely available. The NTOF facilities consists of 30-100 meter flight paths at angles of 0, 12, 30, 45, 90, and 135/… more

Date: January 1, 1988

Creator: Ward, T.E.; Alessi, J.; Brennan, J.; Grand, P.; Lankshear, R.; Snead, C.L. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Rf cavity primer for cyclic proton accelerators

The purpose of this note is to describe the electrical and mechanical properites of particle accelerator rf cavities in a manner which will be useful to physics and engineering graduates entering the accelerator field. The discussion will be limited to proton (or antiproton) synchrotron accelerators or storage rings operating roughly in the range of 20 to 200 MHz. The very high gradient, fixed frequency UHF or microwave devices appropriate for electron machines and the somewhat lower frequency … more

Date: April 1, 1988

Creator: Griffin, J.E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Considerations for high-brightness electron sources

Particle accelerators are now used in many areas of physics research and in industrial and medical applications. New uses are being studied to address major societal needs in energy production, materials research, generation of intense beams of radiation at optical and suboptical wavelengths, treatment of various kinds of waste, and so on. Many of these modern applications require a high intensity beam at the desired energy, along with a very good beam quality in terms of the beam confinement, … more

Date: January 1, 1990

Creator: Jameson, Robert A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Fermilab Tevatron and Pbar source status report

The antiproton production cycle is enumerated, and the commissioning of the antiproton source is described, giving milestones and major obstacles. The Tevatron collider operation is described, including procedure to load the Tevatron with three bunches of protons and three bunches of antiprotons. Commissioning of the Main Ring and Tevatron for collider operation is described. Development and accelerator studies in four areas were necessary: main ring RF manipulations; controls and applications … more

Date: August 1, 1986

Creator: Edwards, H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Study of federal microwave standards

Present and future federal regulatory processes which may impact the permissible levels of microwave radiation emitted by the SPS Microwave Power Transmission (MPTS) were studied. An historical development of US occupational and public microwave standards includes an overview of Western and East European philosophies of environmental protection and neurophysiology which have led to the current widely differing maximum permissible exposure limits to microwaves. The possible convergence of microw… more

Date: August 1, 1980

Creator: David, L.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Linear accelerators of the future

Some of the requirements imposed on future linear accelerators to be used in electron-positron colliders are reviewed, as well as some approaches presently being examined for meeting those requirements. RF sources for use in these linacs are described, as well as wakefields, single bunches, and multiple-bunch trains. (LEW)

Date: July 1, 1986

Creator: Loew, G.A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Development program for a 200 kW, CW gyrotron. Quarterly report No. 3, January-March 1980

The objective of this program is the design and development of a millimeter-wave device to produce 200 kW of continuous-wave power at 60 GHz. The device, which will be a gyrotron oscillator, will be compatible with power delivery to an electron-cyclotron plasma. Smooth control of rf power output over a 17 dB range is required, and the device should be capable of operation into a severe time-varying rf load mismatch. The duration of the program is 36 months, to encompass the building and test up… more

Date: January 1, 1980

Creator: Arnold, K.W.; Tancredi, J.J.; Caplan, M.; Ha, K.W.; Birnbaum, D.N. & Weiss, W.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Bootstrap and fast wave current drive for tokamak reactors

Using the multi-species neoclassical treatment of Hirshman and Sigmar we study steady state bootstrap equilibria with seed currents provided by low frequency (ICRF) fast waves and with additional surface current density driven by lower hybrid waves. This study applies to reactor plasmas of arbitrary aspect ratio. IN one limit the bootstrap component can supply nearly the total equilibrium current with minimal driving power (< 20 MW). However, for larger total currents considerable driving power… more

Date: September 1, 1991

Creator: Ehst, D.A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Flow shear suppression of turbulence using externally driven ion Bernstein and Alfven waves

The utilization of externally-launched radio-frequency waves as a means of active confinement control through the generation of sheared poloidal flows is explored. For low-frequency waves, kinetic Alfven waves are proposed, and are shown to drive sheared E {times} B flows as a result of the radial variation in the electromagnetic Reynolds stress. In the high frequency regime, ion Bernstein waves are considered, and shown to generate sheared poloidal rotation through the ponderomotive force. In … more

Date: January 1, 1991

Creator: Biglari, H.; Ono, M. (Princeton Univ., NJ (United States). Plasma Physics Lab.); Diamond, P.H. (California Univ., San Diego, La Jolla, CA (United States). Dept. of Physics) & Craddock, G.G. (Science Applications International Corp., San Diego, CA (United States))

Item Type: Article

Partner: UNT Libraries Government Documents Department

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RF voltage modulation at discrete frequencies with applications to crystal channeling extraction

RF voltage modulation at a finite number of discrete frequencies is described in a Hamiltonian resonance framework. The theory is applied to the problem of parasitic extraction of a fixed target beam from a high energy proton collider, using a bent crystal as a thin septum'' within an effective width of about one micron. Three modes of employment of discrete resonances are proposed.First, a single relatively strong static drive'' resonance may be used to excite a test proton so that it will pen… more

Date: May 1, 1992

Creator: Gabella, W.; Rosenzweig, J. (California Univ., Los Angeles, CA (United States). Dept. of Physics); Kick, R. (Illinois Math and Science Academy, Aurora, Illinois (United States)) & Peggs, S. (Fermi National Accelerator Lab., Batavia, IL (United States))

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Rf power sources for 1990 and beyond

This paper will discuss the types of devices and system architectures that show promise in providing rf power sources for future space requirements. It will extrapolate these solutions to accelerators that are now being planned for construction and commissioning in the 1990s and will suggest technological advantages of using SDI-developed rf systems. Finally, the present state of the various SDI-sponsored high-powered rf-development programs will be reviewed.

