Speaker
Mr
Arnaud MADUR
(SOLEIL)
Description
SOLEIL Synchrotron is a set of 3 electron accelerators (LINAC, Booster and Storage
Ring).The 354m circumference storage ring is dedicated to synchrotron radiation for
fundamental and applied physics research.The most sensitive components of the
Storage
Ring are quadrupoles therefore manufacturing requirements are very strict: 5.10^{-4}
of the gradient for magnetic field harmonics, +/-25 µm for magnetic axis location in
the transverse plane (x,z) and +/- 0.1 mrad for magnetic roll angle orientation.
To check magnetic properties of the magnets, it was necessary to measure entities at
a lower level than the specifications required by the beam dynamic: less than 10^{-
4}
for harmonics, 5 µm for magnetic axis location and 2$ µrad for magnetic roll
angle.To
measure such low values, harmonic coils method was chosen with the use of printed
circuit technology for sensitive coils.There were 160 quadrupoles to measure.
It means that measurements were to be very durable which implies an accurate
manufacturing of the bench, especially of the sensor.That is why the mechanical
structure of the bench sensor has been particularly elaborated.
To check the manufacturing quality, a quadripolar permanent magnet has been
manufactured.This magnet is a reference and was used to quantify all imperfections
of
the bench like sag effect, positioning and orientation errors of the sensitive
coils.
Such a magnet is easy to handle and can be measured in several positions (8) thanks
to its mechanical octagonal interface.This type of mechanical interface permits us
to
know imperfections by making only a few amount of swing measurements which do not
require absolute knowledge of the magnetic field produced.
The presentation will describe the SOLEIL Multipolar Magnetic Measurements Bench
(SMB) and the way taken to avoid manufacturing errors effects. Finally, some figures
about performances of the bench will be given to show the low level of residual
positioning and angular offsets obtained after shims adjustments.
Author
Mr
Arnaud MADUR
(SOLEIL)
