LINAC 2006 - List of Keywords (space-charge)

A B C D E F G H I K L M O P Q R S T U V W

space-charge

Paper	Title	Other Keywords	Page
MOP024	Electromagnetic Green's-Function-Based Simulations of Photocathode Sources	simulation, cathode, electromagnetic-fields, gun	88
	M. Hess, D. Bolton, C. S. Park, L. Zhu IUCF, Bloomington, Indiana
	We show the results of beam simulations for photocathode sources using a newly developed Green's function based code called IRPSS (Indiana Rf Photocathode Source Simulator). In general, a fully electromagnetic treatment of space-charge fields within simulations of photocathode sources is typically difficult since the beam is most often tightly bunched. The problem is further complicated by the inclusion of nearby conducting structures, i.e. cathode and cavity walls, from which the fields are reflected. The entire problem can be solved self-consistently using an electromagnetic Green's function method. Since Green's functions are generated by a Delta function source while simultaneously satisfying the boundary conditions of the system, they are an effective tool when solving for fields within photocathode source simulations. Using IRPSS we show the results of multiparticle simulations for a variety of photocathode source experiments.

MOP051	Development of an Intense Neutron Source FRANZ in Frankfurt	rfq, proton, ion, emittance	159
	O. Meusel, L. P. Chau, I. Mueller, U. Ratzinger, A. Schempp, K. Volk, C. Zhang IAP, Frankfurt-am-Main S. Minaev ITEP, Moscow
	The Stern-Gerlach-Center recently founded at the University of Frankfurt gives the possibility for experiments in accelerator physic, astrophysic and material sience research. It is planned to develop an intense neutron generator within the next 4 years. The proton driver linac consists of a high voltage terminal already under construction to provide primary proton beam energies of max. 150 keV. A volume type ion source will deliver a DC beam current of 100-250 mA at a proton fraction of 90%. A low energy beam transport using two solenoids will inject the proton beam into an RFQ while a chopper at the entrance of the RFQ will create a pulse length of 50 ns and a repetition rate up to 250 kHz. A drift tube cavity for the variation of the beam energy in a range of 1.9 – 2.4 MeV will be installed downstream of the RFQ. Finally a bunch compressor of the Mobley type forms a proton pulse length of 1 ns at the Li target. The maximum energies of the neutrons being adjustable between 100 keV and 500 keV by the primary proton beam. The detailed concept of the high current injector, numerical simulation of beam transport and losses will be presented together with first experimental results.

TU3001	High-Current Proton Beam Investigations at the SILHI-LEBT at CEA/Saclay	emittance, ion, proton, ion-source	232
	R. Hollinger, W. Barth, L. A. Dahl, M. Galonska, L. Groening, P. S. Spaedtke GSI, Darmstadt R. Gobin, P.-A. Leroy CEA, Gif-sur-Yvette O. Meusel IAP, Frankfurt-am-Main
	For the injection of a high current proton beam into the future proton LINAC at GSI for FAIR the ion source and the low energy beam transport system have to deliver a 100 mA proton beam with an energy of 95 keV within an acceptance of 0.3 mm mrad (normalized, rms) at the entrance of the RFQ. Besides the ion source a 2-solenoid focusing system is foreseen as an injection scheme for the subsequent RFQ. The beam parameters of the SILHI ion source and the 2-solenoid LEBT setup generally meet these requirements. Therefore joint emittance measurements on various beam parameters have been performed at the end of the LEBT system. In the frame work of the design study for the future proton LINAC it was a unique possibility to investigate the injection of a high current proton beam into a low energy beam transport system under the influence of space charge. The measurements reveal that a proton current of 100 mA can be achieved at the end of the LEBT while the emittance (95 %, rms, normalized) is as high as 0.3 to 0.5 mm mrad.

