JLab, Newport News, Virginia, USA
SLAC, Menlo Park, California, USA
Self Employment, Private address, USA
The JLEIC is proposed as a next-generation facility for the study of strong interaction (QCD). Achieving its goal luminosity of up to 1034 cm-2s−1 requires good dynamical properties and a large dynamic aperture (DA) of ~ ±10 σ of the beam size. The limit on the DA comes primarily from non-linear dynamics, element misalignments, magnet multipole components, and detector solenoid effect. This paper presents a complete simulation including all of these effects. We first describe an orbit correction scheme and determine tolerances on element misalignments. And beta beat, betatron tunes, coupling, and linear chromaticity perturbations also be corrected. We next specify the requirements on the multipole components of the interaction region magnets, which dominate the DA in the collision mode. Finally, we take special care of the detector solenoid effects. Some of the complications are an asymmetric design necessary for a full acceptance detector with a crossing angle of 50 mrad. Thus, in addition to coupling, the solenoid causes closed orbit excursion and excites dispersion. It also breaks the figure-8 spin symmetry. We present a scheme with correction of all of these effects.
Texas A&M University, College Station, USA
DCI-UG, León, Mexico
The JLEIC project requires 3 T superferric dipoles and quadrupoles for the half-cell arcs of its Ion Ring and Booster. A superferric design using NbTi cable-in-conduit conductor is being developed. A mockup winding has been completed, with the objectives to develop and evaluate the coil structure and the winding tooling and methods, and to measure errors in the position of each cable turn in the dipole body. The results of the mockup winding study are presented. The CIC design is now ready for construction and testing of a first model dipole.
UMD, College Park, Maryland, USA
The intensity frontier is limited by the ability to propagate substantial amounts of beam current without resulting in particle scrapping and/or losses from resonant growth and halo formation. Modern accelerators are based on the theories developed in the 1950's that assume particle motion is bounded and subject to linear forces. Recent theoretical developments have demonstrated that a strongly nonlinear lattice can be used to stably transport an intense beam has resulted in a fundamental rethinking of the conventional wisdom. A lattice composed of strong nonlinear magnets is predicted by theory to damp resonances while maintaining dynamic aperture. Results of rotating coil measurements, magnetic field scans and simulations will be presented, quantifying the multi-pole moments and fringe fields in the 1st generation Printed Circuit Board (PCB) octupoles for UMER's nonlinear lattice experiments.
Northern Illinois University, DeKalb, Illinois, USA
* A.Gee and B.Erdelyi, "A Differential Algebraic Framework for the Fast Indirect Boundary Element Method," in Proc. IPAC'16. Busan, South Korea.
JLab, Newport News, Virginia, USA
GWU, Washington, USA
UCR, Riverside, California, USA
Muons, Inc, Illinois, USA
Skew Parametric-resonance Ionization Cooling (Skew PIC) is an extension of the Parametric-resonance Ionization Cooling (PIC) framework that has previously been explored as the final 6D cooling stage of a high-luminosity muon collider. The addition of skew quadrupoles to the PIC magnetic focusing channel induces coupled dynamic behavior of the beam that is radially periodic. The periodicity of the radial motion allows for the avoidance of unwanted resonances in the horizontal and vertical transverse planes, while still providing periodic locations at which ionization cooling components can be implemented. Properties of the linear beam dynamics have been previously reported and good agreement exists between theory, analytic solutions, and simulations. Progress on aberration compensation in the coupled correlated optics channel is presented and discussed.
ANL, Argonne, Illinois, USA
BNL, Upton, Long Island, New York, USA
The Advanced Photon Source (APS) at Argonne National Laboratory (ANL) is considering upgrading the current double-bend, 7-GeV, 3rd generation storage ring to a 6-GeV, 4th generation storage ring with a Multibend Achromat (MBA) lattice. In this study, a novel method is proposed to determine fabrication and assembly tolerances through a combination of magnetic and mechanical tolerance analyses. Mechanical tolerance stackup analyses using Teamcenter Variation Analysis are carried out to determine the part and assembly level fabrication tolerances. Finite element analyses using OPERA are conducted to estimate the effect of fabrication and assembly errors on the magnetic field of a quadrupole magnet and to determine the allowable tolerances to achieve the desired magnetic performance. Finally, results of measurements in R&D quadrupole prototypes are compared with the analysis results.
ANL, Argonne, Illinois, USA
The proposed upgrade of the Advanced Photon Source (APS) to a multibend-achromat lattice requires shorter and much stronger quadrupole magnets than are present in the existing ring. This results in longitudinal gradient profiles that differ significantly from a hard-edge model. Additionally, the lattice assumes the use of five-segment longitudinal gradient dipoles. Under these circumstances, the effects of fringe fields and detailed field distributions are of interest. We evaluated the effect of soft-edge fringe fields on the linear optics and chromaticity, finding that compensation for these effects is readily accomplished. In addition, we evaluated the reliability of standard methods of simulating hard-edge nonlinear fringe effects in quadrupoles.
Fermilab, Batavia, Illinois, USA
ANL, Argonne, Illinois, USA
The Advanced Photon Source is in the process of developing an upgrade (APS-U) of the storage ring from a double-bend to a multi-bend lattice. A swap-out injection is planned for the APS-U lattice to keep a constant beam current and accommodate small, dynamic aperture. A septum magnet that has a minimum thickness of 2 mm with an injection field of 1.06 T has been designed. The stored beam chamber has an 8 mm x 6 mm super-ellipsoidal aperture. The required total deflecting angle is 89 mrad with a ring energy of 6 GeV. The magnet is straight, but is tilted in yaw, roll, and pitch from the stored beam chamber in order to meet the swap out injection requirements for the APS-U lattice. In order to minimize the leakage field inside the stored beam chamber, four different techniques were utilized in the design. As a result, the horizontal deflecting angle of the stored beam was held to only 5 μrad, and the integrated skew quadrupole inside the stored beam chamber was held to 0.09 T. The detailed techniques that were applied to the design, the field multipoles, and the resulting trajectories of the injected and stored beams are reported.