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New Development in WARP: Progress Toward End-to-End Simulation

Description: The development of a high current, heavy-ion beam driver for inertial confinement fusion requires a detailed understanding of the behavior of the beam, including effects of the strong self-fields. The necessity of including the self-fields of the beam makes particle-in-cell (PIC) simulation techniques ideal, and for this reason, the multi-dimensional PIC/accelerator code WARP has been developed. WARP has been used extensively to study the creation and propagation of ion beams both in experiments and for the understanding of basic beam physics. An overview of the structure of the code will be presented along with a discussion of features that make the code an effective tool in the understanding of space-charge dominated beam behavior. Much development has been done on WARP increasing its flexibility and generality. Major additions include a generalized field description, an efficient steady-state modelling technique, a transverse slice model with a bending algorithm, further improvement of the parallel processing version, and capabilities for linking to chamber transport codes. With these additions, the capability of modeling a large scale accelerator from end-to-end comes closer to reality.
Date: November 7, 1997
Creator: Grote, D.P.; Friedman, A.; Haber, I.; Fawley, W. & Luc Vay, J.
Partner: UNT Libraries Government Documents Department

Relativistic multireference many-body perturbation theory calculations on Au64+ - Au69+ ions

Description: Many-body perturbation theory (MBPT) calculations are an adequate tool for the description of the structure of highly charged multi-electron ions and for the analysis of their spectra. They demonstrate this by way of a re-investigation of n=3, {Delta}n=0 transitions in the EUV spectra of Na-, Mg-, Al-like, and Si-like ions of Au that have been obtained previously by heavy-ion accelerator based beam-foil spectroscopy. They discuss the evidence and propose several revisions on the basis of the multi-reference many-body perturbation theory calculations of Ne- through P-like ions of Au.
Date: March 31, 2006
Creator: Vilkas, M J; Ishikawa, Y & Trabert, E
Partner: UNT Libraries Government Documents Department

Status of U.S. Plans for an Advanced ISOL Facility, A Brief Report

Description: A brief discussion is provided of the current status of plans to build an advanced ISOL radioactive ion beam facility in the US. Designs for this new facility, which was recommended as the next major construction project of the DOE Nuclear Physics Program Office, have been proposed by two US national laboratories, Argonne National Laboratory and Oak Ridge National Laboratory. The new facility will provide orders-of-magnitude higher radioactive beam currents than existing facilities of this type and will cost in the range of $250 million.
Date: November 13, 1998
Creator: Bertrand, F.E.
Partner: UNT Libraries Government Documents Department

Heavy ion fusion experiments at LBNL and LLNL

Description: The long-range goal of the US Heavy Ion Fusion (HIF) program is to develop heavy ion accelerators capable of igniting inertial fusion targets to generate fusion energy for electrical power production. Accelerators for heavy ion fusion consist of several subsystems: ion sources, injectors, matching sections, combiners, induction acceleration sections with electric and magnetic focusing, beam compression and bending sections, and a final-focus system to focus the beams onto the target. We are currently assembling or performing experiments to address the physics of all these subsystems. This paper will discuss some of these experiments.
Date: August 19, 1998
Creator: Ahle, L
Partner: UNT Libraries Government Documents Department

Concept for high-charge-state ion induction accelerators

Description: This work describes a particular concept for ion induction linac accelerators using high-charge-state ions produced by an intense, short pulse laser, and compares the costs of a modular driver system producing 6.5 MJ for a variety of ion masses and charge states using a simple but consistent cost model.
Date: November 15, 1996
Creator: Logan, B.G.; Perry, M.D. & Caporaso, G.J.
Partner: UNT Libraries Government Documents Department

Beam matching and halo control

Description: The authors present an overview of the status of ongoing work on physics models describing beam matching and halo control for particle accelerators, particularly high power ion linacs. They consider moments and various new variables that more naturally describe beam halo evolution. The authors compute matched beams and {open_quotes}mode invariants{close_quotes} (analogs of moment invariants) using primarily symbolic techniques.
Date: May 1, 1997
Creator: Lysenko, W. & Parsa, Z.
Partner: UNT Libraries Government Documents Department

Beam charge and current neutralization of high-charge-state heavy ions

Description: High-charge-state heavy-ions may reduce the accelerator voltage and cost of heavy-ion inertial fusion drivers, if ways can be found to neutralize the space charge of the highly charged beam ions as they are focused to a target in a fusion chamber. Using 2-D Particle-In- Cell simulations, we have evaluated the effectiveness of two different methods of beam neutralization: (1) by redistribution of beam charge in a larger diameter, preformed plasma in the chamber, and (2), by introducing a cold-electron-emitting source within the beam channel at the beam entrance into the chamber. We find the latter method to be much more effective for high-charge-state ions.
Date: October 29, 1997
Creator: Logan, B.G. & Callahan, D.A.
Partner: UNT Libraries Government Documents Department

