Technical Design Report Super Fragment Separator

DRAFT
The Quench Heaters Tests has to be performed for all magnets equipped with quench heaters.
Some of the SIS100 quadrupole (6) are equipped with quench heaters.
Quench heaters have to be powered after each action which can affect the integrity of its circuits
(after QH installation, cryostating and installation on the test bench). The voltage and current of the
Quench Heater Test must correspond to defined patterns. These guarantee proper QH performance
and assert that the QH will release sufficient amount of energy to warm up the magnet during the
quench.
Vacuum and Leakage Tests
The leakage of the cryostat has to be tested and has to show a leak rate better than 10 -8 mbar/s. Also
all helium process lines should have a leak rate better than 10 -8 mbar/s. The helium process volumes
will be checked with a pressure 1.4 times higher than the design pressure.
Cold Magnetic Measurements
Cold magnetic measurements are performed with the magnet at operating (cryogenic) temperatures
while the measuring equipment is working at room temperature. Anti-cryostats are inserted in
magnets with a cold bore (the SIS 100, SIS 300 and HESR magnets), wherein the measurement
equipment is placed. The use of a non-metallic anti-cryostat is preferred over a metallic warm bore
(e.g. used for LHC series measurements) to avoid additional eddy current losses in fast-ramped
magnets, which also affect the quality of the measurement. For other magnet types only the coils
are housed in a cryostat, the iron of the pole shoes and the bore is at room temperature. The quantities
to be measured are listed in section 2.4.A5.1. However, in addition the time dependence of the
multipoles has to be measured.
The cold magnetic measurements are performed by operating the magnet at 4 K while the measuring
equipment is working at room temperature. Four methods were selected for the various
superconducting magnet types [108]:
• Mole based approach for magnets operated at cryogenic temperatures: A mole is a rotating
coil probe based magnetometer, where the main auxiliary components (the motor, the inclinometer
and the angular encoder) form an entity (see Figure 2.4.158) able to operate in
high magnetic field.
• Search coils for bent dipole magnets, or magnets with warm iron and a warm bore (Super-
FRS dipoles).
• Rotating coils for quadrupole and corrector magnets with a warm bore: These instruments
differ from the mole as only the coil probe itself is exposed to the magnetic field.
• Stretched wire measurement for quadrupole or corrector magnet types, which are fabricated
in small numbers. The stretched wire is versatile equipment and can cover the whole aperture
of nearly any magnet (see Figure 2.4.1).
Thus the Super-FRS dipole magnets will be measured using search coils providing data about the
main field strength and the field homogeneity. The axis and angle will be provided by the pole
shoes. The quadrupoles and correctors will be measured using rotating coils (see also Table 2.4.45).
Both methods have been applied frequently at GSI in the past [109,110]. If the rotating coil cannot
cover the whole field region due to the pole shoes, an additional stretched wire measurement can
assert the quality there. The SIS 100 and SIS 300 magnets are supposed to be measured using the
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