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.
FCC-ee, the lepton version of the Future Circular Collider (FCC), is a 100 Km future machine under study to be built at CERN. It acquires two experiments with a highest beam energy of 182.5 GeV. ...FCC-ee aims to operate at four different energies, with different luminosities to fulfil physics requirements. Beam-beam effects at such a high energy/luminosity machine are very challenging and require a deep understanding, especially in the presence of x-y coupling sources. Beam-beam effects include the beamstrahlung process, which limits the beam lifetime at high energies, as well as dynamic effects at the Interaction point (IP) which include changes in the beta functions and emittances. In this report, we will define the beam-beam effects and their behaviours in the FCC-ee highest energy lattice after introducing x-y coupling in the ring.
A blowup of vertical emittance has been observed in particle tracking simulations with beam-beam and lattice misalignments. It was somewhat unexpected, since estimation without lattice errors did not ...predict such a blowup unless a residual vertical dispersion at the interaction point (IP) is larger than a certain amount. Later such a blowup has been seen in a tracking of lattices without beam-beam effect. A possible explanation of the blowup is given by a Vlasov model for an equilibrium of quadratic transverse moments in the synchrotron phase space. This model predicts such a blowup as a synchro-beta resonance mainly near the first synchrotron sideband of the main x-y coupling resonance line.
The Snowmass 2021 Implementation Task Force has been established to evaluate the proposed future accelerator projects for performance, technology readiness, schedule, cost, and environmental impact. ...Corresponding metrics has been developed for uniform comparison of the proposals ranging from Higgs/EW factories to multi-TeV lepton, hadron and ep collider facilities, based on traditional and advanced acceleration technologies. This report documents the metrics and processes, and presents evaluations of future colliders performed by Implementation Task Force.
The FCC-ee is a proposed future high-energy, high-intensity and high-precision lepton collider. Here, we present the latest development for the FCC-ee interaction regions, which shall ensure optimum ...conditions for the particle physics experiments. We discuss measures of background reduction and a revised interaction region layout including a low impedance compact beam chamber design. We also discuss the possible impact of the radiation generated in the interaction region including beamstrahlung.
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