First pre-series sextupole for the SESAME storage ring

Margarita Synanidi — Thu, 20 Nov 2014 16:07:44 +0000

First pre-series sextupole for the SESAME storage ring
by Attilio Milanese (CERN)

First SESAME sextupole pre-series undergoing magnetic measurements in the ISR tunnel at CERN. The electric and hydraulic connections are in test configuration. Image credit: CERN

In November 2013, CERN has completed the first assembly of a pre-series sextupole for the SESAME storage ring, within the CESSAMag European project. This is indeed the first magnet for the new synchrotron light source in construction in Jordan.

The magnetic design of the sextupole has been finalized at CERN on the basis of the initial proposal of SESAME. The compact magnet is actually multi-purpose, incorporating – on top of the main sextupolar field – three correctors, namely the horizontal / vertical dipole and a skew quadrupole. Since the aperture (75 mm diameter) is comparable to the length (iron length 100 mm), the optimization of the pole tip geometry was carried out directly in 3D. A peculiar feature from the magnetic viewpoint is the unconventional choice of avoiding any end pole chamfering, while still minimizing the first allowed harmonic. This was obtained by introducing a careful bias in the 2D design, that cancels out in 3D due to edge effects. This simplifies the manufacture without compromising on the field quality. Indeed a magnetic measurement on the pre-series confirmed the simulations, with a first allowed harmonics of 0.4∙10-4 at a reference radius of 24 mm.

This pre-series sextupole validates the design and opens the way for the 64 units needed for the SESAME storage ring. Contracts for the main components are on-going in Europe, whereas for the final assembly and testing options in Cyprus and Pakistan are currently being finalized.

Read more >>

Tags:

SESAME

CESSAMag

sextupole

issue 9

First industry magnet for SESAME storage ring

Margarita Synanidi — Thu, 18 Sep 2014 08:58:29 +0000

First industry magnet for SESAME storage ring
by Attilio Milanese (CERN)

   Fig1: View of the first series SESAME sextupole from the correctors connection side.
   Image credit: CNE Technology Center

In July 2014, a sextupole corrector magnet for the SESAME storage ring arrived at CERN for tests and magnetic measurements. It is the first unit out of 32 to be delivered by CNE Technology Center, a Cypriot based company under the EU-CERN CESSAMag project.

In November last year, a pre-series sextupole for SESAME was prepared at CERN, to check the design and to tune the manufacturing procedures before placing the order for the series production to industry. The contracts were then awarded to a Cypriot and a Pakistani company. The CERN team has been working closely with both companies to transfer the knowledge from CERN needed to build these magnets.

The first unit out of the 32 magnets from Cyprus has already arrived and was tested at CERN. Measurements carried out at CERN together with SESAME colleagues on this magnet show a very precise assembly, resulting in magnetic field homogeneity of 0.2‰ within 2/3 of the aperture. The unit is also mechanically, electrically and hydraulically sound, assuring good reliability during operation. This makes the magnet apt for the lattice of a synchrotron light source such as SESAME and it is a major step in preparing the SESAME storage ring.

The Cypriot company has in parallel also assembled more than 50% of the components needed for the rest of the contract. At this point the first magnet from Pakistan is currently being assembled.