| Paper |
Title |
Other Keywords |
Page |
| TUP010 |
The Beam Halo Monitor of SARAF
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proton, target, vacuum, scattering |
265 |
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- I. Mardor, D. Berkovits, Y. Eisen, G. Haquin, D. Hirschmann, E. Meroz
Soreq NRC, Yavne
- M. Hass, O. Heber, Y. Shachar
Weizmann Institute of Science, Physics, Rehovot
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A main requirement for the SARAF accelerator is ‘hands-on’ maintenance, which implies a maximum beam loss of 1 nA per meter. In Phase I of SARAF (4-5 MeV ions at full current), we need to map the beam halo (BH) down to below 1 nA in order to predict, using beam dynamics calculations, the beam loss in the full accelerator. Mapping the halo of a 4 MeV, 2 mA ion beam down to below 1 nA is unprecedented, so we developed a BH monitor, which incorporates a direct charge measurement and several nuclear techniques, including Rutherford scattering 197Au(p,p)197Au, 7Li(p,n)7Be leading to both neutrons and the radio-isotope 7Be (measured offline post irradiation) and 19F(p,alpha)16O leading to high energy gamma rays. The current is derived using published cross sections. In this paper, we present the SARAF Phase I BH monitor and describe the various measurement techniques. In addition, results of feasibility studies at the Pelletron accelerator of the Weizmann Institute are given. The results of the various current measurement techniques are consistent with the standard Pelletron Faraday Cup to better than 20%. This is sufficient for mapping the SARAF beam halo to the desired accuracy.
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| TUP064 |
Adaptive Three-Dimensional RMS Envelope Simulation in the SAD Accelerator Modeling Environment
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space-charge, simulation, optics, controls |
397 |
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- C. K. Allen
LANL, Los Alamos, New Mexico
- K. Furukawa, M. Ikegami, K. Oide
KEK, Ibaraki
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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.
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| TUP080 |
Tuning the Magnetic Transport of an Induction Linac Using Emittance
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emittance, simulation, diagnostics, optics |
444 |
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- T. L. Houck, C. G. Brown, M. M. Ong, A. Paul, J. M. Zentler
LLNL, Livermore, California
- P. E. Wargo
Bechtel Nevada, Los Alamos, New Mexico
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The Lawrence Livermore National Laboratory Flash X-Ray (FXR) machine is a linear induction accelerator used to produce a nominal 20-MeV, 3-kA, 60-ns pulse width electron beam for hydrodynamic radiographs. A common figure of merit for this type of radiographic machine is the x-ray dose divided by the spot area on the bremsstrahlung converter. Several characteristics of the beam affect the minimum attainable x-ray spot size. The most significant are emittance, chromatic aberration, and beam motion. FXR is in the midst of a multi-year optimization project to reduce the spot size. This paper describes the effort to reduce beam emittance by adjusting the fields of the transport solenoids. If the magnetic transport is not correct, the beam will be mismatched and undergo envelop oscillations increasing the emittance. We measure the divergence and radius of the beam in a drift section after the accelerator by imaging the optical transition radiation (OTR) and beam envelope on a foil. These measurements are combined with transport simulations to calculate an emittance. Relative changes in the emittance can be quickly estimated allowing for an efficient, real-time study.
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| TUP091 |
Choice of Ion Linac as Neutron Generator for Contraband-Detection System
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proton, linac, target, rfq |
475 |
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- Y. A. Svistunov, M. F. Vorogushin
NIIEFA, St. Petersburg
- D. S. Semenov, B. D. Vodennikov
Scientific Research Institute of Pulse Technique, Moscow
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8 Mev proton linac and 4 Mev deuteron linac with working frequency 433 MHz are considered as neutron generator for detection system of explosive and fission. Required beam parameters, target materials, pulsed modulation and detection methods are discussed. Possible schemes of accelerating system of contraband detection complex are proposed. One supposes using of RFQ for deuteron linac and RFQ with IH cavity as proton one. Choice is determined by some few criterions: cost, sizes, safety, hardness of manufacturing and tuning.
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