10 Tesla WLS on Spring-8 ... 9 Tesla superbend prototype for BESSY-2 (2003) ... coils. Room temperature vacuum chamber. Beam orbit. Liquid helium vessel.
Superconducting magnets for SR generation in Budker INP: the status of works N.A. Mezentsev Budker INP, Novosibirsk, Russia
RUPAC-2006, Novosibirsk
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INTRODUCTION In Budker INP of Siberian Branch of Russian Academy of Science already more than 25 years there is an activity on creation of superconducting special magnets for generation synchrotron radiation, such as superconducting 3-pole magnets – «shifters», superconducting multipole magnets – «wiggler» and bending superconducting magnets – «superbends». Spectral characteristics of Synchrotron Radiation (SR) from bending magnet are determined by two parameters: electron energy E and magnetic field B, εс~E2B. There are two ways how to make a spectrum harder : •to increase electron energy •to increase magnetic field in radiation point. The first way of increase of hardness has many advantages, but demands big material and manpower resources, while the second way is cheap enough and rather simple at use of insertion devices like •superconducting wave length shifters •superconducting wigglers •superconducting high field bending magnets (superbends).
RUPAC-2006, Novosibirsk
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Superconducting Wave Length Shifters (WLS) Shifter represents 3-pole magnet with zero first and second field integrals along a trajectory. The central pole of the magnet has strong magnetic field and is used for generation of hard X-ray SR, while side poles are used for orbit correction.
List of Superconducting Wave Length Shifters at Budker INP Year
Magnetic Magnetic Magnetic Vertical field, T gap, mm length, aperture, mm mm Max/ normal
Electron energy GeV
Liquid helium consumption, LHe liter/hour
WLS for Siberia-1 (Moscow)
1985
5.8 (4.5)
32
350
22
0.45
2-2.5
WLS for PLS (Korea)
1995
7.68 (7.5)
48
800
26
2
1.5-2
WLS for LSU- 1998 CAMD (USA)
7.55 (7.0)
51
972
32
1.5
1.2-1.6
WLS for SPring-8 2000 (Japan)
10.3 (10.0)
40
1042
20
8
0.4-0.6
BAM WLS for (BESSY-II, Gernany) PSF-WLS (BESSY-II, Germany) Superbend (BESSY, Germany)
2000
7.5 (7.0)
52
972
32
1.9
0.4-0.5
2001
7.5 (7.0)
52
972
32
1.9
0.4-0.5
2004
9.6 (8.5)
46
177
32
1.9
0.5
RUPAC-2006, Novosibirsk
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Beam orbit inside a standard (three-pole) wiggler has a bump so, that a point of radiation from Field maximum of of central pole is not on wiggler axis and During field change it moves in horizontal direction perpendicular to beam movement.
10 Tesla WLS on Spring-8
RUPAC-2006, Novosibirsk
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7 Tesla WLS for BESSY-2
General view
SC WLS
Side view
e-
Superconducting magnets
Normal conducting Corrector-magnets
Longitudinal magnetic field distribution along staight section for different field levels: 2.3, 4, 6, 7 Tesla
7 6
Correctors
Magnetic field, Tesla
5
Top view
4 3 2 1
•
0 -1 -2 -2000
-1500
-1000
-500
0
500
1000
1500
2000
Longitudinal distance, mm
Orbit displacement in straight section at 1.9 GeV for different field levels: 2.3, 4, 6, 7 Tesla 16 15 14
Orbit displacement, mm
13 12 11 10 9
•
8 7 6 5 4 3 2 1 0 -2000
-1500
-1000
-500
0
500
1000
Longitudinal distance, mm
RUPAC-2006, Novosibirsk
1500
2000
Wave Length Shifter with fixed radiation point, where the superconducting part of magnet has non-zero first field integral and requirements of zero field integrals are performed by normally conducting correcting magnets which are outside of shifter cryostat. This variant of shifter allows to compensate for the first and second field integrals over each ½ shifter parts so that in the central pole the radiation point will be always on an straight section axis at any field level of the shifter.
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9 Tesla superbend prototype for BESSY-2 (2003)
Main parameters of SuperBend Maximum Field (required /reached), T Magnetic gap, mm Beam vacuum chamber: Vertical, mm Horizontal, mm Current in superconducting coils, A Storage energy, kJ Cold mass, kg Liquid helium consumption, l/h Ramping time to 9 T Bending angle, degree Bending radius, m Edge angle, degree Effective magnetic length, m Distance from flange to flange, m
9 .0 / 9.6 46 30 75 300 220 ~1300
