LHC is now delivering proton and heavy ion collisions at the highest energy. Upgrading the LHC beyond its design performance is a long term program that started during the LHC construction, with some fundamental R&D programs. The upgrade program is based on a vigorous superconductor and magnet R&D, aimed at increasing the field in accelerator magnets from 8 T to 12 T for the luminosity upgrade, with the scope of increasing the collider luminosity by a factor 5 to 10 from 2022. The upgrade program might continue with the LHC energy upgrade, which would require magnets producing field in the range of 16-20 T. The results obtained so far and the future challenges are discussed together with the possible plan to reach the goals.
A three-pole hybrid wiggler has been developed at the Saga Light Source synchrotron radiation facility. The development goal was to realize a three-pole wiggler with high operational stability and reliability under conditions of limited human resources and maintenance cost. The wiggler consists of a 4 T superconducting main pole and two 1 T normal-conducting side poles. The main pole can generate hard X-rays in the energy range up to approximately 40 keV. Use of the normalconducting side poles ensures significant margins for stationary and transient heat loads on the cryogenic system. The cryocooler cools the superconducting coils and iron poles via mechanical contact without liquid helium. To suppress the beam displacement due to the second integral of the magnetic field of the main pole, the main pole was designed to have relatively large field clamps at both pole ends. The wiggler was manufactured in FY2009 and was installed at the Saga Light Source storage ring in March 2010. Synchrotron radiation from the wiggler was observed at the beam line BL7 in late June 2010. Official user operation of the wiggler started in November 2010. To date, the wiggler has operated stably.