INSTRUMENTATION FOR TXRF AND GI-XRF - Total-Reflection X-Ray Fluorescence Analysis and Related Methods - page 137

Figure3.5. Schematic diagram of the set-up between synchrotron storage ring and experimental
hutch. The beamline leaves the storage ring through a concrete wall and enters the beam adjusting
hutch with, for example, double-crystal monochromator. Finally, it reaches the experimental hutch,
which may contain a sample holder and X-ray detector. For hard X-rays, an interlock safety circuit
is installed.
mirrors, and monochromators. It is especially used for the selection of a specific
energy band used for excitation, particularly by Si (111), Si (311), and InSb
(111). A second hutch with individual equipment follows. Such a station can be
flexible or fixed, and can incorporate the experimental setup, for example, a
sample holder, a goniometer with 6 degrees of freedom for the sample stage, a
spectrometer, and a detector. A last block of some 10 cm lead is used as beam-
stopper. A particular hutch may be used as a control center, where the intended
experiments are controlled remotely by motors or robotic devices.
3.3.2Undulators,Wigglers,andFELs
As mentioned before, bending dipole magnets were first used in the circular
sections of a storage ring to produce synchrotron radiation. In order to generate
an even stronger flux and brilliance, sophisticated insertion devices were
employed in the straight sections of the storage ring—so-called wigglers and
undulators. These periodic arrays are composed of 10-100 dipole magnets with
spatially alternating north and south poles as demonstrated in Figure 3.6. Their
field vectors are vertical to the straight-line path of the electrons and usually
they are also vertical to the horizontal orbit plane. If the magnetic fields are
within the orbit plane this leads to certain focusing problems. The magnetic