Search

The proposed electron-ion collider JLEIC would make high-luminosity collisions of polarized ions and polarized electrons with electron energy up to 12 GeV and ion energy up to 40 GeV/u. Both the luminosity and the collision energy could be increased by doubling the dipole field in the ion ring from 3 T to 6 T, and the enhanced performance would access the full range of parameters for the physics objectives of the project. The Texas A group has developed the large-aperture 3 T dipoles for the baseline project, based upon a novel superconducting cable-in-conduit. (CIC). A closely similar 6 T design is being developed, utilizing a 2-layer CIC. Details of the magnet design and development of the 2-layer CIC will be presented., Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia

With the completion of the National Academies of Sciences Assessment of a US Electron-Ion Collider, the prospects for construction of such a facility have taken a step forward. This paper provides an overview of the two site-specific EIC designs: JLEIC (Jefferson Lab) and eRHIC (BNL) as well as brief overview of ongoing EIC R, Proceedings of the North American Particle Accelerator Conference, NAPAC2019, Lansing, MI, USA

There is new physics-driven interest in the concept of an LHC doubler with collision energy of 30 TeV and high luminosity. The cost-driver challenge for its feasibility is the ring of 16 T dual dipoles. Recent developments in cable-in-conduit (CIC) technology offer significant benefit for this purpose. The CIC windings provide robust stress management at the cable level and facilitate forming of the flared ends without degradation. The CIC windings provide a basis for hybrid windings, in which the innermost layers that operate in high field utilize Bi-2212, the center layers utilize Nb₃Sn, and the outer layers utilize NbTi. Cryogen flows through the interior of all cables, so that heat transfer can be optimized throughout the windings. The design of the 18 T dipole and the 23 kA CIC conductor will be presented. Particular challenges for integration in an LHC doubler will be discussed., Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia

Magnetized electron cooling of ion beams requires pre-cise alignment of the electron beam with the equilibrium trajectory of the ion bunch. For the parameters required for JLEIC, a solenoid with bore field ~1 T, length ~30 m, and rms alignment of ~μrad is required. Such precise alignment has never been accomplished in a 1 T solenoid. The design of a micro-aligned solenoid is presented. A gap-separated stack of thin steel washers is located inside the solenoid. The washer stack shields transverse magnet-ic fields from its interior by a factor of ~10. A 30-washer module of the structure was built and measured using ultra-sensitive capacitive probes using a coordinate meas-uring machine. The r.m.s. coplanarity of the washer gaps was measured to be 5 μm, consistent with the required micro-alignment., Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia

The Mexican Particle Accelerator Community is currently designing the first Mexican RF eLINAC that will have three beamlines at 10, 60 and 100 MeV. In this work, we present an optimized design in terms of field quality and production cost for the 5 T/m normal conducting quadrupoles of the 10-MeV beamline. Several candidate materials for the yoke were studied based on their availability and machinability, with the aim to optimize in-house production cost (Mexico) while restricting a low multipole content., Proceedings of the 9th Int. Particle Accelerator Conf., IPAC2018, Vancouver, BC, Canada

Results are presented from end-to-end simulation of a 100 MeV strong focusing cyclotron (SFC). The develop-ment of the high-current SFC is motivated by applica-tions for production of medical isotopes and for a proton driver for subcritical fission. It uses a novel superconducting cavity to provide suffi-cient energy gain to fully separate all turns. An arc-contour F-D doublet, trim dipole winding, and sextupole are located along each turn within the aperture of each sector dipole to control the betatron and synchrotron motion and to stabilize non-linear dynamics with high-current operation. The phase space evolution of a proton bunch in the SFC was simulated using both the code OPAL and an ad hoc Runge-Kutta tracker. Iterative optimization of the dipole, quadrupole, and sextupole fields was used to provide precise isochronicity, favorable betatron phase advance, and cancellation of dispersion in each cell., Proceedings of the 9th Int. Particle Accelerator Conf., IPAC2018, Vancouver, BC, Canada

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., Proceedings of the North American Particle Accelerator Conf., NAPAC2016, Chicago, IL, USA

