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MOP058 |
Heavy-Ion-Beam Emittance Measurements at the GSI UNILAC
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177 |
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- W. B. Bayer, W. Barth, L. A. Dahl, L. Groening, S. Yaramyshev
GSI, Darmstadt
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The GSI UNILAC, a linac for high current heavy ion beams, serves as an injector for the synchrotron SIS 18 and hence being a part of the future FAIR (Facility for Antiproton and Ion Research) project. The UNILAC post stripper section consists of an Alvarez accelerator with a final energy of 11.4 MeV/u. In order to meet the requirements of the FAIR project (15emA U28+, transversal normalised emittances of ex = 0.8 and ey = 2.5 mm mrad) a part of the UNILAC upgrade program is the increase of the beam brilliance. A detailed understanding of the correlation between space charge forces and focusing during acceleration of high intensity ion beams is necessary. A suited quantity to study is the beam brilliance dependency on the phase advances in the Alvarez section. Measurements are planned in 2006 and coincide with the beam dynamics work package of the European network for High Intensity Pulsed Proton Injector (HIPPI). Results of the measurements are presented as well as corresponding beam dynamics simulations.
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MOP059 |
Long-Term Perspective for the UNILAC as a High-Current, Heavy-Ion Injector for the FAIR-Accelerator Complex
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180 |
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- W. Barth, L. A. Dahl, L. Groening, S. Yaramyshev
GSI, Darmstadt
- U. Ratzinger
IAP, Frankfurt-am-Main
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The present GSI-accelerator complex, consisting of the linear accelerator UNILAC and the heavy ion synchrotron SIS 18, is foreseen to serve as an U28+-injector for up to 10+12 particles/s for FAIR. In 2003 and 2004 different hardware measures and careful fine tuning in all sections of the UNILAC resulted in an increase of the beam intensity to 9.5·10+10 U27+ ions per 100 mks (max. pulse beam power of 0.5 MW). In addition a dedicated upgrade program for the UNILAC will be performed until 2009. It is intended to fill the SIS 18 up to the space charge limit of 2.7·10+11 U28+ ions per cycle. After completion of the FAIR complex in 2015 the running time for the accelerator facility at least will be 20 years, while the UNILAC will then be in operation for more than 60 years as a high duty factor heavy ion linac. Different proposals for a new advanced short pulse, heavy ion, high intensity, high energy linac, substituting the UNILAC as a synchrotron injector, will be discussed. This new "High Energy-UNILAC" has to meet the advanced FAIR requirements, will allow for complete multi-ion-operation and should provide for reliable beam operation in the future.
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MOP060 |
A New LEBT and RFQ Radial Matcher for the UNILAC Front End
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183 |
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- L. A. Dahl, W. Barth, S. Yaramyshev
GSI, Darmstadt
- S. A. Visotski, I. Vorobyov
ITEP, Moscow
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The UNILAC heavy ion accelerator will serve as a high current injector for the future FAIR accelerator complex of GSI. This requires to inject 2.7x1011 ions/0.1x10-6s of U28+ into the existing synchrotron (SIS). Additionally, the UNILAC serves in multi beam operation experiments with high duty factor beams of different species. To meet all future demands a dedicated upgrade programme of the UNILAC is in work. This paper focuses on front end improvements. A new beam transport system will provide achromatic deflection and high mass resolution for the heavy ion beams from both existing ion source terminals. A new terminal for high current ion sources with a straight line solenoid based beam channel will be added. E.g. U3+ and U4+ ions with and a total beam current of 55mA will be injected into the RFQ for a maximum intensity yield of U4+-beam at the exit. To optimize the total front end beam transmission a redesigned radial input matcher of the RFQ is already implemented. It enables a smoother RFQ input matching of the high current beam resulting in smaller beam diameter and in lower particle losses. Beam measurements comparing old and new input radial matchers are presented.
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MOP061 |
The 70-MeV Proton Linac for the Facility for Antiproton and Ion Research FAIR
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186 |
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- L. Groening, W. Barth, L. A. Dahl, W. Vinzenz, S. Yaramyshev
GSI, Darmstadt
- G. Clemente, U. Ratzinger, A. Schempp, R. Tiede
IAP, Frankfurt-am-Main
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A significant part of the experimental program at FAIR is dedicated to antiproton (pbar) physics requiring up to 7·1010 cooled pbars per hour. Taking into account the pbar production and cooling rate, this is equivalent to a primary proton beam of 2·1016 protons per hour to be provided by a 70 MeV proton linac preceding two synchrotrons. It has to deliver a pulsed proton beam of 70 mA of 36 μs duration at a repetition rate of 4 Hz. The normalized transverse emittances must not exceed 2.8 mm mrad and the total relative momentum spread must be less than 0.1%. The normal conducting DTL comprises 12 Crossed-bar H-cavities (CH) fed by six rf-power sources in total. The basic layout of the linac as well as the overall cost estimate has been completed including several reviews by external committees. A technical report has been completed in May 2006. This paper gives a general overview on the status of the project.
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TUP078 |
Status of the End-to-End Beam Dynamics Simulations for the GSI UNILAC
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438 |
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- W. Barth, W. B. Bayer, L. A. Dahl, L. Groening, S. Yaramyshev
GSI, Darmstadt
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The heavy ion high current GSI linac UNILAC serves as an injector for the synchrotron SIS18. The UNILAC mainly consists of a High Current Injector (HSI), the stripper section at 1.4 MeV/u, and the Alvarez postaccelerator (11.4 MeV/u). During the last years the systematic experimental and numerical studies resulted in an increase of the U73+ beam intensity of up to a factor of seven. The needs of the FAIR project (Facility for Antiproton and Ion Research at Darmstadt) require further improvement of the beam brilliance coming from UNILAC up to a factor of five. End-to-end beam dynamics simulations with the DYNAMION code have already been started. The general goal is to establish a simulation tool which can calculate the impact of the planned upgrade measures on the performance of the whole UNILAC. The results of the HSI calculations including influence of the beam intensity on the beam parameters (current, emittance, Twiss-parameters) at the stripper section are presented. Recent calculations and measurements of the beam matching to the Alvarez section under space charge conditions are discussed in the paper.
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TUP086 |
Linac Code Benchmarking for the UNILAC Experiment
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460 |
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- 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
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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.
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