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Berkeley Proton Linear Accelerator

Description: Construction of a linear accelerator which increases the energy of protons from a 4 Mev Van de Graaff injector to a final energy of 31.5 Mev.
Date: November 30, 1948
Creator: Alvarez, Luis W.; Bradner, Hugh; Gordon, Hayden; Panofsky, Wolfgang K. H.; Richman, Chaim & Woodyard, John R.
Partner: UNT Libraries Government Documents Department

A High-Current Radio-Frequency Ion Accellerator

Description: Abstract: "A radio-frequency ion accelerator is described which is capable of continuous currents of protons of 250 ma at an energy of 500 kev. The beam is less than 3 in. in diameter and has a divergence of less than 2 degree half angle. Operation of the machine accelerating deuterons to an energy of 1000 kev is also described."
Date: February 1957
Creator: Lamb, William A. S.; Hester, Ross E. & Kippenhan, Dean O.
Partner: UNT Libraries Government Documents Department

Linear Accelerator for Heavy Ions

Description: The following report discusses the construction of two heavy-ion linear accelerators, one at the the University of California Radiation Laboratory and the other at Yale University. The goal for these accelerators is to produce ions of masses up to that of neon with energies of 10 Mev per nucleon.
Date: March 27, 1959
Creator: Wells, Don
Partner: UNT Libraries Government Documents Department

A method for measuring dark current electron beams in an rf linac

Description: X-ray fluorescence from thin foils inserted into the NPS linac has been used to measure the integrated electron beam intensity when the accelerator is operating with dark current. The measured x-ray flux, the known inner shell ionization cross sections and radiative transition probabilities are used to obtain measurements of dark currents of the order of 10{sup -14} amperes. The same arrangement allows continuous, in-situ energy calibration of our SiLi detector in the electromagnetic noise environment of the linac. This technique was orginally developed to perform absolute production efficiency measurements of parametric x-ray generation in the 5-50 keV range.
Date: December 31, 1993
Creator: Maruyama, X. K.; Fasanello, T.; Rietdyk, H.; Piestrup, M. A.; Rule, D. W. & Fiorito, R. B.
Partner: UNT Libraries Government Documents Department

Performance of the Argonne Wakefield Accelerator Facility and initial experimental results

Description: The Argonne Wakefield Accelerator facility has begun its experimental program. It is designed to address advanced acceleration research requiring very short, intense electron bunches. It incorporates two photocathode based electron sources. One produces up to 100 nC, multi-kiloamp `drive` bunches which are used to excite wakefields in dielectric loaded structures and in plasma. The second source produces much lower intensity `witness` pulses which are used to probe the fields produced by the drive. The drive and witness pulses can be precisely timed as well as laterally positioned with respect to each other. This paper discusses commissioning, initial experiments, and outline plans for a proposed 1 GeV demonstration accelerator.
Date: October 1, 1996
Creator: Gai, W.; Conde, M.; Cox, G.; Konecny, R.; Power, J.; Schoessow, P. et al.
Partner: UNT Libraries Government Documents Department

Beam break up analysis for the Berkeley femtosource

Description: We present a study of the single-bunch beam break up (BBU) instability for a proposed x-ray facility, based on a recirculating linac, to be built in Berkeley. The effects of injection errors, both position and angle, and of misalignments in the linac are investigated. We propose possible methods for limiting the consequent emittance increase.
Date: May 30, 2002
Creator: De Santis, Stefano & Zholents, Alexander A.
Partner: UNT Libraries Government Documents Department

High-Current Linear Accelerators

Description: This report analyzes two high-current linear accelerators, the A-54--a 48.5 megacycle resonant cavity accelerator--and the A-48, that is under construction during the time this report is written.
Date: June 27, 1955
Creator: Clark, A. F.; Jopson, R. C.; Lamb, W. A. S.; Smith, Lloyd & Van Atta, Chester Murray
Partner: UNT Libraries Government Documents Department

