| Paper |
Title |
Page |
| THPP082 |
Residual Activity Induced by High-energy Heavy Ions in Stainless Steel and Copper
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3551 |
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- I. Strasik, I. Hofmann, E. Kozlova, E. Mustafin
GSI, Darmstadt
- L. N. Latysheva, N. Sobolevskiy
RAS/INR, Moscow
- M. Pavlovic
STU, Bratislava
- A. Smolyakov
ITEP, Moscow
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The activation of accelerator structures due to beam loss is already intensity limiting problem for existing (SNS or RHIC) and planned (LHC or FAIR) hadron facilities. While beam-losses of 1 W/m are recognized as a tolerable beam-loss level for proton machines, the beam-loss tolerances for high-power heavy-ion accelerators have not yet been quantified. In this work the residual activity was calculated by Monte-Carlo particle transport codes and compared with experimental data. Simulations were performed for projectiles from proton to uranium. Experiments were performed with uranium ions at 120, 500 and 950 MeV/u irradiating copper and stainless steel targets. It was found that the isotope inventory contributing over 90% to the total activity does not depend on the projectile species, it depends only on the target material and projectile energy. This allowed establishing a scaling law for induced activity as a function of ion mass. The activity per nucleon induced by ion scales down with increasing ion mass. For example, 1 GeV/u uranium ion induces 5-times less activity per nucleon compared to 1 GeV proton. The beam-loss criteria for different projectile species are presented.
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| THPP102 |
Radiation Damage Studies for the Slow Extraction from SIS100
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3602 |
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- A. Smolyakov
ITEP, Moscow
- E. Mustafin, N. Pyka, P. J. Spiller
GSI, Darmstadt
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During the slow extraction from SIS100 synchrotron 5% of the beam will hit the wires of the electrostatic septum and will be lost. These losses produce very high radiation damage to the superconducting quadrupole doublet situated downstream of the extraction point. These beam losses were simulated with the help of Fluka code for U28+ and Ne5+ beams. Non-zero cross-section and non-zero angular divergence were assumed for the lost beam, allowing distributed modeling of the slow extraction losses. The radiation damage to different layers of the superconducting quadrupole cables was calculated. The lifetime of the s.c. cables of the quadrupoles was found to be too short. Thus, alternative quadrupole designs with higher radiation tolerances were investigated: with stainless steel shielding of the s.c. cables and with a gap in the mid-plane between the s.c. cables.
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