Date: January 1, 1986

Creator: Reid, D.W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Frontiers of particle beam physics

First, a review is given of various highly-developed techniques for particle handling which are, nevertheless, being vigorously advanced at the present time. These include soft superconductor radio frequency cavities, hard superconductor magnets, cooling rings for ions and anti-protons, and damping rings for electrons. Second, attention is focused upon novel devices for particle generation, acceleration, and focusing. These include relativistic klystrons and free electron laser power sources, b… more

Date: November 1, 1989

Creator: Sessler, Andrew M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Breakdown phenomena in high power klystrons

In the course of developing new high peak power klystrons at SLAC, high electric fields in several regions of these devices have become an important source of vacuum breakdown phenomena. In addition, a renewed interest in breakdown phenomena for nanosecond pulse, multi-megavolt per centimeter fields has been sparked by recent R and D work in the area of gigawatt RF sources. The most important regions of electrical breakdown are in the output cavity gap area, the RF ceramic windows, and the gun … more

Date: March 1, 1988

Creator: Vlieks, A. E.; Allen, M. A.; Callin, R. S.; Fowkes, W. R.; Hoyt, E. W.; Lebacqz, J. V. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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New rf power system for SuperHILAC

The upgraded rf system for the SuperHILAC is now operational using 9 new tetrode amplifiers. Each amplifier can produce in excess of 1MW of 70 Mhz pulsed rf power. Ferrite is used to decouple the screen grid circuit and to absorb parasitic oscillations. This results in a very stable amplifier with reasonable gain. This system uses a common 8 MW anode power supply and crowbar system. Overall system efficiency has been increased significantly. We project a 3 year payback on the equipment cost, re… more

Date: May 1, 1985

Creator: Fugitt, J.; Lancaster, H. & Sorensen, R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Experimental and theoretical investigation of high gradient acceleration

This report contains a technical progress summary of the research conducted under the auspices of DOE Grant No. DE-FG0291ER-40648. Experimental and Theoretical Investigations of High Gradient Acceleration.'' This grant supports three research tasks: Task A consists of the design and fabrication of a 17GHz of photocathode gun, Task B supports the testing of high gradient acceleration using a 33GHz structure, and Task C comprises theoretical investigations, both in support of the experimental tas… more

Date: February 1, 1992

Creator: Bekefi, G.; Chen, C.; Chen, S.; Danly, B.; Temkin, R.J. & Wurtele, J.S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Resonators for heavily beam-loaded linacs

Capacitively loaded resonant line section accelerating structures are discussed. Prototype models were measured at low levels, and calculations were made to predict high level operation. High current composite beams of multiple-beamlets as accelerated by a MEQALAC were assumed.

Date: April 28, 1980

Creator: Sanders, R.T.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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The ion cyclotron heating (ICH) system for BPX

The ICH system is required to deliver at least 20 MW of rf power to the BPX plasma for pulse lengths of up to 15 s over a range of plasma operating conditions (e.g., average plasma densities from 0.5 to 4.5 {times} 10{sup 20} m{sup {minus}3}, toroidal fields from 5 to 8 T). The power must be delivered to the plasma over a range of frequencies corresponding to the different operating conditions. On the basis of calculations of the load resistance that the antennas will see because of the presenc… more

Date: January 1, 1991

Creator: Swain, D. W.; Yugo, J. J.; Williamson, D. E.; Batchelor, D. B.; Carter, M. D. & Goulding, R. H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Conceptual design of the Relativistic Heavy Ion Collider: RHIC

The complete Relativistic Heavy Ion Collider (RHIC) facility will be a complex set of accelerators and beam transfer equipment connecting them. A significant portion of the total facility either exists or is under construction. Two existing Tandem Van de Graaff accelerators will serve for the initial ion acceleration. Ions with a charge of -1 would be accelerated from ground to +15 MV potential, pass through a stripping foil, and accelerate back to ground potential, where they would pass throug… more

Date: May 1, 1986

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Positron injection linac system for the Argonne Light Source

The Argonne 6 GeV Light Source will use positrons rather than electrons in order to avoid ion trapping of the residual gas. One of the primary requirements of the linac system is the capability to deliver relatively intense short bunches of positrons in the stationary buckets of the booster synchrotron without utilizing a positron accumulator ring. A linac system for accomplishing this task is described. It consists of a 200-MeV, high-current, electron linac and a 450-MeV positron linear accele… more

Date: January 1, 1986

Creator: Mavrogenes, G.; Cho, Y. & Khoe, T.

Item Type: Article

Partner: UNT Libraries Government Documents Department