Attainment of submillimeter periods and a 0.3-T peak field in a novel micropole undulator device

Abstract

A micropole undulator is defined here as an undulator with a very short (submillimeter) period and correspondingly shorter poles. The availability of micropole undulators is expected to profoundly affect the development of x-ray sources. For example, with such devices x-ray beams comparable to those from conventional undulators will be attainable on storage rings of much lower energy (and emittance) than those presently in use. X-ray instrumentation will also be affected, e.g., micropole undulators of sufficient length can provide extremely monochromatic outputs, obviating the need for expensive and complex ultrahigh vacuum monochromator systems. Here we describe the design and practical construction of a prototype 35 period micropole undulator whose total length is 2.54 cm. The device is of a novel hybrid/electromagnetic bias design. We also present results of field profile measurements along the central plane of the new device.