Aa. Varfolomeev et al., DEVELOPMENT OF FOCUSING UNDULATORS ON THE BASIS OF SIDE MAGNET ARRAYS, Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment, 359(1-2), 1995, pp. 85-88
Hybrid focusing undulators were designed, manufactured and tested for
some high power FEL and FEM projects. The magnetic fields of the undul
ators themselves provide electron beam focusing in both transverse dir
ections during e-beam transport through the interaction region. The ne
w element of these devices is a side magnet array. The focusing transv
erse magnetic field profile and enhancement of the magnetic field ampl
itudes resulted from these side magnets. It is shown that wide range t
unable focusing strengths can be ensured by a simple variation of the
configuration of the side magnets. A flexible combination of quadrupol
e focusing and sextupole periodic focusing is possible with using of t
hese schemes.