A design is presented for a hadron collider in which the magnetic storage ring is configured as a circular pipeline, supported in neutral buoyancy in the sea at a depth of ~100 m. Each collider detector is housed in a bathysphere the size of the CMS hall at LHC, also neutral-buoyant. Each half-cell of the collider lattice is ~300 m long, housed in a single pipe that contains one dipole, one quadrupole, a correction package, and all umbilical connections. A choice of ~4 T dipole field, 2000 km circumference provides a collision energy of 700 TeV. Beam dynamics is dominated by synchrotron radiation damping, which sustains luminosity for >10 hours. Issues of radiation shielding and abort can be accommodated inexpensively. There are at least ten sites world-wide where the collider could be located, all near major urban centers. The paper summarizes several key issues; how to connect and disconnect half-cell segments of the pipeline at-depth using remote submersibles; how to maintain the lattice in the required alignment; provisions for the injector sequence., Proceedings of the North American Particle Accelerator Conf., NAPAC2016, Chicago, IL, USA

The strong-focusing cyclotron is an isochronous sector cyclotron in which slot-geometry superconducting half-cell cavities are used to provide sufficient energy gain per turn to fully separate orbits and superconducting quadrupoles are located in the aperture of each sector dipole to provide strong focusing and control betatron tune. The SFC offers the possibility to address the several effects that most limit beam current in a CW cyclotron: space charge, bunch-bunch interactions, resonance-crossing, and wake fields. Simulation of optical transport and beam dynamics entails several new challenges: the combined-function fields in the sectors must be properly treated in a strongly curving geometry, and the strong energy gain induces continuous mixing of horizontal betatron and synchrotron phase space. We present a systematic simulation of optical transport using modified versions of MAD-X and SYNERGIA. We report progress in introducing further elements that will set the stage for studying dynamics of high-current bunches., Proceedings of the North American Particle Accelerator Conf., NAPAC2016, Chicago, IL, USA

The strong-focusing cyclotron is a high-current proton/ion accelerator in which superconducting rf cavities are used to provide enough energy gain per turn to fully separate orbits, and arc-shaped beam transport channels are located in the sector dipole aperture to provide strong focusing of all orbits. An optimization method has been devised by which the orbit separations can be adjusted to provide sufficient separation while maintaining isochronicity on all orbits. The transport optics of the FD lattice is also optimized to provide stable transport and to lock the betatron tunes to a favorable value over the full range of acceleration., Proceedings of the 6th Int. Particle Accelerator Conf., IPAC2015, Richmond, VA, USA

The proposed designs for polarized-beam electron-ion colliders require cooling of the ion beam to achieve and sustain high luminosity. One attractive approach is to make a fixed-energy storage ring in which ions are con-tinuously cooled and stacked during a collider store, then transferred to the collider and accelerated for a new store when the luminosity decreases. An example design is reported for a 6 GeV/u superferric storage ring, and for a d.c. electron cooling system in which electron space charge is fully neutralized so that high-current magnetized e-cooling can be used to best advantage., Proceedings of the 6th Int. Particle Accelerator Conf., IPAC2015, Richmond, VA, USA

The Strong Focusing Cyclotron development at Texas A&M University has evolved from stacks of cyclotrons to a single layer high brightness, low emittance to produce greater than 10 mA of proton beam to a desired target at 800 MeV. The latest design has a major geometric design optimization of strong focusing quadrupoles and a modified algorithm of high gradient cavities to address the small turn separation, and interaction of radially neighboring bunches and reduced the number of turns necessary to reach the desired final energy under control conditions. In this paper, we present the new design, physics of nonlinear synchrobetratron coupling, mνh+nνv=p causing beam blow-up in other form of cyclotrons and how we have resolved it. The cavity beam loading and space charge effects of multi turns at low energies to reduce losses are discussed., Proceedings of the 6th Int. Particle Accelerator Conf., IPAC2015, Richmond, VA, USA

We present an update on the design of the ion collider ring of the Medium-energy Electron-Ion Collider (MEIC) proposed by Jefferson Lab. The design is based on the use of super-ferric magnets. It provides the necessary momentum range of 8 to 100 GeV/c for protons and ions, matches the electron collider ring design using PEP-II components, fits readily on the JLab site, offers a straightforward path for a future full-energy upgrade by replacing the magnets with higher-field ones in the same tunnel, and is more cost effective than using presently available current-dominated super-conducting magnets. We describe complete ion collider optics including an independently-designed modular detector region., Proceedings of the 6th Int. Particle Accelerator Conf., IPAC2015, Richmond, VA, USA