Demagnetization of undulator magnets irradiated high energy electrons

Bizen, Teruhiko; Tanaka, Takashi; Asano, Yoshihiro; Kim, D.E.; Bak, J.S.; Lee, H.S.; Kitamura, Hideo

doi:10.1016/s0168-9002(01)00270-4

Cited by 44 publications

(25 citation statements)

References 5 publications

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“…24 These experiments suggest that the performance of high-coercivity NdFeB magnets at this radiation environment is comparable to that of the SmCo magnets. Experiments were performed using one SmCo magnet and several NdFeB magnets with different coercivities.…”

Section: Electron Beam (2 Gev) Irradiationmentioning

confidence: 80%

LCLS prototype undulator report.

Dejus¹

2004

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Section: Electron Beam (2 Gev) Irradiationmentioning

confidence: 80%

LCLS prototype undulator report.

Dejus¹

2004

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“…However, the superior magnetic properties of NdFeB magnets make them a good choice for many accelerator applications. For this reason there are many papers looking at their resistance to protons [4,6,7,8,9,10], neutrons [5,11,12,13,14], electrons [15,16,17,18,19] and gammas [17,20,21,22]. These studies show that the amount of demagnetisation observed is not dependent on the deposited energy, but depends on the type of particle [19].…”

Section: Effect Of Radiation On Magnetsmentioning

confidence: 99%

Design considerations and performance of a PM linear actuator in a radiation environment

Mohammad

Booth

Hodgson

et al. 2008

4th IET International Conference on Power Electronics, Machines and Drives (PEMD 2008)

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This paper discusses design considerations for a water cooled high acceleration 3-phase air-cored brushless DC PM linear actuator used in a vacuum radiation environment. Radiation can cause damage to magnets, and the requirement for a vacuum chamber around the moving parts imposes additional constraints that further complicate the electromagnetic and mechanical design of the actuator. This paper discusses the selection of suitable materials and bearings that are compatible with operation in vacuum and can cope with the required millions of actuation cycles. The selection of suitable bearings with low friction and wear is discussed and the design of a low inertia shaft is described. The factors that have an influence on the susceptibility of the magnets to radiation damage are discussed. These factors include magnet dimensions, magnet material, external magnetic field, temperature and the directions of both the magnetic flux and radiation. FLUKA simulations are presented showing the fluences of protons, neutrons, electrons and gamma radiation to which the magnets are exposed.Based on these simulations, loss of magnetisation for different magnet materials can be predicted, and used to estimate the effect of magnet radiation ageing on actuator current, and increased temperature rise. The paper also presents transient electromagnet FEA computation of the force produced by the actuator when magnets are housed in a stainless steel vacuum chamber.

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“…The results presented in Fig. 3a of the paper [2] (Fig. 1a below) showed that the change in magnetic field intensity was, respectively, larger with a tantalum target than with a copper target or without target.…”

mentioning

confidence: 92%

“…[2]. NEOMAX35EH [3] magnets (W ¼ 46 mm Â H ¼ 12 mm Â T ¼ 8 mm, vertical magnetization M z ) were irradiated with a 2 GeV electron beam under various experimental conditions.…”

mentioning

confidence: 99%