Longitudinal Resistive Stability of an Intense Charge Bunch in a Linear Accelerator

Description: A simple, but realistic, model is used to theoretically investigate the longitudinal stability of a non-relativistic bunch in the limit of small wall resistivity compared to self-reactance. It is shown that to lowest order--and in contrast with an infinitely long beam--that an intense bunch is stable against longitudinal collective modes. It is concluded that an induction linac remains a viable option as a driver for heavy ion inertial fusion.
Date: July 1, 1980
Creator: Channell, P.J.; Wurtele, J.S. & Sessler, A.M.
Partner: UNT Libraries Government Documents Department

Absolute beam flux measurement at NDCX-I using gold-melting calorimetry technique

Description: We report on an alternative way to measure the absolute beam flux at the NDCX-I, LBNL linear accelerator. Up to date, the beam flux is determined from the analysis of the beam-induced optical emission from a ceramic scintilator (Al-Si). The new approach is based on calorimetric technique, where energy flux is deduced from the melting dynamics of a gold foil. We estimate an average 260 kW/cm2 beam flux over 5 {micro}s, which is consistent with values provided by the other methods. Described technique can be applied to various ion species and energies.
Date: April 1, 2011
Creator: Ni, P. A.; Bieniosek, F. M.; Lidia, S. M. & Welch, J.
Partner: UNT Libraries Government Documents Department

Beam intensity expectations for a 200 MeV/u 400 kW radioactive beam driver accelerator.

Description: The expected radioactive ion production rate for a 200 MeV/u 400 kW driver linac using four different production methods is discussed. For each isotope the optimum method is identified and the rate is calculated based on different model assumptions, empirical observation and extrapolations. The results are compared to the rates expected for a 550 MeV proton driver machine with a beam power of 50 kW, as well as the full RIA facility with a 400 MeV/u 400 kW production linac.
Date: December 31, 2006
Creator: Back, B. B.; Jiang, C. L. & Physics
Partner: UNT Libraries Government Documents Department

Monthly Progress Report No. 57 for January 1948

Description: This report gives a short summary of the work done in the following fields for the month of January 1948: (1) 184-inch cyclotron; (2) 60-inch cyclotron; (3) synchrotron; (4) linear accelerator; (5) experimental physics; (6) theoretical physics; (7) isotope research; (8) chemistry; (9) medical physics; and (10) health physics and chemistry.
Date: January 1, 1948
Creator: Authors, Various
Partner: UNT Libraries Government Documents Department

Parallel beam dynamics simulation of linear accelerators

Description: In this paper we describe parallel particle-in-cell methods for the large scale simulation of beam dynamics in linear accelerators. These techniques have been implemented in the IMPACT (Integrated Map and Particle Accelerator Tracking) code. IMPACT is being used to study the behavior of intense charged particle beams and as a tool for the design of next-generation linear accelerators. As examples, we present applications of the code to the study of emittance exchange in high intensity beams and to the study of beam transport in a proposed accelerator for the development of accelerator-driven waste transmutation technologies.
Date: January 31, 2002
Creator: Qiang, Ji & Ryne, Robert D.
Partner: UNT Libraries Government Documents Department

FXR accelerator cavity impedance experiments

Description: One of the goals of the present Flash X-Ray (FXR) accelerator upgrade effort [1][2] at Lawrence Livermore National Laboratory (LLNL) is to reduce the cavity transverse impedance, since it has been shown that beam stability is significantly affected by this parameter [3]. Recently, we have evaluated various techniques and cell modifications to accomplish that, both through lab measurements and computer models. A spare cell, identical in every way to cells in the accelerator, was specially modified for the experiments. The impedance measurements were done without the beam, by applying twin-wire techniques. This report describes the results of these experiments and suggests possible cell modifications to improve their performance. The techniques and modifications which are suggested might also be applicable to AHF and DARHT-2 long-pulse accelerator development.
Date: January 5, 1998
Creator: Avalle, C.A.
Partner: UNT Libraries Government Documents Department

