JLab, Newport News, Virginia, USA
BNL, Upton, New York, USA
ODU, Norfolk, Virginia, USA
SBU, Stony Brook, New York, USA
The possibility of two interaction regions (IRs) is a design requirement for Electron-Ion Collider (EIC). There is also a significant interest from the nuclear physics community to have a 2nd IR with measurement capabilities complementary to those of the 1st IR. While the 2nd IR will be in operation over the entire energy range of ~20GeV to ~140GeV center of mass (CM). The 2nd IR can also provide an acceptance coverage complementary to that of the 1st. In this paper, we present a brief overview and the current progress of the 2nd IR design in terms of the parameters, magnet layout, and beam dynamics.
JLab, Newport News, Virginia, USA
Fermilab, Batavia, Illinois, USA
BNL, Upton, New York, USA
The central detector in the present EIC design includes a 4 m long solenoid with an integrated strength of up to 12 Tm. The electron beam passes on-axis through the solenoid, but the hadron beam has an angle of 25 mrad. Thus the solenoid couples horizontal and vertical betatron motion in both electron and hadron storage rings, and causes a vertical closed orbit excursion in the hadron ring. The solenoid also couples the transverse and longitudinal motions of both beams, when crab cavities are also considered. In this paper, we present schemes for closed orbit correction and coupling compensation at the IP, including crabbing.
BNL, Upton, New York, USA
JLab, Newport News, USA
SLAC, Menlo Park, California, USA
This paper presents an overview of the Interaction Region (IR) design for the planned Electron-Ion Collider (EIC) at Brookhaven National Laboratory. The IR is designed to meet the requirements of the nuclear physics community *. The IR design features a ±4.5 m free space for the detector; a forward spectrometer magnet is used for the detection of hadrons scattered under small angles. The hadrons are separated from the neutrons allowing detection of neutrons up to ±4 mrad. On the rear side, the electrons are separated from photons using a weak dipole magnet for the luminosity monitor and to detect scattered electrons (e-tagger). To avoid synchrotron radiation backgrounds in the detector no strong electron bending magnet is placed within 40 m upstream of the IP. The magnet apertures on the rear side are large enough to allow synchrotron radiation to pass through the magnets. The beam pipe has been optimized to reduce the impedance; the total power loss in the central vacuum chamber is expected to be less than 90 W. To reduce risk and cost the IR is designed to employ standard NbTi superconducting magnets, which are described in a separate paper.
* An Assessment of U.S.-Based Electron-Ion Collider Science. (2018). Washington, D.C.: National Academies Press. https://doi.org/10.17226/25171
BNL, Upton, New York, USA
The planned electron-ion collider (EIC) at Brookhaven National Laboratory (BNL) is designed to deliver a peak luminosity of 1x1034 cm-2 s-1. This paper presents an overview of the magnets required for the interaction region of the BNL EIC. To reduce risk and cost the IR is designed to employ conventional NbTi superconducting magnets. In the forward direction the magnets for the hadrons are required to pass a large neutron cone and particles with a transverse momentum of up to 1.3 GeV/c, which leads to large aperture requirements. In the rear direction the synchrotron radiation fan produced by the electron beam must not hit the magnet apertures, which determines their aperture. For the forward direction a mostly interleaved scheme is used for the optics, whereas for the rear side 2-in-1 magnets are employed. We present an overview of the EIC IR magnet design including the forward spectrometer magnet B0.
BNL, Upton, New York, USA
JLab, Newport News, Virginia, USA
SLAC, Menlo Park, California, USA
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
Fermilab, Batavia, Illinois, USA
ODU, Norfolk, Virginia, USA
FRIB, East Lansing, Michigan, USA
The design of the electron-ion collider EIC to be constructed at Brookhaven National Laboratory has been continuously evolving towards a realistic and robust design that meets all the requirements set forth by the nuclear physics community in the White Paper. Over the past year activities have been focused on maturing the design, and on developing alternatives to mitigate risk. These include improvements of the interaction region design as well as modifications of the hadron ring vacuum system to accommodate the high average and peak beam currents. Beam dynamics studies have been performed to determine and optimize the dynamic aperture in the two collider rings and the beam-beam performance. We will present the EIC design with a focus on recent developments.
BNL, Upton, New York, USA
FRIB, East Lansing, Michigan, USA
ODU, Norfolk, Virginia, USA
JLab, Newport News, Virginia, USA
LBNL, Berkeley, California, USA
The Electron-Ion Collider (EIC) is aiming at a design luminosity of 1e34 cm-2s−1. To maintain such a high luminosity, both beams in the EIC need an acceptable beam lifetime in the presence of the beam-beam interaction. For this purpose, we carried out weak-strong element-by-element particle tracking to evaluate the long-term dynamic aperture for the hadron ring lattice design. We improved our simulation code SimTrack to treat some new lattice design features, such as radially offset on-momentum orbits, coordinate transformations in the interaction region, etc. In this article, we will present the preliminary dynamic aperture calculation results with β*- function scan, radial orbit shift, crossing angle collision, and magnetic field errors.
Brookhaven National Laboratory (BNL), Electron-Ion Collider, Upton, New York, USA
BNL, Upton, New York, USA
The interaction region chamber has a complex geometry at the crossing location of electron and proton beam pipes. In the direction of the electron beam, the pipe is designed in a way to avoid joints with cavity characteristics. The horizontal slot on the upstream side and the tapered transition on the downstream side are applied to minimize the IR chamber contribution to the total impedance of the electron ring and to avoid generating Higher Order Modes and heating-related issues. The synchrotron radiation mask is included to protect the IR chamber from synchrotron radiation without significant aperture reduction. In the direction of the proton beam, the main area for optimization is the transition area right after the detector.