BNL, Upton, Long Island, New York, USA
Tech-X, Boulder, Colorado, USA
We have refined the design for the Rapid Cycling Synchrotron (RCS) polarized electron injector for eRHIC. The newer design includes bypasses for the eRHIC detectors and definition of the lattice layout in the existing RHIC tunnel. Additionally, we provide more details on the RF, alignment and orbit control, and magnet specifications.
BNL, Upton, Long Island, New York, USA
Fermilab, Batavia, Illinois, USA
The electron-ion collider eRHIC aims at a luminosity around 1034cm-2sec-1, using strong cooling of the hadron beam. Since the required cooling techniques are not yet readily available, an initial version with a peak luminosity of 3*1033cm-2sec-1 is being developed that can later be outfitted with strong hadron cooling. We will report on the current design status and the envisioned path towards 1034cm-2sec-1 luminosity.
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
BNL, Upton, Long Island, New York, USA
JLab, Newport News, Virginia, USA
Cockcroft Institute, Warrington, Cheshire, United Kingdom
Cornell University, Ithaca, New York, USA
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
HZB, Berlin, Germany
A collaboration between Cornell University and Brookhaven National Laboratory has designed and is constructing CBETA, the Cornell-BNL ERL Test Accelerator on the Cornell campus. The ERL technology that has been prototyped at Cornell for many years is being used for this new accelerator, including a DC electron source and an SRF injector Linac with world-record current and normalized brightness in a bunch train, a high-current linac cryomodule optimized for ERLs, a high-power beam stop, and several diagnostics tools for high-current and high-brightness beams. BNL has designed multi-turn ERLs for several purpose, dominantly for the electron beam of eRHIC, its Electron Ion Collider (EIC) project and for the associated fast electron cooling system. Also in JLEIC, the EIC designed at JLAB, an ERL is envisioned to be used for electron cooling. The number of transport lines in an ERL is minimized by using return arcs that are comprised of a Fixed Field Alternating-gradient (FFA) design. This technique will be tested in CBETA, which has a single return for the 4-beam energies with strongly-focusing permanent magnets of Halbach type. The high-brightness beam with 150~MeV and up to 40~mA will have applications beyond accelerator research, in industry, in nuclear physics, and in X-ray science. Low current electron beam has already been sent through the most relevant parts of CBETA, from the DC gun through both cryomodules, through one of the 8 similar separator lines, and through one of the 27 similar FFA structures. Further construction is envisioned to lead to a commissioning start for the full system early in 2019.
BNL, Upton, Long Island, New York, USA
The Interaction Region (IR) magnets for future Electron Ion Colliders (EIC), such as eRHIC at BNL, JLEIC at JLab and LHeC at CERN, must satisfy strongly opposing requirements. EIC IR superconducting quadrupole coils must provide strong focusing gradients, leading to large peak fields, for the high momentum hadron beam while permitting the nearby electron beam to pass through a nearly field free region. An actively shielded coil geometry does this using nested, opposite polarity, quadrupoles where the combined external fields cancel while leaving a net gradient inside. In order to fabricate and test this concept in a timely and cost effective manner we propose to reuse the inner coils from an existing high gradient Nb3Sn LARP quadrupole inside a new structure with a new NbTi active shield coil. The main challenge is to design a compact structure for applying prestress to the Nb3Sn coil that fits the restricted space inside the shield coil. We first construct a 15 cm long mechanical model of this structure with coil strain gauges to verify the design concept before proceeding with the full coil. Mechanical modeling results and our preliminary design concept are reported here.
BNL, Upton, Long Island, New York, USA
Presently the electron-ion collider eRHIC is under design, which aims to provide a facility with a peak luminosity of 1034cm-2sec-1. This paper outlines different concepts for the so-called B0 magnet, which is the first bending magnet after the interaction region. The B0 magnet has to provide a 1.3 T dipole field to the hadron beam, while the nearby electron beam should not be exposed to any field. Several possible solutions have been evaluated, each with their specific strengths and shortcomings. This paper presents an overview of the solutions.
BNL, Upton, Long Island, New York, USA
Presently the electron-ion collider eRHIC is under design, which aims to provide a facility with a peak luminosity of 1034cm-2sec-1. Part of the eRHIC design is a rapid cycling synchrotron, which accelerates electrons from 1-18 GeV. In this paper we present conceptual designs of the required dipole, quadrupole and sextupole magnets. The magnets meet the specifications in terms of performance and field quality with an acceptable power dissipation. The power supply requirements are also discussed.
BNL, Upton, Long Island, New York, USA
Presently the electron-ion collider eRHIC is under design, which aims to provide a facility with a peak luminosity of 1034cm-2sec-1. Part of the eRHIC accelerator is the addition of an electron storage ring to the existing tunnel. This paper describes the magnets required for this storage ring. The necessary bending is provided by a triplet of dipole magnets, which generate excess bending to create additional radiation damping to allow a larger beam-beam tune shift. Each triplet consists of two long, low field magnets and a short, high-field magnet. This paper also describes the quadrupole and sextupole magnets necessary for this machine. All magnets require a large aperture to accommodate the beam-pipe.
BNL, Upton, Long Island, New York, USA
The electron-ion collider eRHIC requires a variety of kickers and septa for injection and extraction of beams throughout the entire collider complex. We plan to use pulsed systems for beam injection and extraction in Electron RCS, Electron Storage Ring, and Hadron ring. In this paper, we describe the pulsed systems required for beam transfer in the eRHIC Ring-Ring Pre-conceptual Design. We will outline the parameter ranges, technology choices, and opportunities for research and development in pulsed power technology.