CERN-EC SUPPORT FOR SESAME MAGNETS

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1 1. PUBLISHABLE SUMMARY CERN-EC SUPPORT FOR SESAME MAGNETS WP1 Project Management and Technical Coordination A complex preparation involving several CERN offices (Director-General, Legal service, Procurement office, CESSAMag management) was necessary to create the best environment for this unusual project. A highly competent technical team was gathered, motivated by the technical and science-for-peace aspects of the project. Tight links were kept or developed with the CERN Directorate, the SESAME Directorate and President of Council, and the project officer of the European Commission, to ensure best coherence of the action, including its political aspects. The invitation by the SESAME Council of the CESSAMag coordinator at its meetings, with delegation from the CERN Director-General, has had an excellent added value for communication and new collaborations, given the attendance of these meetings (delegates from SESAME Members, Observers, and delegates from International Organizations and from Foundations). Voluntary support by Pakistan, Turkey and Iran were negotiated there and implemented. The technical work is carried out in tight collaboration with the SESAME Technical Director and his team. Video-meetings are held regularly. Visits and stays at CERN of SESAME staff are regular as well, from a few days up to 9 months, mostly financially supported by IAEA. This allows knowledge and experience transfer to an enthusiastic team of young SESAME engineers, with the goal that SESAME fully masters the equipment, once delivered. The project planning, in spite of some delays for intermediate results, appears to be on schedule and costs are mastered to the extent that savings might allow reducing the SESAME share. Communication and outreach are actively pursued. Figure 1: left: signature at CERN of the CERN-SESAME agreement relative to CESSAMag by the CERN Director-General and SESAME Director, in presence of the SESAME President of Council and the two vice Presidents; right: Meeting at SESAME between CERN-CESSAMag coordinator and team members with the scientific and technical SESAME Directors and staff. Grant Agreement / 5

2 WP2 Magnet Design and Engineering Study Starting and building up upon the SESAME study, the design of the dipoles, focusing and defocusing quadrupoles and sextupoles were revisited and discussed with SESAME. A full 3D analysis was carried out to finalize the geometry of the poles and the pole ends. Provisions were anticipated for the adjustment of the integrated strength and of the multipole content, should the measurement of the prototypes call for such trimmings before entering production. While the specifications for field quality were being elaborated, the design study opted for best quality following CERN practices for CERN magnets, at no cost increase. The design and engineering study resulted in three reports, one per magnet type. These documents summarize the requirements from SESAME, the design study, the engineering study and the technical drawings. They followed a formal approval process at CERN and SESAME, are stored in a dedicated database accessible from CERN and SESAME and form the background for the technical specifications needed for tendering. This database will collect all information on design, fabrication, tests and acceptance. Figure 2: Cross-section of the SESAME dipole, showing the magnetic flux density distribution at nominal excitation WP3 Magnet Procurement The tendering process followed CERN practices, with the participation of SESAME. A Specification Committee was held to comment the details of the tendering documents, including the plans for quality assurance. The Invitations to Tender or Price Enquiries were issued by the CERN Purchasing office. The bids were open in a selection committee with participation of SESAME. Finally, the contracts were adjudicated considering the economic and technical content of the offers. All the main contracts are now signed and well underway. Some delays were experienced in placing these contracts, due to the special legal situation of CERN; however, the safety margin included in the first estimates of the schedule could cope with them, in such a way that the delivery time of the last magnets is according to plan. Today, one prototype of each magnet type is delivered to CERN; the sextupole is of outstanding quality; the quadrupole is within specifications, but can and will be improved. The dipole has just been delivered. The further few months delay in the delivery of these prototypes is not unusual and all companies still adhere to the planned date of delivery of the last magnets. Even though the bulk of the orders were placed in experienced European companies, CERN made special effort to identify commercial partners in the SESAME States and involved Grant Agreement / 5

3 inexperienced companies demonstrating motivation and potential: CNE in Cyprus and Somnez Transformers in Turkey. In addition, Pakistan, via HMC3, has donated to CERN/CESSAMag 50% of the sextupole assembly. Figure 3: prototype dipole (TESLA, UK), quadrupole (Elytt, Spain, Somnez, Turkey); sextupole (CNE, Cyprus, HMC3, Pakistan, SEF, France) WP4 Magnetic Measurements The quadrupole and sextupole measuring bench was designed during the 1 st half of 2013 with the help of a junior SESAME engineer, at CERN for 9 months to learn magnetic measurement technology, with the financial support of IAEA. A dedicated rotating shaft, equipped with the measuring coils, was assembled. The measuring bench gives high quality measurements for both the multipole content and the positioning of the magnetic axis. An existing quadrupole was donated by CERN to become the mechanical reference jig allowing perfect alignment of the magnetic axis with respect to the reference surfaces on the final girders. The system is ready for installation at SESAME, including the data acquisition and the main power supply. It has been used at CERN for high quality measurements on prototypes over the last year and will be shipped when the SESAME roof is repaired. CERN staff made three visits at ALBA Synchrotron, Barcelona, to setup the collaboration for the measurement of the combined function curved main dipoles. The detailed technical addendum of the existing collaboration agreement was signed in June The Hall plate based 3D bench has been adapted for the SESAME dipoles. In particular the power supply has been modified to match the SESAME dipole requirements. A DCCT, to measure synchronously the instantaneous current and the Hall plate voltage, is operational to reduce the measurement noise by a factor of 2 to 10. This improvement will be quantified with the measurement of the first series dipole, due to arrive to ALBA beginning of November Grant Agreement / 5

4 Figure 4 left: quadrupole and sextupole measuring bench at CERN; right: dipole measuring bench at ALBA- Synchrotron WP5 Magnet Power Supplies: Specifications and Procurement Most of the activities of WP5 Magnet Power Supplies started in the summer of A powering strategy was defined and approved by a CERN internal technical review on the 15 th October 2013 as well as an external review organized on the 8 th November 2013 with SESAME and external light source experts. It departs from the initial plans where SESAME was due to order turnkey systems. The new strategy unifies all controls that are integrated, and Figure 5: CERN-SESAME power supplies team simplifies the maintenance and minimizes the time-for-repair by a standardization of power sources, except for the dipole. On the 23th November 2013, the SESAME Technical Advisory Committee expressed its support to the proposed strategy. After the approval of the strategy by CERN and SESAME, procurement of the power supplies started. By May 2014 all contracts had been placed. In October 2014 the first power supplies were delivered to CERN. In the meanwhile, new electronic modules required for the control of the power supplies were developed and prototypes were produced. These prototypes were tested in collaboration with the SESAME team in October Test beds for the evaluation of the power supplies and the control electronics are being prepared and reception tests will start soon. WP6 Support for Magnet Integration and Commissioning This activity is planned for the second period. Grant Agreement / 5

5 Coordinator: CERN Partners: CERN, SESAME (third party), ALBA-Synchrotron (subcontractor) Website: Grant Agreement / 5