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Page |
| TUOCFI01 |
Radiation Measurements vs. Predictions for SNS Linac Commissioning
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977 |
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- I.I. Popova, F. X. Gallmeier, P. L. Gonzalez, D. C. Gregory
ORNL, Oak Ridge, Tennessee
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Detailed predictions for radiation fields, induced inside and outside of the accelerator tunnel, were performed for each of the SNS accelerator commissioning stages, from the ion source through the entire LINAC. Analyses were performed for normal commissioning parameters, for worst possible beam accidents, and for beam fault studies, using the Monte Carlo code MCNPX. Proper temporary shielding was developed and installed in local areas near beam termination points (beam stops) and some critical locations, such as penetrations, in order to minimize dose rates in general occupied areas. Areas that are not full-time occupied and have dose rates above a specified limit during beam accident and fault studies were properly restricted. Radiation monitoring was performed using real time radiation measurement devices and TLDs to measure absorbed dose and dose equivalent rates. The measured radiation fields were analyzed and compared with transport simulations. TLD readings vs. calculations are in a good agreement, generally within a factor of two difference. A large inconsistency among instrument readings is observed, and an effort is underway to understand the variations.
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Transparencies
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| TUOCFI02 |
First Results of SNS Laser Stripping Experiment
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980 |
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- V.V. Danilov, A.V. Aleksandrov, S. Assadi, J. Barhen, Y. Braiman, D.L. Brown, W. Grice, S. Henderson, J.A. Holmes, Y. Liu, A.P. Shishlo
ORNL, Oak Ridge, Tennessee
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Thin carbon foils are used as strippers for charge exchange injection into high intensity proton rings. However, the stripping foils become radioactive and produce uncontrolled beam loss, which is one of the main factors limiting beam power in high intensity proton rings. Recently, we presented a scheme for laser stripping of an H- beam for the SNS ring. First, H- atoms are converted to H0 by a magnetic field, then H0 atoms are excited from the ground state to the upper levels by a laser, and the excited states are converted to protons by a magnetic field. This paper presents first results of the SNS laser stripping proof-of-principle experiment. The experimental setup is described, and possible explanations of the data are discussed.
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Transparencies
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| TUOCFI03 |
RF Cavity with Co-based Amorphous Core
|
983 |
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- M. Kanazawa, T. Misu, A. Sugiura
NIRS, Chiba-shi
- K. Katsuki
Toshiba, Yokohama
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A compact acceleration cavity has been developed with new Co-based amorphous cores, which will be used in a dedicated synchrotron for cancer therapy. This core has high permeability that makes the cavity length short, and the cavity with no tuning system is possible with low Q-value of about 0.5. An acceleration cavity consists of two units that have a single acceleration gap at the center, and at the both side of the gap there are quarter wave coaxial resonators. Considering the requirements for easy operation, a transistor power supply was used instead of commonly used tetrode in the final stage RF amplifier. Each resonator has maximum impedance about 400? at 3MHz, and has been attached with 1:9 impedance transformer. In the frequency range from 0.4 to 8 MHz, the acceleration voltage of more than 4kV can be obtained with total input RF power of 8kW. With these performances, the cavity length is short as 1.5m. In this paper the structure of the cavity and their tested high power performances are presented.
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Transparencies
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