Vibrational stability of NLC linac and final focus components

Description: Vertical vibration of linac components (accelerating structures, girders and quadrupoles) in the NLC has been studied experimentally and analytically. Effects such as structural resonances and vibration caused by cooling water both in accelerating structures and quadrupoles have been considered. Experimental data has been compared with analytical predictions and simulations using ANSYS. A design, incorporating the proper decoupling of structure vibrations from the linac quadrupoles, is being pursued.
Date: February 6, 2003
Creator: al., F. Le Pimpec et
Partner: UNT Libraries Government Documents Department

The CEBAF control system for the CHL

Description: The CEBAF Central Helium Liquefier (CHL) control system consists of independent safety controls located at each subsystem, CAMAC computer interface hardware, and a CEBAF-designed control software called Thaumaturgic Automated Control Logic (TACL). The paper describes how control software was interfaced with the subsystems of the CHL. Topics of configuration, editing, operator interface, datalogging, and internal logic functions are presented as they relate to the operational needs of the helium plant. The paper also describes the effort underway to convert from TACL to the Experimental Physics and Industrial Control System (EPICS), the new control system for the CEBAF accelerator. This software change will require customizing EPICS software to cryogenic process control.
Date: August 1, 1996
Creator: Keesee, M.S. & Bevins, B.S.
Partner: UNT Libraries Government Documents Department

Accelerator break-out group summary

Description: Interesting developments in accelerators have shown that they can be used as {open_quote}factory{close_quote}-type systems with the choice of technology dependent on the specific requirements of the application. The status and future possibilities for cyclotrons and linear accelerators are compared briefly, based on discussions at a break-out session on accelerators. Only high power systems with beam powers in excess of a MW average power were considered.
Date: December 31, 1996
Creator: Schriber, S.O. & Mandrillon, P.
Partner: UNT Libraries Government Documents Department

Alignment and steering scenarios for the APT linac

Description: The Accelerator for the Production of Tritium (APT) requires a very high proton beam current (100 mA cw). Requirement for hands-on maintenance limits the beam spill to less than 0.2 nA/m along most of the linac. To achieve this, it is important to understand the effects of fabrication, installation and operational errors, establish realistic tolerances, and develop techniques for mitigating their consequences. A new code, PARTREX, statistically evaluates the effects of alignment, quadrupole field, and rf phase and amplitude errors in the linac. This paper reviews the effects of quadrupole misalignments and present two steering algorithms that minimize the potential for particle loss from the beam halo. These algorithms were tested on the 8-to-20 MeV portion of the APT linac.
Date: September 1, 1996
Creator: Stovall, J.E.; Gray, E.R.; Nath, S.; Takeda, H.; Wood, R.L.; Young, L.M. et al.
Partner: UNT Libraries Government Documents Department

Physics design of APT linac with normal conducting rf cavities

Description: The accelerator based production of tritium calls for a high-power, cw proton linac. Previous designs for such a linac use a radiofrequency quadrupole (RFQ), followed by a drift-tube linac (DTL) to an intermediate energy and a coupled-cavity linc (CCL) to the final energy. The Los Alamos design uses a high-energy (6.7 MeV) RFQ followed by the newly developed coupled-cavity drift-tube linac (CCDTL) and a CCL. This design accommodates external electromagnetic quadrupole lenses which provide a strong uniform focusing lattice from the end of the RFQ to the end of the CCL. The cell lengths in linacs of traditional design are typically graded as a function of particle velocity. By making groups of cells symmetric in both the CCDTL and CCL, the cavity design as well as mechanical design and fabrication is simplified without compromising the performance. At higher energies, there are some advantages of using superconducting rf cavities. Currently, such schemes are under vigorous study. This paper describes the linac design based on normal conducting cavities and presents simulation results.
Date: September 1, 1996
Creator: Nath, S.; Billen, J.H.; Stovall, J.E.; Takeda, Harunori & Young, L.M.
Partner: UNT Libraries Government Documents Department