LOCAL DECOUPLING IN THE LHC INTERACTION REGIONS

Description: Local decoupling is a technique to correct coupling locally and operationally, that is, without a priori knowledge of the underlying skew quadrupole errors. The method is explained and applied to the correction of coupling in the interaction regions of the LHC at collision.
Date: September 7, 1999
Creator: PILAT,F.
Partner: UNT Libraries Government Documents Department

Heavy ions acceleration in RF wells of 2-frequency electromagnetic field and in the inverted FEL

Description: Last results of the study of heavy ions acceleration by electrons trapped in moving 2-frequency 3-D RF wells are described. A linearized theoretical model of ions acceleration in a polarized spheroidal plasmoid is proposed. The equilibrium state of this plasmoid is described by the modified microcanonical distribution of the Courant-Snyder invariant ({open_quotes}quasienergy{close_quotes} of electrons). Some new results of computational simulation of the acceleration process are given. The method of computation takes into account the given cylindrical field E{sub 011}({var_phi},r,z) and the self fields of electrons and ions. The results of the computation at relatively short time intervals confirm the idea and estimated parameters of acceleration. The heavy ion accelerator using this principle may be constructed with the use of compact cm band iris-loaded and biperiodical waveguides with double-sided 2-frequency RF feeding. It can accelerate heavy ions with a charge number Z{sub i} from small initial energies {approximately} 50 keV/a.u. with the rate {approximately} Z{sub i} {center_dot} 10 MeV/m. Semirelativistic ions may be accelerated with similar rate also in the inverted FEL.
Date: March 1, 1995
Creator: Dzergach, A.I.; Kabanov, V.S.; Nikulin, M.G. & Vinogradov, S.V.
Partner: UNT Libraries Government Documents Department

MULTIPARTICLE PRODUCTION AT RHIC AND LHC: A CLASSICAL POINT OF VIEW.

Description: We report results of our ongoing nonperturbative numerical study of a classical effective theory describing low-x partons in the central region of a heavy-ion collision. In particular, we give estimates of the initial transverse energies and multiplicities for a wide range of collision regimes, including those at RHIC and at LHC.
Date: October 9, 2000
Creator: KRASNITZ,A. & VENUGOPALAN,R.
Partner: UNT Libraries Government Documents Department

EXPERIMENTAL STUDY OF ION INJECTION INTO AN EXTENDED TRAP OF THE BNL EBIS.

Description: Experiments on the BNL EBIS Test Stand (EBTS) with the ion trap extending beyond the edges of the superconducting solenoid had the main goal to study ion trap operation with a trap length exceeding that of the normal EBTS trap. Preliminary results indicate that the ion trap with length 107 cm is stable and controllable in the same fashion as our normal 70 cm trap with a multiampere electron beam. EBTS operation with ion trap 145 cm long and with electron current up to 3 A in earlier experiments also was stable and yielded more ions than from the basic ''short'' trap. These results increased our confidence in operation of the proposed RHIC in a stable mode and in the correctness of linear scaling of ion intensity with the length of the ion trap.
Date: September 2, 2001
Creator: Pikin, A.; Alessi, J.; Beebe, E.; Kponou, A. & Prelec, K.
Partner: UNT Libraries Government Documents Department

Design study for a staged Very Large Hadron Collider

Description: Advancing accelerator designs and technology to achieve the highest energies has enabled remarkable discoveries in particle physics. This report presents the results of a design study for a new collider at Fermilab that will create exceptional opportunities for particle physics--a two-stage very large hadron collider. In its first stage, the machine provides a facility for energy-frontier particle physics research, at an affordable cost and on a reasonable time scale. In a second-stage upgrade in the same tunnel, the VLHC offers the possibility of reaching 100 times the collision energy of the Tevatron. The existing Fermilab accelerator complex serves as the injector, and the collision halls are on the Fermilab site. The Stage-1 VLHC reaches a collision energy of 40 TeV and a luminosity comparable to that of the LHC, using robust superferric magnets of elegant simplicity housed in a large-circumference tunnel. The Stage-2 VLHC, constructed after the scientific potential of the first stage has been fully realized, reaches a collision energy of at least 175 TeV with the installation of high-field magnets in the same tunnel. It makes optimal use of the infrastructure developed for the Stage-1 machine, using the Stage-1 accelerator itself as the injector. The goals of this study, commissioned by the Fermilab Director in November 2000, are: to create reasonable designs for the Stage-1 and Stage-2 VLHC in the same tunnel; to discover the technical challenges and potential impediments to building such a facility at Fermilab; to determine the approximate costs of the major elements of the Stage-1 VLHC; and to identify areas requiring significant R and D to establish the basis for the design.
Date: June 26, 2001
Creator: al., Peter J. Limon et
Partner: UNT Libraries Government Documents Department

