Hadron-Electron Ring Accelerator

Hadron-Electron Ring Accelerator
Jason Schwartz (talk) · CC BY-SA 3.0 · source
Name	Hadron-Electron Ring Accelerator
Type	Particle accelerator

Hadron-Electron Ring Accelerator The Hadron-Electron Ring Accelerator was a proposed collider project conceived to collide protons or ion beams with electron beams in a ring configuration to probe deep inelastic scattering and electroweak phenomena. The proposal sat amid initiatives such as the Large Hadron Collider, Relativistic Heavy Ion Collider, HERA and Stanford Linear Accelerator Center concepts, aiming to combine insights from experiments like ATLAS, CMS, ZEUS, and H1. It interfaced with communities centered on facilities including CERN, DESY, SLAC National Accelerator Laboratory, Brookhaven National Laboratory, and Fermilab.

Overview

The project scope resembled hybrid efforts linking technologies found at LEP and the Super Proton Synchrotron with innovations pursued by DESY for HERA II upgrades and proposals from Jefferson Lab. Scientific drivers echoed results from the European Organization for Nuclear Research programs and discoveries associated with Quantum Chromodynamics tests performed by collaborations such as UA1, UA2, CDF, and D0. Policy discussions invoked stakeholders like European Council, German Federal Ministry of Education and Research, US Department of Energy, and multinational consortia modeled on ITER governance.

Design and Technical Specifications

Design studies referenced accelerator physics traditions from Kraków-based institutes, Budker Institute of Nuclear Physics, and KEK proposals, adopting superconducting magnet developments akin to Giant Magellan Telescope cryogenics and National Institute of Standards and Technology techniques. The ring geometry paralleled the circumference scaling seen in Large Electron–Positron Collider designs, while radiofrequency systems drew from International Linear Collider research and European XFEL superconducting cavity programs. Beam instrumentation strategies were informed by diagnostics used at TRIUMF, GSI Helmholtz Centre for Heavy Ion Research, and Rutherford Appleton Laboratory.

Accelerator Components and Beam Dynamics

Core components included storage rings and linacs similar to those at DESY, SLAC, and KEK-B, with interaction regions designed to accommodate detectors comparable to ATLAS and CMS. Beam dynamics modeling utilized frameworks developed by groups at CERN Accelerator School, Oak Ridge National Laboratory, and Lawrence Berkeley National Laboratory. Key subsystems—superconducting cavities comparable to TESLA proposals, beam collimation from Diamond Light Source practice, and vacuum technology from European Synchrotron Radiation Facility—were integrated to control emittance, synchrotron radiation, and beam-beam tune shifts relevant to experiments pursued by collaborations like H1 Collaboration and ZEUS Collaboration.

Scientific Goals and Experiments

Scientific aims paralleled measurements achieved at HERA and extended programs from LHeC studies, focusing on parton distribution functions central to analyses by CTEQ and NNPDF groups, precision tests contested in LEP Electroweak Working Group reports, and searches for phenomena analogous to discoveries at Higgs boson experiments like ATLAS and CMS. Experimental proposals envisioned detector concepts borrowing calorimetry designs from CALICE R&D, tracking technologies from ALICE, and vertexing approaches used by LHCb to study heavy flavor physics and electroweak structure through neutral current and charged current processes investigated by collaborations such as HERMES.

Construction, Operation, and Timeline

Project planning phases echoed timelines set by projects like HERA II and International Linear Collider proposals, with stages of conceptual design, technical design report, site selection, and construction milestones resembling processes used by CERN for LHC upgrades and by DESY for the XFEL. Commissioning strategies were informed by operational lessons from Relativistic Heavy Ion Collider startup and commissioning campaigns at Fermilab’s Tevatron. Decommissioning planning referenced best practices from shut-downs at LEP and facility transitions at BESSY.

Collaborations, Funding, and Site

The initiative required multinational collaboration modeled after CERN membership, with funding considerations involving agencies such as European Commission, Deutsche Forschungsgemeinschaft, National Science Foundation, and Ministry of Education, Culture, Sports, Science and Technology in Japan. Potential host sites discussed referenced established laboratories including DESY, CERN, Fermilab, Brookhaven National Laboratory, and SLAC National Accelerator Laboratory, each illustrated by prior large-scale collaborations like LHCb, ALICE, and ATLAS.

Legacy and Impact on Particle Physics

Even as a conceptual project, the accelerator influenced designs for successors such as LHeC and informed technical developments adopted by HL-LHC upgrade programs, contributing to magnet technology from EuCARD studies and superconducting cavity improvements comparable to European XFEL advancements. The conceptual work fed into global accelerator roadmaps promoted by bodies like ICFA and shaped training networks associated with Marie Skłodowska-Curie Actions and doctoral programs at University of Oxford, University of Cambridge, MIT, and ETH Zurich.

Category:Proposed particle accelerators