TUP064	Adaptive Three-Dimensional RMS Envelope Simulation in the SAD Accelerator Modeling Environment	simulation, optics, controls, background	397
	C. K. Allen LANL, Los Alamos, New Mexico K. Furukawa, M. Ikegami, K. Oide KEK, Ibaraki
	The capability for three-dimensional RMS envelope simulation, including space charge, has been implemented in the SAD accelerator modeling environment used at KEK. The SAD (for Strategic Accelerator Design) modeling system consists of a compiled simulation engine, an in-house scripting language SADScript, and user interface support both in Tcl/tk script and SADScript. The RMS envelope simulator is implemented primarily in the SADScript language, which much resembles the Mathematica language. The dynamics within the model are similar to that used by TRACE3D, TRANSPORT, and XAL. Specifically, the symmetric matrix of all second-order beam moments is propagated using a linear beam optics model for the beamline. However, the current simulation engine employs an adaptive space-charge algorithm which actively adjusts the solution integration to maintain a specified accuracy, as well as imposing the symplectic condition. It is designed to keep the integration step size as large as possible while enforcing that the residual solution error remain below a given tolerance. The paper concentrates primarily on the adaptive nature of the RMS simulation, since this is the novel feature.

TUP086	Linac Code Benchmarking for the UNILAC Experiment	emittance, simulation, linac, lattice	460
	F. Franchi, W. B. Bayer, G. Franchetti, L. Groening, I. Hofmann, A. Orzhekhovskaya, S. Yaramyshev, X. Yin GSI, Darmstadt G. Bellodi, F. Gerigk, A. M. Lombardi, T. Mütze CERN, Geneva G. Clemente, A. C. Sauer, R. Tiede IAP, Frankfurt-am-Main R. Duperrier, D. Uriot CEA, Gif-sur-Yvette
	In the framework of the European network HIPPI (High Intensity Pulsed Proton Injectors) a linac code comparison and benchmarking program have been promoted. An intermediate goal is to compare different space charge solvers and lattice modelling implemented in each code in preparation of experimental validations from future measurements to be carried out at the UNILAC of GSI. In the last two years a series of different tests and comparisons among several codes (DYNAMION, HALODYN, IMPACT, LORASAR, PARMILA, PATRAN, PATH and TOUTATIS) have been undertaken. The quality of Poisson solvers has been evaluated and a number of code adjustments has been carried out to obtain the best agreement in terms of RMS moments. In this paper we report on the status of this program.

TUP088	Benchmarking of Simulation Codes TRACK and ASTRA for the FNAL High-Intensity Proton Source	simulation, emittance, rfq, proton	466
	J.-P. Carneiro Fermilab, Batavia, Illinois
	The FNAL High Intensity Proton Source is an 8-GeV superconducting H-minus Linac conceived with the primary mission of enabling 2 MW beam power from the Main Injector at 120 GeV for the Fermilab neutrino program. The main tool used for the design of this accelerator is the beam dynamics code TRACK developed by Argonne National Laboratory to fulfill the requirements of proton and heavy-ion linacs. ASTRA, developed by DESY (Hamburg, Germany) and mainly used for the design of electron photo-injectors, also offers the possibility to simulate acceleration of hydrogen ions. Benchmarking of TRACK and ASTRA is presented in this paper for a zero current and a 30 mA beam from the exit of the RFQ (2.5 MeV) to the end of the accelerating section (8 GeV).

TUP089	Computer Simulations of a High-Current Proton Beam at the SILHI-LEBT	ion, emittance, proton, simulation	469
	M. Galonska, M. Galonska IAP, Frankfurt-am-Main R. Gobin CEA, Gif-sur-Yvette R. Hollinger GSI, Darmstadt
	For the injection of a proton beam into the future proton LINAC for FAIR the ion source and the low energy beam transport system have to deliver a 100 mA proton beam with an energy of 95 keV at the entrance of the RFQ within an acceptance of 0.3 π mm mrad (normalized, rms). A 2-solenoid focusing system is foreseen as an injection scheme. The beam parameters of the SILHI ion source and the 2-solenoid LEBT setup at CEA/Saclay fulfill these requirements. Therefore joint emittance measurements on various beam parameters have been performed at the end of 2005. This article presents the computer simulations of the ion source extraction and LEBT, which supplemented these measurements using the KOBRA3-INP computer code in order to study the influence of space charge effects. These simulations have been performed for various solenoid settings and for different space charge compensation degrees clearly revealing that the ion beam transport within the LEBT is influenced by space charge forces.