Permanent Magnet Quadrupole for Final Focus Lens in a Linear Collider
Grant-in-Aid for Scientific Research (A)
|Allocation Type||Single-year Grants|
|Research Institution||KYOTO UNIVERSITY|
IWASHITA Yoshihisa KYOTO UNIVERSITY, Institute for Chemical Research, Associate Professor, 化学研究所, 助教授 (00144387)
KUMADA Masayuki National Institute of Radiological Sciences, Senior Researcher, 加速器物理工学研究部, 主任研究員 (50044748)
KUROKAWA Shin-ichi High Energy Asselerator Research Organization, KEK, Accelerator Laboratory, Professor, 加速器研究施設, 教授 (90044776)
YOKOYA Kaoru High Energy Asselerator Research Organization, KEK, Accelerator Laboratory, Professor, 加速器研究施設, 教授 (40141973)
SASAO Noboru Kyoto University, Department of Science, Professor, 理学研究所, 教授 (10115850)
MASUDA Kai Kyoto University, Institute of Advanced Energy, Associate Professor, エネルギー理工学研究所, 助教授 (80303907)
|Project Period (FY)
2002 – 2005
Completed(Fiscal Year 2005)
|Budget Amount *help
¥55,380,000 (Direct Cost : ¥42,600,000、Indirect Cost : ¥12,780,000)
Fiscal Year 2005 : ¥5,850,000 (Direct Cost : ¥4,500,000、Indirect Cost : ¥1,350,000)
Fiscal Year 2004 : ¥11,960,000 (Direct Cost : ¥9,200,000、Indirect Cost : ¥2,760,000)
Fiscal Year 2003 : ¥22,360,000 (Direct Cost : ¥17,200,000、Indirect Cost : ¥5,160,000)
Fiscal Year 2002 : ¥15,210,000 (Direct Cost : ¥11,700,000、Indirect Cost : ¥3,510,000)
|Keywords||linear collider / final focus lens / magnetically saturated iron / super strong permanent magnet / extended Halbach configuration / quadrupole magnet / multipole magnet / 飽和鉄 / リニアーコーライダー|
Super strong permanent magnet technology reaches as strong as up to 5.5T with the extended Halbach configuration, which partially replaces permanent magnet by soft magnet material. Although superconducting magnets can generate stronger field than even super strong permanent magnets, they are not superior when the number of poles is more than four, because of their dead space caused by coil bobbin and cryostat. Thus we have investigated the feasibility of the Super strong Permanent Magnet Quadrupole(PMQ) as a final focus doublet for a linear collider.
The first prototype PMQ fabricated with the extended Halbach configuration achieved the strong field gradient of a world record as a permanent magnet on the first FY, which proved the principle of the extended super strong permanent magnet technology on a quadrupole magnet.
The variable PMQ, whose feature is required as a component of an optics, was designed and fabricated in second FY. The double ring structure is adopted, where the outer ring is rotated while the inner ring is fixed to minimize the shift of magnet center. The rotation angle positions are restricted only at 0 and 90 degrees to eliminate the skewing effect. This variable PMQ was measured in the third FY at SLAC. It is found that
1)the strength is fairly high, 2)the dynamic range of the variability is more that 5 times, 3)positional reproducibility of the magnetic center is better than 3 μm.
The field gradient can be further raised by reducing the bore size of the inner ring. Such an inner ring was fabricated in the last year. A new magnet measurement system with a rotation coil was designed and some of the parts were fabricated within the last year.
Research Products (8results)