Development of a two-beam high-current ion accelerator based on Doppler effect. Final report (1994)

Description: This Final Report presents the results of work accomplished in accordance with the Scope of Work to the Purchase Order No 4596310. The amount of works includes the following items: 1. Start of the manufacture of the Experimental Accelerating Stand (EAS)-the section for proton acceleration from 5 MeV to 8 MeV, in which RF fields are excited by an electron beam at the anomalous Doppler effect. 2. Theoretical investigation and computer simulation of field excitation and ion acceleration in the EAS. Under item 1, the EAS manufacturing is begun. To present time, a pedestal for the EAS and a stainless steel vacuum chamber for RF resonator are made (length of the chamber is about 180 cm, diameter is about 40 cm). Besides, parts of the EAS resonator with the acceleration structure are manufactured, and its assembly is begun. Under item 2, it is realized three works: calculation of increment and frequency shift of the EAS resonator excited by electron beam, calculation of the solenoid for creation of magnetic field with required spatial distribution, and theoretical investigation and computer simulation of ion acceleration in the EAS. 14 figs., 16 refs.
Date: March 1, 1995
Creator: Ivanov, B.I. & Yegorov, A.M.
Partner: UNT Libraries Government Documents Department

Preliminary Ionization Efficiencies of {sup 11}C and {sup 14}O with the LBNL ECR Ion Sources

Description: High charge states, up to fully stripped {sup 11}C and {sup 14}O ion, beams have been produced with the electron cyclotron resonance ion sources (LBNL, ECR and AECR-U) at Lawrence Berkeley National Laboratory. The radioactive atoms of {sup 11}C and {sup 14}O were collected in batch mode with an LN{sub 2} trap and then bled into the ECR ion sources. Ionization efficiency as high as 11% for {sup 11}C{sup 4+} was achieved.
Date: October 5, 1998
Creator: Xie, Z.Q.; Cerny, J.; Guo, F.Q.; Joosten, R.; Larimer, R.M.; Lyneis, C.M. et al.
Partner: UNT Libraries Government Documents Department

Recent progress in the development of a circular ion induction accelerator for space charge dominated beams at LLNL

Description: The Heavy Ion Fusion Group at Lawrence Livermore National Laboratory has for several years been developing the world�s first circular ion induction accelerator. This machine has recently been extended to 90 degrees, or 10 half-lattice periods (HLP) with full beam transport. In addition, induction cores have been installed on five of the HLP�s, each with an independent arbitrary waveform pulser. An arbitrary waveform pulser for the bending electrostatic dipoles has also been enabled. Together, they have allowed the first attempts at coordinated bending and acceleration of the beam. The results of these first attempts will be reported on in the paper by examining the output of various diagnostic devices, such as the capacitive Beam Probes (C-probes), slit scanners, and the Gated Beam Imager(GBI).
Date: August 19, 1998
Creator: Ahle,L; Autrey,D; Barnard, J; Berners ,D; Craig, G; Debeling, A et al.
Partner: UNT Libraries Government Documents Department

Superconducting heavy-ion accelerating structures

Description: This paper briefly reviews the technical history of superconducting ion-accelerating structures. Various superconducting cavities currently used and being developed for use in ion linacs are discussed. Principal parameters and operational characteristics of superconducting structures in active use at various heavy-ion facilities are described.
Date: August 1, 1996
Creator: Shepard, K.W.
Partner: UNT Libraries Government Documents Department

Report on the Workshop on Atomic and Plasma Physics Requirements for Heavy Ion Fusion : Argonne National Laboratory, December 13-14, 1979

Description: Atomic, molecular, and plasma physics areas that are relevant to inertial confinement fusion by energetic heavy ions are identified. Discussions are confined to problems related to the design of heavy ion accelerators, accumulation of ions in storage rings, and the beam transport in a reactor vessel.
Date: 1980?
Creator: Kim, Yong-Ki & Magelssen, Glenn
Partner: UNT Libraries Government Documents Department

ATLAS: a Proposal for a Precision Heavy Ion Accelerator at Argonne National Laboratory

Description: The objective of the proposed Argonne Tandem-Linac Accelerator System (ATLAS) is to provide precision beams of heavy ions for nuclear physics research in the region of projectile energies comparable to nuclear binding energies (5-25 MeV/A). By using the demonstrated potential of superconducting radiofrequency technology, beams of exceptional quality and flexibility can be obtained. The system is designed to provide beams with tandem-like energy resolution and ease of energy variation, the energy range is comparable to that of approximately 50 MV tandem and, in addition, the beam will be bunched into very short (approximately 50 psec) pulses, permitting fast-timing measurements that can open up major new experimental approaches.
Date: February 1978
Creator: Bollinger, L. M.
Partner: UNT Libraries Government Documents Department