Paper |
Title |
Page |
TOAA006 |
Development of Superconducting Combined Function Magnets for the Proton Transport Line for the J-PARC Neutrino Experiments
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495 |
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- T. Nakamoto, Y. Ajima, Y. Fukui, N. Higashi, A. Ichikawa, N. Kimura, T. Kobayashi, Y. Makida, T. Ogitsu, H. Ohhata, T. Okamura, K. Sasaki, M. Takasaki, K. Tanaka, A. Terashima, T. Tomaru, A. Yamamoto
KEK, Ibaraki
- M. Anerella, J. Escallier, G. Ganetis, R.C. Gupta, M. Harrison, A.K. Jain, J.F. Muratore, B. Parker, P. Wanderer
BNL, Upton, Long Island, New York
- T. Fujii, E. Hashiguchi, T. Kanahara, T. Orikasa
Toshiba, Yokohama
- Y. Iwamoto
JAERI, Ibaraki-ken
- T. Obana
GUAS/AS, Ibaraki
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A second generation of long-baseline neutrino oscillation experiments has been proposed as one of the main projects at J-PARC jointly built by JAERI and KEK. Superconducting combined function magnets, SCFMs, will be utilized for the 50 GeV, 750 kW proton beam line for the neutrino experiment and an R&D program is in underway at KEK. The magnet is designed to provide a combined function of a dipole field of 2.6 T with a quadrupole field of 19 T/m in a coil aperture of 173.4 mm. A series of 28 magnets in the beam line will be operated DC in supercritical helium cooling below 5 K. A design feature of the SCFM is the left-right asymmetry of the coil cross section: current distributions for superimposed dipole- and quadrupole- fields are combined in a single layer coil. Another design feature is the adoption of glass-fiber reinforced phenolic plastic spacers to replace the conventional metallic collars. To evaluate this unique design, fabrication of full-scale prototype magnets is in progress at KEK and the first prototype will be tested at cold soon. This paper will report the development of the SCFMs.
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WPAT008 |
Recent Status of RF Source in J-PARC Linac
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1123 |
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- E. Chishiro, T. Hori, H. Suzuki, M. Yamazaki
JAERI, Ibaraki-ken
- S. Anami, S. Fukuda, Y. Fukui, M. Kawamura, S. Yamaguchi, M. Yoshida
KEK, Ibaraki
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The construction of the J-PARC (Japan Proton Accelerator Research Complex) linac is under going. RF sources for the low beta linac section use 324-MHz klystrons and after the evaluation of seven prototype tubes, mass production of 20 tubes are conducted. These will be installed in the linac building from April 2005. Performances of the 324-MHz klystrons are described in this paper. The prototype klystron of 972-MHz klystron, which is planed to be installed in high beta linac section, oscillated strongly without any drive rf power, and it had been investigated to solve it. Though it was doubted to be a diode oscillation at first, recent experiment showed the drift-tube oscillation and we succeeded in stopping oscillation by deforming the integrated cavity and detuning. After this experiment, we built a new tube and started to test it. This experiment is written in this paper. Other status of construction related to the rf sources is also shown in this paper.
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TOAD004 |
The Possibility of Noninvasive Micron High Energy Electron Beam Size Measurement Using Diffraction Radiation
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404 |
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- G.A. Naumenko, A. Potylitsyn
Tomsk Polytechnic University, Physical-Technical Department, Tomsk
- S. Araki, A. Aryshev, H. Hayano, V. Karataev, T. Muto, J.U. Urakawa
KEK, Ibaraki
- D. Cline, Y. Fukui
UCLA, Los Angeles, California
- R. Hamatsu
TMU, Hatioji-shi,Tokyo
- M.C. Ross
SLAC, Menlo Park, California
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During the last years a noninvasive method for beam size measurement based on the optical diffraction radiation (ODR) has been in progress (P. Karataev, et al., Physical Review Letters 93, 244802 (2004). However this technique encounters with hard sensitivity limitation for electron energies larger than several GeV. For example, for SLAC conditions the sensitivity of this method is 4 orders smaller than an appropriate one. We suggest to use a "dis-phased" slit target, where two semi-planes are turned with respect to each other at a small "dis-phased" angle. In order to ensure the interference between the diverged radiation beams we use a cylindrical lens. This method has much better sensitivity and resolution. A "dis-phased" angle 10 milliradians gives the optimal sensitivity to 5 microns transversal beam size. The theoretical model for calculating the ODR radiation from such targets (including focusing by cylindrical lens) is presented. It is shown that the sensitivity of this method does not depend on the Lorenz-factor directly. The target with the "dis-phased" angle 6.2 milliradians and the slit width 425 microns was manufactured for experimental test. Some preliminary experimental results are presented.
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TPPP051 |
A Muon Cooling Ring with Curved Lithium Lenses
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3167 |
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- Y. Fukui, D. Cline, A.A. Garren
UCLA, Los Angeles, California
- H.G. Kirk
BNL, Upton, Long Island, New York
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We design a muon cooling ring with curved Lithium lenses for the 6 dimensional muon phase space cooling. The cooling ring can be the final muon phase space cooling ring for a Higgs Factory, a low energy muon collider.Tracking simulation shows promising muon cooling with simplified magneti element models.
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RPAT077 |
Beam Test Proposal of an ODR Beam Size Monitor at the SLAC FFTB
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4015 |
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- Y. Fukui, D. Cline, F. Zhou
UCLA, Los Angeles, California
- A. Aryshev, V. Karataev, T. Muto, M. Tobiyama, J.U. Urakawa
KEK, Ibaraki
- P.R. Bolton, M.C. Ross
SLAC, Menlo Park, California
- R. Hamatsu
TMU, Hatioji-shi,Tokyo
- G.A. Naumenko, A. Potylitsyn, A. Sharafutdinov
Tomsk Polytechnic University, Physical-Technical Department, Tomsk
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We design a single bunch transverse beam size monitor which will be tested to measure the 29 GeV electron/positron beam at the SLAC FFTB beam line.The beam size monitor uses a CCD camera to make images of the interference pattern of the optical diffraction radiation from conductive slit target which are placed close to the beam path. In this method, destruction of the accelerated electron/positron beam bunches due to the beam size monitoring is negligible, which is vital to the operation of the Linear Collider project. A dis-phased conductive slit target and a lens system allow us to recover the sensitivity of the transverse beam size with a small photon yield ratio at the valley to that at the peak due to the large gamma*λ, and with the near field effect due to the large λ*gamma**2. A solution for non-negligible divergence at the SLAC FFTB is also discussed.
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