Advanced Photon Source

A U.S. Department of Energy, Office of Science,
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Undulator Workshop 2010

Radiation Induced Damage

 

                                                        

 

The radiation effects studies focus on the radiation-induced demagnetization of the Insertion Devices (IDs) at the APS.  The studies involve radiation dose monitoring, retuning of the radiation damaged undulators and investigation of the processes that can lead to radiation induced demagnetization in the IDs at the APS storage ring.

The IDs at the APS are composed of NdFeB high-coercive-type permanent magnets.  They are subjected to a harsh radiation environment which can lead to radiation-induced demagnetization.  This radiation environment is primarily composed of a broad energy spectrum of gamma rays, x-rays, electrons and neutrons. 

Radiation damage has now been observed in a few IDs in the APS storage ring.  The measures taken to date to "cure" the damaged undulators are:

1. application of mechanical shimming to adjust the peak magnetic field.
2. introduction of taper to correct the peak field gradient.
3. application of pole shims to boost the peak magnetic field.
4. application of phase shims to correct the phase error.
5. replacement of the damaged magnets with undamaged ones.
6. rotation of the damaged magnets to move the damaged region away from the side that faces the beam.
7. remagnetization of the damaged magnets.

Group Publications on Radiation Effects:

1. M. Petra, P.K. Den Hartog, E.R. Moog, S. Sasaki, N. Sereno and I.B. Vasserman, “Radiation Effects Studies at the Advanced Photon Source,” Proc. 24^th International Free Electron Laser Conference, pp. 422-425, Argonne, IL (2002).
2. E.R. Moog, P.K. DenHartog, E.J. Semones and P.K. Job, "Radiation Doses to Insertion Devices at the Advanced Photon  Source," Synchrotron Radiation Instrumentation, Tenth US National Conference (1997) 219.  Copyright (1997) American Institute of Physics.  This article may be downloaded for personal use only.  Any other use requires prior permission of the author and the American Institute of Physics.  The following article appeared in CP417, Synchrotron Radiation Instrumentation:  Tenth US National Conference Proceedings and be found at http://proceedings.aip.org/proceedings/confproceed/417.jsp

 

 

 

Updated: October 6, 2010